某350MW汽轮机高压叶片断裂失效分析  

Analysis on Fracture Causes of Turbine Blades in a Power Plant

作　　者：范念青[1] 赖云亭[1] 杨路宽 唐敏锦 FAN Nian-qing;LAI Yun-ting;YANG Lu-kuan;TANG Min-jin(Suzhou Nuclear Power Research Institute,Suzhou 215004,China)

机构地区：[1]苏州热工研究院有限公司,苏州215004

出　　处：《汽轮机技术》2023年第3期237-240,共4页Turbine Technology

摘　　要：对某电厂350MW汽轮机断裂的高压叶片及相邻叶片(材料22Cr12NiWMoV)进行宏观形貌、化学成分、金相组织以及扫描电镜和元素能谱分析,结果表明,叶片材质满足技术规范要求,且无明显腐蚀现象;对失效叶片的仿真计算表明,叶片在正常情况下应力及振动特性符合要求。失效叶片裂纹源处的磨损特征表明叶片可能存在松动的问题。叶片在某松动条件下的仿真表明,松动叶片的频率将大幅下降,并可能落入危险共振频率区域,该叶片将发生高频扭转振动,振动传递至叶根处,造成叶片的疲劳断裂。The blade is the core component of steam turbine for a power plants,which may cause large economic losses after failure.Failure analysis of high pressure blades for a 350MW power plant,which is at the same stage with the cracking high pressure blades,was conducted by macroscopic and metallographic observations,chemical composition analysis,as well as SEM examination with EDAX analysis.The result shows that the blade material meets the requirements of technical specifications,and no obvious corrosion phenomenon.The simulation results show that the blade vibration characteristics meet the requirements.The wear characteristics at the crack source of the failed blade indicate that the blade may be loosened.The simulation calculation of the blade under a certain loosening condition shows the decrease of blade frequency and the occurrence of high frequency vibration,and the vibration is transmitted to the blade root to complete the fatigue fracture of the blade.

关 键 词：汽轮机 高压叶片 22Cr12NiWMoV 断裂 振动特性 

分 类 号：TK267[动力工程及工程热物理—动力机械及工程]