Machinability evaluation in hard turning of cold work tool steel (D2) with ceramic tools using statistical techniques

Turning hardened tool steel using ceramic cutting tool, has certain advantages over the traditional turning/hardening/cylindrical grinding practice in terms of increased productivity and reduced power consumption. The hard turning is generally performed without a coolant (additional environmental advantage). An experimental investigation was carried out using ceramic cutting tools, composed approximately with (70%) of Al2O3 and (30%) of TiC, in surface finish operations on cold work tool steel D2 (AISI) heat treated to a hardness of 60 HRC. A plan of experiments, based on orthogonal arrays, was made in turning with prefixed cutting parameters in tool steel workpieces. A combined technique using orthogonal array and analysis of variance (ANOVA) was employed to investigate the machinability of cold work tool steel. The results of the tests shows that with a appropriate cutting parameters choice is possible to obtain a surface roughness (Ra < 0.8 μm) that allows to eliminate cylindrical grinding operations.