Rail grinding is a widely-used method to eliminate surface damages on railway tracks. The grinding chips are closely related to the grinding parameters and the grinding quality. Therefore, the investigation on the characteristics and the formation mechanism of chips from rail grinding is beneficial for the optimization of rail grinding process. In the present study, the grinding chips from the real rail grinding in the field and from the rail grinding experiments in the laboratory were analyzed in terms of their morphologies, microstructural evolution and chemical characteristics. The results showed that flowing, knife, slice and spherical chips were generated during rail grinding. The formation mechanism of flowing, knife and slice chips was plastic deformation by forces from abrasive grains with oxidation in air by grinding heat. Primary and secondary shear zones and central zones were generated. In the primary shear zone, cracks were generated in knife and slice chips. In the secondary shear zone, obvious plastic deformation was formed in knife and slice chips and a significant white etching layer (WEL) was generated in knife chips. The formation mechanism of spherical chips was melting of small powdery grinding debris by the high temperature and the subsequent solidification, accompanied with severe oxidization in air. The oxides produced in chips consisted of FeO, Fe₃O₄, Fe₂O₃ and AlFe₂O₄. The grinding quality could be predicted through observing the grinding debris. The larger percentage of flowing chips represented the better grinding quality (smaller surface roughness, slighter surface burn and thinner WEL on ground rail), which could be the goal for the grinding parameters choice.

钢轨磨削是一种广泛使用的消除铁路轨道表面损伤的方法。磨屑与磨削参数和磨削质量密切相关。因此，研究钢轨磨削切屑的特征及形成机理，有利于钢轨磨削工艺的优化。在本研究中，对现场实际钢轨磨削和实验室钢轨磨削实验产生的磨屑的形态、微观结构演变和化学特性进行了分析。结果表明，钢轨磨削过程中产生流屑、刀屑、切片和球状切屑。流动切屑、刀切屑和薄片切屑的形成机理是磨粒在空气中受到磨削热氧化作用而产生的塑性变形。产生了主要和次要剪切带和中心带。在主剪切区，刀屑和片屑产生裂纹。在二次剪切区，刀屑和切片产生明显的塑性变形，刀屑产生明显的白色蚀刻层（WEL）。球状切屑的形成机制是细小的粉状磨屑被高温熔化并随后凝固，并在空气中严重氧化。芯片中产生的氧化物由 FeO、Fe 球状切屑的形成机制是细小的粉状磨屑被高温熔化并随后凝固，并在空气中严重氧化。芯片中产生的氧化物由 FeO、Fe 球状切屑的形成机制是细小的粉状磨屑被高温熔化并随后凝固，并在空气中严重氧化。芯片中产生的氧化物由 FeO、Fe₃ O ₄、Fe ₂ O ₃和AlFe ₂ O ₄。通过观察磨屑可以预测磨削质量。较大比例的流动切屑代表更好的磨削质量（更小的表面粗糙度、更轻微的表面烧伤和接地轨上的更薄的 WEL），这可能是磨削参数选择的目标。