低压转子末级叶片开裂原因分析  

Cause Analysis on Cracking of Last Stage Blade of Low Pressure Rotor

作　　者：王智春[1] 蒋楠[1] 李炜丽[1] 

机构地区：[1]国网冀北电力有限公司电力科学研究院(华北电力科学研究院有限责任公司),北京100045

出　　处：《华北电力技术》2015年第7期56-60,共5页North China Electric Power

摘　　要：通过对某300 MW机组末级断裂叶片的宏观断口、理化性能、热处理工艺、结构和受力状态等因素进行系统的分析和研究,发现叶片热处理和高频淬火控制不当引起了叶片过渡区和附近基体区的金相组织不良,过渡区残余应力值较大等问题。提出显微组织不佳、残余应力过大是导致叶片开裂的根本原因。This study has analyzed the macroscopic fracture, physical and chemical properties, heat treatment process, structure,force status and other factors of the broken last stage blade of a 300 MW unit. It has been discovered that the adverse microstructure in the transition zone and nearby area of the blades,and high residual stress in the transi- tion zone would appear if heat treatment and high-frequency hardening to these blades were not controlled properly. The poor microstructure and excessive residual stress are regarded as the main factors leading to the crackings of the blades.

关 键 词：末级叶片 断裂 高频淬火 

分 类 号：TK263.3[动力工程及工程热物理—动力机械及工程] TG115.2[金属学及工艺—物理冶金]