Effective FE model to predict surface layer characteristics of ultrasonic surface rolling with experimental validation

Abstract

The present paper presents a numerical approach to investigate the surface layer characteristics after ultrasonic surface rolling process (USRP), which is a severe plastic deformation process involving complex static extrusion and dynamic impact. Efforts are made in the development of finite element model (FEM), accompanied by assessment of material constitutive relation and meshing accuracy as well as definition of loading condition according to the technological principle of USRP. The majority of processing parameters have been taken into account, and results are discussed in terms of residual stress, surface roughness and workhardening. As supplied 40Cr disc was subjected to ultrasonic surface rolling for validation of FEM, and the residual stresses predicted from the FEM are in good agreement with the measurements obtained by X-ray diffraction method, indicating that the present FEM can be used as a fast prediction tool for the design of ultrasonic surface rolling parameters.