Infrastructure Access Reports
Infrastructure FH-IWES Offshore Field Test Facilities
Assessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy
(MRE) devices (Phase 4) User-Project CoMaRE Phase 4
CTC-CENIM-TECNALIA
Marine Renewables Infrastructure Network
Status Final Version 02 Date 30-Oct-2015
EC FP7 ldquoCapacitiesrdquo Specific Programme Research Infrastructure Action
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 2 of 20
ABOUT MARINET MARINET (Marine Renewables Infrastructure Network for emerging Energy Technologies) is an EC-funded network of research centres and organisations that are working together to accelerate the development of marine renewable energy - wave tidal amp offshore-wind The initiative is funded through the ECs Seventh Framework Programme (FP7) and runs for four years until 2015 The network of 29 partners with 42 specialist marine research facilities is spread across 11 EU countries and 1 International Cooperation Partner Country (Brazil) MARINET offers periods of free-of-charge access to test facilities at a range of world-class research centres Companies and research groups can avail of this Transnational Access (TA) to test devices at any scale in areas such as wave energy tidal energy offshore-wind energy and environmental data or to conduct tests on cross-cutting areas such as power take-off systems grid integration materials or moorings In total over 700 weeks of access is available to an estimated 300 projects and 800 external users with at least four calls for access applications over the 4-year initiative MARINET partners are also working to implement common standards for testing in order to streamline the development process conducting research to improve testing capabilities across the network providing training at various facilities in the network in order to enhance personnel expertise and organising industry networking events in order to facilitate partnerships and knowledge exchange The aim of the initiative is to streamline the capabilities of test infrastructures in order to enhance their impact and accelerate the commercialisation of marine renewable energy See wwwfp7-marineteu for more details
Partners
Ireland University College Cork HMRC (UCC_HMRC)
Coordinator
Sustainable Energy Authority of Ireland (SEAI_OEDU)
Denmark Aalborg Universitet (AAU)
Danmarks Tekniske Universitet (RISOE)
France EcoleCentrale de Nantes (ECN)
Institut Franccedilais de Recherche Pour lExploitation de la Mer (IFREMER)
United Kingdom National Renewable Energy Centre Ltd (NAREC)
The University of Exeter (UNEXE)
European Marine Energy Centre Ltd (EMEC)
University of Strathclyde (UNI_STRATH)
The University of Edinburgh (UEDIN)
Queenrsquos University Belfast (QUB)
PlymouthUniversity(PU)
Spain Ente Vasco de la Energiacutea (EVE)
Tecnalia Research amp Innovation Foundation (TECNALIA)
Belgium 1-Tech (1_TECH)
Netherlands Stichting Tidal Testing Centre (TTC)
StichtingEnergieonderzoek Centrum Nederland (ECNeth)
Germany Fraunhofer-GesellschaftZurFoerderung Der AngewandtenForschung EV (Fh_IWES)
Gottfried Wilhelm Leibniz Universitaumlt Hannover (LUH)
Universitaet Stuttgart (USTUTT)
Portugal Wave Energy Centre ndash Centro de Energia das Ondas (WavEC)
Italy UniversitagravedegliStudi di Firenze (UNIFI-CRIACIV)
UniversitagravedegliStudi di Firenze (UNIFI-PIN)
UniversitagravedegliStudidellaTuscia (UNI_TUS)
ConsiglioNazionaledelleRicerche (CNR-INSEAN)
Brazil Instituto de Pesquisas Tecnoloacutegicas do Estado de Satildeo Paulo SA (IPT)
Norway SintefEnergi AS (SINTEF)
NorgesTeknisk-NaturvitenskapeligeUniversitet (NTNU)
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 3 of 20
DOCUMENT INFORMATION Title Assessment and mitigation of Marine Corrosion in metallic components in Marine
Renewable Energy (MRE) devices (Phase 4)
Distribution Public
Document Reference MARINET-TA2-CoMaRE Phase 4
User-Group Leader Lead Author
David Fernaacutendez de Rucoba CTC Phone +34 942 76 69 76 Email dfernandezctcomponentescom
User-Group Members Contributing Authors
Rauacutel Rodriguez Arias CTC Daniel de la Fuente CENIM Manuel Morcillo CENIM Jean Baptiste Jorcin TECNALIA Marta Tejero Gracia TECNALIA
Infrastructure Accessed FH-IWES Offshore Field Test Facilities
Infrastructure Manager (or Main Contact)
Mario Houmlrnig Oliver Holger Kranz
REVISION HISTORY Rev Date Description Prepared by
(Name) Approved By Infrastructure
Manager
Status (DraftFinal)
01 29102015 Draft for Approval David Fernaacutendez de Rucoba
Draft
02 30102015 Final David Fernaacutendez de Rucoba
Mario Houmlrnig Final
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 4 of 20
ABOUT THIS REPORT One of the requirements of the EC in enabling a user group to benefit from free-of-charge access to an infrastructure is that the user group must be entitled to disseminate the foreground (information and results) that they have generated under the project in order to progress the state-of-the-art of the sector Notwithstanding this the EC also state that dissemination activities shall be compatible with the protection of intellectual property rights confidentiality obligations and the legitimate interests of the owner(s) of the foreground The aim of this report is therefore to meet the first requirement of publicly disseminating the knowledge generated through this MARINET infrastructure access project in an accessible format in order to
progress the state-of-the-art
publicise resulting progress made for the technologyindustry
provide evidence of progress made along the Structured Development Plan
provide due diligence material for potential future investment and financing
share lessons learned
avoid potential future replication by others
provide opportunities for future collaboration
etc In some cases the user group may wish to protect some of this information which they deem commercially sensitive and so may choose to present results in a normalised (non-dimensional) format or withhold certain design data ndash this is acceptable and allowed for in the second requirement outlined above
ACKNOWLEDGEMENT The work described in this publication has received support from MARINET a European Community - Research Infrastructure Action under the FP7 ldquoCapacitiesrdquo Specific Programme
LEGAL DISCLAIMER The views expressed and responsibility for the content of this publication lie solely with the authors The European Commission is not liable for any use that may be made of the information contained herein This work may rely on data from sources external to the MARINET project Consortium Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data The information in this document is provided ldquoas isrdquo and no guarantee or warranty is given that the information is fit for any particular purpose The user there of uses the information at its sole risk and neither the European Commission nor any member of the MARINET Consortium is liable for any use that may be made of the information
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 5 of 20
