抄録
Stress corrosion cracking (SCC) is one of the most serious problems for ensuring safety of nuclear power plants. For SCC-resistant materials, residual stress due to the welding process is an important factor of SCC. Therefore, evaluating the residual stress in welds is great important, and X-ray stress measurements are superior to other stress measurement methods because they are nondestructive and provide high-resolution results. However, it is well known that texture in welds is found in some materials such as austenitic stainless steel and Ni-based alloys, and that such texture can greatly degrade the measurement accuracy. In this study, an attempt was made to improve the accuracy of X-ray stress measurements for welds with texture. To evaluate the residual stress in welds with texture, a new method was developed for evaluating plane stress from the elastic compliance, the value fraction of the crystal, and measurements in two orthogonal directions. Moreover, in a SUS316L weld specimen, the residual stress evaluated by the proposed method agreed very well with that evaluated by the stress relief method. Thus, the proposed method has the potential to be effective for measuring residual stress in welds with texture.
