The oxidation behavior and mechanism of as-received and 30 ％ cold-rolled alumina-forming austenitic (AFA) steel were investigated in dry air at 700 ℃.The results show that the mass gain per unit area curves of as-received and 30 ％ cold-rolled steels subject to near-parabolic law before 100 h oxidation time.Two samples both show higher high-temperature oxidation resistance due to the formation of dense Al2O3 oxide scale.Gradual spallation of outer scale results in the formation of continuous and dense alumina scale.Dislocations can act as short-circuit diffusion channel for the diffusion of Al from alloy matrix to surface,and also provide nucleation sites for B2-NiAl phase,which ensure the continuous formation of Al2O3 scale.