Fracture Analysis of 60Si2MnA Spring Rod

Fatigue life test was conducted to 60Si2MnA spring rod.The experimental results show that the fatigue life does not reach the standard requirement.The fracture cause of the spring rod was analyzed by macro and micro observation of fracture surface,metallographic examination,hardness testing,and chemical analysis.The results show that the fracture mode of the spring rod is fatigue fracture resulting from co-effect of bending and twisting,and the fracture surface could be obviously divided into three zones: fatigue source zone,propagation zone and final fracture zone.The results show that the fatigue crack originated from the surface.The poor surface quality of the spring rod is the main cause of the fracture.In addition,the lower fatigue resistance caused by the existence of surface decarburized layer promoted the fracture.