In situ observation of damage structure in ODS austenitic steel during electron irradiation

The oxide dispersion strengthening method was applied to an austenitic stainless steel based on SUS316 by mechanical alloying with additions of minor alloying elements. This ODS austenitic stainless steel was electron-irradiated to investigate the damage structure. Microstructural observation revealed that ODS austenitic stainless steel has a fine distribution of complex oxides. The in-situ observation during electron irradiation showed that both dislocation loops and small cavities nucleated at the interface between oxide particles and matrix. In the case of helium implantation, defect clusters also nucleated at the interface. These results suggest that the oxide interface is an effective sink for irradiation-induced point defects and helium atoms.