Experimental Study And Optimization Of The Wear Characteristics Of Abrasive Materials For High-speed EMUs

In this paper,the performances of three kinds of new anti-stick abrasives are studied,and the optimum material is selected.Then,the friction and wear behavior of rails with different materials is explored under the optimum abrasive condition.The results are as follows:According to the mechanical properties and durability tests of different material grinders,the three new grinders meet the requirements of national standards.Among them,the impact strength of # 1 grinder is the highest,and the compressive strength of # 2 grinder is the highest.The bond strength of three kinds of abrasives is greater than 10 KN,which shows that the three kinds of abrasives can fully meet the friction performance requirements of high-speed train at 50 kg.From the moment endurance test,all three kinds of grinders meet the requirements within the national standard range,and in the tests exceeding the national standard(1.0 MPa),it is found that only 1 type grinder is still sustainable.It can be concluded that the durability of 1 type abrasives is better.Through the selection test of creep rate,it can be concluded that at 10% creep rate,the adhesion coefficient is the largest,the moment of wheel is converted to the maximum adhesion between wheel and rail,and the wheel and rail are in the steady-state operation area.Therefore,10% creep rate is selected for the subsequent test of wheel-rail wear.From the friction and wear test of the grinder,it can be concluded that 1 type grinder has the best effect of reducing adhesion,and 1 type grinder has the lowest wear rate.From the point of view of wheel-rail wear rate,the rail sample with 1 type grinder has the lowest wear rate.It is concluded that the 1 type abrasive has the best performance.It can be concluded thatThe wear comparative test of different material rails(U68CuCr,U71 Mn,U75V,U77MnCr)after applying #1 grinder shows that the wear of U68 CuCr rails is the largest in terms of wear amount.And the smaller the hardness ratio of wheel to rail,the greater the total wear of wheel and rail.From the change of material hardness,the closer the hardness of wheel and rail is to the contact surface of wheel and rail,the faster the hardness change speed of specimen,and the thickness of plastic deformation layer of rail specimen is roughly distributed between 25 and 40 microns.From the plastic deformation layer,with the decrease of the hardness ratio of wheel to rail in four groups of tests,the rail test results show that the hardness ratio of wheel to rail decreases.The results show that the thickness of the stripping layer increases with the decrease of hardness ratio,the slight stripping of the surface layer of rail material changes to deep stripping wear,and the fatigue damage of the surface of railspecimen develops from fatigue crack to larger stripping pit.The wear pattern of rail specimens changed from fatigue wear to fatigue wear,adhesion wear and abrasive wear.