INFLUENCE OF CUTTING SPEED AND GEOMETRY OF THE CUTTING PART ON THE COMPONENT CUTTING FORCES AND ROUGHNESS OF THE TREATED SURFACE DURING CLEAN TURNING OF SHH15 HARDENED STEEL WITH PсBN COMPOSITE CUTTERS

Abstract

The effect of the cutting speed and the geometry of the cutting part on the components of the cutting force and the roughness of the machined surface during the finishing turning of hardened steel SHH15 with cutters made of PcBN composites was investigated in the paper. The materials of the plates differed in terms of phase composition, dispersion of the structure, and physical and mechanical characteristics. The experimental part consisted of two stages, the first, where the turning took place with a radius sharpening of the plates at the top, and the second with a sharper edge. It is shown that during the finishing turning of the hardened SHH15 steel with a sharp cutting edge shape, the nature of the change in the components of the cutting force as a function of speed had the same tendency, but the nature of the change differed from the experiments with the radius shape of the cutting edge. During the turning of hardened steel SHH15 with sharp plates the first group of plates 1, 2 and 3, in which the cubanite grain size is 2/1, 3/2, 7/5, and the phase composition is 90%BN+10AlN, 90%BN+ 10AlN, 87%BN+13AlN, showed the best results in terms of roughness.