Evaluation of creep properties of welded joint for reduced activation ferritic/martenstic steel

Nakata, Toshiya; Tanigawa, Hiroyasu; Kimura, Kazuhiro*

Since nuclear fusion reactors, except the DEMO reactor, are steadily operated, creep or creep fatigue is the main damage in blanket structure materials. Welding is mostly used for producing blanket modules, which use F82H as a structural material. This is because an early fracture occurs because of the Type IV damage, in which cracks occur during welding in the softening region of the heat-affected zone. This study evaluates microstructure for the F82H TIG and EB welded joints creep rupture materials, and discusses the evaluated the conditions for the occurrence of the Type IV damage.