弹簧钢60Si2Mn疲劳试验断裂分析

对60Si2Mn弹簧钢进行了疲劳寿命试验.试验结果表明,疲劳寿命较低,未达到标准要求(不低于20万次).采用化学成分检测、断口扫描观察、能谱分析和金相检验等方法,对疲劳试验中断裂弹簧进行了分析、检测.分析结果表明,钢丝表面微裂纹是导致弹簧疲劳断裂的直接原因,该裂纹是由于母材表面存在轧制缺陷,经过拉拔表面产生硬化组织,由...

Fracture analysis of 60Si2Mn spring steel in fatigue test

The fatigue life test of 60Si2Mn spring steel was conducted. The experimental results showed that the fatigue life was relatively short, which could not meet the standard requirements (≥2×105times). The fractured spring in fatigue test was analyzed and detected by the means of chemical composition analysis, fracture observation, energy spectrum analysis and metallographic examination. The results showed that the microcrack on the surface of steel wire was the direct reason to cause spring fatigue fracture. The microcrack was caused by the rolling defects on the surface of base metal. The hardened tissue was formed on surface after drawing and the microcrack was generated due to the insufficient ductility. Supersize inclusions existed near the surface of steel wire. They were typical foreign macroscopic inclusions in continuous casting process, which accelerated the spring fatigue fracture indirectly.