某烟气轮机叶片断裂原因分析

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.