Experimental analysis of the impact of an artificially generated tool wear pattern on the residual stress induced by 15-5PH steel turning

Abstract

Finish turning is one of the key operations governing the residual stress of functional surfaces. The residual stress state is determined by the cutting conditions and the selected cutting tool system (macro geometry, cutting edge preparation, tool substrate, multi-layer coating…). However, this initial configuration evolves over time due to tool wear. Therefore, it seems very instructive to reproduce the wear process of the tool in order to understand the evolution of thermo-mechanical loadings applied to the machined surface. Flank wear is a parameter which can be difficult to fully control, and it is complex to reproduce experimentally. In this work, a simple, controlled and repeatable method of producing a known flank wear state is introduced and the impact of the flank wear on the surface integrity is assessed. This involves two parts, first reproducing a given flank wear state and second, evaluating experimentally the residual stress induced by the flank wear state on the workpiece. Carbide tools are used to turn 15-5PH steel under dry conditions. It is shown that the method produces consistent results. The effect of flank wear on residual stress is most notable and can generate data to validate numerical modelling. Areas for improving the method are also discussed.