シアパンチ試験による原子炉圧力容器鋼の引張特性評価技術の開発

抄録

Shear punch test specimen, whose dimensions are small as 8 mm-diameter × 0.5 mm thickness, is recently closed up as one of the alternative for tensile specimen. In this study, a Japanese reactor pressure vessel (RPV) steel was subjected to the shear punch test at temperatures from –120°C to R.T. using a shear punch test frame newly developed and the capability of the test technique for uniaxial tensile property evaluation was investigated. Shear punch test specimens with a dimension of 8 mm-diameter and 0.5 mm of a thickness were machined from the Japanese RPV steel; SQV2A plate. A puncher with a diameter of 3.0 mm gives compressive load to center of the specimen and then the shear stress is generated in the specimen. The tests were continued in stroke control mode (0.25 mm/min) until the load remarkably drops at the specimen failure. Stress – strain curves were successfully obtained at temperatures from –120°C to R.T. and the shear punch yield stress could be evaluated from the stress – strain curve. The shear punch yield stress increased with decreasing test temperature and this temperature dependence is similar with that of uniaxial yield stress. From this result, the capability of the shear punch test for tensile property evaluation was demonstrated.