EXECUTIVE SUMMARY Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation In this report an on-going research and experimental project is presented The project CoMaRE -Assessment and mitigation of marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices- is focused in the assessment of the marine corrosion phenomena on metallic components in MRE devices from a practical point of view and in the evaluation of different components This project has an estimated duration of two years therefore several phases are needed to achieve the desired results During this fourth phase of project CoMaRE main activity has been the control and removal of part of tested coupons in field at Helgoland and the accelerated weathering tests below different exposure conditions at the CTCrsquos laboratory Additionally CTC has analysed the test of novel coating systems with nanoparticles of oxides and graphene oxide The trials at the Fraunhofer IWES offshore field test facilities were developed in the North Sea at the Island Helgoland (Germany) and additional results were obtained Mooring chains slide (with and without a Thermally Sprayed Aluminium coating ndash TSA) pieces of fibre ropes of different diameters steel plates (with and without coatings) and polymer composite specimens were tested at the offshore test rig in diverse marine conditions (tidal splash and submerged) and atmospheric in the CTCacutes facilities (Santander Spain) Accelerated weathering tests were also carried out at CTCrsquos Laboratory (UV cyclic weathering and salt spray tests) Steel coated coupons with antifouling (AF) paints including the use of oxide nanoparticles and graphene were exposed to different environments Surface of non additivated coating showed less roughness than additivated coating in nano-metrical scale and roughness in both cases was found to increase after salt spray exposure In any of the AF coated samples macrofouling was not found at surface Results in terms of estimated corrosion rate were obtained for chain slide samples in submerged zone for different exposure periods
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 6 of 20
CONTENTS
1 INTRODUCTIONamp BACKGROUND 7
11 INTRODUCTION 7 111 Task 1 Field test 7 112 Task 2 Workshop activities 7 113 Tasks 3 amp 4 Laboratory tests analysis and correlation 7 114 Task 5 Dissemination 8
12 DEVELOPMENT SO FAR 8 121 Plan For This Access 8
2 OUTLINE OF WORK CARRIED OUT 9
21 SETUP 9 22 TESTS 10 221 Test Plan 10
23 RESULTS 13 24 ANALYSIS amp CONCLUSIONS 16
3 MAIN LEARNING OUTCOMES 18
31 PROGRESS MADE 18 311 Progress Made For This User-Group or Technology 18 312 Progress Made For Marine Renewable Energy Industry 18
32 KEY LESSONS LEARNED 18
4 FURTHER INFORMATION 19
41 SCIENTIFIC PUBLICATIONS 19 42 WEBSITE amp SOCIAL MEDIA 19
5 REFERENCES 19
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 2 of 20
ABOUT MARINET MARINET (Marine Renewables Infrastructure Network for emerging Energy Technologies) is an EC-funded network of research centres and organisations that are working together to accelerate the development of marine renewable energy - wave tidal amp offshore-wind The initiative is funded through the ECs Seventh Framework Programme (FP7) and runs for four years until 2015 The network of 29 partners with 42 specialist marine research facilities is spread across 11 EU countries and 1 International Cooperation Partner Country (Brazil) MARINET offers periods of free-of-charge access to test facilities at a range of world-class research centres Companies and research groups can avail of this Transnational Access (TA) to test devices at any scale in areas such as wave energy tidal energy offshore-wind energy and environmental data or to conduct tests on cross-cutting areas such as power take-off systems grid integration materials or moorings In total over 700 weeks of access is available to an estimated 300 projects and 800 external users with at least four calls for access applications over the 4-year initiative MARINET partners are also working to implement common standards for testing in order to streamline the development process conducting research to improve testing capabilities across the network providing training at various facilities in the network in order to enhance personnel expertise and organising industry networking events in order to facilitate partnerships and knowledge exchange The aim of the initiative is to streamline the capabilities of test infrastructures in order to enhance their impact and accelerate the commercialisation of marine renewable energy See wwwfp7-marineteu for more details
Partners
Ireland University College Cork HMRC (UCC_HMRC)
Coordinator
Sustainable Energy Authority of Ireland (SEAI_OEDU)
Denmark Aalborg Universitet (AAU)
Danmarks Tekniske Universitet (RISOE)
France EcoleCentrale de Nantes (ECN)
Institut Franccedilais de Recherche Pour lExploitation de la Mer (IFREMER)
United Kingdom National Renewable Energy Centre Ltd (NAREC)
The University of Exeter (UNEXE)
European Marine Energy Centre Ltd (EMEC)
University of Strathclyde (UNI_STRATH)
The University of Edinburgh (UEDIN)
Queenrsquos University Belfast (QUB)
PlymouthUniversity(PU)
Spain Ente Vasco de la Energiacutea (EVE)
Tecnalia Research amp Innovation Foundation (TECNALIA)
Belgium 1-Tech (1_TECH)
Netherlands Stichting Tidal Testing Centre (TTC)
StichtingEnergieonderzoek Centrum Nederland (ECNeth)
Germany Fraunhofer-GesellschaftZurFoerderung Der AngewandtenForschung EV (Fh_IWES)
Gottfried Wilhelm Leibniz Universitaumlt Hannover (LUH)
Universitaet Stuttgart (USTUTT)
Portugal Wave Energy Centre ndash Centro de Energia das Ondas (WavEC)
Italy UniversitagravedegliStudi di Firenze (UNIFI-CRIACIV)
UniversitagravedegliStudi di Firenze (UNIFI-PIN)
UniversitagravedegliStudidellaTuscia (UNI_TUS)
ConsiglioNazionaledelleRicerche (CNR-INSEAN)
Brazil Instituto de Pesquisas Tecnoloacutegicas do Estado de Satildeo Paulo SA (IPT)
Norway SintefEnergi AS (SINTEF)
NorgesTeknisk-NaturvitenskapeligeUniversitet (NTNU)
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 3 of 20
DOCUMENT INFORMATION Title Assessment and mitigation of Marine Corrosion in metallic components in Marine
Renewable Energy (MRE) devices (Phase 4)
Distribution Public
Document Reference MARINET-TA2-CoMaRE Phase 4
User-Group Leader Lead Author
David Fernaacutendez de Rucoba CTC Phone +34 942 76 69 76 Email dfernandezctcomponentescom
User-Group Members Contributing Authors
Rauacutel Rodriguez Arias CTC Daniel de la Fuente CENIM Manuel Morcillo CENIM Jean Baptiste Jorcin TECNALIA Marta Tejero Gracia TECNALIA
Infrastructure Accessed FH-IWES Offshore Field Test Facilities
Infrastructure Manager (or Main Contact)
Mario Houmlrnig Oliver Holger Kranz
REVISION HISTORY Rev Date Description Prepared by
(Name) Approved By Infrastructure
Manager
Status (DraftFinal)
01 29102015 Draft for Approval David Fernaacutendez de Rucoba
Draft
02 30102015 Final David Fernaacutendez de Rucoba
Mario Houmlrnig Final
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 4 of 20
ABOUT THIS REPORT One of the requirements of the EC in enabling a user group to benefit from free-of-charge access to an infrastructure is that the user group must be entitled to disseminate the foreground (information and results) that they have generated under the project in order to progress the state-of-the-art of the sector Notwithstanding this the EC also state that dissemination activities shall be compatible with the protection of intellectual property rights confidentiality obligations and the legitimate interests of the owner(s) of the foreground The aim of this report is therefore to meet the first requirement of publicly disseminating the knowledge generated through this MARINET infrastructure access project in an accessible format in order to
progress the state-of-the-art
publicise resulting progress made for the technologyindustry
provide evidence of progress made along the Structured Development Plan
provide due diligence material for potential future investment and financing
share lessons learned
avoid potential future replication by others
provide opportunities for future collaboration
etc In some cases the user group may wish to protect some of this information which they deem commercially sensitive and so may choose to present results in a normalised (non-dimensional) format or withhold certain design data ndash this is acceptable and allowed for in the second requirement outlined above
ACKNOWLEDGEMENT The work described in this publication has received support from MARINET a European Community - Research Infrastructure Action under the FP7 ldquoCapacitiesrdquo Specific Programme
