O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY Lara-Curzio et al. IGTI-2004. Page 1...
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Transcript of O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY Lara-Curzio et al. IGTI-2004. Page 1...
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 1 of 45
Screening and Evaluation of Materials for Advanced Microturbine Recuperators
Edgar Lara-Curzio, R. M. Trejo, K. L. More,P.A. Maziasz, B. A. Pint
Metals & Ceramics DivisionOak Ridge National Laboratory
Oak Ridge, TN 37831-6069
ASME Turbo Expo ASME Turbo Expo Vienna, AustriaVienna, Austria
June 16, 2004June 16, 2004
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 2 of 45
Acknowledgments
Research sponsored by the U.S. Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy,
Office of Power Technologies, Microturbine Materials Program, under contract DE-AC05-00OR22725 with UT-Battelle, LLC
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 3 of 45
Outline
• Background
• Microturbine Recuperator Testing Facility• Test Procedure
• Results• 347 Stainless Steel
• HR230®
• HR120®
• Summary, Current and Future Work
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 4 of 45
Outline
• Background
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 5 of 45
Background
2000 2002 2004
$500/kW
40% Efficiency
40,000-hr life
2006 2008 2010
U.S. DOE Advanced Microturbines Program
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 6 of 45
Background (cont.)
2000 2002 2004 2006 2008 2010
higher TIT
higher TET
advanced materials
U.S. DOE Advanced Microturbines Program
$500/kW
40% Efficiency
40,000-hr life
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 7 of 45
Background (cont.)
• Temperature
• Environment (combustion gases can lead to corrosion)
• Mechanical Stress (pressure differential can induce creep deformation)
Main parameters to consider for the selection of materials for microturbine recuperators
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 8 of 45
Outline
• Background
• Microturbine Test Facility• Testing Procedure
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 9 of 45
Microturbine Test Facility
gas compressor
shelter housing instrumentation
Capstone 60kW microturbine
As part of the Advanced Materials for Recuperators Program, ORNL established a microturbine test facility to screenscreen and evaluateevaluate candidate materials for advanced microturbine recuperators
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 10 of 45
ORNL’s Microturbine Test Facility (cont.)
• Modified Capstone C60 microturbine
• Higher TET (850°C)
• Placement of test specimens at the entrance of recuperator.
thermocouples
water-cooled block
pressure transducer
air line
water lines
sample holder
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 11 of 45
Microturbine Test Facility (cont.)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 12 of 45
• Four (4) laser-welded foils in each sample holder
• foil temperatures are monitored using type-K thermocouples
• sample holders are pressurized with air to simulate the pressure differential experienced by recuperator cells
welded foils
ORNL’s Microturbine Test Facility (cont.)
sample holder
thermocouples
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 13 of 45
Temperature distribution along sample holder
TET=800°C
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 14 of 45
Effect of microturbine exposure on tensile properties
Foils are removed from the sample holder and miniature test specimens, obtained by electric discharge machining, are evaluated in tension.
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 15 of 45
Temperature History for 500-hr test
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 16 of 45
Outline
• Background
• Microturbine Test Facility• Testing Procedure
• Results• 347 Stainless Steel
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 17 of 45
347-stainless steel after 500-hr exposure (TET=800°C)
0.0
89
mm
0.0
89
mm
0.0
89
mm
0.0
89
mm
A758°C
B736°C
C697°C
D632°C
60 psi internal pressure -> 50 MPa hoop stress
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 18 of 45
Significant corrosion and spalling of oxidation products on foil exposed to highest temperature (758°C)
347-stainless steel after 500-hr exposure
ballooning due to creep deformation
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 19 of 45
D C B A
cool end630°C
hot end758°C
air side
exhaust side
Position D500 h @ ~632°C
very little corrosion
Position C500 h @ ~697°C
thin scale
Position B500 h @ ~736°C
~3 µm scalePosition A
500 h @ ~758°C~20 µm scale
347-stainless steel after 500-hr exposure
ballooning due to creep deformation
“wart”
cross-sectional analysis
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 20 of 45
347-stainless steel after 500-hr exposure
Fe Ni
Nb
O
Cr
Foil A
exhaust side
air side
Foil exposed at 758°C
• Multilayered oxide scale:
• Ni-Cr-O
• Fe-O
• Depletion of Cr at GBs
• Carbide formation
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 21 of 45
Tensile strength of as-processed 347-stainless steel
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 22 of 45
Tensile strength of 347-stainless steel
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 23 of 45
Tensile strength of 347-stainless steel
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 24 of 45
Tensile strength of 347-stainless steel
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 25 of 45
Tensile strength of 347-stainless steel
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 26 of 45
Tensile strength of 347-stainless steel
• Dimples characteristic of plastic deformation.
