Hyeoung-Ho Park1, Min-Ho Lee2, Shoji Goto3, Setsuo Aso3 and Yoshinari Komatsu3
1Department of Metallurgical Engineering, Chonbuk National University, Chonju 561-756, Korea
In order to evaluate the corrosion resistance of a cathode-side separator for a molten carbonate fuel cell (MCFC), SUS316 and SACC-SUS316, in which chromium and aluminum were simultaneously deposited by diffusion into a SUS316 austenitic stainless-steel substrate by a pack-cementation process, were used as separator materials. In the case of SUS316, corrosion proceeds via three steps: formation of a corrosion product until the corrosion product becomes stable, protection against corrosion until breakaway occurs and the advance of corrosion after breakaway. Because SUS316 exhibited a rapid corrosion rate in the cathode environment, it would be impossible to use this separator without suitable surface modification due to the occurrence of a severe problem involving the stability of the cell during long-time operation. In contrast, SACC-SUS316 was demonstrated to exhibit more effective corrosion resistance than the present separator, SUS316. In particular, there was no corrosion behavior exhibited by SACC-SUS316 after 480 h at 923 K. Moreover, it is considered that this will be very useful as an alternative separator at the cathode side in MCFCs in the future.
(Received September 18, 2000)
separator, molten carbonate fuel cell, corrosion rate, SUS316 austenitic stainless steel, coating
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