Effect to machinability of aisi d2 cold work tool steel of deep cryogenic treatment

In this study, the effects of deep cryogenic treatment and tempering on the surface roughness (Ra) and tool wear in hard turning of the AISI D2 cold work tool steel were investigated. However, it was analyzed that effects on microstructure and mechanical properties (macrohardness and microhardness) of the deep cryogenic processing. Test samples currently consists CHT, DCT-36 and DCTT-36 from the three groups. Samples of the first group has just brought to 62 HRC hardness subjected to conventional heat treatment. The second group consists of the deep cryogenic treatment sample treated for 36 hours at 145°C after conventional heat treatment. The latter group has seen both conventional heat treatment and after the deep cryogenic treatment is composed of 200°C for 2 hours was applied tempered sample. In the experiments as cutting tools, Al2O3 + TiC matrix composite alumina ceramic based uncoated (AB30) and Al2O3 + TiC and TiN coated ceramic based matrix with PVD (AB2010) cutting tools are used. In the experiments, three different cutting speeds (50, 100, 150 m/min), three different feed rate (0.08, 0.16, 0.24 mm/rev) and three different depth of cuts (0.25, 0.50, 0.75 mm) parameters are selected. The tool wear experiments, cutting speed of 150 m/min, feed rate of 0.08 mm/rev and the cutting depth of 0.6 mm were carried out. The experiments show that; the best results in terms of surface roughness and tool wear were obtained by DCTT-36 sample. When compared to cutting tools, as well as surface roughness and nose wear best results were obtained with coated ceramic cutting tools (AB2010). Microhardness and macrohardness values of samples in the DCT-36 has increased to the highest level. In terms of microstructure, more homogeneous and the second carbide formation of finer seen DCTT-36 samples were found to exhibit the best results. As a result, deep cryogenic process applied to AISI D2 cold work tool steels, it has been observed to exhibit positive results in terms of the surface roughness, tool wear, mechanical properties and microstructure.