Investigating the Impact of Cutting Variables on Specific Metal Removal Rate and Surface Roughness in Restricted Turning of IS-2062 and AISI-4140 Steel Materials

Abstract

Metal cutting is a prominent aspect of the manufacturing industry since the need for new parts or the replacement of worn-out parts always arises. Of the several metal shaping techniques, the use of machines has occupied the central stage, and the versatile nature of lathe machines can never be overstressed. Even with the use of a lathe machine, a primal desire is to maximize output at the expense of the input parameters. Therefore, in this study, the impacts of cutting conditions and tool geometry on the specific metal removal rate and surface roughness in restricted turning operations were investigated. Experiments based on nine cutting tests were carried out on a conventional lathe using IS-2062 and AISI-4140 work specimens. Analysis of variance was applied to identify the impact of machining variables on the specific metal removal rate and surface roughness, while signal-to-noise ratio (S-N) analysis investigated the economical combination of depth of cut, feed rate, tool nose radius, and cutting speed for optimum outputs. The larger the better S-N and the least the better S-N criteria were used for specific metal removal rates and surface roughness, respectively. Results revealed that depth of cut contributed 46.66% effect on the specific metal removal rate for AISI-4140 steel and 1.79% for IS-2062 steel. Also, the tool nose radius contributed 15.62% to the specific metal removal rate for AISI 4140 steel and 5.84% for IS-2062 steel. Cutting speed contributed a 15.65% effect on the specific metal removal rate for AISI 4140 and 30.95% for IS-2062 steel, while the effect of feed rate on specific metal removal rate was 0.96% and 21.94% for AISI 4140 steel and IS-2062 steel, respectively. Similarly, depth of cut contributed a 3.32% effect on surface roughness for AISI 4140 steel and 3.02% for IS-2062 steel; tool nose radius contributed 28.53% for AISI 4140 and 28.12% for SI-2062. Also, cutting speed contributed 3.75% effect on surface roughness for AISI 4140 steel and 1.29% for IS-2062, while feed rate contributed 61.58% for AISI-4140 and 65.34% for IS-2062. The most feasible parametric setting for minimum surface roughness for AISI-4140 steel and IS-2062 steel were tool nose radius, N_R (0.35mm), cutting speed, V_w (101m/min), feed rate, R_f (0.2mm/rev); and N_R (0.35mm), V_w (101m/min), and R_f (0.2mm/rev), respectively, while maximum specific metal removal rate for AISI-4140 steel and IS-2062 steel were achieved at the following parametric setting N_R (0.35mm), U_{o :}(0.9mm), Vw (101m/min), Rf (0.3mm/rev) and N_R (0.35mm), U_o (0.9mm), V_w (65m/min), R_f (0.2mm/rev), respectively. It was noted that feed rate had the most manifested influence on surface roughness for both materials, and depth of cut affected specific metal removal rates the most. Results showed that AISI-4140 had a maximum specific metal removal rate of mm³/sec. Kw and minimum surface roughness of 4.643 .