火电机组阀门用410阀杆失效分析

Failure Analysis of 410 Valve Stem for Thermal Power Unit Valve

阀门是火电项目机组中非常重要的核心设备,阀杆失效会使阀门无法正常工作,可能会导致机组非正常停机并引发安全事故。通过采用有限元模拟和理化检测的方法,针对火电机组主蒸汽阀用410不锈钢阀杆的断裂进行了失效分析并提出改进措施,结果表明,该失效是由于闸阀电动执行机构设置不当和阀杆退刀槽处应力集中导致的。通过改进阀杆结构并对阀杆增加渗氮处理工艺,可改善阀杆应力分布,提高阀杆表面硬度和耐磨性能。

The valve is a very important core equipment in the thermal power plant,valve stem failure will make the valve can not work properly,which may lead to abnormal unit shutdown and cause safety accidents.By using finite element simulation and physical and chemical testing methods,failure analysis and improvement measures were proposed for the fracture of 410 stainless steel stem for the main steam valve of the thermal power unit.The results of the analysis showed that the failure was caused by improper setting of the electric actuator of the gate valve and stress concentration at the retraction groove of the stem.By improving the stem structure and adding nitriding treatment to the stem,the stress distribution of the stem can be improved and the surface hardness and wear resistance can be increased.