Scanning Vibrating Electrode (SVET) Secondary Ion Mass ...
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Surface Characterisation Techniques Four techniques were used to characterise corroded surfaces of cladding materials in pondwater. Each technique scans the surface and records different chemical or physical changes while the metal is corroding. By clarifying those corrosion processes with respect to time, one can propose a mechanism and offers solutions to inhibit, contain or monitor the corrosion processes in ponds. Contact: Alice Laferrere, Research Scientist Telephone: 01453 853 615 E-mail: [email protected] Techniques with low resolution such as SVET and TLI are suited to corrosion processes happening at a constant rate over a large area (pit growth and filiform corrosion). Techniques with high resolution such as SIMS and AFM are suited to localised corrosion processes with a stochastic nature (pit initiation and crack formation). Acknowledgements: The authors are grateful for the support and hospitality of the University of Swansea and the University of Bristol staff. This work was partly funded by Sellafield Limited and by NNL through its Signature Research programme. Increasing Resolution Increasing Scan Rate Scanning Vibrating Electrode (SVET) Magnox clad: Evolution of a stable pit in 5% chloride. The strong anodic peak is surrounding by a cathodic “circle”. Anodes are in red, cathodes are in blue. Secondary Ion Mass Spectroscopy (SIMS) CHROMIUM CARBON NICKEL Stainless steel clad: Grain boundary composition in sensitised stainless steel, prior to immersion. Grain boundaries structure and composition can be linked to intergranular stress corrosion cracking. Time Lapse Imaging (TLI) Active areas are in black, passive areas are shaded in grey. Magnox (Mg Non-Oxidising): Evolution of filiform corrosion in 2.5% chloride. Hydrogen bubbles cover surface. Atomic Force Microscopy (AFM) Stainless steel in seawater: Thanks to electrochemical noise measurement, corrosion processes were identified after several hours of immersion. An AFM map revealed that the pits developed at grain boundaries. Pit geometry and stability govern the pit to small crack transition. Figures from DOI: 10.5772/52698. 8h 9.5 h 11 h 11.5 h time (hour s ) 3h 6.5 h 9h 11 h time (h o ur s)
Transcript of Scanning Vibrating Electrode (SVET) Secondary Ion Mass ...
Surface Characterisation Techniques
Four techniques were used to characterise corroded surfaces of cladding materials in pondwater. Each technique scans the surface and records different chemical or physical changes while the metal is corroding. By clarifying those corrosion processes with respect to time, one can propose a mechanism and offers solutions to inhibit, contain or monitor the corrosion processes in ponds.
Contact: Alice Laferrere, Research Scientist Telephone: 01453 853 615 E-mail: [email protected]
Techniques with low resolution such as SVET and TLI are suited to corrosion processes happening at a constant rate over a large area (pit growth and filiform corrosion). Techniques with high resolution such as SIMS and AFM are suited to localised corrosion processes with a stochastic nature (pit initiation and crack formation).Acknowledgements:The authors are grateful for the support and hospitality of the University of Swansea and the University of Bristol staff. This work was partly funded by Sellafield Limited and by NNL through its Signature Research programme.
Increasing Resolution
Incr
easi
ngS
can
Rat
e
Scanning Vibrating Electrode (SVET)Magnox clad:Evolution of a stable pit in 5% chloride.
The strong anodic peak is surrounding by a cathodic “circle”.
Anodes are in red, cathodes are in blue.
Secondary Ion Mass Spectroscopy (SIMS)
CHROMIUM
CARBONNICKEL
Stainless steel clad:Grain boundary composition in sensitised stainless steel, prior to immersion.
Grain boundaries structure and composition can be linked to intergranular stress corrosion cracking.
Time Lapse Imaging (TLI)
Active areas are in black, passive areas are shaded in grey.
Magnox (Mg Non-Oxidising): Evolution of filiform corrosion in 2.5% chloride.
Hydrogen bubbles cover surface.
Atomic Force Microscopy (AFM)
Stainless steel in seawater:Thanks to electrochemical noise measurement, corrosion processes were identified after several hours of immersion. An AFM map revealed that the pits developed at grain boundaries. Pit geometry and stability govern the pit to small crack transition.
Figures from DOI: 10.5772/52698.
8 h
9.5 h
11 h
11.5 h
time (hours)
3 h
6.5 h
9 h
11 h
time
(hours)
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