某重型汽车钢板弹簧在服役期间异常断裂。采用宏观观察、化学成分分析、金相检验、扫描电镜及能谱分析等方法,对该弹簧断裂原因进行了分析。结果表明:该弹簧拉应力一侧有较多的腐蚀凹坑,在弹簧服役时,凹坑处萌生了疲劳裂纹,最终诱发弹簧发生多源疲劳断裂。

The leaf spring of a heavy truck broke abnormally during service. The fracture reasons of the spring were analyzed by means of macroscopic observation, chemical composition analysis, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that there were many corrosion pits on the tensile stress side of the spring, and fatigue cracks were initiated in the pits during the service of the spring, which eventually induced the multi-source fatigue fracture of the spring.