汽轮机调节阀阀杆断裂失效分析  

Fracture Failure Analysis on Valve Stem Cracking of Steam Turbine Regulating Valve

作　　者：房文轩 陈浩[1] 孙云飞 杨晓冬 刘小恺 FANG Wenxuan;CHEN Hao;SUN Yunfei;YANG Xiaodong;LIU Xiaokai(Inner Mongolia Power Research Institute,Hohhot 010020,China;Inner Mongolia Electric Power Survey&Design Institute Co.,Ltd.,Hohhot 010010,China)

机构地区：[1]内蒙古电力科学研究院,呼和浩特010020 [2]内蒙古电力勘测设计院有限责任公司,呼和浩特010010

出　　处：《内蒙古电力技术》2021年第2期48-50,54,共4页Inner Mongolia Electric Power

基　　金：内蒙古电力科学研究院科技项目“基于因子关联技术的电站金属设备大数据分析和可靠性评价研究”(2018-ZC-05)。

摘　　要：某火电机组汽轮机在运行过程中,调节阀阀杆发生断裂故障。利用力学性能测试、金相组织检验、有限元模拟等分析手段进行失效原因研究,结果表明,阀杆的金相组织不佳,铁素体含量偏高,导致材料抗拉强度、屈服强度、冲击吸收能量低于标准要求;且阀杆结构存在设计缺陷,变截面部位未经过圆弧或倒角处理,应力集中严重,裂纹极易萌生、扩展,最终超出承载极限失稳断裂。During the operation of steam turbine of a thermal power unit,the valve stem of regulating valve breaks.Mechanical performance testing,metallographic structure inspection,finite element simulation and other analytical methods are carried out.The results show that the metallographic structure of the valve stem is not good and the ferrite content is high,which leads to the tensile strength,yield strength and impact absorbed energy of the material are lower than the standard.Moreover,there are design defects in the valve stem structure,and the variable section parts have not been treated with arc or chamfer,so the stress concentration is serious,and the cracks are easy to initiate and expand,which finally exceed the bearing limit and destabilize and fracture.

关 键 词：汽轮机调节阀 35CRMO钢 裂纹 疲劳断裂 应力集中 

分 类 号：TK268[动力工程及工程热物理—动力机械及工程]