在厚度为 0 .3— 2 .0mm的 5Cr4Mo3SiMnVAl( 0 1 2Al)模具钢和Cr1 2MoV模具钢薄板上 ,采用脉冲Nd :YAG激光进行了激光熔凝实验 ,研究了工艺参数 (脉冲宽度和脉冲频率 )、材质和材料厚度对激光熔凝后熔凝层几何形状特征的影响 ,并用一维解析模型进行了熔化深度的计算。结果表明 :随着脉冲宽度的增加或脉冲频率的减少 ,激光熔凝区的宽度和深度增加 ;Cr1 2MoV模具钢的激光熔化区宽度和深度比 0 1 2Al模具钢的大 ;随着材料厚度的增加 ,激光熔凝区的宽度增加 ,深度减小 ;用一维温度场解析模型进行熔化深度的计算是有效的。激光熔凝工艺参数、材料的热扩散情况和材料的热物性参数的不同是造成上述现象的主要原因 Laser cladding experiments were conducted on 5Cr4Mo3SiMnVA1 (0 1 2Al) die steel and Cr1 2MoV die steel sheets with thickness of 0.3-2.0mm. The effects of process parameters (pulse width and pulse frequency ), The effect of material and material thickness on the geometrical characteristics of the fused layer after laser fusion, and the calculation of the melt depth by one-dimensional analytical model. The results show that the width and depth of the laser melting zone increase with the increase of the pulse width or the decrease of the pulse frequency. The width and depth of laser melting zone of Cr1 2MoV die steel are larger than that of 0 1 2Al die steel. Increase, the width of the laser melting zone increases, the depth decreases; one-dimensional temperature field analytical model for the calculation of the melting depth is effective. Laser welding process parameters, thermal diffusion of materials and material thermal properties of different parameters is the main reason for the above phenomenon