Study Of Wheel/Rail Materials Friction And Wear Behavior

It is an important academic value, realistic economic and security implications to research the damage mechanism of wheel-rail friction and their occurrence of wear behavior, and it is beneficial for the rail wear of prevention mitigation and improvement of the life in the wheel orb. This paper is based on Hertz experiment simulation rules, sample size wheel design lab and test parameters are designed. Simulating the actual operation of 25 t axle load heavy rail and 17 t axle load high-speed rail operation by friction and wears experiments. The optical microscope(OM), scanning electron microscope(SEM) were used to observe the microstructure of the friction pairs, and the energy dispersive spectroscopy(EDS) was used to analyze the composition of the grinding marks, and the hardness of the micro region was tested. Analyzing the tribological behavior under dry and damage situation, according to observation analysis, surface composition analysis and wear test. The main contents and conclusions are as follows:U68CuCr rail, U75 V rail samples were composed of steel samples with D2 wheel friction to simulate the 17 t axle load high-speed rail operation. U68 CuCr rail, U75 V rail samples were composed of steel samples with ER8 wheel friction to simulate the 25 t axle load heavy-rail operation. The wear test results showed that the abrasion loss of the wheel is more than that of the rail in the same set of friction pairs under the same conditions. The abrasion loss of U75 V rail pairing wheel samples is more than U68 CuCr rail pairing wheel samples, the wear resistance of U68 CuCr rail specimen is better than that of the U75 V rail specimen, it may be because U68 CuCr rail has a fine pearlite structure, which is more conducive to improve the wear resistance of the rail.Under heavy load conditions, when the experimental time is 5 h, white layer within wheel/rail specimens did not appear, only the plastic deformation layer emerges. When experimental time is 11 h, plastic deformation layer and white layer appeared in wheel/rail specimens and wheel sample has been seriously damaged. The difference between the abrasion loss of U68 CuCr rail and U75 V rail becomes smaller, and the abrasion loss bettween the ER8 wheel matching U68 CuCr rail and the ER8 wheel matching U75 V rail is increased.At the high speed(low axle load), the oxidation wear is the predominant of the wheel-rail wear mechanism, the abrasive wear and adhesive wear has minor effects. At the heavy load(high axle load), the oxidation wear and abrasive wear is the predominant wheel-rail wear mechanisms, the adhesive wear plays a relatively minor role.