Abstract:The oxidation kinetics of austenitic Fe24Mn4Al5Cr alloy oxidized at 800 °C for 160 h and 950 °C for 10 h in air, and the surface morphology, composition and the microstructure of the oxide scales were investigated in order to improve the corrosion resistance. An oxidation-induced Mn depletion layer between the alloy matrix and the oxide scales formed at the two oxidation temperatures by the selective oxidation of Mn. The results show that after oxidation at 800 °C for 160 h, the continueous and smooth ferrite layer about 9 μm thick near the scale-metal interface has an enrichment of Fe content of 83 at%~72 at% and Cr content of 8 at%, and a depletion Mn of 6 at%~19 at%. However, at 950 °C for 10 h, the ferrite layer about 6 μm thick is in curved shape with the enrichment in Fe of 85at% and the depletion in Mn of 5at%. The anodic polarization curves of the Mn depletion layer at 800 °C for 160 h in 1 mol·L-1 Na2SO4 solution has a self-passivation, with the higher corrosion potential of 57 mV(SCE) and the lower passive current density of 0.7 μA/cm2, compared with –710 mV(SCE) and 3.3 μA/cm2 for Fe24Mn4Al5Cr austenitic alloy. Therefore, the corrosion resistance of the oxidation-induced Mn depletion layer on Fe24Mn4Al5Cr alloy increases