Experimental Study On Tribological Properties Of Wheel-rail Materials

Railway transportation has attracted more and more attention because of its advantages such as fast,safe,economic and large volume.Chinese railway transportation,especially high-speed railway transportation,is developing very rapidly.By the end of 2016s,the total mileage of China’s railways has reached 124,000 kilometers,ranking second in the world.Among them,25,000 kilometers of high-speed railways rank first in the world.The double-track rate and electrification rate of the national railways have reached 54.9%and 64.8%respectively,and more trunk lines and urban areas are planned to be built in the future.Rail and light rail transit.With the increasing number of railway projects,railway transportation safety issues are more and more.Railway operation safety,stability and comfort have become an inevitable requirement for the development of railway industry in the new era.Wheel-rail relationship,as one of the key technical problems in railway operation,has very important research significance.With the development trend of high-speed and heavy-duty railway transportation,the research on wheel-rail friction becomes more important.In this paper,the wheel-rail is taken as the research object,and the ring-block friction and wear test is made based on the wheel-rail material.Combined with the computer technology and the numerical analysis method,the friction and wear tests are carried out from three aspects:theoretical analysis,experimental research and numerical simulation,respectively.Considering the influence of load and velocity,the tribological properties of wheel-rail materials are analyzed systematically and deeply.The main contents are as follows:(1)Wheel/rail materials CL65(track material),AB1(wheel material)and U75V(wheel material)are set as test objects to make ring-block friction pair.Ring-block wear test is carried out by using MRH-5A ring block wear tester.Considering the influence of material properties,contact surface load,relative sliding speed and friction coefficient,the temperature variation value and variation curve of different materials on grinding under different working conditions are obtained;(2)According to the friction and wear test conditions,the ring-block model is simulated and analyzed,and the temperature appreciation of the simulation model is compared with the test temperature appreciation,the error is less than 5%.The feasibility of the finite element simulation analysis method to solve the complex nonlinear tribological problems is verified,which provides the tribological theoretical basis for the temperature field analysis of wheel-rail materials;(3)When the friction pair material is ground on the MRH-5A ring block wear tester,the friction coefficient read from the test machine is used for the friction coefficient value needed for the later simulation.The simulation results are in good agreement with the test results,the accuracy of the friction coefficient measured by the test machine is determined,and the feasibility of using the friction coefficient measured by the test prototype is verified.