摘 要激光+MIG复合焊接是一种高效率的新型焊接方法。本文采用光纤激光+MIG复合焊工艺在8mm的Q235钢试板上进行堆焊，通过改变光丝间距、离焦量、激光功率等工艺参数，研究各工艺参数对焊缝成形的影响规律；采用高速摄影系统采集熔滴过渡行为，并结合激光+MIG复合焊接的熔滴受力分析，对比分析了焊接工艺参数对焊缝成形的影响规律，试验结果表明：

在高速焊接条件下，相比于单MIG焊，激光+MIG复合焊接更易实现良好的焊缝成形，其焊接过程也较单独MIG焊稳定；激光+MIG复合焊接中，光丝间距是影响焊接稳定性的重要因素之一。光丝间距过大或过小，都会使焊接过程趋于不稳定。在本次试验中，焊接过程稳定的光丝间距为2-4mm。78228

激光+MIG复合焊接的焊缝分为激光区与电弧区，在不同的功率参数中，激光功率对焊缝熔深和熔宽影响最大。在本次试验参数范围内，优化的焊接工艺参数为光丝间距为：2-4mm，离焦量为-3mm。

毕业论文关键词：激光；复合焊接；熔滴过渡行为；焊接稳定性；焊接工艺； 

Abstract Laser MIG hybrid welding is a new welding method for high efficiency。 In this paper, fiber laser + MIG hybrid welding of Q235 steel in 8mm test board surfacing experiment found that in high-speed welding conditions compared to the single MIG welding, laser + MIG hybrid welding easier to achieve a good weld, which the welding process is also more stable MIG welding alone。 High-speed photography system acquisition droplet transfer behavior, and laser hybrid welding +MIG droplet stress analysis to study the stability of the laser hybrid welding arc welding process, HLAW, the light wire spacing affect weld stability one of the important factors。 In the laser power and arc current of these parameters are different, there will be a suitable light wire spacing, it is possible to obtain a good weld and stable welding process。 If the light wire spacing is too large or less, the welding process will tend to be unstable。 In this experiment, a large laser power current most stable light wire spacing of 4mm, small laser power small MIG current most stable light wire spacing of 4mm。

MIG Laser hybrid welding seam zone is pided into laser and arc zone in different power parameters, the laser power is weld penetration and weld width greatest impact parameters。 Optimized parameters: light wire spacing: 2-4mm, defocus amount -3mm。

By changing the light wire spacing, the amount of defocus, laser power and other parameters studied the influence of various process parameters on the weld; while light wire spacing for forming quality welds were studied; + MIG and laser research hybrid welding method for welded joints under mechanical properties and microstructure, laser+MIG hybrid welding joint weld HAZ relatively thick weld zone hardness is generally higher than the base metal。

Keywords：Composite welding; Droplet transfer behavior; Welding stability; Welding proces

目 录

第一章 绪论 1

1。1课题背景 1

1。2激光焊接 4

1。2。1激光焊接的原理 4

1。2。2激光焊接与其他焊接工艺的对比 6

1。3激光+MIG复合焊接 8

1。3。1激光+MIG复合焊接的原理及特点 8

1。3。2激光+MIG复合焊接的发展现状 8

第二章 试验设备，材料与实验方案 9

2。1试验设备 10

2。11激光+MIG焊接系统