某烟气轮机叶片断裂原因分析

Blades Fracture Failure Analysis of a Certain Flue Gas Turbine

分析了某催化裂化装置烟气轮机动叶片和静叶片的断裂失效原因。通过采用金相组织分析、扫描电镜分析、X射线光电子能谱分析等手段,对动叶片根部被磨损处进行了金相组织和化学成分分析,对动叶片、静叶片以及螺栓的室温、高温硬度进行检测分析,发现动叶片根部磨损不是因催化剂颗粒冲刷造成,而是由静叶片的断裂件磨损所致。静叶片断裂件与动叶片榫齿部位发生严重磨损,导致动叶片过载发生断裂。对静叶片进行了断口组织和化学成分分析,发现静叶片断裂是由于叶片内部金属氧化膜引起。指出改善静叶片铸造工艺、消除铸造缺陷是确保烟气轮机长期安全运行的有效手段。

The fracture failures of the rotor blades and stator blades in the flue gas turbine of a catalytic cracking unit were investigated. The worn surfaces and their compositions on the root of rotor blades were analyzed by means of metallographic structure, scanning electron microscopy,X-ray photoelectron spectroscopy techniques. Combining the hardness data of the rotor blades,stator blades and bolts at room temperature and high temperatures with the composition analysis of the worn surface,it is deduced that the wearing reason of the rotor blade roots is not caused by catalyst particle erosion,but by the broken pieces of the stator blades. By analyzing the microstructure and the composition analysis on the abnormal fractures surface of the broken stator blades,the fracture reason of the stator blade was determined to be caused by the formation of metal oxide film inside the stator blade. It is pointed out that improving the casting technique of the static blade to eliminate casting defection is an effective means to ensure the long-term safe operation of the gas turbine.