Effects of Fe self-ion irradiation on a low carbon MX-ODS steel at 550°C

• Published in: Frontiers in energy research 2023-01, Vol.10
• Main Authors: Xu, Yuwen, Yun, Di, Yan, Xu, Zhang, Ping, Yan, Wei, Li, Yanfen, Li, Chao, Li, Jiao, Zhang, Tongmin, Li, Jun, Zhou, Junjun, Kang, Long, Lu, Chenyang
• Format: Article
• Language: English
• Subjects: ion irradiation; MX phase; ODS steel; oxide nano-precipitate; void swelling
• ISSN: 2296-598X; 2296-598X
• DOI: 10.3389/fenrg.2022.988745

Oxide Dispersion Strengthened (ODS) steels with nano-scale oxides have become one of the candidate materials used in advanced nuclear reactor systems. A novel MX-ODS steel with extremely low carbon content was irradiated with 3 MeV Fe ions at 550°C up to peak damage of 70 dpa. The steel contains uniformly distributed Y 2 O 3 nano-precipitates with an average size of 3.5 nm and a number density of 5 × 10 22 /m 3 . A V-rich shell was found surrounding the core of Y, O, and Si at some particles. Two types of large precipitates, Y-Ta-Si oxides, and VN, were observed in the steel instead of carbides. Voids of very small size are present due to irradiation and the calculated void swelling was only 0.004%, suggesting good irradiation tolerance of the MX-ODS steel in this study. Fine and dense oxide nano-precipitates and their shell-core structure remained stable while the shape of large precipitates changed after irradiation.