汽车用轮毂螺栓裂纹分析

Fracture Analysis about Hub Bolts for Car Wheels

某紧固件生产厂家,在生产规格为M22×1.5×125的汽车用轮毂圆头花齿轮毂螺栓时,出现纵向贯穿裂纹。采用化学成分分析、硬度分析和金相分析等测试方法,对轮毂螺栓的断裂进行了分析。结果表明:螺栓存在明显带状组织偏析,淬火后组织不均匀,内应力较大且不均匀,造成淬火开裂。

A fastener manufacturer found the longitudinal penetration cracks when it produced the round head gear hub bolts for automobile wheels(SIZE:M22×1.5×125).Longitudial penetration cracks were analyzed by chemical composition,hardness,and microstructure.The results show that the bolts have obvious banded segregation,the structure is uneven after quenching,and the internal stress is large and uneven,which causes quenching cracking.