Multi-physics modeling and simulations of surface microstructure alteration in hard turning

Surface microstructure alteration is a major concern in industry to implement hard turning for bearing steels. The formation of white layer in hard turning can be attributed to two main factors: thermally driven phase transformation and mechanical grain refinement due to severe plastic deformation. The purpose of this study is to quantitatively disseminate the underlying mechanisms through prediction of the microstructure change using a multi-physics model, which considers both phase transformation and grain refinement. 3D hard turning simulations are undertaken via AdvantEdge FEM software incorporating these two mechanisms as user-defined subroutines to investigate the surface microstructure alteration for AISI 52100 steel. Comparisons with the experimental data at various cutting conditions prove that the proposed model can accurately predict the critical surface microstructural attributes such as phase compositions, grain size, microhardness, and residual stress during hard turning of AISI 52100 steel.