LEGAL DISCLAIMER The views expressed and responsibility for the content of this publication lie solely with the authors The European Commission is not liable for any use that may be made of the information contained herein This work may rely on data from sources external to the MARINET project Consortium Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data The information in this document is provided ldquoas isrdquo and no guarantee or warranty is given that the information is fit for any particular purpose The user there of uses the information at its sole risk and neither the European Commission nor any member of the MARINET Consortium is liable for any use that may be made of the information
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 5 of 20
EXECUTIVE SUMMARY Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation In this report an on-going research and experimental project is presented The project CoMaRE -Assessment and mitigation of marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices- is focused in the assessment of the marine corrosion phenomena on metallic components in MRE devices from a practical point of view and in the evaluation of different components This project has an estimated duration of two years therefore several phases are needed to achieve the desired results During this fourth phase of project CoMaRE main activity has been the control and removal of part of tested coupons in field at Helgoland and the accelerated weathering tests below different exposure conditions at the CTCrsquos laboratory Additionally CTC has analysed the test of novel coating systems with nanoparticles of oxides and graphene oxide The trials at the Fraunhofer IWES offshore field test facilities were developed in the North Sea at the Island Helgoland (Germany) and additional results were obtained Mooring chains slide (with and without a Thermally Sprayed Aluminium coating ndash TSA) pieces of fibre ropes of different diameters steel plates (with and without coatings) and polymer composite specimens were tested at the offshore test rig in diverse marine conditions (tidal splash and submerged) and atmospheric in the CTCacutes facilities (Santander Spain) Accelerated weathering tests were also carried out at CTCrsquos Laboratory (UV cyclic weathering and salt spray tests) Steel coated coupons with antifouling (AF) paints including the use of oxide nanoparticles and graphene were exposed to different environments Surface of non additivated coating showed less roughness than additivated coating in nano-metrical scale and roughness in both cases was found to increase after salt spray exposure In any of the AF coated samples macrofouling was not found at surface Results in terms of estimated corrosion rate were obtained for chain slide samples in submerged zone for different exposure periods
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 6 of 20
CONTENTS
1 INTRODUCTIONamp BACKGROUND 7
11 INTRODUCTION 7 111 Task 1 Field test 7 112 Task 2 Workshop activities 7 113 Tasks 3 amp 4 Laboratory tests analysis and correlation 7 114 Task 5 Dissemination 8
12 DEVELOPMENT SO FAR 8 121 Plan For This Access 8
2 OUTLINE OF WORK CARRIED OUT 9
21 SETUP 9 22 TESTS 10 221 Test Plan 10
23 RESULTS 13 24 ANALYSIS amp CONCLUSIONS 16
3 MAIN LEARNING OUTCOMES 18
31 PROGRESS MADE 18 311 Progress Made For This User-Group or Technology 18 312 Progress Made For Marine Renewable Energy Industry 18
32 KEY LESSONS LEARNED 18
4 FURTHER INFORMATION 19
41 SCIENTIFIC PUBLICATIONS 19 42 WEBSITE amp SOCIAL MEDIA 19
5 REFERENCES 19
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 3 of 20
DOCUMENT INFORMATION Title Assessment and mitigation of Marine Corrosion in metallic components in Marine
Renewable Energy (MRE) devices (Phase 4)
Distribution Public
Document Reference MARINET-TA2-CoMaRE Phase 4
User-Group Leader Lead Author
David Fernaacutendez de Rucoba CTC Phone +34 942 76 69 76 Email dfernandezctcomponentescom
User-Group Members Contributing Authors
Rauacutel Rodriguez Arias CTC Daniel de la Fuente CENIM Manuel Morcillo CENIM Jean Baptiste Jorcin TECNALIA Marta Tejero Gracia TECNALIA
Infrastructure Accessed FH-IWES Offshore Field Test Facilities
Infrastructure Manager (or Main Contact)
Mario Houmlrnig Oliver Holger Kranz
REVISION HISTORY Rev Date Description Prepared by
(Name) Approved By Infrastructure
Manager
Status (DraftFinal)
01 29102015 Draft for Approval David Fernaacutendez de Rucoba
Draft
02 30102015 Final David Fernaacutendez de Rucoba
Mario Houmlrnig Final
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 4 of 20
ABOUT THIS REPORT One of the requirements of the EC in enabling a user group to benefit from free-of-charge access to an infrastructure is that the user group must be entitled to disseminate the foreground (information and results) that they have generated under the project in order to progress the state-of-the-art of the sector Notwithstanding this the EC also state that dissemination activities shall be compatible with the protection of intellectual property rights confidentiality obligations and the legitimate interests of the owner(s) of the foreground The aim of this report is therefore to meet the first requirement of publicly disseminating the knowledge generated through this MARINET infrastructure access project in an accessible format in order to
progress the state-of-the-art
publicise resulting progress made for the technologyindustry
provide evidence of progress made along the Structured Development Plan
provide due diligence material for potential future investment and financing
share lessons learned
avoid potential future replication by others
provide opportunities for future collaboration
etc In some cases the user group may wish to protect some of this information which they deem commercially sensitive and so may choose to present results in a normalised (non-dimensional) format or withhold certain design data ndash this is acceptable and allowed for in the second requirement outlined above
ACKNOWLEDGEMENT The work described in this publication has received support from MARINET a European Community - Research Infrastructure Action under the FP7 ldquoCapacitiesrdquo Specific Programme
LEGAL DISCLAIMER The views expressed and responsibility for the content of this publication lie solely with the authors The European Commission is not liable for any use that may be made of the information contained herein This work may rely on data from sources external to the MARINET project Consortium Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data The information in this document is provided ldquoas isrdquo and no guarantee or warranty is given that the information is fit for any particular purpose The user there of uses the information at its sole risk and neither the European Commission nor any member of the MARINET Consortium is liable for any use that may be made of the information
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 5 of 20
EXECUTIVE SUMMARY Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation In this report an on-going research and experimental project is presented The project CoMaRE -Assessment and mitigation of marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices- is focused in the assessment of the marine corrosion phenomena on metallic components in MRE devices from a practical point of view and in the evaluation of different components This project has an estimated duration of two years therefore several phases are needed to achieve the desired results During this fourth phase of project CoMaRE main activity has been the control and removal of part of tested coupons in field at Helgoland and the accelerated weathering tests below different exposure conditions at the CTCrsquos laboratory Additionally CTC has analysed the test of novel coating systems with nanoparticles of oxides and graphene oxide The trials at the Fraunhofer IWES offshore field test facilities were developed in the North Sea at the Island Helgoland (Germany) and additional results were obtained Mooring chains slide (with and without a Thermally Sprayed Aluminium coating ndash TSA) pieces of fibre ropes of different diameters steel plates (with and without coatings) and polymer composite specimens were tested at the offshore test rig in diverse marine conditions (tidal splash and submerged) and atmospheric in the CTCacutes facilities (Santander Spain) Accelerated weathering tests were also carried out at CTCrsquos Laboratory (UV cyclic weathering and salt spray tests) Steel coated coupons with antifouling (AF) paints including the use of oxide nanoparticles and graphene were exposed to different environments Surface of non additivated coating showed less roughness than additivated coating in nano-metrical scale and roughness in both cases was found to increase after salt spray exposure In any of the AF coated samples macrofouling was not found at surface Results in terms of estimated corrosion rate were obtained for chain slide samples in submerged zone for different exposure periods
