高温高压导气管法兰连接螺栓断裂分析  

Analysis of Fracture Occurred in Connecting Bolts in Flange for High Temperature and High Pressure Gas Pipe

作　　者：刘巍栋 Liu Weidong(Datang Northeast Electric Power Test&Research Institute,Changchun 130012,China)

机构地区：[1]大唐东北电力试验研究院有限公司,吉林长春130102

出　　处：《化工设备与管道》2022年第6期25-27,36,共4页Process Equipment & Piping

摘　　要：某热电机组汽轮机20Cr1Mo1VTiB钢高压导气管螺栓发生断裂失效,通过宏观断口观察、化学成分分析、金相组织分析、硬度检验、常温冲击试验等,对断裂原因进行了综合分析。结果表明,由于制造过程中热加工或热处理工艺不当,导致材料局部存在宏观粗晶组织,螺栓冲击性能较差,不能满足高温、复杂应力工况下的长期服役要求,最终发生脆性断裂。建议加强20Cr1Mo1VTiB(争气2号)以及同系列的20Cr1Mo1VNbTiB(争气1号)螺栓粗晶问题的监督检查,并简述了常用检查方法。The bolt made of 20Cr1Mo1VTiB used in high pressure pipe for steam turbine in thermal power plant was fractured.With the measures of macro fracture observation,chemical composition analysis,metallographic structure analysis,hardness test,and impact test at normal atmospheric temperature,the cause of fracture was comprehensively analyzed.It was shown from the results that due to inappropriate heat machining and treatment processes in manufacture,there is local coarse-grained structure in the material,which made the bolt have poor impact property and cannot reach the requirements for working in high temperature and in the service for long term,so that brittle fracture finally occurred.Thus,it was proposed to strengthen the examination of the problem of coarse grain existed in the bolts made of 20Cr1Mo1VTiB and 20Cr1Mo1VNbTiB,and at the same times,the common examining method was presented.

关 键 词：20Cr1Mo1VTiB钢 高温螺栓 脆性断裂 粗晶 检验方法 

分 类 号：TQ050.3[化学工程] TH122[机械工程—机械设计及理论]