Analysis and Predict Surface Roughness in the Hard Turning of Hardened SKD11 Steel using Mixed Ceramic Inserts

- SKD11 steel is a high-carbon and high-chromium alloy tool steel used to do cold work or hot work dressing dies, sides of rollers, and screw heading molds. The hardened SKD11 steel has a high hardness of 58-62HRC, good wear resistance, and good toughness. Hard turning is an important process because manufacturers continually seek ways to manufacture their parts with lower cost, higher quality, rapid setups, lower investment, and smaller tooling inventory while eliminating non-value-added activities where Surface roughness is an important parameter determining the accuracy and quality of parts. In this paper, an analysis of the surface roughness of SKD11 steel in hard turning with mixed ceramic inserts is performed based on variables like cutting speed, feed, and depth of cut. The feed rate is the most significant parameter affecting the surface roughness in the machining process. Prediction of surface roughness considering the simultaneous effect of cutting parameters is very difficult. Here, a mathematical model is developed based on the simultaneous effect of depth, cutting speed, and feed rate. Moreover, the developed model is validated using different sets of cutting conditions and found in close agreement with experimental results.