摘要
某电厂1号、2号机组给水泵汽轮机第3级叶片运行过程中发生了断裂及裂纹故障,经现场勘察、运行数据调查、材料检验断口分析及静强度数值校核后,认为叶片断口开裂性质为微动磨损疲劳断裂。断裂原因是该级叶片叶根和轮盘槽加工装配质量不良及叶片围带接触不佳,叶片振动下传至叶根第一齿工作面处,在交变力作用下背弧侧叶根与轮槽的第一齿接触面处发生周期性分离与接触及往复微小滑移,接触表面层材料晶体滑移、硬化和塑性变形,逐渐产生微动磨损疲劳和显微裂纹,不断扩展并最终断裂。
Fracture and crack failure occurred on the third stage blade of feed pump turbine of unit 1 and unit 2 in a power plant during operation.Field investigation,operation data investigation,material inspection fracture analysis and static strength value verification were carried out.It is considered that the fracture nature of the blade is fretting wear fatigue fracture.The reason for the fracture is that the processing and assembly quality of the blade root and wheel groove was poor,and the blade shroud was not in contact.The vibration of the blade was easy to be transmitted to the working surface of the first tooth of the blade root.With the action of alternating force,the periodic separation,contact and reciprocating micro slip occurred at the first tooth contacting surface of the back arc side blade root and the wheel groove,resulting in crystal sliding,hardening and plastic deformation of the contacting surface layer material,and the formation of fretting wear fatigue and micro-cracks.The cracks continued to expand and eventually fractured.
作者
张永海
谷伟伟
曾立飞
姚强
支德胜
管志伟
张振虎
张晓峰
史志刚
ZHANG Yong-hai;GU Wei-wei;ZENG Li-fei;YAO Qiang;ZHI De-sheng;GUAN Zhi-wei;ZHANG Zhen-hu;ZHANG Xiao-feng;SHI Zhi-gang(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China;Guodian Hami Coal and Electricity Development Co.,Ltd.,Hami 839000,China;Shenzhen Mawan Electric Power Co.,Ltd.,Shenzhen 518054,China)
出处
《汽轮机技术》
北大核心
2020年第6期455-458,461,共5页
Turbine Technology
关键词
给水泵汽轮机
叶片
断裂
微动磨损
疲劳
feed pump steam turbine
blade
fracture
fretting wear
fatigue
