Modeling of cutting forces considering progressive flank wear in finish turning of hardened AISI D2 steel with CBN tool

AISI D2 steel is widely used as a material for bearing races, forming dies, punches, forming rolls, etc. because of its excellent wear and abrasion properties. Understanding the mechanism of oblique turning of hardened materials is important to industries manufacturing components like bearings, dies, and tools. Experiments on finish turning of hardened AISI D2 steel using CBN (cubic boron nitride) tools is performed with different combinations of cutting speed (80, 116, and 152 m/min), feed (0.04, 0.12, and 0.2 mm/rev), and tool nose radius (0.4, 0.8, and 1.2 mm) using full-factorial design of experiments. Based on experimental force results, empirical model for cutting forces is developed as a function of cutting parameters (i.e., cutting speed, feed, and tool nose radius). Optimum cutting parameters are those corresponding to minimum surface roughness of machined surface. Force model is extended considering progression of flank wear using analytical approach based on Waldorf’s theory at optimum cutting conditions. Developed force model is validated using additional set of experiments and found to be with reasonable accuracy. Outcome of the reported results may be of great importance to the machining industry and tool manufacturers.