Analysis and Application of Train Wheel Flange Lubrication Materials

Wheel-rail lubrication, as an economical and effective method to slow down wheel-rail wear, is widely used by railway operation departments. It can not only significantly reduce the wear of wheel flange and prolong the service life of wheel-rail, but also reduce the running resistance and save energy. In order to study the anti-friction and wear-resistant mechanism and practical application effect of wheel-rail lubricating materials, three kinds of flange lubrication rods were selected as the research objects in this paper. The friction, wear and contact fatigue damage of wheel flange material specimens under dry friction and three kinds of wheel flange lubrication rods working conditions were studied through basic friction and wear tests. The wear surface morphology, damage characteristics and wear groove geometry were observed with scanning electron microscope (SEM) and surface measuring instrument. Energy dispersive spectroscopy (EDS) was conducted on three kinds of wheel flange lubrication rods to explore the influence of lubricating material composition on wheel rail material wear reduction. According to the laboratory results, two months of on-site locomotive flange wear tracking tests were carried out. The research results showed that the interface friction coefficient of the specimens under dry friction condition was about 0.51, and the wear rate was 0.240 0 µm/m. The interface friction coefficient could be reduced to 0.15~0.50 after the flange lubrication rod were applied as the lubricating medium, and the improvement of the lubrication condition significantly reduced the wear of the specimens. Compared with dry friction condition, the wear rates of the specimens under three kinds of flange lubricating rods conditions decreased by 17.21%, 28.58% and 20.50% respectively. Under the dry friction condition, the surface of the friction groove mark of the specimen had severe flake material peeling and rolled up irregular metal wear debris. The friction damage on the surface of the specimen decreased to varying degrees after the addition of the flange lubricating rod. Among them, the flange lubricating rod B had the best effect to reduce the contact fatigue damage. According to the test results, the ' oil wedge effect ' similar to grease would not appear in the solid lubricating material to aggravate the crack propagation. The fatigue crack branch propagation degree under the rim lubrication rod condition was roughly equal to that under the dry friction condition. At the same time, the dense lubricating film formed by the solid lubricating component at the contact interface of the specimens greatly reduced the surface wear of the specimens. The study of lubricant composition showed that the graphite-molybdenum disulfide wheel flange lubricating rod could form a dense solid lubricating film with strong ductility and high coverage on the friction contact surface, effectively reducing the wear of the specimen material. After completing the test in the laboratory, the field test was carried out in a freight station with many railway curves, especially small radius curves, to verify the effect of flange lubrication rod B. In the field test, the lubrication of the first wheelset of the DF12 locomotive was changed to the flange lubrication rod B, and the flange wear of the first axle wheelset and the fourth axle wheelset was tracked and recorded. The results showed that: after the DF12 locomotive was equipped the flange lubrication rod B, the flange wear was obviously improved, and the thickness wear ratio of the 1st /4th axle wheel set flange was reduced by 50%.