Study on fretting friction properties based on GCr15 alloy and liquid epoxy resin protective coatings on GCr15 alloy

GCr15 alloy steel is a representative alloy steel of high carbon chromium bearing steel, with good comprehensive performance. However, the fretting wear and fatigue at the interface of the GCr15 friction pair greatly reduce its service life. In this study, the friction pair of GCr15 alloy was prepared by the surface treatment of epoxy resin coating. The tangential fretting wear experiments were conducted on the samples with the point contact mode in an SRV-IV multifunctional tester to investigate the evolution law of coefficient of fretting wear, dissipation energy and damage varying with the normal load and displacement amplitude. The results showed that the coefficients of the friction pairs treated with epoxy resin composite materials are lower than those of GCr15-GCr15 friction pairs under the same normal load and displacement amplitude, and the friction coefficients of both types of friction pairs gradually decreased with the increase of normal load and the decrease of displacement amplitude. At the same time, epoxy resin coating treatment reduced the dissipation energy of fretting wear. From the perspective of damage protection, GCr15-GCr15 exhibits severe scratch damage, micropores, and microcracks after friction experiments, while the epoxy resin coating mainly showed furrow. In addition, the decrease in hardness of polymer composite coating increased the wear rate of the samples to a certain extent.