|
|
EFFECT OF LaCoO3 COATING ON THE INTERMEDIATE TEMPERATURE OXIDATION BEHAVIOR OF SUS 430 METALLIC INTERCONNECT |
HUA Bin 1; ZHANG Jianfu 2; LU Fengshuang 2; KONG Yonghong 1; PU Jian 1; LI Jian 1 |
1. College of Materials Science and Engineering; State Key Laboratory of Material Processing and Die & Mould Technology; Huazhong University of Science & Technology; Wuhan 430074
2. Central Iron & Steel Research Institute; Beijing 100081 |
|
Cite this article:
HUA Bin ZHANG Jianfu LU Fengshuang KONG Yonghong PU Jian LI Jian. EFFECT OF LaCoO3 COATING ON THE INTERMEDIATE TEMPERATURE OXIDATION BEHAVIOR OF SUS 430 METALLIC INTERCONNECT. Acta Metall Sin, 2009, 45(5): 605-609.
|
Abstract Low costly ferritic stainless steels, especially the Cr2O3–forming alloys, are promising interconnect materials for solid oxide fuel cells (SOFCs) due to their thermal expansion compatibility with other cell components. However, the oxidation resistance of commercial ferritic stainless steels in the operating temperature range of 600—800 ℃ is not adequate, forming relatively thick, poorly conducting oxide scale on the surface of the stainless steel interconnect and decreasing the cell performance. Surface modification is necessary to improve the oxidation behavior and electrical property. The present study investigates the effect of a LaCoO3 protective coating by the sol–gel process on the intermediate temperature oxidation behavior of SUS 430 alloy, which is frequently considered as the interconnect material for SOFCs. X–ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the phase structure, surface morphology and composition of the coating and the oxide scale. The "4–probe" method was employed to determine the area specific resistance (ASR) of the surface oxides. Long–term thermally cyclic oxidation at 750 ℃in air has shown that the oxidation kinetics obeys the parabolic rule with a rate constant of K=4.18×10−15 g2/(cm4·s), which is 1—2 orders of magnitude lower than that of the uncoated alloy, the LaCoO3 protective coating effectively suppresses the formation of Cr2O3 and slows down the growth of MnCr2O4 spinel. As a result, the oxidation resistance and electrical conductivity of the coated SUS 430 alloy are significantly enhanced, resulting in an ASR at 750 ℃of only 3.13 m·cm2 after oxidation at 750 ℃ for 850 h in air and an extrapolated ASR of 21.5 m·cm2 for 4×104 h oxidation.
|
Received: 20 October 2008
|
|
Fund: Supported by National High Technology Research and Development Program of China (No.2006AA03Z227) and National Natural Science Foundation of China (No.50771048) |
1] Fergus J W. Mater Sci Eng, 2005; A397: 271
[2] Huang K, Hou P Y, Goodenough J B. Solid State Ionics, 2000; 129: 237
[3] Brylewski T, Nanko M, Maruyama T, Przybylski K. Solid State Ionics, 2001; 143: 131
[4] Horita T, Xiong Y, Yamaji K, Sakai N, Yokokawa H. J Electrochem Soc, 2003; 150A: 243
[5] Kurokawa H, Kawamura K, Maruyama T. Solid State Ionics , 2004; 168: 13
[6] Yang Z, Hardy J S,Walker M S, Xia G, Simner S P, Stevenson J W. J Electrochem Soc, 2004; 151A: 1825
[7] Simner S P, Anderson M D, Xia G G, Yang Z, Pederson L R, Stevenson J W. J Electrochem Soc, 2005; 152A: 740
[8] Pu J, Li J, Hua B, Xie G. J Power Sources, 2006; 158: 354
[9] Jiang S P, Zhang S, Zhen Y D. J Mater Res, 2005; 20: 747
[10] Jiang S P, Zhen Y D, Zhang S. J Electrochem Soc, 2006; 153A: 151
[11] Hilpert K, Das D, Miller M, Peck D H, Weiss R. J Electrochem Soc, 1996; 143: 3642
[12] Stanislowski M,Wessel E, Hilpert K, Markus T, Singheiser L. J Electrochem Soc, 2007; 154A: 295
[13] Fergus J W. Solid State Ionics, 2004; 171: 1
[14] Zhu J H, Zhang Y, Basu A, Lu Z G, Paranthaman M, Lee D F, Payzant E A. Surf Coat Technol, 2004; 177–178: 65
[15] Kim J H, Song R H, Hyun S H. Solid State Ionics, 2004; 174: 185
[16] Chu C L, Wang J Y, Lee S. Int J Hydrogen Energy, 2008; 33: 2536
[17] Stanislowski M, Froitzheim J, Niewolak L, Quadakkers W J, Hilpert K, Markus T, Singheiser L. J Power Sources, 2007; 164: 578
[18] Qu W, Li J, Ivey D G. J Power Sources, 2004; 138: 162
[19] Qu W, Li J, Ivey D G, Hill J M. J Power Sources, 2006; 157: 335
[20] Lobnig R E, Schmidt H P, Hennesen K. Oxide Met, 1992; 37: 81 |
No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|