Effects of minor alloy additions and oxidation temperature on protective alumina scale formation in creep-resistant austenitic stainless steels

Niobium was found to be beneficial for alumina scale formation in newly developed creep-resistant austenitic stainless steels. Additions of both Ti and V degraded alumina scale formation, whereas alloys with individual additions of Ti or V were able to form protective alumina scales. The ability to form external alumina scales was lost in the lower Al- and Nb-containing alloys between 800 and 900 °C. Compositions with the potential to form alumina at 900 °C were identified.