Effects of Cr and Si addition on the high-temperature oxidation resistance in high-Mn alumina-forming oxide dispersion strengthened austenitic steels

Abstract

Oxide dispersion-strengthened (ODS) steels are promising candidates for constructing nuclear reactors. Considering a high-temperature environment, ODS austenitic steels could provide superior performance compared to the current ODS ferritic steels. To meet the reduced activation requirement, the compositions of ODS austenitic steels have to be carefully adjust. Currently, the authors focus on the ODS austenitic steels with the austenite stabilizer of Mn, and several amounts of Al are added to improve their high-temperature oxidation resistance. This study investigates the third-element effects of Cr and Si on the high-temperature oxidation resistance of high-manganese alumina-forming ODS austenitic steels. Generally, Si-containing steel exhibits superior oxidation resistance owing to the formation of a continuous inner layer of amorphous alumina. In contrast, the Cr-containing steel does not possess a continuous alumina layer, resulting in insufficient oxidation resistance. The reported phenomenon is believed to be a reference for the development of ODS austenitic steels in the future.

Keywords

• Oxidation
• Amorphous alumina
• Silica
• X-ray photoelectron spectroscopy
• Oxide dispersion-strengthened steels
• High-Mn austenitic steels