基于城轨新材质车轮性能的分析研究

Performance study of the wheels made of new materials for urban rail vehicles

为提高城轨车辆车轮的硬度和强度,大幅提升车轮材料的力学性能与服役表现,文章对车轮的化学成分、拉伸性能、硬度均匀性、显微硬度、踏面变形层EBSD组织、磨损性能均匀性进行分析研究。结果表明:高Cr高V的车轮比低Cr低V的车轮强度和韧性高;两种车轮的表面变形层显微硬度分布均表现出较大的波动性,低Cr低V车轮表层硬化程度较高Cr高V车轮显著;低Cr低V车轮局部表层晶粒变形和细化程度以及塑性变形和位错密度高于高Cr高V车轮,随着距离踏面深度的增加,两种车轮表面变形层微观组织结构差异逐渐减小。材料抗磨损性能随深度增加而缓慢下降;高Cr高V车轮强度和韧性指标高于低Cr低V车轮。

For the purpose of enhancing the hardness and strength of wheels on urban rail vehicles and dramatically increasing the mechanical properties and service performance of wheel materials,this paper studies the chemical composition,tensile strength,hardness uniformity,microhardness,EBSD microstructure at the wheel deformation layer and the uniformity of wear performance.The study indicates that the wheels with high Cr and V content have higher strength and toughness than those with low Cr and V content;the microhardnesss distribution at both wheels’surface deformation layers show big fluctuation,with the surface hardenability of the wheels with low Cr and V content being higher than the those with high Cr and V content;the surface deformation,fineness,plastic deformation and dislocation density of the wheels with low Cr and V content is higher than high Cr and V wheels,with the increase of the depth from tread,the microstructure differences between the two kinds of wheels decrease at the surface deformation layer.The wear resistance of the materials slowly decreases with the increase of depth;the strength and toughness index of the wheels with high Cr and V content are higher than those with low Cr and V content.