某型摩托车车架服役中断裂失效分析

Fracture Failture Analysis of a Motorbike Frame in Service

通过对服役中断裂失效的摩托车车架进行综合分析,表明该车架的断裂主要是由于车架材料的组织中,存在有较严重的沿晶分布游离渗碳体。这种游离渗碳体的存在,导致材料在冷加工过程中于内部形成微裂纹,并在外力的作用下,微裂纹最终扩展并导致疲劳断裂。

A synthetic analysis to a fractured motorbike frame in service has been made and indicated that much free-cementite precipitated at grain boundaries as network results in failure. Free-cementite preecipitated at grain boundaries induces inter-microcrack found in the workpiece after cold forming. Final fatigue failure is due to inter-microcrack prepagation by external force.