利用光纤激光-MAG复合焊工艺焊接了14 mm厚的EH36高强钢, 研究了激光功率、焊接速度和焊接电流对焊缝成形的影响, 并分析了优化工艺下焊接接头的组织和性能。结果表明, 随着激光功率的增大, 焊缝的熔深增大, 熔宽基本不变; 随着焊接速率的增大, 焊缝的熔宽减小; 随着焊接电流的增大, 焊缝的熔宽基本不变。最佳焊接工艺下得到的焊缝成形良好且无焊接缺陷存在; 焊缝及热影响区的组织主要由板条马氏体组成; 焊缝金属的硬度大于母材的; 拉伸试样断裂位置在母材; 焊缝横向侧弯试验后, 拉伸面没有出现裂纹; 焊缝冲击试样断面为准解理断口形貌。

The 14 mm thick EH36 high strength steels are welded by the fiber-laser-MAG hybrid welding process. The effects of laser power, welding speed and welding current on the weld formation are investigated and the microstructures and perfomances of welded joint under the optimal process parameters are analyzed. The results show that the weld penetration increases and the weld width is basically unchanged with the increase of laser power. With the increase of welding speed, the weld width decreases and with the increase of welding current, the weld width is basically unchanged. Under the optimal welding process parameters, the weld formation is good and there are no welding defects. The microstructures of the heated affected zone and weld zone are mainly composed of lath martensite. The hardness of weld metal is greater than that of the base metal. The fracture position of the tensile specimen is within the base metal. There are no cracks on the tensile surface after the transverse bending test. The fracture morphology of weld impact specimen is quasi cleavage fracture.