Proton irradiation effects on tensile and bend-fatigue properties of welded F82H specimens

Saito, Shigeru   ; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Ishikawa, Akiyoshi; Nishino, Yasuharu ; Endo, Shinya; Kawai, Masayoshi*; Dai, Y.*

In several institutes, R&D for an ADS have been progressed. Ferritic / martensitic (F/M) steels are the candidate material for the beam window. To obtain the irradiation data, the PIE work of the SINQ target irradiation program (STIP) specimens was carried out at JAEA. In this study, the results of PIE on F/M steel F82H and its welded joint will be reported. The results of tensile tests indicate that the irradiation hardening occurred with increasing dpa up to 10.1 dpa below 320C irradiation. At higher dose (- 11.8 dpa) and higher temperature (- 380C), irradiation hardening and degradation of ductility relaxed. In this study, all specimens kept its ductility after irradiation and fractured in ductile manner. The fatigue life of F82H base metal is almost the same as that of unirradiated specimens. Though the number of specimen is limited, the fatigue life of F82H EB welded joints seems to increase after irradiation. The fracture surfaces of the specimens showed transgranular morphology. While F82H TIG welded specimens were not fractured by 10 cycles.