激光功率对镀Cu-Ni低碳钢/不锈钢焊点性能的影响

为了研究激光功率对不锈钢与铜-镍镀层低碳钢激光焊点性能的影响，采用300W的Nd∶YAG激光器焊接不锈钢与铜-镍镀层低碳钢，用光学显微镜观察焊点并测量尺寸，用万能拉伸试验仪测试焊点结合强度。结果表明，随着激光功率的增加，低碳钢一侧焊点截面的尺寸增加。在焊点边缘原镀层区域附近富集的铜会导致裂纹的产生，而激光功率的变化并不能消除焊点边缘铜的富集。激光功率的增加，焊接模式由热导焊向深熔焊过渡，导致焊点的尺寸显著增加，焊点的结合强度提高。该结果对于研究激光功率对铜镍镀层低碳钢/不锈钢激光点焊是有帮助的。

Effect of laser power on performance of dissimilar joints between Cu-Ni coated low carbon steel and stainless steel

In order to study the effect of laser power on performance of dissimilar lap joints of austenite stainless steel and Cu-Ni coated low carbon steel, Nd∶YAG laser with 300W power was used to weld stainless steel and Cu-Ni coated low carbon steel. Optical microscope was adopted to observe the joint and measure the size of weld spot, and universal tensile machine was used to test the bond strength. The results indicate that the size of cross section of weld spot increases with the increase of laser power. The variation of laser power has no influence on the concentration of copper within weld joint which leads to the formation of weld crack. The increasing laser power leads to the transition of laser welding mode from conduction to keyhole. The transition causes the significant growth of weld size and the improvement of bond strength. The research is useful for studying the influence of laser power on laser welding between Cu-Ni coated low carbon steel and stainless steel.