Investigation on microstructure and wear characteristic of laser cladding Fe-based alloy on wheel/rail materials

The aim of this study is to investigate the influence of laser cladding Fe-based alloy on microstructure and wear characteristic of wheel/rail materials using a rolling-sliding wear testing apparatus. Especially, the effect of lanthanum oxide on the properties of laser cladding coating was explored in detail. The results show that the laser cladding Fe-based alloy coating consists of dendrites and eutectic and is composed of (Fe, Ni) solid solution and Cr7C3 carbide. The hardness and wear-resistance of wheel/rail materials are enhanced using laser cladding. The wear and surface damage of wheel/rail rollers dramatically alleviate owing to the refinement of the microstructure when adding lanthanum oxide into laser cladding coating. The wear mechanism of wheel/rail rollers turns from severe spalling and delamination wear (untreated specimens) to slight peeling (with 1.2% La2O3). Furthermore, the plastic deformation of wheel/rail rollers undergoing laser cladding is significantly thinner than that of untreated rollers. In summary, laser cladding Fe-based alloy coating can be used to prolong the wear life of wheel and rail materials.