摘要
60Si2MnA钢制弹条进行疲劳寿命试验,未达到规定的疲劳寿命时发生断裂。通过断口宏微观观察、金相组织检查、硬度检测、化学成分检测,对弹条断裂原因进行了分析。结果表明:弹条断裂性质为弯曲-扭转疲劳断裂,其断口明显分成疲劳源区、扩展区和瞬断区3个区域,疲劳源区位于弹条表面;弹条断裂主要原因与弹条表面质量差有关,弹条表层存在脱碳层导致弹条抗疲劳性能降低,也是弹条疲劳断裂的又一原因。
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.
出处
《失效分析与预防》
2011年第2期90-93,123,共5页
Failure Analysis and Prevention
关键词
弹条
疲劳断裂
表面质量
脱碳层
spring rod
fatigue fracture
surface quality
decarburized layer
