High-temperature oxidation behavior of modified 4Al alumina-forming austenitic steel: Effect of cold rolling

The oxidation behavior and mechanism of as-received and 30 % cold-rolled alumina-forming austenitic (AFA) steel were investigated in dry air at 700 degrees C. 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. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The oxidation behavior and mechanism of as-received and 30% cold-rolled alumina-forming austenitic steel were studied. Both types of steel demonstrated improved high-temperature oxidation resistance due to the formation of dense Al2O3 oxide scale. Gradual spallation of outer scale led to the formation of continuous and dense alumina scale.