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 6 of 20
CONTENTS
1 INTRODUCTIONamp BACKGROUND 7
11 INTRODUCTION 7 111 Task 1 Field test 7 112 Task 2 Workshop activities 7 113 Tasks 3 amp 4 Laboratory tests analysis and correlation 7 114 Task 5 Dissemination 8
12 DEVELOPMENT SO FAR 8 121 Plan For This Access 8
2 OUTLINE OF WORK CARRIED OUT 9
21 SETUP 9 22 TESTS 10 221 Test Plan 10
23 RESULTS 13 24 ANALYSIS amp CONCLUSIONS 16
3 MAIN LEARNING OUTCOMES 18
31 PROGRESS MADE 18 311 Progress Made For This User-Group or Technology 18 312 Progress Made For Marine Renewable Energy Industry 18
32 KEY LESSONS LEARNED 18
4 FURTHER INFORMATION 19
41 SCIENTIFIC PUBLICATIONS 19 42 WEBSITE amp SOCIAL MEDIA 19
5 REFERENCES 19
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 4 of 20
ABOUT THIS REPORT One of the requirements of the EC in enabling a user group to benefit from free-of-charge access to an infrastructure is that the user group must be entitled to disseminate the foreground (information and results) that they have generated under the project in order to progress the state-of-the-art of the sector Notwithstanding this the EC also state that dissemination activities shall be compatible with the protection of intellectual property rights confidentiality obligations and the legitimate interests of the owner(s) of the foreground The aim of this report is therefore to meet the first requirement of publicly disseminating the knowledge generated through this MARINET infrastructure access project in an accessible format in order to
progress the state-of-the-art
publicise resulting progress made for the technologyindustry
provide evidence of progress made along the Structured Development Plan
provide due diligence material for potential future investment and financing
share lessons learned
avoid potential future replication by others
provide opportunities for future collaboration
etc In some cases the user group may wish to protect some of this information which they deem commercially sensitive and so may choose to present results in a normalised (non-dimensional) format or withhold certain design data ndash this is acceptable and allowed for in the second requirement outlined above
ACKNOWLEDGEMENT The work described in this publication has received support from MARINET a European Community - Research Infrastructure Action under the FP7 ldquoCapacitiesrdquo Specific Programme
LEGAL DISCLAIMER The views expressed and responsibility for the content of this publication lie solely with the authors The European Commission is not liable for any use that may be made of the information contained herein This work may rely on data from sources external to the MARINET project Consortium Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data The information in this document is provided ldquoas isrdquo and no guarantee or warranty is given that the information is fit for any particular purpose The user there of uses the information at its sole risk and neither the European Commission nor any member of the MARINET Consortium is liable for any use that may be made of the information
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 5 of 20
EXECUTIVE SUMMARY Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation In this report an on-going research and experimental project is presented The project CoMaRE -Assessment and mitigation of marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices- is focused in the assessment of the marine corrosion phenomena on metallic components in MRE devices from a practical point of view and in the evaluation of different components This project has an estimated duration of two years therefore several phases are needed to achieve the desired results During this fourth phase of project CoMaRE main activity has been the control and removal of part of tested coupons in field at Helgoland and the accelerated weathering tests below different exposure conditions at the CTCrsquos laboratory Additionally CTC has analysed the test of novel coating systems with nanoparticles of oxides and graphene oxide The trials at the Fraunhofer IWES offshore field test facilities were developed in the North Sea at the Island Helgoland (Germany) and additional results were obtained Mooring chains slide (with and without a Thermally Sprayed Aluminium coating ndash TSA) pieces of fibre ropes of different diameters steel plates (with and without coatings) and polymer composite specimens were tested at the offshore test rig in diverse marine conditions (tidal splash and submerged) and atmospheric in the CTCacutes facilities (Santander Spain) Accelerated weathering tests were also carried out at CTCrsquos Laboratory (UV cyclic weathering and salt spray tests) Steel coated coupons with antifouling (AF) paints including the use of oxide nanoparticles and graphene were exposed to different environments Surface of non additivated coating showed less roughness than additivated coating in nano-metrical scale and roughness in both cases was found to increase after salt spray exposure In any of the AF coated samples macrofouling was not found at surface Results in terms of estimated corrosion rate were obtained for chain slide samples in submerged zone for different exposure periods
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 6 of 20
CONTENTS
1 INTRODUCTIONamp BACKGROUND 7
11 INTRODUCTION 7 111 Task 1 Field test 7 112 Task 2 Workshop activities 7 113 Tasks 3 amp 4 Laboratory tests analysis and correlation 7 114 Task 5 Dissemination 8
12 DEVELOPMENT SO FAR 8 121 Plan For This Access 8
2 OUTLINE OF WORK CARRIED OUT 9
21 SETUP 9 22 TESTS 10 221 Test Plan 10
23 RESULTS 13 24 ANALYSIS amp CONCLUSIONS 16
3 MAIN LEARNING OUTCOMES 18
31 PROGRESS MADE 18 311 Progress Made For This User-Group or Technology 18 312 Progress Made For Marine Renewable Energy Industry 18
32 KEY LESSONS LEARNED 18
4 FURTHER INFORMATION 19
41 SCIENTIFIC PUBLICATIONS 19 42 WEBSITE amp SOCIAL MEDIA 19
5 REFERENCES 19
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 5 of 20
