球圧子押込み法による鋼溶接熱影響部の局所力学特性推定

抄録

In this study, a semi-nondestructive procedure for stress - strain curve estimation was developed using instrumented indentation technique. Additionally, to estimate local stress - strain curve in the welds with mechanical heterogeneity, a relation between spherical indentation size and measuring range of mechanical property was quantified by using finite element analysis of spherical indentation technique. First, the developed technique was applied to estimate mechanical property of low alloy steel to validate the estimation accuracy. Next, the developed technique was applied to estimate mechanical properties of low alloy steel welds with mechanical heterogeneity. To obtain mechanical heterogeneity in welds, two pass welding was performed on the surface of material with a certain level of transverse distance. With appropriate indentation size, distinguished stress - strain curve was successfully obtained at each position, such as weld metal, heat affected zone and base metal. Thus, it was concluded that the developed technique was useful to estimate mechanical heterogeneity in the welds with a high degree of accuracy through simple process.