60Si2MnA钢弹簧断裂失效分析

Fracture failure analysis of 60Si2MnA spring steel

某公司使用60Si2MnA钢制造车用螺旋压缩弹簧,在装配过程中出现弹簧断裂现象。采用宏观检验、化学成分分析、金相检验和扫描电镜分析等方法对弹簧断裂原因进行了分析。结果表明：整个弹簧断面均为沿晶断裂形貌,造成弹簧断裂的主要原因是原材料（圆钢）存在表面裂纹缺陷,同时弹簧原始组织存在过热现象,一定程度上引起了晶界弱化,对其断裂具有促进作用。

A company used 60 Si2 MnA steel to manufacture the spiral compression spring for vehicles,and the spring fracture occurred during the assembly process. The causes of spring fracture were analyzed by macroscopic test,chemical composition analysis,metallographic examination and scanning electron microscope analysis. The results showed that the whole section of spring was the intergranular fracture,which was mainly caused by the surface crack defect of raw material（round steel）.The overheating phenomenon of spring original structure led to the weakening of grain boundary to some extent,which could promote its fracture.