The study of universality of a method for predicting surface nanocrystallization after high energy shot peening based on finite element analysis

Abstract Shot peening (SP) is one kind of effective mechanical surface treatment to improve the surface mechanical property. Increasing SP intensity can not only introduce compressive residual stresses into the layer near the treated surface, but also produce nanocrystalline layer near the treated surface. This paper investigated the method of predicting the generation of refined grains after high energy shot peening (HESP) proposed by previous works. In that method, the equivalent plastic strain (PEEQ) was considered as a critical value for estimating the grain refinement level. The main contribution of this paper was to prove the applicability of the proposed method of predicting nanostructured surface layer in different HESP conditions via a HESP model with different numbers of shots and impact patterns. The simulated results show the ultimate PEEQ value is independent of the element size in all HESP conditions, which confirms this method is a practical and effective tool to evaluate surface nanocrystallization phenomenon during HESP process.