EFFECTS OF PRE-ROLLING AND METAL REMOVAL ON THE FATIGUE LIFE OF LUBRICATED ROLLING SLIDING CONTACT/

In this experiment, after the test specimens are preloaded at differen t first-step rolling cycles, the surface layer of the lower speed roll er is ground to different depths by a grinder along the radial directi on. With a new higher speed roller, the effects of the ground depth an d first-step rolling cycle on the fatigue life of lubricated rolling/s liding contact are investigated using a 0.45% carbon steel pair. Resul ts show that the prerolling cycles with metal removal can improve the rolling fatigue life. It is found that when the surface hardness of th e specimen starts to approximate the saturated value at the first-step rolling cycle with the ground depth to the position of its maximum ha rdness, 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 explai ned by the measured plastic flow of the surface layer and the theoreti cal results of the residual stress below the contact surface. (C) 1998 Elsevier Science S.A. All rights reserved.