Prediction of residual stresses induced in turning – Influence of cutting tool geometry

It has long been recognised that machining processes induce residual stresses in machined surfaces. This article focuses on the longitudinal turning process of the martensitic stainless steel 15-5PH. The aim is to investigate the influence of tool geometry, specifically rake angle and edge sharpness, on surface residual stresses. Three turning tools were studied both experimentally and through numerical simulations using the MISULAB software. The results show that the geometry of the cutting tool does not significantly affect the residual stress state in the outer layer. On the contrary, edge radius and rake angle determine the thickness of the affected layer as well as the intensity of the compression peak below the outer layer. Cutting tools with a large edge radius and a small rake angle result in a thick affected depth, characterised by a deep compression peak below the outer layer. The trends observed experimentally are well predicted by the numerical simulations, providing new insights for the design of new cutting tools dedicated to the optimisation of the residual stress state.