| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 272028 | Fusion Engineering and Design | 2012 | 5 Pages |
The effect of He-injection on irradiation-induced segregation of aging treated Fe–12%Cr–15%Mn austenitic steels, which are candidate materials as the reduced radio-activation of structure material for nuclear and/or fusion reactors was investigated by using the 1250 kV high voltage electron microscope (HVEM) connected with an ion accelerator. The Fe–Mn–Cr steel has been irradiated at 573 K by three irradiation modes of single electron-beam irradiation, electron-beam irradiation after He-injection and electron/He+-ion dual-beam irradiation in a HVEM. Irradiation-induced segregation analyses were carried out by an energy dispersive X-ray analyzer (EDX) in a 200 kV FE-TEM with beam diameter of about 0.5 nm. Dislocation loops with strain contrast were formed during irradiation and the loop numbers density increased rapidly with irradiation dose for He-pre-injected specimens. Voids were not observed after irradiations with three irradiation modes up to 5.4 dpa at 573 K. Irradiation-induced segregations of Cr and Mn near grain boundary were observed in each irradiation condition, but the amounts of Mn segregation decreased in the cases of electron/He+-ion dual-beam irradiation compared with single electron-beam and electron-beam irradiation after He-injection conditions.
► Dislocation loop number densities increased rapidly with irradiation dose for He- pre-injected specimens because of loop nucleation effects of pre-existing He atoms. ► Voids were not observed even after irradiation to 5.4 dpa at 573 K by electron-beam, electron-beam after He-injection and electron/He+-ion dual-beam irradiation. ► Irradiation-induced segregations of Cr and Mn at grain boundary were observed in each irradiation condition.
