Mechanics characteristics of surface damage on sliding-rolling friction pair under high-speed and heavy-load condition

An elasto-plastic contact model of M50 steel sliding-rolling friction pair was built by using the finite element method. Under the high-speed and heavy-load condition that the contact stress was about 4.0GPa and the velocity was about 50 m·s^-1, the Von Mises stress, shear stress and plastic deformation of surface layer were analyzed, the effects of the friction coefficient and the relative sliding velocity on the contact behaviors of the M50 steel sliding-rolling friction pair were studied, and the plastic deformations of surface layers were compared in M50 steel double-roller sliding-rolling test result. Calculation result shows that the differences of maximum contact stresses and major and minor axis lengths of elliptical contact region between the finite element analysis result and the Hertz theory calculation result are 2.66%, 0.26% and 6.43%, respectively. When the friction coefficient increases from 0.1 to 0.5, the location of maximum Von Mises stress gradually moves from the friction pair subsurface at about 0.5 mm to thecontact surface. When the scuffing failure of friction pair surface occurs, the friction coefficient is more than 0.3, and the maximum Von Mises stress is over 1 700 MPa. When the scuffing failure occurs, the stress and plastic strain of M50 steel friction pair have specific direction. Under the condition that sliding-rolling ratios are 0.12 and 0.15, respectively, the maximum Von Mises stresses are 2 847 MPa and 2 689 MPa on the contact point with higher linear velocity, which leads to relatively large plastic strain, and the maximum values are 0.062 and 0.061, respectively. However, on the surface with lower linear velocity at the two sliding-rolling ratios, the maximum Von Mises stresses are 2 269 MPa and 2 101 MPa, respectively, the plastic strains are smaller, and the maximum values are 0.040 and 0.039, respectively.