Improved oxidation resistance of 15 wt.% Cr ferritic stainless steels containing 0.08–2.45 wt.% Al at 1000 °C in air

Abstract

Improved oxidation resistance of 15wt.% Cr ferritic stainless steels at 1000°C in air has been obtained. Weight gain per unit area is in parabolic relation to oxidation time and parabolic rate constant significantly decreases with increased Al content. Diffusion of Al is enhanced and the porous Cr2O3 rich outer layer is replaced by a more compact Al2O3 rich outer layer in steels with higher Al contents. The appearance of continuous and compact Al2O3 oxide scale contributes to the significantly improved oxidation resistance property and the oxidation mechanism has been suggested based on microstructural observations.