Experimental study on white layers in high-speed grinding of AISI52100 hardened steel

Ground white layer structure is an untempered martensitic due to grinding heat and plastic deformation. Many researchers have studied the formation of white layers at low grinding speed. However, few studies were found on white layer at high grinding speed. Therefore, to minimize white layer, it would be very useful to know the formation of white layer in the high-speed grinding. We performed grinding experiments using hardened AISI52100 steel with cubic boron nitride (CBN). Grinding force and grinding temperature were online measured during grinding process. Surface roughness, residual stress and white layer were also examined, respectively. The influence of grinding wheel speed on grinding force and surface integrity was analyzed. Formation of white layer was also studied. Experimental results show that grinding force and plastic deformation decrease significantly at higher grinding speed. Meanwhile, white layer depth and residual stress value increase with the grinding wheel speed, and residual stress is well correlated with ground white layer depth. White layer during high-speed grinding process results from phase transformation due to grinding heat and rapid cooling, while the plastic deformation may be ignored for the ground white layer.