Influence of White Layer and Residual Stress Induced by Hard Cutting on Wear Resistance During Sliding Friction

The white layer and residual stress formed in a hard cutting process significantly influence the wear resistance of the workpiece. Orthogonal hard cutting experiments were performed on AISI 52100 steel with PCBN inserts. The results reveal that the white layer is formed on machined surfaces. Moreover, residual compressive stress exists in the white layers when the workpieces are cut by unworn tools, whereas tensile stress exists in the white layers when the workpieces are cut by worn tools. Under lubricated condition, the white layer (with the characteristics of high hardness and grain refinement) improves the resistance to abrasive wear. The high retained austenite content improves the resistance to fatigue wear. Furthermore, the residual compressive stress in the white layer inhibits the initiation and propagation of cracks, thereby increasing the fatigue wear resistance. Meanwhile, the residual tensile stress increases the speed of crack propagation in the white layer, which decreases the fatigue wear resistance. Under dry condition, the high hardness and grain refinement of the white layer increase the strength of the machined surface, thereby improving the adhesive wear resistance. The residual stress does not affect the wear resistance.