钢轨踏面斜裂纹伤损原因及对策的研究

广深准高速铁路全长139km。对准高速区段和非准高速区段曲线上钢轨进行探伤检查,发现在44个曲线,37km长的范围内存在踏面斜裂纹,斜裂纹主要发生在上下行上股钢轨,斜裂纹呈成段、非连续、跳跃式分布。踏面斜裂纹及断口的宏观形貌和理化检验与分析表明,踏面斜裂纹伤损属于滚动接触疲劳裂纹伤损类型。研究认为:钢轨性能、线路状况、车辆性能及运行速度、车轮踏面形状等是产生斜裂纹的主要原因。提高钢轨的接触疲劳强度,在曲线上使用微合金淬火钢轨,研究和改善轮轨接触方式,加强轨道的养护维修,合理地进行预防性打磨和校正性打磨是解决钢轨踏面斜裂纹伤损的主要措施。

Causes of Rail Tread Oblique Crack and Countermeasures

The total length of Guangzhou-Shenzhen Quasi High-speed Railway is 139 km. Flow detection has been conducted on both quasi high-speed section and non-quasi high-speed section. Oblique cracks have been found on rails of 44 curves on 37 km tracks. Oblique crack mainly appears on the rail tread of the outside rail, segmental and non-continuous. The macro profile and physicochemical examination of the tread oblique crack shows that the crack falls into the category of rolling contact fatigue type. The research draws the conclusion that its occurrence is related to factors such as rail performance, track condition, train performance, operation speed of trains as well as wheel tread profile. Countermeasures to address this issue include the enhancement of the contact fatigue intensity, employment of micro-alloy head hardened rail on curves, improvement of the wheel-rail contact mode, strengthening the maintenance of rail, and the execution of rational preventive grinding and corrective grinding.