U75V钢轨断件断裂原因分析

Study on the reason of U75V rail's cracking

随着铁路运输的高速化和重载化,钢轨的伤损日趋严重,传统钢轨损坏形式主要有钢轨局部的磨耗、机车轮空转打滑所产生的踏面擦伤、轨端淬火层的剥落等,列车通过时巨大的冲击载荷易促使这些损伤部位裂纹发展形成轨头横向疲劳裂纹,将降低线路质量,影响行车安全。针对成都焊轨段闪光焊U75V钢轨断件,从宏观和微观两个方面分析其产生断裂的原因,研究钢轨中夹杂物如硫化物、硅酸盐、Al2O3等对钢轨产生断裂的影响。研究表明:本钢轨断件的破坏是由于疲劳裂纹扩展引起的断裂,即钢轨核伤;而疲劳裂纹是由氧化铝及钙铝酸盐非金属夹杂物引起。

With the high speed and over-loading of the rail-borne,the rail＇s damage is more an more serious.A portion of the damage is generented on the good running,for instance,partial abrasive wear of the rail,the scrape of the seating face because of the surge of the locomotive wheel and the enormous impact load is the reason of the lateral fatigue cracking when the train is on running.The research is analyzing the reseon of U75V rail＇s cracking,researches on the affection of the inclusion in the rail that causeing the cracking of the rail.The research demonstrate that：the cracking of the rail is fatigue-crack propagation,fatigue cracking is caused by alumina calcium-Aluminates-non-metallic inclusion.