定電位エッチング手法によるオーステナイト系ステンレス鋼の塑性予ひずみ検出・定量化

（塑性変形様式に及ぼす積層欠陥エネルギーの影響）

抄録

In recent years, the demand has been increased for establishing nondestructive testing technique for detection of pre-existing plastic strain to ensure integrity of the structure such as nuclear power plant. In this study, potentiostatic etching method is applied to evaluate plastic strain imposed to austenitic stainless steel by tensile straining. After potentiostatic etching (1N HNO₃, -650 mV_SCE, 10 min, 35°C), twin lines and slip lines appear as etched grooves on the surface of specimen because of the preferential dissolution of the both bands. However, effects of a chemical composition and a deformation temperature on the relationship between the strain and the etched deformation twin density are not considered. Therefore, the objective of this study was to clarify the quantitative relationship between the strain and the etched deformation twin density with using deformation temperature and stacking fault energy of materials as experimental parameters. Even if the stacking fault energy or deformation temperature changes, the relationship between strain and etched deformation twin density shows that the slope does not change and the intercept tends to move. By extending the data from now on, it is possible to evaluate the strain from the relationship between the strain and the etched deformation twin density with stacking fault energy and deformation temperature as a parameter.