系统研究了双光束焊接过程中能量比对焊缝成形以及能量利用率的影响，采用高速摄像技术实时观察了不同能量比下的熔池行为，分析了能量比对双光束焊接特性的影响机制。结果表明，随着能量比增大，双光束焊缝熔深先减小后增大，熔宽变化规律与之相反，并在能量比为50/50时获得最小熔深和最大熔宽。不同能量比下能量利用率差别较大，能量比为20/80和50/50时分别获得最大值32.7%和最小值27.8%。熔池尺寸同样受能量比的影响，随着能量比增大，熔池长度先增大后减小，而宽度一直减小。能量比对双光束焊接特性的影响主要归因于焊接过程中匙孔状态以及熔池流动方式的改变。

Effect of energy ratio on weld formation and energy efficiency in the dual beam welding process was systematically studied. Molten pool behaviors under different energy ratios were observed in real time by the high speed video system. Influence mechanism of the energy ratio on dual beam laser welding characteristics was also revealed. Results show that the weld penetration depth increases and then decreases as the energy ratio increases, while the weld width shows the opposite variation tendency. The minimum penetration depth and maximum width are obtained at the energy ratio of 50/50. Energy efficiency is significantly different from each other with different energy ratios. The maximum energy efficiency is 32.7% at the energy ratio 20/80, while the minimum is 27.8% at the energy ratio 50/50. Molten pool size is also affected by the energy ratio. Molten pool length increases first and then decreases, and the molten pool width always decreases with the increase of energy ratio. The effect of energy ratio on dual beam laser welding characteristics is mainly attributed to the variation of keyhole and molten pool flow pattern in the welding process.