Effect of White Layer Obtained by Hard Cutting on the Friction and Wear Performances of GCr15 Bearing Steel Surface

In order to study the effect of the white layer obtained by hard cutting on the friction and wear performances of the specimen surface, the polycrystalline cubic boron nitride tool was used to cut the GCr15 bearing steel hardly. The hardness of the white layer was measured, and friction and wear tests of both hard - cutting specimen and uncut specimen were carried out using the pin - disk friction and wear machine. In addition, the wear surfaces were observed through scanning electron microscope. Results showed that compared with the uncut surface, a white layer with a thickness of 6 μm was generated on the surface of the hard - cutting specimen. The surface hardness of the hard - cutting specimen was higher than that of the uncut specimen due to the formation of martensite and the grain refinement. Compared with the uncut surface, the hard - cutting surface with a white layer possessed a lower friction coefficient and abrasion loss. Therefore, the white layer on hard cutting surface could improve the friction and wear performances of the surface.