Thermal degradation mechanism of ferritic alloy (Crofer 22 APU)

Abstract

The oxidation mechanism of Crofer 22 APU, one of the most preferred interconnects for solid oxide fuel cells (SOFCs), was explored in air. Crofer 22 APU showed two-step thermal behavior during thermal exposure, based on the varying growth rate of the chromia scale. The growth rate of the chromia scale abruptly increased at a certain annealed time, suggesting that its formation kinetics changed during thermal exposure. A thickness prediction model for the entire scale of Crofer 22 APU, based on the observed two-step oxidation mechanism, was established using the parabolic rate law.