Effects of pre-rolling and metal removal on the fatigue life of lubricated rolling/sliding contact

Abstract

In this experiment, after the test specimens are preloaded at different first-step rolling cycles, the surface layer of the lower speed roller is ground to different depths by a grinder along the radial direction. With a new higher speed roller, the effects of the ground depth and first-step rolling cycle on the fatigue life of lubricated rolling/sliding contact are investigated using a 0.45% carbon steel pair. Results show that the prerolling cycles with metal removal can improve the rolling fatigue life. It is found that when the surface hardness of the specimen starts to approximate the saturated value at the first-step rolling cycle with the ground depth to the position of its maximum hardness, the rolling fatigue life with this preloading operation is 3.3 times that with the normal operation for the second-step load of 588 N. This increment in the rolling fatigue life can be reasonably explained by the measured plastic flow of the surface layer and the theoretical results of the residual stress below the contact surface.