Structure of nano-size oxides in ODS steels and its stability under electron irradiation

Oka, Keiichiro*; Onuki, Somei*; Yamashita, Shinichiro   ; Akasaka, Naoaki; Otsuka, Satoshi   ; Tanigawa, Hiroyasu

For understanding the microstructural details of nano-size oxide particles, three types of ODS ferritic and austenitic steels were examined by high voltage electron microscopy, EDS and AP-FIM. The oxide included Y, Ti and O and showed a shell-like structure with different composition. The shell-like structure depends on crystal structure of the matrix during fabrication process. To evaluate the irradiation stability of the oxide particles, the electron irradiation was carried out to 47 dpa in the temperature range between room temperature and 923 K. During the irradiation, the oxide particles did not show obvious change in size. The irradiation behavior is discussed comparing with the results recently reported.