EXECUTIVE SUMMARY Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation In this report an on-going research and experimental project is presented The project CoMaRE -Assessment and mitigation of marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices- is focused in the assessment of the marine corrosion phenomena on metallic components in MRE devices from a practical point of view and in the evaluation of different components This project has an estimated duration of two years therefore several phases are needed to achieve the desired results During this fourth phase of project CoMaRE main activity has been the control and removal of part of tested coupons in field at Helgoland and the accelerated weathering tests below different exposure conditions at the CTCrsquos laboratory Additionally CTC has analysed the test of novel coating systems with nanoparticles of oxides and graphene oxide The trials at the Fraunhofer IWES offshore field test facilities were developed in the North Sea at the Island Helgoland (Germany) and additional results were obtained Mooring chains slide (with and without a Thermally Sprayed Aluminium coating ndash TSA) pieces of fibre ropes of different diameters steel plates (with and without coatings) and polymer composite specimens were tested at the offshore test rig in diverse marine conditions (tidal splash and submerged) and atmospheric in the CTCacutes facilities (Santander Spain) Accelerated weathering tests were also carried out at CTCrsquos Laboratory (UV cyclic weathering and salt spray tests) Steel coated coupons with antifouling (AF) paints including the use of oxide nanoparticles and graphene were exposed to different environments Surface of non additivated coating showed less roughness than additivated coating in nano-metrical scale and roughness in both cases was found to increase after salt spray exposure In any of the AF coated samples macrofouling was not found at surface Results in terms of estimated corrosion rate were obtained for chain slide samples in submerged zone for different exposure periods
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 6 of 20
CONTENTS
1 INTRODUCTIONamp BACKGROUND 7
11 INTRODUCTION 7 111 Task 1 Field test 7 112 Task 2 Workshop activities 7 113 Tasks 3 amp 4 Laboratory tests analysis and correlation 7 114 Task 5 Dissemination 8
12 DEVELOPMENT SO FAR 8 121 Plan For This Access 8
2 OUTLINE OF WORK CARRIED OUT 9
21 SETUP 9 22 TESTS 10 221 Test Plan 10
23 RESULTS 13 24 ANALYSIS amp CONCLUSIONS 16
3 MAIN LEARNING OUTCOMES 18
31 PROGRESS MADE 18 311 Progress Made For This User-Group or Technology 18 312 Progress Made For Marine Renewable Energy Industry 18
32 KEY LESSONS LEARNED 18
4 FURTHER INFORMATION 19
41 SCIENTIFIC PUBLICATIONS 19 42 WEBSITE amp SOCIAL MEDIA 19
5 REFERENCES 19
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 6 of 20
CONTENTS
1 INTRODUCTIONamp BACKGROUND 7
11 INTRODUCTION 7 111 Task 1 Field test 7 112 Task 2 Workshop activities 7 113 Tasks 3 amp 4 Laboratory tests analysis and correlation 7 114 Task 5 Dissemination 8
12 DEVELOPMENT SO FAR 8 121 Plan For This Access 8
2 OUTLINE OF WORK CARRIED OUT 9
21 SETUP 9 22 TESTS 10 221 Test Plan 10
23 RESULTS 13 24 ANALYSIS amp CONCLUSIONS 16
3 MAIN LEARNING OUTCOMES 18
31 PROGRESS MADE 18 311 Progress Made For This User-Group or Technology 18 312 Progress Made For Marine Renewable Energy Industry 18
32 KEY LESSONS LEARNED 18
4 FURTHER INFORMATION 19
41 SCIENTIFIC PUBLICATIONS 19 42 WEBSITE amp SOCIAL MEDIA 19
5 REFERENCES 19
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 7 of 20
1 INTRODUCTIONamp BACKGROUND
11 INTRODUCTION Degradation due to the environment in marine devices and components is one of the main issues facing the offshore industry and is an even greater issue in devices with a high degree of autonomous operation This project is focused on the practical aspects of one degradation mechanism corrosion of metallic components in Marine Renewable Energy devices The selected testing infrastructure is unique in the MARINET consortium and also across Europe as it is located in a real offshore environment As the main objectives of the project are to assess the marine corrosion mechanisms and to evaluate different candidate corrosion protection techniques it is essential to carry out the tests in real extreme conditions The technological and scientific support offered by the well-experienced staff of the selected infrastructure is another reason to propose the access to these test facilities Taking into account the scientific background of the User Group (UG) it is expected that as a result of this project further lines of collaboration and research will be established between the institutions In the following points the tasks for Phase 4 proposed in 5th Call of MARINET are shown These tasks were completed during the 5th Call access period (01022014-31122014)
111 Task 1 Field test The objective of this task is testing several samples for assessing the marine corrosion rate at the offshore field test facilities Some examples that were described in the proposal for Phase 4 are listed below (non exhaustive)
bull CLIMAT coupons [1] bull Mooring systems (mooring chains fibre ropes) bull Standards coupons with and without coatings bull Coupons of wind blade composite bull Coupons for accelerated tests
Further description of the components actually tested during phase 4 is included in section 12 Field tests have also included the development of atmospheric corrosion tests in the CTCs facilities These tests have the aim to check if any correlation between accelerated and real field tests exists
112 Task 2 Workshop activities Workshop of the UG will be done in following phases Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
113 Tasks 3 amp 4 Laboratory tests analysis and correlation Once the field tests are finished the samples will be analysed applying standard practices in the laboratory These studies will mainly consist on weight loss evaluation and microstructural characterization of the samples by means of Optical and Atomic Force Microscopy (AFM) A general morphological evaluation of the samples will be also carried out in order to identify the corrosion phenomena suffered In the case of composite coupons tensile tests were made to verify the environmental effect over the mechanical properties
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 8 of 20
Accelerated weathering tests were planned to be carried out
114 Task 5 Dissemination It was planned to attend to a European congress and write some scientific articles based on the experiences but due to corrosion phenomenon takes a long time to develop they will be done in following phases
12 DEVELOPMENT SO FAR
121 Plan For This Access The tasks of the Phase 4 of the project are herein referred and their development in this access is shown below
1211 Task 1 Field tests
The components tested during this phase include
Standard steel coupons with antifouling (AF) coating system including oxide nano-particles (NPs new in this phase)
Standard steel coupons only with 1 layer of AF coatings including graphene oxide (GO) addition (new in this phase)
Standard coupons of anticorrosive coating systems for Tecnalia
Mooring systems chains with and without coatings fibre ropes with steel core
Coupons of composite unsaturated polyester (UPS) with and without carbon nanotubes
Coupons of composite pre-preg epoxy reinforced with glass fiber
CLIMAT coupons to obtain different corrosivity indexes [1]
Coupons for accelerated tests Pre-preg epoxy composite polyester and antifouling coated coupons
Reference un-aged coupons
1212 Task 2 Workshop activities
Proposal for the 6th Call of MARINET was elaborated instead of Workshop activities It was a good opportunity to continue the project as the duration of the field test exceeding the time of the previous calls
1213 Tasks 3 amp 4 Laboratory tests analysis and correlation
Stress-strain curves have been obtained from unaged composite coupons in the first phase Besides in the following phases stress-strain curves have been obtained for exposed composite coupons in marine and atmospheric conditions AFM images were obtained from the surface of unexposed coupons with different AF coating systems and after salt spray weathering Mean thickness loss and estimated corrosion rate due to corrosion is obtained from uncoated chain slides by means of chemical cleaning of corroded steel following ISO 8407 standard method C31[2] In the case of composites UVA 340 nm artificial exposure as well as water spray cyclic weathering was done according EN 12224 [3] For the coated steel plates with antifouling a salt spray test (acc to ISO 9227 [4]) was carried out with substitute sea water with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed
