某核电厂汽轮机高压调节阀阀杆断裂原因分析  

Causes of Valve Stem Fracture in High Pressure Regulating Valve for a Nuclear Power Plant Steam Turbine

作　　者：杜爱国 杨兴旺[1] 李清泉[1] DU Ai-guo;YANG Xing-wang;LI Qing-quan(Jiangsu Nuclear Power Company,Lianyungang 222042,China)

机构地区：[1]江苏核电有限公司,连云港222042

出　　处：《汽轮机技术》2024年第4期294-298,282,共6页Turbine Technology

摘　　要：某核电厂汽轮机高压调节阀阀杆发生断裂,采用化学成分分析、力学性能分析、金相检验、扫描电镜观察、能谱分析以及力学分析等方法,分析了阀杆断裂的原因。结果表明阀杆断裂失效类型为高周疲劳开裂,阀杆与球头连接焊缝及热影响区硬度偏高,阀杆部分螺纹牙底圆弧半径过小,在阀芯受到汽流冲击引起的振动交变应力作用下,最终导致阀杆断裂。A steam turbine high-pressure regulating valve stem fracture was found in a nuclear power plant.The causes of the valve stem fracture were analyzed using chemical composition analysis,mechanical property analysis,metallographic examination,scanning electron microscope observation,energy spectrum analysis,and mechanical analysis.The results show that the failure type of valve stem fracture is high cycle fatigue cracking,the hardness of heat affected zone of the weld between the valve stem and the ball joint is relatively high,and the arc radius of the thread bottom of the valve stem is too small.Under the action of vibration alternating stress caused by steam flow impact on the valve core,the valve stem fracture is ultimately caused.

关 键 词：阀杆 断裂 高周疲劳 交变应力 振动 

分 类 号：TG174[金属学及工艺—金属表面处理]