Original paper(Vol.49 No.6 pp.651)

Effect of Grain Shapes on Residual Stress Distribution due to Shot Peening

Takanori Kitamura, Toshio Terasaki and Tetsuya Akiyama

Abstract:New shot peening method, which gives larger residual stress and smaller transformation than usual method, is required. In this study, residual stress distributions due to two shot peening conditions were measured by inherent strain method. One shot peening condition was using steel grid which was angular shape. Another was using steel shot which was spherical shape. Residual stress by steel grid was larger than that by steel shot. And inherent strain by steel grid existed on narrower zone than that by steel shot. Moreover, deflection of specimen by steel grid was smaller than that by steel shot. As results, it has been recognized that shot peening using steel grid was very useful. And residual stress distribution can't be estimated by deflection of specimen, on the other hand, inherent strain method is effective to estimate residual stress distribution due to shot peening.

Key Words:Shot peening, Residual stress, Grain shape, Inherent strain