1214 Task 5 Dissemination
In previous phases of the project 2 posters have been presented in Eurocorr 2013 and in Thetis MRE 2013 In this phase a conference paper was presented in IWEC 2014 (wwwiwec2014de) in Hannover titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo [5]
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 9 of 20
On the webpage of the CTC a reference is included to this project (httpctcomponentesesencomare-2[10]5010)
2 OUTLINE OF WORK CARRIED OUT
21 SETUP
The recent work continues the one started in CoMaRE Phase 1 [6] CoMaRE Phase 2 [7] and CoMaRE Phase 3 [8] which overlaps in time with CoMaRE Phase 4 In Figure 21 several coupons are shown which have been prepared for exposure in the splash zone at the facility
The main activities in the 4th Phase were related to
1 Control of on-going test coupons the number of coupons in the tests needs to be controlled Several inspections have been done to the coupons by Fraunhofer IWES in this phase during the environmental tests to check that the conditions of the tests are kept
2 Removal of tested coupons once the coupons have finished their exposure time they were removed from test rig
3 Analysis of tested coupons cleaning procedure was done acc to ISO 8227 [2] for uncoated chain slides in submerged condition MCI index was obtained Final inspection was done to the removed coupons
Figure 21 Coupons of Phase 3 amp 4 being tested in the splash zone (from left to right fibre ropes coated steel plates and offshore chain slices)
Environmental Site at CTCrsquos headquarters At the CTCrsquos headquarters roof (2 Km from shoreline) the following activities were achieved
Control of tested coupons coupons need to be controlled during its exposure
Removal and analysis of tested coupons Laboratory accelerated weathering at CTC In the case of composites UVA 340 nm artificial exposure as well as distilled water spray cyclic weathering was done according EN 12444 [3] In Figure 22 coupons installed in the UV chamber are observed For the coated steel plates with antifouling a salt spray test (acc to ISO 9227) was carried out with substitute sea water (prepared acc to ASTM D1141 [9]) with the same chemical composition of natural seawater Accelerated test (UV exposure and salt fog tests) were performed but results are still being analysed
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 10 of 20
Figure 22 Coupons of Phase 4 (Pre-preg epoxy and UPS composite coupons) ready for exposure in UV chamber
22 TESTS
221 Test Plan During this Fourth Phase of the project we have followed the previous test plan [6] which served as a basis for the tests which will be followed in the upcoming phase The next phase will be necessary in order to be able to obtain a more clear correlation between field tests and the accelerated ones at laboratory after analysing all the results As part of the development of the project the three companies (Degima Vicinay Cadenas and Itsaskorda) that were testing their components ldquoin kindrdquo continued the tests Therefore the testing program for this Phase 4 follows the one proposed for Phase 3 after the Phase 1 and 2 of the project In the following graph timing for CTCrsquos tests is summarized CENIM will start their activities in the next phase Tecnalia exposed different coating systems during this phase CTC has continued the activities already started following the chronogram showed in the Figure 23
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 11 of 20
Figure 23 CoMaRE access periods and tests chronogram
Project Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
CTC Composite (Polyester+GF)
Composite (Polyester+GF) + MWCNT
Prepreg Epoxi+GF
CLIMAT
DEGIMA Uncoated steel plates (S355J2+N)
Coated coupons (AFAF+NPs in topcoat)
Coated coupons (AFAF+GO)
ITSASKORDA Seine Rope D=46mm
Malleta D=38mm
Combirope D=18mm
VCSA Uncoated HSS chain slides
TSA coated HSS chain slides
Coordination MARINET Calls
1st Access Period
2nd Access Period
3rd Access Period
5th Access Period
6th Access Period
Visits to Helgoland
Visual inspections
Workshops
Other
Closing Calls
CTC visits
Visual inspections by FH-IWES
Install probes
Remove probes
2012 2013 2014 2015
v v
v
v v
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 12 of 20
2211 Description of the coupons
As previously described [6]-[8] Fraunhofer IWES operates a marine corrosion tests facility in the inner side of the seawall of Helgolandrsquos harbour In this test site there are three different areas that can be classified attending the accepted criteria [10] [11] in marine corrosion Splash Tidal and Submerged zones
Each coupon was coded and a shorter code system was selected for labelling on the tested specimens as described in previous reports
2212 Phase 1 - Phase 4 test coupons for CTC
CTC following the test plan [6] has fabricated prepared and tested the following specimens along Phase 4 Several CLIMAT Coupons [1] were prepared by CENIM and later located in the splash zone in Helgoland and on the roof of the CTCs facilities These standard coupons are widely used for the analysis of the corrosivity in different atmospheric conditions [12]-[14] All the samples for CTC along this project are classified according to Table 21
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (280x25mm)
Lab (250x25mm)
Composite (Polyester+GF) 1(3) 1(3) 1(3) 3 6
Composite (Polyester+GF) + MWCNT 1(3) 1(3) 1(3) 3 6
Composite (Epoxy+GF Prepreg) 1(3) 1(3) 1(3) 3 6
CLIMAT 4 - - 4 -
Table 21 Number of coupons planned in the phase 1 - phase 4 for each exposition zone fabricated at CTC
2213 Phase 1 ndashPhase 4 test coupons for Degima
Samples tested in different environments during Phase 3 are summarized in Table 22 Coated coupons were installed in the 4th Phase Consequently different coated samples were installed
Multilayer steel coated coupons o Coupons (400x90x4 mm) of S355J2+N steel with the upper half part coated with option (a) and the
lower half with option (b) o Standard coupons for accelerated laboratory tests (150x75x4mm) four of them were coated with
option (a) and the other four with option (b)
One-layer steel coated coupons o Standard coupons (400x90x4 mm) of S355J2+N steel with the upper half was coated with option (c)
and the lower half of the coupons was coated with option (d)
Helgoland (400x90mm) CTC
Splash Tidal Submerged Atmospheric (400x90mm)
Lab (150x75mm)
Uncoated Plate (S355J2+N) 3 3 3 - -
Coated with AF frac12 with oxide NPs 3 3 3 3 4+4
Coated with AF 1 layer with frac12 GO 3 - - - -
Table 22 Number of coupons exposed in the Phase 3 for each zone fabricated and coated at Degima
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 13 of 20
2214 Phase 1 ndash Phase 4 test coupons for Itsaskorda
The specimens exposed to environmental conditions in the case of Itsaskorda consist on rope segments of 30 cm length making a total of 8 specimens for each type of rope Different rope types are studied [6] As commented in [6] they are located in tidal and submerged areas and they will have two different ageing times 12 and 24 months Table 23 contains the number of each type of rope specimen as well as the exposure environment
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
SeineRope Oslash46 - 4 4 - -
Malleta Oslash38 - 4 4 - -
Combirope Oslash18 - 4 4 - -
Table 23 Number of coupons planned in phase 1 for each exposition zone fabricated at Itsaskorda
2215 Phase 1 - Phase 4 test coupons for Vicinay Cadenas
Itrsquos planned to expose to different marine environments samples of Vicinayrsquos high strength steel chain links These coupons were extracted from the side of Vicinayrsquos chain links which are used to moor offshore floating structures [7] Two options are investigated herein an uncoated R3S high strength steel and a R3S high strength steel coated with TSA A total of 48 specimens divided between the splash tidal and submerged environments were installed in previous phases as shown in Table 24
