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基于有限元软件SYSWELD平台,建立激光熔凝三维有限元模型,编制宽带热源的FORTRAN子程序,采用不同的工艺参数对42CrMo钢表面的单道激光宽带熔凝区的组织和残余应力进行数值计算与分析.测定了激光熔凝表层的热循环曲线,利用扫描电镜(SEM)观察熔凝区相变.结果表明,工艺参数对熔凝区残余应力分布状态影响较大,激光线能量密度(ρE)过高或过低,均影响熔凝层的表面成型质量;当激光束输出功率为3500 W,扫描速率在600~1000 mm/min时(即ρE=20.9~35.0 J/mm2),熔凝区可获得有利的残余压应力分布.42CrMo钢母材组织为铁素体+珠光体,经激光处理后,熔凝区组织转变生成的马氏体相比例高达95%以上.
Based on the finite element software SYSWELD platform, a three-dimensional finite element model of laser cladding was established, and a FORTRAN subroutine of wideband heat source was programmed. The microstructure and residual stress of single laser wide band fusion zone on 42CrMo steel were numerically calculated by using different process parameters The thermal cycling curve of the laser cladding layer was measured and the phase transition of the melting zone was observed by scanning electron microscopy (SEM) .The results show that the process parameters have a great influence on the residual stress distribution in the melting zone, and the laser energy density (ρE) When the output power of the laser beam is 3500 W and the scanning rate is 600-1000 mm / min (ie ρE = 20.9-35.0 J / mm2), the melting zone And the favorable residual compressive stress distribution can be obtained.42CrMo steel base metal is ferrite + pearlite, after laser treatment, the proportion of martensite phase in the melting zone is up to 95%.