Effect of wheel cladding on wear and damage property of wheel/rail under heavy-haul condition

Laser cladding Co-based alloy coating on surface of wheel/rail specimens by CO2multimode laser.The wear property and damage mechanism of wheel/rail were investigated using a MMS-2Arolling wear testing apparatus.The results indicate that the organizations of coating layers are obviously thinner than substrate.The surface hardness of wheel/rail increased significantly and was about 1.5times than that of substrate.With an increasing axle load,the friction coefficients and wear rate of wheel/rail specimens increased and the wear rate of wheel specimens was only 1/5-1/8of rail specimens'.The wear volume of wheel/rail specimens linearly increased with the time increasing.The damage of wheel/rail specimens was more severe with the increase of axle load and the damage of wheel specimen was slighter than that of rail under the same condition.For coating layers of wheel,the adhesive and oxidative wears were dominating and the fatigue and oxidative wear for rail at low axle load.With an increase of axle load,serious fatigue damage was dominating for wheel/rail specimens and slight oxidative wear exists.