THE EXPERIMENTAL AND STATISTICAL INVESTIGATION OF THE EFFECTS OF CUTTING PARAMETERS AND COATING MATERIALS ON THE MACHINABILITY OF HADFIELD STEEL

Abstract

In this study, during the turning of Hadfield steel, the effects of coating materials of the cutting tools and cutting parameters (cutting speed, feed rate) on the cutting forces, surface roughness and tool wear were investigated. Cutting experiments were made on the CNC lathe under dry cutting conditions by employing CVD TiCN/Al2O3/TiN, PVD TiAlN and PVD TiAlN/AlCrO coated cementite carbide inserts. As the cutting parameters, four different cutting speeds (100, 140, 180, 220 m/min), two different feed rates (0.2, 0.3 mm/rev) and 0.8 mm constant cutting depth were used. At the end of the tests variance analysis (ANOVA) and multiple regression analysis were made to the obtained cutting force and surface roughness results. According to the experimental results, from the point of view of cutting forces, surface roughness and tool wear, PVD TiAlN coating came out to be better than CVD TiCN/Al2O3/TiN and PVD TiAlN/AlCrO coatings. The correlation coefficients of the statistical model that were developed at the end of the analysis came out to be R2= 0.99 and R2= 0.993 for the cutting forces and surface roughness respectively. The feed rate was found to be the most effective parameter on the cutting forces and surface roughness with the 91.34% and 94.8% contribution ratios.