1032 Effect of Applied Stress on the Compressive Residual Stress of Weidment after Laser Peening

Laser peening is one of effective technique to prevent SCC initiation. However, it has possibilities that compressive residual stress appended by laser peening is affected by applied stresses during plant operation. In this study, in order to evaluate the effect of applied stress on the compressive residual stress of weldment after laser peening, laser peening were conducted for weldment test specimen of SUS316L and NCF600, and their surface residual stress were measured by X-ray diffraction method before and after loading. In case of applying stress larger than 0.2 %proof stress, it was confirmed that compressive stress remained and the behavior of relaxation in heat affected zone is same as that of base metal.