过渡合金层对激光多层堆焊组织性能影响

The Influnece of Transition Alloy Bead Weld by Laser on Microstructure and Property of Bead Welded Layer

采用45钢作为基体材料，在不预热情况下通过增加过渡合金粉堆焊层，再选用专用焊丝进行堆焊试验。由于过渡合金粉中的Ni、Cr提高的奥氏体的稳定性，产生FeNi缓解了高硬度焊丝中碳化物内产生的残余应力，多次堆焊加热使其热应力在该区域得到缓解，减少了裂纹倾向，同时焊丝中的C、V等形成碳化物，因此提高了堆焊层的硬度。

Using 45 steel as matrix material, in the case of no preheating and thickening transition alloy bead welded layer as well as special welding powder, the laser bead welding was investigated. For the reason that Ni and Cr in the transition powder increase stability of austenlte, that FeNi relaxes the residual stress in carbide in high hardness welding wire, that hardness gradient retarded and that multiple-heating for bead welding relax thermal stress, the tendency to crack will be reduced. Meanwhile, C,V in the special welding wire can form carbide, so the hardness of the bead welded layer will be increased.