Investigation of the machinability properties at turning of heat treated bohler K340 cold work tool steel

SUMMARY In this study, machinablity of the BOHLER K340 cold work tool steel produced by powder metallurgy method was investigated in terms of turning operations. The test sample was hardened at 59 HRC prior to the turning experiments. DNGA 150608 AB30 composite ceramic cutting inserts were used in the experiments. Four different cutting speeds (80-120-160-200 m / min), feed (0.05-0.1-0.15-0.2 mm / rev) and three different cutting depths (0.25-0.50-0.75 mm) were applied under dry cutting conditions. In the investigation of machinability, cutting forces, average surface roughness (Ra) and tool wear were considered evaluation criteria. Analytical and statistical analyzes of the obtained results were made. Analysis of variance (ANOVA) was used in statistical analysis. The increase in the feed values is the most effective parameter on the surface roughness (Ra) and cutting forces. The lowest Ra value was obtained as 0.14 μm. It has been observed that the wear types most commonly seen at the cutting edges are crater wear and plastic deformation. The effects of minor abrasive, extensively adhesive and diffusion wear mechanisms on the cutter have been determined.