42CrMoE制连杆螺栓断裂失效分析  

Failure Analysis on Ruptured Connecting Rod Bolt Made by 42CrMoE

作　　者：吕文涛[1] 钱英豪[1] 赵福兴[1] 许明明[1] 

机构地区：[1]江苏省特种设备安全监督检验研究院苏州分院,江苏苏州215128

出　　处：《热加工工艺》2015年第14期238-240,244,共4页Hot Working Technology

摘　　要：对断裂后的42CrMoE钢制连杆螺栓进行了失效分析,研究了螺栓的冲击功、硬度等力学性能,对其元素组成及含量进行了测定,采用金相显微镜分析其非金属夹杂物含量、显微组织,观察宏观断面形貌,及采用扫描电镜观测断口微观形貌。结果表明,螺栓的硬度及冲击功无明显异常现象,非金属夹杂物含量符合相应国家标准。表层和中层金相组织为回火索氏体、铁素体和下贝氏体,心部金相组织为回火托氏体、回火索氏体、铁素体及下贝氏体,晶粒度均为9~8级;螺栓失效属疲劳断裂,整体显微组织分布不均匀也是导致其断裂的重要原因;The failure analysis of a ruptured connecting rod bolt made by 42 CrMoE was studied, the properties, including impacting energy, and the hardness was studied. The chemical composition was determined. The sonims content and microstructure of the samples was analyzed by microscope. The macro-morphology was observed and the fractography was observed by SEM. The results indicate that the hardness and impacting energy are normal. The sonims contents can meet a criterion. The surface microstructure and microstructure between surface and centre are temper sorbite, ferrite and lower banite. The centre microstructure is temper sorbite, temper troostite, ferrite and lower banite. The grain size is all about rank9-8. The reason for crack is fatigue failure. An important reason for rupturing is the unevenness of microstructure.

关 键 词：42CrMoE 非金属夹杂物 力学性能 显微组织 

分 类 号：TH457[机械工程—机械制造及自动化] TG142[一般工业技术—材料科学与工程]