Long-term (4 year) degradation behavior of coated stainless steel 441 used for solid oxide fuel cell interconnect applications

The present work aims to investigate the long-term stability of Ce/Co coated AISI 441 used as an interconnect material in solid oxide fuel cells (SOFC). Being a commercially available alloy the use of AISI 441 would greatly reduce the cost of SOFCs in comparison to tailor-made interconnect materials such as Crofer 22 APU. To analyze the long-term stability Ce/Co coated AISI 441 is exposed in air at 800 °C for up to 38 000 h. Mass gain values are recorded continuously. After 7 000, 23 000, and 35 000 h area specific resistance (ASR) measurements are performed, and cross-sections are prepared and analyzed using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. Cr-evaporation measurements are conducted on samples exposed for up to 38 000 h.