Abstract: The high mechanical-heat load is generated in hard cutting, so white layers is produced on the work-piece surface, the study of the white layer formation mechanism and the prediction of white layer thickness have an important theoretical guidance significance in developing the hard cutting technology. In order to research the white layer formation mechanism, the thermal-mechanical coupling cutting simulation model is established based on the elastic-plastic mechanics, thermodynamics and material phase transition, the temperature field and stress field is simulated in cutting process, the organization transformation process of the work-piece surface is analyzed, the phase transformation temperature affected by thermal and mechanical in hard cutting is used to estimate white layer, Taking bearing steel GCr15 as the object, white layer thickness under the different cutting parameters is predicted, and the prediction method is validated. The results as following, for white layers produced on the work-piece surface in hard cutting, the predicting method based on the phase transformation theory is feasible.

Key words: stress field, temperature field, thermal-mechanical coupling, white layer, hard cutting