Investigating the effects of cryogenic machining on white layer formation and microstructural changes in AISI 52100 steel through a physically based numerical model

Abstract This research presents a novel Finite Element (FE) model that significantly advances the understanding of the mechanisms that lead to the white layer formation during the cryogenic machining of AISI 52100 steel samples of varying hardness levels, under different cutting conditions and tool geometries. By incorporating a physically based constitutive approach, the model accurately predicts microstructural changes under both conventional and cryogenic cooling conditions. The outcomes highlight the superior capability of cryogenic cooling in mitigating the thermally induced phase transformations, resulting in a lower formation of the white layer. By distinctly separating thermal and mechanical influences on the machined surface, the model also permits to evaluate the role of cutting parameters and initial material conditions on microstructural evolution. Through the use of customized user subroutine, the material behavior accounts for metallurgical phenomena arising from plastic deformation, such as recrystallized nanograins and increased dislocation densities. This advanced FE model is a crucial tool for optimizing machining parameters and predicting surface integrity of machined components.