浅析350MW汽轮机低压转子叶片叶根裂纹超声波表面波检测

Analysis on the Ultrasonic Rayleigh Wave Detection of Cracks on the Root of the Blades of the Low-pressure Rotor of 350MW Steam Turbine

某发电厂汽轮机为哈尔滨汽轮机有限公司以300MW汽轮机机组为基础改进生产的N350-16.7/538/538型亚临界、自然循环、一次中间再热、高中压合缸、双缸、双排汽、单轴、反动、凝汽式汽轮机。汽轮机低压转子叶片材质为0Cr17Ni4Cu4Nb。检修过程中采用超声表面波检测低压转子叶片叶根,发现次末级3片叶片的叶根存在裂纹。

The steam turbine of a power plant is the N350-16.7/538/538 type,which is the subcritical,natural circulation,intermediary reheating for the first time,high and medium pressure cylinder,double cylinder,double exhaust steam,single shaft,reverse rotation,condensing steam turbine.It is produced by Harbin Steam Turbine Co.,Ltd.based on 300MW steam turbine units.The low-pressure rotor blades of the steam turbine are made of 0Cr17Ni4Cu4Nb.During the maintenance process,we used the ultrasonic Rayleigh waves to detect the roots of the low-pressure rotor blades.It was found that there were cracks on the root of the blades of the last 3 levels.