Analysis Of Vibration Damping Performance Of Steam Turbine Blade Surface Coating

With the continuous development of the petrochemical industry,the reliability and durability of steam turbine impellers have gradually become the focus of attention,Turbine blades are often damaged by vibrations generated by continuous high-intensity operation.Therefore,the protection of the blade is more important,and a hard coating is added to the blade,Part of the kinetic energy is absorbed through the damping effect of the hard coating,To achieve the purpose of increasing the service life of steam turbine blades.This paper sorts out and derives the energy consumption formula of hard coating.On the mechanical structure of cantilever-like structure,By comparing the size of the energy storage ratio of the hard coating,the damping and damping performance of hard coatings of different materials are compared,Choose a hard coating with better effect.Use UG modeling software to model the turbine wheel,A model of the impeller of the steam turbine with coating is obtained.Import the model into ANSYS to find its first6 natural frequencies,And get the vibration mode diagram.The analysis of the vibration pattern shows that the main deformation of the impeller occurs in the blade.Model the blade and import it into ANSYS to get the Al-Ti film,Al film,Ti film and uncoated blade model.Harmonic response analysis was carried out to obtain data such as the vibration frequency and amplitude of the four specimens after the coating was added under external excitation.Using magnetron sputtering,S304 stainless steel sheet was plated with Al film,Ti film,first Al film and then Ti film.Scanning electron microscopy experiments were carried out on the three test pieces to characterize the micro-morphology of the test pieces.And X-ray polycrystalline powder diffractometer experiment was carried out on the three coated specimens to obtain data such as crystal block size and micro-strain on the coating surface of the specimen.Three-point bending experiment was carried out on the four test pieces through a mechanical dynamic thermal analyzer,The data of the damping loss factors of four test pieces varying with amplitude and frequency are obtained,and the damping performance of the four test pieces is compared.The results show that:In order to increase the service life of steam turbine blades,it is feasible to add a hard coating to the surface of steam turbine blades.All three hard coatings can reduce the vibration amplitude of the blade under external excitation,Among them,the damping performance of Al-Ti film is the best.The research content of this paper has laid a theoretical foundation for the practical application of hard coating vibration reduction technology.