Failure Analysis Of Key Components Of Blast Furnace Gas Turbine Rotor

This paper mainly analyzes the failure of the rotor blade,corrosion blade and broken shaft of the Blast Furnace Top Gas Recovery Turbine Unit(TRT).Firstly,the fatigue test is carried out on the TRT moving blade for the first time maintenance using the conventional single point test method to obtain the residual fatigue life of the moving blade.The fatigue curve is obtained based on the life,and the fatigue limit of the 2CR13 material is obtained.The logarithmic fatigue life of the moving blade follows the normal distribution by estimating the maternal parameter method.The fatigue life of the root of the moving blade is studied by the theory of heteroscedastic regression analysis.The S-N curve and the P-S-N curve of the 2Cr13 blade are obtained under logarithmic coordinates.The regression equation provides a reference for obtaining a more accurate fatigue curve of 2CR13 material with a small amount of sample.The median life,dispersion coefficient and safe life of the corresponding stress were obtained by the dispersion coefficient method.The fatigue fracture morphology was observed by SEM and the fracture reason was analyzed.secondly,the typical parts of the worn and corroded blades are sampled,and metallographic samples are prepared and analyzed by spectral analysis,optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive(EDS),microhardness testing and other material analysis methods.The study obtained the typical material characteristics of the blade;then the general cause of the pitting corrosion of the blade was analyzed.Finally,the fracture axis of 45 steel was systematically analyzed from the macroscopic morphology of the fracture and the observation and force analysis of the microstructure.From the macroscopic morphology and microscopic observation of scanning electron microscopy,it can be judged that the fracture property of the broken shaft is torsional fatigue fracture.The material was tested for hardness,and the hardness curve was obtained for metallographic analysis.Then the force analysis of the broken shaft is carried out,and the shear stress safety assessment and the fatigue strength safety factor check are performed on the broken shaft,and corresponding improvement suggestions are put forward.