In-situ stress measurement in the heat affected zone during TIG welding process

Zhang, S.; Shobu, Takahisa  ; Shiro, Ayumi; Hashimoto, Tadafumi*; Tsuji, Akihiro*; Okano, Shigetaka*; Mochizuki, Masahito*

In the structural material, it is important to decrease the residual stress of the welded joints because residual stress generated by welding promotes brittle fracture, stress corrosion cracking. Mathematical model has been used to evaluate residual stresses around welding. In the welding simulation, the physical properties can be measured by thermal simulation experiments. However, it is difficult to simulate those residual stresses, because the welding process was quite complex. In order to resolve this problem, it is necessary to clarify physical properties such as stress, strain and thermal expansions during welding process. In this study, we has been developed an in-situ stress measurement system using synchrotron radiation X-rays at BL22XU at SPring-8. Residual stresses to the transverse and longitudinal distributions in the heat affected zone (HAZ) have been investigated with a time resolution of 0.1 seconds.