Empirical models for cutting forces in finish dry hard turning of hardened tool steel at different hardness levels

In this research, the exponential and quadratic polynomial empirical models for three-component cutting forces by employing five factors, such as the cutting speed, depth of cut, feed, workpiece hardness, and nose radius, were developed by utilizing the orthogonal regression methodology (ORM) and response surface methodology (RSM). On the other hand, an attempt has been made to experimentally investigate the effects of those factors on three-component cutting forces in finish dry hard turning (FDHT) of tool steel AISI D2 with the PCBN tool. In this investigation, based on five-factor three-level orthogonal experiments, three-component cutting forces were measured, and then, analysis of variance (ANOVA) was performed to estimate the significance of developed models and analyze the main and interaction effects of the factors. The experimental results indicated that the RSM quadratic polynomial empirical model (RSMQPEM) is much more accurate and credible than the ORM exponential empirical model (ORMEM) in predicting the three-component cutting forces. It was also found that the cutting speed and feed are the two dominant factors affecting the main cutting forces FZ; the feed is the one dominant factor affecting radial cutting force FY and the feed cutting force FX. Additionally, the optimum cutting parameters for the hardened materials with 51, 55, 60, and 64 HRC was found.