某60Si2MnA钢片弹簧在使用10 h后出现批量断裂,对断裂片弹簧进行了化学成分分析、硬度测试、金相检验以及断口微观形貌观察,以查明其断裂原因.结果表明:片弹簧断裂是由于在酸洗、电镀过程中析氢反应的发生,使其产生氢脆现象;同时由于热处理工艺过程控制不当,造成组织异常,硬度高于技术要求,加快了其氢脆倾向,最终导致片弹簧在外应力作用下发生氢脆断裂.

Mass fracture appearance happened to 60Si2MnA steel leaf springs after service only for 10 h,and means such as chemical compositions analysis,hardness testing,metallographic examination and micro fracture analysis were used to find out the fracture reasons.The results show that the hydrogen evolution reaction happening in the process of pickling and electroplating made the leaf springs produce hydrogen embrittlement phenomenon.At the same time,the improper heat treatment operations resulted in abnormal microstructure and higher hardness than the technical requirement,which accelerated the hydrogen embrittlement tendency of the leaf springs and eventually led to hydrogen embrittlement fracture under the action of external stress.