Helgoland CTC
Splash Tidal Submerged Atmospheric Lab
HSS 8 8 8 - -
HSS coated with TSA 8 8 8 - -
Table 24 Number of coupons installed in previous phases for each exposure zone fabricated at Vicinay Cadenas
23 RESULTS Uncoated Chain slides samples Uncoated chain slides provided by Vicinay Cadenas were cleaned after exposure acc to ISO 8407 method C31 and weight loss due to corrosion was calculated for two specimens in submerged condition for 6 12 18 and 24 months of exposure The following figure summarizes the estimated results for averaged surface mean value of corrosion rate and mean corrosion depth
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 14 of 20
Figure 24 Estimated corrosion rate for 4 exposure periods of uncoated chain slides in submerged zone
Figure 25 Mean corrosion depth for 4 exposure periods of uncoated chain slides in submerged zone
AFM observations over AF coating surfaces Atomic Force Microscope (AFM) was used for the analysis of surface with and without Nanoparticles (NPs) addition Observations were also made after 240 hours of salt spray testing with substitute ocean water Roughness measurements (Ra values) were obtained for four points of the surface of each coupon In the next chart bars measurements are collected
0000
0025
0050
0075
0100
0125
0150
0175
0200
0225
0 6 12 18 24 30
corr
osi
on
rat
e m
my
Time (months)
R5S Submerged
1018
1593
22512346
0
50
100
150
200
250
0 6 12 18 24 30
Co
rro
sio
n d
ep
th micro
m
Time (months)
R3S Submerged
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 15 of 20
Figure 26 Image Ra of AF coatings surface for 4 coupons and their mean value before (blue) and after (red) accelerated salt spray tests
GFRP UPS composite samples The main result of the project so far is the assessment of the increment of weight and the variation of the strength of the unsaturated polyester fibre reinforced composite material (GFRP UPS) in unexposed and exposed sites and the observations made at the field to all the exposed coupons at the end of the third phase The results (maximum stress and maximum deformation) of tensile testing of the unexposed vs exposed coupons are presented and discussed in [5]
Rest of the samples In the last inspection it was found that several specimens showed signs of oxidation and rusting processes as can be observed in [5] Marine growth was also observed in the tidal and submerged zones As an example the Figure 29 shows the antifouling coating system coupons before and after 12 months of exposure in splash tidal and submerged zones Visual inspection has been carried out for all the samples
000
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
with NPs without NPs
Ra
[nm
]
1LAB 2LAB 3LAB 4LAB Mean 1LAB 2LAB 3LAB 4LAB Mean
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 16 of 20
Spla
sh
Tid
al
Sub
me
rge
d
Figure 27 AF multilayer coated samples Initial aspect and after 9 months of exposure (front face)
24 ANALYSIS amp CONCLUSIONS From the visual inspection of the coupons and the after-exposure tests we conclude that the corrosiondegradation processes developed in the specimens located in the different zones more significantly in uncoated ones In fact submerged and tidal specimens also showed marine growth Sorted by type of coupon
1 Composite unsaturated polyester coupons (GFRP UPS) no major surface chalking or degradation damage on field test was shown Some whitening around fibre glass was observed in coupons without MWCNT addition The addition of multi-walled carbon nanotubes (MWCNT) has decreased the mean loss of mechanical properties due to natural weathering in all the marine environments
o Atmospheric zone weight loss was observed and the highest rate of mechanical properties loss was measured
o Splash zone Weight gain was observed but less than tidal and submerged zones Less effect in mechanical properties was observed in the case of coupons with MWCNT
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 17 of 20
o Tidal zone The composite coupons were more covered by algae than metallic ones Generally less weight gain was also observed in the case of coupons with MWCNT compared to submerged zone
o Submerged zone specimens showed marine growth but less than metallic coupons The Mechanical properties loss is more relevant in this marine environment so it could be related with algae and microbial activity The highest weight gain was measured
o Accelerated cyclic UV tests whitening around glass fibers in MWCNT was also observed Mechanical tests will be done in next phase
2 Pre-preg epoxy composite coupons
o Atmospheric and splash zones no major changes were observed in both o Tidal zone barnacles and algae colonized some parts of the coupons o Accelerated cyclic UV tests changes in dark colour were observed in contrast from less exposed
parts
3 Uncoated steel plate coupons (from previous phases) o Splash zone showed noticeable traces of corrosion o Submerged and tidal zones medium fouling and rusting was observed
4 AF Multilayer steel coated coupons AFM images of unexposed samples were obtained showing differences
between the coatings with and without nano-additions The main issues observed so far o Splash zone only whitening of the topcoat was observed as can be seen in Figure 27 No marine
growth or rusting This degradation effect is likely to be produced by the combination of different environmental factors including salt concentration temperature variations and solar UV radiation among others
o Tidal zone no significant marine growth Some marks of fouling in the lower part of the coupons o Submerged zone algae marine growth is not again observed after 9 months so its antifouling
property seems to be partially effective only some brown biological fouling is attached to coupons This fouling had slightly less coverage in the lower part (with oxide nanoparticles)
o Accelerated salt spray tests an increase in mean measured roughness (Image Ra) is observed in the coupons by means of AFM Microscopy after exposure
5 AF One-layer steel coated coupons in the splash zone both parts of the coupons with and without graphene
oxide have shown clear rusting whitening of the coating and delamination in the images with a greater corrosion creepage in the upper part (non additivated) which increased in comparison to previous phases
6 Tecnaliarsquos samples marine trials were finished
7 Fibre rope coupons heavy marine growth (barnacles algaehellip) was observed in the tidal zone and some rusting in the metal core of the edges of the ropes
8 Coupons from the offshore chain clear rusting was shown in the uncoated ones while the coated ones showed relevant degradation of the TSA (Thermally Sprayed Aluminium) coating especially in the tidal and submerged zone In submerged zone all the coupons were completely covered by macro-fouling TSA coating was observed to be damaged particularly by barnacle growth Corrosion rate estimated in submerged zone for uncoated chain coupons indicates a decrease of corrosion rate with time (from 020 to 012 mmyear) Corrosion rate is in good agreement with literature values for offshore chains [16]
9 CLIMAT (Wire-on-bolt) coupons First results for the MCI (Marine Corrosion Index) and ACI (Atmospheric
Corrosion Index) values were obtained for splash and atmospheric zones Following the classification of atmospheric corrosivity [17] Helgoland was classified as very severe and Santander (CTCs facilities) as moderate The indexes were in good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 18 of 20
3 MAIN LEARNING OUTCOMES
31 PROGRESS MADE All the planned coupons in the test plan have been installed in the marine test rig and to the atmospheric test rig We have exposed all the coupons planned by the UG for this phase Laboratory tests started but more results will be obtained in next phase Results in composite polyester coupons coated steel plates and chain slide coupons were obtained
