Effects Of Vanadium And Rare Earth On Microstructure And Wear-resistance Of Bainite Hardfacing Alloy Used In Rail

With the development of the rail transportation, the requirements for quality andperformance of rail are increased. The main failure mode of rail is wear. For failed rail,the surface hardfacing method can be adopted to repair it and higher properties can beobtained. Therefore, it is significant for developing the hardfacing materials with specialproperties.Effects of the alloy element vanadium (V) and rare earth (RE) oxide La2O3on themicrostructure and mechanical property of hardfacing alloy have been studied in thispaper, which were studied by optical microscope (OM), Field Emission ScanningElectron Microscope (FESEM) with Energy Dispersive Spectroscopy (EDS) and X-RayDiffractometer (XRD). The experimental results were also analyzed by Thermo-Calcsoftware and Jmatpro software.The results show that, the granular bainite microstructure can be obtained with theaddition of alloy element V, and the MC carbide precipitates in the matrix. When thecontent of alloy element V is0.14wt.%, the hardfacing alloy gets the best mechanicalperformance. Meanwhile, the MC carbide can pin the austenite grain boundaries and actas the heterogeneous nucleus of ferrite. The finer the austenite grain and ferrite are, thehigher the mechanical property is. The granular bainite and white netty martensitemicrostructure were obtained with the addition of RE oxide La2O3. The RE oxide La2O3can refine the austenite grain, so the wear resistance can be improved.