| This paper takes the rotor shaft of large turbogenerator as the research object,aiming at the problem of excessive wear of the bearing journal of the rotor shaft which has existed in the operation of power plant,the laser cladding remanufacturing repair scheme is adopted for processing,and the fatigue life prediction of the rotor shaft after remanufacturing is analyzed.The specific work content is as follows:In order to determine the suitable production process parameters of cladding In625nickel-based alloyed powder on ZG06Cr13Ni4Mo stainless steel plate.A series tests of laser cladding parameters was carried out by response surface analysis.The quantitative analysis of variance was analyzed by using the Response Surface module in Desigh-Expert software.It is concluded that the cladding layer is obviously response to laser power and scanning speed when the powder feeding is constant speed.Because the surface morphology and cross-section quality of multiple overlapping laser cladding samples were detected and qualitatively analyzed by metallographic microscope.The optimal cladding process parameters were determined.(laser power 2000 W,powder feeding 84 g?min-1,scanning speed 5 mm?s-1.)The obtained samples were high qualities under the optimal parameters.And there are smooth surface and no porosity cracks in the cladding layers.Secondly,in order to automate the laser cladding process,the laser scanning path is studied.According to the characteristics of the rotor shaft cladding area,a scanning path based on the equal arc length interpolation method and a scanning path based on the"bow"shape based on the equal distance are proposed.The comparison shows that the former is more in line with actual engineering production requirements.Finally,a three-dimensional model of the damaged rotor shaft and a remanufactured rotor shaft were established for finite element static analysis.It was concluded that the laser cladding repair treatment significantly improved the physical properties of the rotor shaft.Combined with the stress fatigue life theory,Ncode software is used to predict the fatigue life of the remanufactured rotor shaft.the resulting remanufactured life is conservative and reliable. |
