Modeling of the Flow Stress for AISI 52100 Bearing Steel during Hard Machining Processes
Hard turning has been proven to be feasible to replace the finishing operation, such as grinding and abrasive-based finishing process. In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where the workpiece material is machined in its hardened condition (56-64HRC). It is well known that hardness modifies the strength and work hardening characteristics of the material being cut. This paper describes a detail procedure for developing the flow stress model of hardened AISI 52100 steel in machining. This model is a function of hardness in addition to effective strain, effective strain rate and temperature. The obtained model and the Brozzo's fracture criterion are incorporated into a viscoplastic FEM for orthogonal machining. The results are validated by comparing predicted cutting force, chip morphologies and residual stresses to those reported in several studies published in literature.
Domenico UMBRELLO, Jiang HUA, Rajiv SHIVPURI
Material Modelling, Machining, FEM, Hard Cutting.