Effect of ultrasonic surface rolling on fretting wear behavior of GCr15 steel

Abstract

Bearings are susceptible to fretting wear between the rolling element and the collar, which affects the normal service of bearings. In order to improve the fretting wear performance of GCr15 bearing steel, ultrasonic surface rolling treatment was performed on GCr15 steel under different static pressures and passes, and the fretting wear test was then carried out. Test results showed that the surface roughness was decreased and the microhardness was increased after ultrasonic surface rolling treatment. With an increase in static pressure and passes, the roughness decreases and the microhardness increased. Besides, a lower steady friction coefficient and fretting wear volume were obtained with the specimens performed by ultrasonic surface rolling treatment. With an increase in static pressure and passes, the wear volume and steady friction coefficient decreased together. Furthermore, the mechanism of fretting wear changed from severe adhesive wear, fatigue wear, and abrasive wear to abrasive wear and slight adhesive wear due to the application of ultrasonic surface rolling treatment.