摘要
针对汽轮机转子轴颈易损伤的问题,采用2kW半导体激光器进行同轴送粉的激光再制造Fe基合金试验,以提升其表面性能,解决失效问题;采用显微硬度计、气蚀装置与残余应力分析仪分别测试了再制造层的显微硬度、抗气蚀性能与残余应力。结果表明,再制造层最高显微硬度为359HV0.2,平均显微硬度为353HV0.2,较基体提高20%,再制造层的抗气蚀性能较基体提高了3倍以上。再制造层的表层两端的残余应力为压应力,中部为拉应力,从基体到热影响区逐渐升高;沿层深由再制造层至热影响区,残余压应力先转变为拉应力,再转变为压应力。另外由实验数据依据弹性力学的叠加原理,提出了确定再制造层残余应力的反推法。
In order to enhance the surface properties and solve the failure problem,Fe-based alloy remanufacturing experiment was performed on steam turbine rotor shaft journal by a 2kW diode laser with coaxial powder feeder.The microhardness,resistance cavitation property and residual stress of the laser remanufacturing layer were examined by the microhardness tester,experimental device for cavitation erosion and residual stress analyzer.The results show that the highest microhardness of remanufacturing layer is about 359HV0.2,and the average microhardness is 353HV0.2,compared with the substrate,which is increased by 20%.The resistance cavitation property of the laser remanufacturing layer is 3times more than that of the substrate.The residual stress in the both ends of surface remanufacturing layer is compressive stress and in the middle is tensile stress.The value of residual stress from substrate to heat affected zone is slowly increased.Along the depth of the layer to the heat affected zone,the residual compressive stress is changed into tensile stress,and then transformed into compressive stress.According to the superposition principle of elastic mechanics based on experimental data,a method for determining the residual stress of remanufacturing layer is proposed.
出处
《应用激光》
CSCD
北大核心
2016年第2期131-135,共5页
Applied Laser
基金
郑州市科技计划项目(项目编号:20150483)
河南省高等学校重点科研项目(项目编号:15A460038)
关键词
激光再制造
半导体激光器
铁基合金
抗气蚀性能
汽轮机转子轴
残余应力
laser remanufacturing
diode laser
Fe-based alloy
cavitation resistance property
shaft of steam turbine rotor
residual stress
