Study on ageing behavior of reprocessing plants, 9; Effect of ageing on mechanical properties of nickel based refractory alloys

Ishijima, Yasuhiro ; Takada, Juntaro; Ueno, Fumiyoshi  ; Yamamoto, Masahiro ; Uchiyama, Gunzo ; Nojima, Yasuo*; Fujine, Sachio*; Kimura, Kazuhiro*

Effect of ageing on mechanical properties of nickel based refractory alloy was evaluated for study on ageing behavior of nuclear fuel reprocessing plants. Solution treated and aged Alloy 625 was elected to test material. Creep tests and tensile tests were carried out at 1027 K. From test results, aged alloy 625 showed linear relationship between test stress and secondary creep rate. On the other hand, solution treated alloy 625 showed deformation behavior change at 100 MPa. This result indicates that the ageing behavior of reducing furnace can evaluate by straight line extrapolation. Aged alloy 625 showed remarkable decreasing of ductility at room temperature. This result suggests that room temperature embrittlement should be considered on the ageing behavior of reducing furnace.