Effect of Cutting Parameters on Surface Integrity in Dry Turning of Hardened Hot Die Steel

This paper presents results of an experimental investigation of turning of hardened AISI H13 die steel, focusing on the effect of cutting parameters on work surface integrity. The experiments were performed under dry cutting conditions using multilayer (TiN/MT TiCN/Al₂O₃) coated carbide tools. Surface integrity parameters like, surface and subsurface alterations and through thickness residual stresses were investigated to establish the effects of dry cutting on the surface integrity of the machined component. Surface and subsurface deformation were examined using a scanning electron microscope (SEM) and the residual stress distributions by X-ray diffraction technique. Various forms of surface damages were observed under different cutting conditions. The results obtained from surface examination showed a strong correlation between cutting conditions and surface integrity. A microstructural analysis shows the formation of a thin white layer less than 3~4 μm and severe plastic deformations beneath the machined surface. The favorable compressive residual stresses were obtained at low cutting speed with high feed rate and depth of cut. A wide range of residual stress distributions beneath the machined surface were obtained depending on the cutting conditions.