Effect of CVD-Coated Multilayer Carbide Insert on Surface Finish of Cryogenically Treated EN31 Hardened Alloy Steel Using Box-Behnken Design

Abstract

The present study is focusing on cryogenically treated (CT) EN31 hardened alloy steels. The experimental runs were designed by using Box-Behnken approach of RSM using multiple process parameters- cutting speed (v, 160-260 m/min), feed (f, 0.1-0.2 mm/rev), depth of cut (d, 0.05-0.15 mm), tool nose radius (re, 0.4-1.2 mm), and hardness (HR, 45-49 HRC) for optimizing surface finish. The specimens and inserts underwent a 24-hour socking time in nitrogen medium (-196° C) as part of the deep cryogenic treatment and hardness of the materials were measured before and after the treatments. In experimentation wet turning was performed on LMW Make LX20T L5 CNC machine with multilayer TiCN+Al2O3+TiN CVD coated inserts. According to the study, Ra dramatically rises with an increase in d and falls with an increase in v. When comparing Ra to the f, re, and HR, comparable variations are seen. The Box-behnken approach of RSM is more capable of predicting surface finish by 99.96% utilizing a polynomial quadratic equation.