Simulation and Experimental Study on Rolling Friction and Wear of Heavy Haul Wheel Tread

Abstract

Rolling friction and wear testing of heavy haul wheel tread was performed. The results show that a new and dominant vibration was generated owing to the surface wear, resulting in the polygonalization wear of the wheel specimen. The slip between wheel and rail specimens accelerated the formation of polygonalization wear. The pearlite and proeutectoid ferrite in the outermost layer were completely fragmented to form a fine grain layer. There was an extreme state for the deformation of the microstructure in the outermost layer, and there was a corresponding extreme value for the hardness. The slip accelerated the surface microstructure to reach the plastic hardening limit, but it had little effect on the extreme value of hardness. The stress distribution of the wheel specimen surface was simulated. The results show that there were alternating principal tensile and compressive stresses at the contact surface of the wheel specimen and shear stresses with alternating directions in the subsurface of the contact patch. The depth of the maximum shear stress from the surface was mainly related to the normal load, while the slip has no significant effect on it. A coupling modeling method of finite-element method (FEM) and smoothed particle hydrodynamics (SPH) was used to simulate the microstructure evolution of CL70 wheel steel. The simulation results show that there was mutual mechanical interaction between ferrite and cementite in pearlite. Their deformation was inconsistent owing to their different mechanical properties, resulting in large tensile stress at the boundary between them, even in the compressive stress area below the contact patch.