A study of PSHG and its characteristic mechanism of residual stress within a hardened layer

Abstract

The pre-stressed hardening grinding (PSHG) combines with the advantages of pre-stressed grinding and grinding hardening. In order to study the characteristic of PSHG, especially its residual stress within a hardened layer after PSHG, the PSHG experiment was carried on. Combining with theory and experiment results, the variation and its mechanism of residual stress were studied. The paper shows the PSHG can obtain a hardened layer with controllable residual stress after the process. The residual stress decreases with the increasing of feeding speed and grinding depth. When the grinding depth is small, the tensile residual stress decreases with the increasing of pre-stress. And when the grinding depth is large, the compressive residual stress decreases first and then increases with the increase of pre-stress because of the comprehensive effect of heat and phase transformation. Then, a finite element method (FEM) simulation was performed to study the variation of thermal stress in a hardened layer after PSHG process. Distribution and variation of thermal stress were obtained. In the end, according to the relationship between residual stress and thermal stress, the distribution and variation mechanisms of phase transformation stress were obtained and studied. They vary along with the level of phase transformation. The compressive phase transformation stress increases with the increasing of grinding depth. And due to the pre-stress’s influence on the phase transformation, it decreases first and then increases with the increase of pre-stress.