Analysis of mechanisms for chip formation simulation of hardened steel

Abstract The machining of hardened steel is characterized by a segmented chip formation. The segmentation is often referred to thermoplastic instabilities or material damage. In this paper the mechanisms for shear band initiation are analyzed and discussed through experimental and simulative investigations. The hardened low alloy steel 51CrV4+Q is machined in an orthogonal cutting process. The chips reveal signs of ductile damage and white layer shear bands. By Finite-Element chip formation simulations the conditions within the primary shear zone are analyzed and based on this an appropriate ductile fracture model for the simulation of shear bands and segmented chips is presented.