• Limited ductility
•758°C•500 hrs•50 MPa (hoop stress due to 60 psi of internal pressure)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 27 of 45
0.4
0.6
0.8
1
0 200 400 600 800
347-Stainless Steel
HR230®
HR120®
(° )Temperature C
Tensile strength 347-stainless steel
• 500-hr test• 60 psi internal
pressure
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 28 of 45
Outline
• Background
• Microturbine Test Facility• Testing Procedure
• Results• 347 Stainless Steel
• HR230®
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 29 of 45
As-processed HR230®
89 µm 89 µm
102 µm 102 µm
tungsten-rich particles
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 30 of 45
0.0
89
mm
0.0
89
mm
0.1
02
mm
0.1
02
mm
A752°C
B730°C
C700°C
D679°C
60 psi internal pressure
HR230® after 500-hr exposure (TET=800°C)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 31 of 45
D C B A
cool end679°C
hot end752°C
Position C500 h @ ~697°C
Position B500 h @ ~730°C
Position A500 h @ ~752°C
cross-sectional analysis
air side
exhaust side
Position D500 h @ ~679°C
HR230® after 500-hr exposure (TET=800°C)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 32 of 45
Cr
O W Ni
Mo C
Foil exposed at 752°C
•Limited corrosion products found on surface
•Significant cracking along grain boundaries
•Grain boundaries near surface are poor in Cr but rich in W and C.
HR230® after 500-hr exposure (TET=800°C)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 33 of 45
0.4
0.6
0.8
1
0 200 400 600 800
347-Stainless Steel
HR230®
HR120®
(° )Temperature C
Tensile strength of HR230® after 500-hr exposure
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 34 of 45
Outline
• Background
• Microturbine Test Facility• Testing Procedure
• Results• 347 Stainless Steel
• HR230®
• HR120®
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 35 of 45
D C B A
cool end632°C
hot end745°C
Position C500 h @ ~700°C
Position B500 h @ ~730°C
Position A500 h @ ~745°C
cross-sectional analysis
air side
exhaust side
Position D500 h @ ~632°C
HR120® after 500-hr exposure (TET=800°C)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 36 of 45
10 µm
Fe Ni Si Cr
Foil exposed at 745°C
•Limited corrosion (oxides of Cr, Si and and Fe)
•Grain boundaries near surface are poor in Cr but rich in Ni
HR120® after 500-hr exposure (TET=800°C)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 37 of 45
0.4
0.6
0.8
1
0 200 400 600 800
347-Stainless Steel
HR230®
HR120®
(° )Temperature C
Tensile strength of HR120® after 500-hr exposure
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 38 of 45
0.4
0.6
0.8
1
0 200 400 600 800
347-Stainless Steel
HR230®
HR120®
(° )Temperature C
Tensile strength of metallic alloys after 500-hr exposure
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 39 of 45
Outline
• Background
• Microturbine Test Facility• Testing Procedure
• Results• 347 Stainless Steel
• HR230®
• HR120®
• Summary, Current and Future Work
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 40 of 45
• A test facility was designed to screen and evaluate candidate materials for advanced microturbine recuperators.
• TET up to 850°C
• Mechanical stressing
• Foils of 347 stainless steel, HR230® and HR120® alloys have been evaluated
• Foils have been welded to sample holders by laser and e-beam.
Summary, Current and Future Work
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 41 of 45
• 347 stainless steel347 stainless steel exhibited significant decrease in tensile strength and ductility, and severe corrosion after 500-hr exposure at 758°C.
• Evidence of creepcreep deformation at temperatures above 700°C at 50 MPa.
• Corrosion products at highest temperature are a mixture of oxides of chromium, nickel and iron.
• Depletion of chromiumchromium from grain boundaries near interface between base metal and oxide layers.
• CarbideCarbide precipitation
Summary, Current and Future Work (cont.)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 42 of 45
• HR230®HR230® retains 70% of its tensile strength after 500-hr exposure at 752°C.
• Limited corrosion products found on surface but significant crackingcracking along grain boundaries
• Grain boundaries near surface are poor in chromium but rich in tungsten and carbon.
Summary, Current and Future Work (cont.)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 43 of 45
• HR120®HR120® exhibited good retention of mechanical properties (e.g.- 85% of its tensile strength) after 500-hr exposure at 745°C.
• Limited corrosion products in the form of oxide of chromium, silicon and iron.
• Depletion of chromium from grain boundaries close to surface exposed to exhaust gases.
Summary, Current and Future Work (cont.)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 44 of 45
• Tests in progress to evaluate HR120®, HR214®, Tests in progress to evaluate HR120®, HR214®, HR230®, ORNL-modified stainless steels, HR230®, ORNL-modified stainless steels, FeCrAlY alloys and alloy 625.FeCrAlY alloys and alloy 625.
• Effect of intermittent operation on durability of Effect of intermittent operation on durability of candidate materials candidate materials
Summary, Current and Future Work (cont.)
OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY Lara-Curzio et al. IGTI-2004. Page 45 of 45