The effect of workpiece hardness and workpiece composition on tool wer mechanism and surface roughness in finished hard turning X12M alloy steel using CBN cutting tool

This paper presents a research on influence of hardness and composition of workpiece material on tool wear and quality of machined surface in finished hard turning X12M alloy steel. This study showed that high workpiece surface hardness results increase of tool wear rate and machined surface roughness. Carbide structure and sizes of workpiece cause abrasion and plastic deformation of cutting edge and tool flank. Workpiece composition has significant effects on wear mechanism of diffusion and chemical interactions, the main factors generate the crater on rake face and the coat of workpiece material outside the tool-chip interface. Also the high hardness leads to thermal break down of cutting tool material.