Abstract
In this paper, the distribution of compressive residual stress caused by shot peening and cavitation peening was estimated by measurements of impact. It is known that the fatigue strength of metallic materials can be improved by introducing compressive residual stress induced by impact during peening process. The compressive residual stress at near surface and its distribution are important factors for improvement of the fatigue strength. In the case of shot peening, it is possible to estimate the distribution of compressive residual stress by numerical simulation using Hertz contact theory. However in the case of cavitation peening, it is hard to estimate residual stress distribution by numerical simulation. In this study, in order to estimate the distribution of compressive residual stress introduced by using shot peening and cavitation peening, plastic deformation pit and impact were measured. It is said that the compressive residual stress introduced region obtained by X-ray diffraction method can estimate by the maximum applied stress obtained by impact measurements and pit shape.
