FRACTURE ANALYSIS OF ROTATING BLADES FOR A FLUE GAS TURBINE
烟气轮机动叶片失效分析

The topography,chemical composition and micro structure of one of the fractured totating blades for a flue gas turbine were investigated by SEM/EDAX and metallography.It was shown that the blade underwent severe internal sulphidation along grain boundaries,and simultaneously increase of local stress.The sulphidation and local stress gave rise to the generation of cracks in the blade.The further sulphidation and the concentrated stress partly due to vibration and temperature difference between the blade and turntable accelerated the crack propagation,eventually resulting in the fracture of the blades.