Effect of Tool Edge Geometry on Cutting Force and Surface Roughness when Hard Turning Tool Steel

High usage of hardened steel in the automotive, gear, bearing, tool and die makingindustries, makes it a highly suitable material for industrial production and research. This study wasundertaken to investigate the performance of coated ceramic insert with different edge preparationsin terms of cutting force and surface roughness. Plain turning experiments were carried out underdry cutting condition at two different cutting speeds and feed rates with a constant depth of cut. Theworkpiece material is ASSAB DF-3 hardened steel with a 55 ±1 HRC hardness. Results showedthat insert edge preparation had a direct influence on the radial and feed forces but not on thetangential force. The use of T-land edge preparation results in the lowest radial and feed forces. Interms of surface finish, the use of honed with finishing wiper insert results in obtaining the lowestsurface roughness values. Feed rate had a significant effect on surface roughness whereby byincreasing feed rate, the surface roughness value also increased, whereas the effect of cutting speedwas found to be insignificant. Increasing cutting speed resulted in lower feed and tangential forceshowever by increasing feed rate all cutting forces increased.