Evaluation of welding residual stresses in austenitic stainless steel using diffraction spot trace method

A diffraction spot trace method (DSTM) was developed to measure internal stresses of materials with coarse grains. The DSTM was applied to light metals, such as aluminum alloy and magnesium alloy. In this study, validity of the DSTM was examined using high energy synchrotron X-rays of 70 keV. The specimen was a welded plate of austenitic stainless steel (SUS316L). The thickness of the specimen was 9 mm. The improved rotating slit-system was used, and PILATUS was used as an area detector. It was difficult to detect the high energy X-rays due to the reduction of counting efficiency of the PILATUS. However, the residual stress map of the welding specimen was obtained spending long exposure time. The residual stresses of the welding specimen were simulated by a finite element method (FEM). The outline of the residual stress measured by the DSTM coincided with that by the FEM. (author)