汽车下摆臂球销座连接螺栓在使用时发生早期断裂。采用金相分析、硬度测试及氢含量测定等方法对其断裂原因进行了分析。结果表明,螺栓在电镀过程引入氢而后续处理时间过短除氢不完全,加上R转角处容易造成应力集中,因此在使用后不久便发生螺栓断裂失效。同时提出了相应的改进措施。 Car pendulum arm ball pedestal connecting bolts in the early rupture occurred. The fracture reason was analyzed by metallographic analysis, hardness test and hydrogen content determination. The results show that the introduction of hydrogen in the electroplating process and subsequent treatment time is too short, hydrogen is not complete, coupled with the R corner is likely to cause stress concentration, so the failure occurred shortly after the bolt rupture. At the same time put forward the corresponding improvement measures.