摘要
某电厂20Cr1Mo1VNbTiB动平衡连接管法兰螺栓在运行时发生断裂,采用宏观检查、化学成分分析、力学性能试验、金相检验、断口分析以及装配环境检查等方法对失效螺栓进行分析。结果表明,失效螺栓的化学性能及力学性能均符合国家标准,断口裂纹为多源断裂,裂纹为沿晶裂纹,失效螺栓为过载断裂,引起螺栓失效的原因主要为螺栓预紧力过大,导致螺栓长期处于高应力状态,最终产生断裂。
The flange bolt of 20Cr1Mo1VNbTiB dynamic balance connecting pipe in a power plant broke during operation.The failed bolt was analyzed by means of macro inspection,chemical composition analysis,mechanical property test,metallographic inspection,fracture analysis and assembly environment inspection.The results show that the chemical and mechanical properties of the failed bolt conform to the the national standards,fracture cracks are multisource cracks,the cracks are intergranular cracks,the failure bolt is overload fracture.The main reason for bolt failure is that the bolt preload is too large,which leads to the bolt in a high stress state for a long time and finally fracture.
作者
王昊
WANG Hao(Datang Central South Electric Power Test Research Institute,Zhengzhou Henan 450000)
出处
《河南科技》
2021年第19期33-36,共4页
Henan Science and Technology
关键词
螺栓
过载断裂
力学性能
金相检验
bolt
overload fracture
mechanical properties
metallographic examination
