Effect of W and Ti addition on oxidation behavior and area-specific resistance of Fe-22Cr-0.5Mn ferritic stainless steel for SOFCs interconnect

Ferritic stainless steel (FSS) is an appropriate material to be used in solid oxide fuel cells (SOFCs) interconnect. Chromium in FSS evaporates at high temperature and it is deposited on the cathode surface of SOFC and makes the cell poisonous. So the present study, the effect of W and Ti addition on oxidation behavior, electrical property and Cr evaporation resistance were discussed in terms of microstructure property of the oxide scale by using SEM analysis. W and Ti addition reduce the oxidation rate, Cr evaporation rate and area-specific resistance of the FSS. Presence of W in this steel formed chi (χ) phase in scale/alloy interface and prevented the diffusion of cation to the oxide scale. It is also a barrier for the influence of the oxygen anion to the inward of the FSS. The presence of high amount of W and low amount of Ti were effective in improving oxidation and electrical conductivity. However, to enhance the Cr evaporation resistance, high Ti content is required.