车轮显微组织对车轮摩擦学性能的影响∗

摘要

利用JD-1型轮轨模拟试验机研究4种不同成分车轮材料微结构对其摩擦学行为的影响。结果表明：随着碳当量升高，车轮材料显微组织中先共析铁素体体积分数逐渐减小，珠光体晶粒大小和珠光体片层间距则有明显增大的趋势；车轮材料显微组织决定其硬度和耐磨性，随着碳当量的升高，车轮材料硬度增加，耐磨性提高，车轮材料的主要磨损机制为疲劳磨损；随着碳当量升高，车轮材料疲劳裂纹萌生的概率越来越大，疲劳裂纹有向长深裂纹扩展的趋势，而且耐磨性的提高也不利于疲劳裂纹的磨除，车轮材料的抗疲劳性能越来越差。%Effect of wheel material microstructure on the tribological behavior of wheel was investigated in a JD-1 wheel/rail simulation facility.The results indicate that with the increase of the carbon equivalent of wheel materials,the volume fraction of proeutectoid ferrite is decreased gradually,the pearlitic colony size and the interlamellar spacing are increased significantly.The hardness and wear resistance of the wheel material is determined by its microstructure,the wheel material with a higher carbon equivalent possesses a higher hardness and a better wear resistance.The main wear mechanism of the wheel material is fatigue wear.With the increasing of carbon equivalent,the fatigue crack will initiate in a much greater probability,and propagate in greater length and depth.Also a better wear resistance of the wheel material is unfavorable to removing the fatigue crack,thus a higher carbon equivalent in the wheel material gives a poor fatigue property.