Improvement of Oxidation Resistance of Fe-Cr Ferritic Alloy Sheets for SOFC Interconnects

Fe-Cr ferritic alloys are applied for interconnects of solid oxide fuel cells (SOFCs) operated at around medium temperatures. The oxidation behavior of sheets with various thicknesses of Fe-22%Cr ferritic alloy, ZMG232L, was investigated. The oxidation rate of thin sheet was much higher than that of thick one because Cr content decreased under oxide layer of edge part of thin sheet and therefore Cr oxide became unstable and Fe was mainly oxidized. Such accelerated oxidation behavior was able to be improved by reducing Mn, increasing Cr, and adding W.