Evolution Behaviors of Oxides in Severely Plastic Deformed Region of AISI 52100 Steel during Dry Sliding Wear

Under dry sliding wear, the evolution of oxides in severely plastic deformed (SPD) regions of metals has a great impact on the wear behaviors. To study the evolution behaviors of oxides in the SPD region, an SPD region was prefabricated on the surface of AISI 52100 steel by supersonic fine particle bombarding (SFPB) treatment. Dry sliding wear tests were carried out on both of the SFPB-treated and original samples. Wear volume loss of the SPBF-treated samples were compared with those of the original samples at different loads. Microstructure, element composition and oxides distribution in the SPD region were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and an electron probe microanalysis (EPMA). The results show that the evolution behaviors of the oxides in the SPD region change significantly with the load. Under low loads, oxides are usually formed on the contact surface. It inhibits adhesive wear on the steel. However, under high loads, oxides are apt to distribute along the cracks in the subsurface layer. The internal oxidation along the cracks can accelerate the cracks propagation, resulting in severe delamination wear on the steel.