核电厂小支管焊缝失效原因分析
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摘要
根据国内外核电厂运行经验反馈,小支管在高振动、应力腐蚀等原因的影响易造成与母管连接处的焊缝失效,发生管内液体泄漏、管内压力降低等风险,进而可能影响机组运行。本文以某核电一回路流量负压腔根阀前焊缝缺陷处理为例,通过对焊缝裂纹观察、金相组织、成分、应力等方面进行分析,得出小支管焊缝失效的主要原因,并提出改进建议,为其他核电厂小支管焊缝失效原因分析及处理提供参考。
According to the operation experience of domestic and foreign nuclear power plants.The influence of small branch pipe on high vibration,stress corrosion and other reasons may easily lead to the failure of the weld at the junction with the master pipe. It will be liquid leakage in the pipe,pressure reduction in the pipe and other risks. It may affect the operation of nuclear power units. In this paper,the treatment of weld defect before a negative pressure cavity valve for a nuclear power plant has been taken as example. Through the analysis of weld crack observation,metallographic structure,composition,stress and other aspects. Find the main causes of failure of small branch pipe weld and propose improvement suggestions. It provides a reference for the failure analysis and treatment of small branch pipe weld in other nuclear power plants.
According to the operation experience of domestic and foreign nuclear power plants.The influence of small branch pipe on high vibration,stress corrosion and other reasons may easily lead to the failure of the weld at the junction with the master pipe. It will be liquid leakage in the pipe,pressure reduction in the pipe and other risks. It may affect the operation of nuclear power units. In this paper,the treatment of weld defect before a negative pressure cavity valve for a nuclear power plant has been taken as example. Through the analysis of weld crack observation,metallographic structure,composition,stress and other aspects. Find the main causes of failure of small branch pipe weld and propose improvement suggestions. It provides a reference for the failure analysis and treatment of small branch pipe weld in other nuclear power plants.
引文
[1]邵震,程晓文,乐宇.核反应堆主管道负压腔根阀焊缝缺陷分析及处理[J].中国核科学技术进展报告(第五卷),2017(10).