在某批厚度为15.9 mm的X52管线钢热轧板卷上发现批量尾部裂纹缺陷。采用光学显微镜、扫描电镜和能谱仪等设备对裂纹缺陷处的微观形貌和化学成分进行观察和分析。结果表明：在热轧制过程中，热轧中间坯存在翘头积水和反冲水拦截除鳞水效果不佳现象，导致带钢局部过冷，因此在精轧过程中带钢表面变形不均匀从而产生局部拉裂。通过改善粗轧翘头现象和调整反冲水角度，可有效控制裂纹的产生。

Surface crack defect were observed on the tail of X52 pipe line steel hot-rolling coil with a thickness of 15.9 mm. The microstructure and chemical composition of the cracks were analyzed by means of optical microscope, scanning electron microscope and energy dispersive spectroscope. The results show that the phenomenon of warping hydrops and poor effect of reverse flushing intercept descaling water in the hot rolling slab of the hot rolling process. This phenomenon leads to the local overcooling of the strip. Therefore, in the process of finishing rolling, the surface deformation of the strip nonuniform so that the pull crack was produced. The crack can be effectively controlled by improving the warping phenomenon of the rough rolling and adjusting the angle of the reverse flushing.