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为解决大型汽轮机转子轴轴颈磨损的修复问题,基于同轴送粉半导体激光熔覆再制造系统,采用激光熔覆再制造方法,以汽轮机转子轴材料为基体,利用激光熔覆再制造专用粉末作为实验材料,针对不同激光熔覆层宽度对汽轮机转子综合跳动的影响进行实验研究与机理模拟验证。结果表明,综合跳动特性与探头直径和激光熔覆层宽度相关,激光熔覆层宽度决定了汽轮机转子表面磁力线、电涡流密度与磁通量密度分布。当激光再制造层宽度小于8 mm时,由于磁力线与表面电涡流密度受基体的干扰,磁通量密度在激光熔覆层的边缘出现突变,实际综合跳动的测量值为基体与激光熔覆层综合作用的结果,造成测量结果偏大。根据数值模拟计算被测金属体表面磁通量密度分布结果,激光熔覆层宽度的临界值为9.82 mm。
In order to solve the problem of repairing the wear of journal shaft of large turbine rotor shaft, based on the coaxial powder feeding semiconductor laser cladding remanufacturing system, the laser cladding remanufacturing method is adopted, the turbine rotor shaft material is taken as the matrix, laser cladding is used to remanufacture the special powder As an experimental material, the influence of different laser cladding width on the synthetic beating of steam turbine rotor was experimentally studied and its mechanism was verified. The results show that the overall jitter characteristics are related to the diameter of the probe and the width of laser cladding. The width of laser cladding determines the distribution of magnetic flux, eddy current density and magnetic flux density on the surface of turbine rotor. When the width of laser remanufactured layer is less than 8 mm, the magnetic flux density changes suddenly at the edge of the laser cladding due to the disturbance of the eddy current density of the magnetic field lines and the surface by the substrate. The measured value of the actual synthetic beating is the combination of the substrate and the laser cladding The result, resulting in large measurement results. According to the numerical simulation of the magnetic flux density distribution on the surface of the metal body under test, the critical value of the width of the laser cladding layer is 9.82 mm.