采用了6 kW光纤激光器, 开展了车身三层搭接钢结构激光飞行焊工艺研究, 阐明了离焦量、焊接速度、焊接功率等主要工艺参数对焊缝熔宽、熔深、结合层宽度及典型缺陷等的影响规律, 建立了三层搭接板激光飞行焊接工艺窗口, 获得了成形良好的焊接接头。在此基础上, 进一步对接头抗拉性能进行分析并与电阻点焊焊接接头的性能进行对比。结果表明, 对于车身三层搭接钢结构, 激光飞行焊接头的最大拉力值达到12.64 kN, 是电阻点焊接头最大拉力值的1.98~2.47倍, 具有显著优势。

Research on laser scanner welding technology of three-layer lapped steel structure of car body was carried out in this paper by 6 kW laser. The influences of defocusing distance, welding speed, welding power on weld width, weld depth, bonding layer width and typical defects were clarified. The process window was established and well-formed welding joints were obtained. On this basis, the tensile strength of the joints were further analyzed and compared with those of the resistance spot welding joint. Results indicate that the maximum tensile strength of the laser scanner welding joints is 12.64 kN, for the triple-layers lap steel structure of the body, which is 1.98~2.47 times of the maximum tensile strength of the resistance spot welding joint, having a significant advantage.