PD3热轧钢轨在弯道半径R=600 m地段使用4 a(年)后部分钢轨出现剥离掉块现象。采用化学成分分析、低倍检验、扫描电镜观察及能谱分析、金相检验和力学性能测试等方法对该钢轨进行了分析。结果表明：轮轨接触应力过大，导致钢轨接触面表层金属发生塑性变形形成疲劳裂纹,当磨耗速率小于疲劳裂纹扩展速率时,便发生剥离掉块现象;同时线路参数设计、线路条件及钢轨的选用也是发生剥离掉块损伤的诱发因素。并提出了改进措施。

After having been used four years in the curve sector R=600 m,some PD3 hot-rolled rails had fatigue damage of desquamation. The damage cause was analyzed by means of chemical composition analysis,mctallographic examination and hardness testing and so on. The result showed that the contact stress of rail and wheel being too excessive,the superficial metal of rail contact surface generated plastic deformation and forms fatigue crack,when the wearing speed rate was less than the fatigue crack expansion rate,the desquamation occured. And the measures were put forward.