High-speed wheel-rail interfacial adhesion and surface damage behavior of wheel in wide temperature range

The wheel-rail rolling tester in a high/low temperature environment was built, and the seasonal damage characteristics of wheel surfaces with delamination and pits appearing in winter, and unusually smooth characteristics presenting in summer in the Harbin-Dalian Railway and other alpine railways, were successfully reproduced under laboratory conditions. The wheel-rail interface adhesion and wheel damage behavior of high-speed trains in a wide temperature range (-50 ℃-60 ℃) were studied. The evolution laws of the adhesion coefficient of wheel-rail rolling contact interface were systematically discussed under different service temperatures, and the important characteristics of wheel surface worn morphology and plastic behavior of surface materials were analyzed. Research results show that the adhesion coefficient of wheel-rail interface decreases with an increase of the service temperature. At the same time, the sizes of the pits on the wheel surface decrease, and the pits disappear and the worn surface becomes smoother at 60 ℃. At a low temperature of -40 ℃, the wheel surface is the roughest with the arithmetic mean roughness of 3.74. As the service temperature increases, the roughness of the wheel surface decreases significantly. At a high temperature of 60 ℃, the roughness of the wheel surface is small, and arithmetic mean roughness is 0.97. As the service temperature increases, the element content ratios of the Fe to O in the wear area of the wheel-rail contact interface decrease gradually. A low-temperature and low-humidity environment inhibits the frictional oxidation of the wheel-rail interface, enhances the frictional shear, aggravates the delamination on the wheel surface and serious plastic deformation, and promotes the initiation and propagation of surface fatigue cracks. Therefore, the wear surface is relatively rough. However, the high-temperature environment accelerates the frictional oxidation of the wheel-rail interface, and the formation of oxidized debris plays a solid lubrication role. Therefore, the adhesion of wheel-rail interface reduces, and the wheel surface is relatively smooth. The wear mechanism gradually changes from the fatigue wear at low temperature (-50 ℃~-20 ℃) to the abrasive wear and oxidation wear at room temperature (20 ℃), and adhesive wear at high temperature (40 ℃~60 ℃). © 2021, Editorial Department of Journal of Traffic and Transportation Engineering. All right reserved.