311 Progress Made For This User-Group or Technology In this technology new materials have been tested in the marine environment to check their behaviour In this phase we have continued the testing already initiated We will have to wait to obtain more results basically because corrosion testing takes time to give relevant information especially in coated coupons AFM images were obtained from the surface of unexposed coated steel samples
3111 Next Steps for Research or Staged Development Plan ndash ExitChange amp RetestProceed
As we have planned the next steps and further results are in the near future for the Fourth Phase as some members the UG are going to start their testing in the different facilities Environmental tests are on-going in offshore and atmospheric marine condition More coupons will be removed and analysed at laboratory in the next phase Accelerated laboratory test are on-going and more results will be shown in the next phase
312 Progress Made For Marine Renewable Energy Industry The UG have started testing different materials used in MRE devices and so far the beneficial effect of coating in the chains has been observed The fibre rope has also been affected by fouling and corrosion Also the marine growth must be considered as it effect is not only due to increase in weight over the structure and itrsquos not only applied to steel structures AF paints tested used in MRE devices didnacutet show a reliable behaviour in long term structures Both mooring systems are commonly used as a solution for mooring the MRE devices Data of atmospheric corrosivity was also obtained at different test sites Corrosion rates were estimated for submerged uncoated chains Therefore these results will be interesting for the durability of MRE devices
32 KEY LESSONS LEARNED
Modified a test plan taking account of possible problems
The collaboration with companies to give coupons ldquoin kindrdquo is interesting
Preparing the coupons to be strongly attached in the testing rig is important for field tests
Coating affects significantly the corrosion and fouling process in offshore chains fibre ropes and steel plates
Oxidation of the metallic core of the fibre ropes was observed
Composite coupons are also affected by marine growth and their mechanical properties are affected by the environmental conditions
The addition of MWCNT has improved the durability of composite polyester coupons
AF topcoat is partially effective in submerged zone slightly improve in this case of nanoparticles addition In the other hand better resistance to fouling was observed in tidal zone
AF coating unexposed surface shows differences between the samples with and without nanoparticles addition in AFM microscope An increase in roughness is also observed after salt spray tests
Estimated corrosion rates in chain slides show good agreement with theoretical values in continuously immersed offshore chains
Atmospheric corrosivity data showed good agreement with theoretical values
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 19 of 20
4 FURTHER INFORMATION
41 SCIENTIFIC PUBLICATIONS List of any scientific publications made (already or planned) as a result of this work (in all the phases of the project)
EUROCORR 2013 Poster in EUROCORR 2013 Congress (wwweurocorr2013org) titled ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo [15] was shown
THETIS Energy Marine Renewable 2013 A Poster session titled ldquoAssessment and mitigation of marine corrosion in metallic components in Marine Renewable Energy devices first experiences from offshore field tests in the North Seardquo about the first phase work was presented (httpwwwthetis-emrcomarticles62-THETIS_MRE_chooses_Brest_to_power_ahead_in_2013 )
IWEC 2014 A paper titled ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo was presented in a session conference (wwwiwec2014de)
42 WEBSITE amp SOCIAL MEDIA Website httpctcomponentesesencomare-2[10]5010
5 REFERENCES
[1] ASTM Standard G116 ndash 99 (2010) ldquoStandard Practice for Conducting Wire-on-Bolt Test for Atmospheric Galvanic Corrosionrdquo ASTM International West Conshohocken PA wwwastmorg 2010
[2] ISO 8407 ldquoCorrosion of metals and alloys Removal of corrosion products from corrosion test specimensrdquo 2009
[3] EN 12224 ldquoGeotextile and geotextile-related products Determination of resistance to weatheringrdquo 2000
[4] ISO 9227 ldquoCorrosion tests in artificial atmospheres Salt spray testsrdquo 2012
[5] Fernandez D Rodriacuteguez R Rodriacuteguez A Yedra A ldquoDegradation and corrosion testing of materials and coating systems for offshore wind turbine substructures in North Sea watersrdquo Proceedings in IWEC 2014 Conference Section 31 Hannover Germany September 2014
[6] Gorrochategui I Rodriacuteguez Arias R Fernaacutendez D De la Fuente D Morcillo M Jorcin JB Azcarate I
Madina V Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 1)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 1 March 2013 Available in httpwwwfp7-marineteupublicdocsCoMaRE_Phase1_Access_Period201pdf
[7] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Madina V
Schnars H ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 2)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 2 November 2013 Available in httpwwwfp7-marineteupublicdocsInfrastructure_Access_Report_CoMaRE20Phase202pdf
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
Infrastructure Access Report CoMaRE Phase 4
Rev 02 30-Oct-2015 Page 20 of 20
[8] Fernaacutendez de Rucoba D Rodriacuteguez Arias R De la Fuente D Morcillo M Jorcin JB Tejero M Houmlrnig M
Kranz OH ldquoAssessment and mitigation of Marine Corrosion in metallic components in Marine Renewable Energy (MRE) devices (Phase 3)rdquo CTC-CENIM-TECNALIA Infrastructure owner Fraunhofer IWES MARINET Infrastructure Access Report CoMaRE Phase 3 August 2015
[9] ASTM D1141-98 ldquoStandard Practice for Preparing Substitute Ocean Waterrdquo ASTM International West Conshohocken PA wwwastmorg 2003
[10] Baboian R et alt ldquoCorrosion Test and Standards Application and Interpretationrdquo Section V Testing in Environments Chapter 30 ldquoSeawaterrdquo Shifler DA Aylor DM 2nd Edition ASTM International West Conshohocken PA wwwastmorg 2005
[11] Stenzel V Plagemann P Momber AW Schneider M ldquoCombined Field-Laboratory Studies on Corrosion Protection for Offshore Windenergy Towersrdquo 4th Intern Symp on Protective Coatings Bombay 2006
[12] Rivero S Chico B de la Fuente D Morcillo M ldquoAtmospheric corrosion of low carbon steel in a polar marine environment Study of the effect of wind regime rdquo (in Spanish) Rev de Metalurgia 43(5) pp 370-383 September 2007
[13] Morcillo M Otero E Chico B de la Fuente D ldquoAtmospheric corrosion studies in a decommissioned nuclear power plantrdquo Nuclear Power Pavel Tsvetkov (Ed) ISBN 978-953-307-110-7 InTech 2010 Available from httpwwwintechopencombooksnuclear-poweratmospheric-corrosion-studies-in-a-retired-nuclear-powerplant
[14] Klassen RD Roberge PR Lenard DR Blenkinsop GN Corrosivity Patterns Near Sources of Salt
Aerosols Outdoor Atmospheric Corrosion ASTM STP 1421 H E Townsend Ed American Society for Testing and Materials International (ASTM) West Conshohocken PA wwwastmorg 2002
[15] Fernaacutendez D Rodriacuteguez R Gorrochategui I ldquoFirst experiences in the assessment and mitigation of marine corrosion in metallic components for Marine Renewable Energy devicesrdquo EUROCORR 2013 Congress European Corrosion Congress Poster September 2013
[16] Melchers RE Moan T Gao Z ldquoCorrosion of working chains continuously immersed in seawaterrdquo J
Mater Sci Tech 12 102-110 Springer June 2006
[17] Roberge PR ldquoHandbook of Corrosion Engineeringrdquo Chapter 2 Environments Ed Mc Graw-Hill 2000
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