Stress corrosion cracking susceptibility of ferritic/martensitic steel in super critical pressurized water

超臨界圧水中でのフェライトマルテンサイト鋼の腐食特性及び応力腐食割れ感受性

廣瀬 貴規; 芝 清之; 榎枝 幹男; 秋場 真人

Hirose, Takanori; Shiba, Kiyoyuki; Enoeda, Mikio; Akiba, Masato

23.5MPa, 280C550Cの超臨界圧水中で低放射化フェライト/マルテンサイト鋼F82Hを対象とした低ひずみ速度引張試験を実施した。この結果、F82Hの超臨界圧水中での応力腐食割れ感受性は極めて低いことが明らかとなった。また、超臨界圧水中におけるF82H鋼の重量は放物線則に従って増加することが明らかとなった。

A reduced activation ferritic/martensitic steel, F82H has been tested through slow strain rate tests with strain rates of 310 s in Super Critical Pressurized Water (SCPW) environment. The water was pressurized up to 23.5 MPa and the range of its temperature was from 280 C to 550 C. The stress drop and the loss of ductility, both due to the stress corrosion cracking, have not been observed in all the specimens. Also the fracture surface showed no brittle fracture. The weight change during the SSRT depends strongly on the test temperature, but dissolved oxygen content does not have significant effects. The time dependence of weight change has been described through the plot of some parabolic curves.