某铁道线路U75全长淬火钢轨发生横向断裂,经对该伤损钢轨进行宏观和微观检验,结合钢轨生产加工工艺及钢轨受力分析,指出钢轨表层形成先共析铁素体,致使该钢轨疲劳性能及耐磨性能下降是导致钢轨断裂的主要原因,为避免线路上类似伤损发生,应严把钢轨质量。 A railroad track U75 full length quenched rail transverse rupture, the macro and micro test of the damaged rail, combined with rail production and processing technology and rail stress analysis, pointed out that the formation of pro-eutectoid ferrite rail surface, causing the rail fatigue Degradation of performance and wear resistance is the main reason leading to rail rupture. In order to avoid the occurrence of similar damage on the line, the rail quality should be strictly controlled.