铁路货车摇枕断裂疲劳失效分析研究

2004年底在黑龙江某地的维修检查中发现某铁路货车1位摇枕裂断,整个断面均为新断面,无旧痕。在裂纹源附近的断口分别进行扫描电镜和金相观察检验,测试了摇枕材料的常规理化性能指标。结果表明断口面上可见人字状裂纹扩展台阶,由摇枕的底部向上部扩展,断口并无明显疲劳断裂贝纹线特征;裂纹源区铸造缺陷及局部富含大量有害元素,如Pb、Sn、S等;常规理化性能检验结果符合标准要求。综合分析认为,摇枕裂断属于脆性断裂,与多种因素相关,但是裂纹源区铸造缺陷及局部富含大量有害元素应是造成疲劳裂纹萌生和扩展的主要原因。

Fatigue Failure Study on the Crack of Truck Bolster of Freight Car

A truck bolster was found cracked during the repairing of freight car in Dec.2004 in Heilongjiang, while the crack surface was fresh mostly. The original fatigue crackles were studied by SEM and Metallographic, at the same time, the physics and chemistry properties were measured. On the crack surface double spur bench tunnel which propagated from the bottom to the top of truck bolster was the main feature. At the original fatigue crackles, cast defect and a plenty of harmful elements enriched locally were found, for example, Pb, Sn, S elements.The test of properties show that the physics and chemistry properties were conformed to standard. Through generalized analysis, the crack of truck bolster mentioned above is belong to fatigue crackles which may be caused by some factors, the cast defect and a plenty of harmful elements should be main reason for the crack initiation and propagation.