Experimental Research On Rolling Wear And Contact Fatigue Damage Behaviors Of Wheel/Rail Materials

With the rapid development of high-speed/heavy-haul railway transportation, the insures of wheel/rail damages become increasingly apparent. At the same time, the new service environment has put the compatibility of wheel/rail materials to a more crucial position. Therefore, it is significant and practical to investigate the compatibility of widely used wheel/rail steel.On the basis of Hertz contact theory, the abrasion resistance and fatigue property of four kinds of wheel steels with different compositions were studied using a JD-1 wheel/rail simulation facility firstly. Also the compatibility of different wheel/rail steel under different axle loads had been investigated using a MMS-2A wear tester. These main results and conclusions can be obtained as follows:1. The increase of the carbon content and silicon content could enlarge the wheel hardness significantly. The higher the wheel hardness is, the better the abrasion resistance is and the worse the fatigue property is.2. Investigation of the friction and wear behavior of the wheel/rail system made of hot rolled U71Mn rail and four kinds of wheel indicates that with the increase of wheel hardness, the wear losses of wheel samples decrease linearly, while that for rail samples increase linearly. What’s more, the larger the wheel hardness is, the more severe the wheel fatigue damage is and the slighter the rail fatigue damage is.3. Investigation of the friction and wear behavior of the wheel/rail system made of hot rolled U75V rail and four kinds of wheel samples indicates that with the increase of wheel hardness, the wear losses of wheel samples decrease linearly, while that for rail samples increase linearly. Due to the large contact stress between wheel and rail, as the wheel hardness increases, the fatigue damage becomes much more severe not only for wheel samples but also for rail samples.4. The increases of axle loads could enlarge the wear losses of wheel and rail samples significantly. At a low axle load, the cracks initiated in the wheel samples are easily removed due to their larger wear losses (compared with the rail samples), however, the crack propagation for rail samples usually is much deeper and the fatigue damage is more severe. On the other hand, the propagating rates of fatigue cracks and wear rates of wheel/rail samples become much greater at a high axle load, the fatigue damage of rail samples is much slighter which is due to its better material properties.5. In analysising with the damage behaviour of wheel and rail samples in wear tests, it could be concluded that as the wheel hardness is close to the rail hardness, the wear losses of wheel/rail systems significantly reduce due to the mild oxidative wear between wheel and rail. Also the hot rolled U75V rail with better microstructure could significantly reduce the wear losses of the wheel/rail systems.