Machinability Investigation of Inconel 657 in High-speed Turning

A high strength nickel chromium alloy (50Cr-50Ni-Nb alloy), commonly referred to as IN-657, is specifically used for components in furnaces which are fired by low grade fuel oils containing high levels of vanadium, sodium and sulphur. The purpose of this study is to experimentally investigatethe effect of machining parameters on machinability in turning of Inconel 657. The considered parameters were cutting speed, feed and tool material. Cutting force components, tool flank wear and surface roughness were measuredbased on design of experiments, and then analysis of variance was performed. Experimental results show that tool wear of CBN tools is 50 %lower than that of carbide tools. The Tool material with percentage contribution of 48% and 56% is the main parameter that influencesthe cutting forces and the flank wear, respectively. Also, the cutting speed with percentage contribution of 48% is the main parameter that effects the surface roughness. The lowest surface roughness is attained by the cutting speed of 250 m/min and the feed of 0.05 mm/rev by the CBN tool.