Abstract Fully penetrated keyhole welding process can be achieved by employing the free burning arc in Tungsten Inert Gas (TIG). The interaction between the heat source and weld pool determines the dynamic behaviour of the keyhole and the resultant weld quality. To determine the energy transfer behaviour, in this paper, the dynamic keyhole behaviour was imaged with the vision system when the heat source was changed by adjusting the welding current or welding speed in real time. It was found that (1) keyhole exit positional and dimensional parameters were all changed as a response to the welding speed changing; (2) keyhole exit size parameters changed much faster than the positional parameters did when the welding current was suddenly decreased or increased; (3) a sharp pulse emerged in the position curve of the keyhole exit center point after the welding current was suddenly changed. The behaviour mechanism was analyzed in view of dynamic changing of the force field and heat field in the arc-keyhole-weld pool system.

中文翻译：

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K-TIG焊接过程中的小孔动态热行为

摘要 在钨极惰性气体保护（TIG）中采用自由燃烧电弧可以实现全熔透锁孔焊接工艺。热源和熔池之间的相互作用决定了小孔的动态行为和最终的焊接质量。为了确定能量传递行为，在本文中，通过实时调整焊接电流或焊接速度来改变热源时，使用视觉系统对动态小孔行为进行成像。发现（1）小孔出口位置和尺寸参数都随着焊接速度的变化而变化；(2)焊接电流突然减小或增大时，小孔出口尺寸参数的变化比位置参数变化快得多；(3)突然改变焊接电流后，在小孔出口中心点位置曲线上出现尖脉冲。针对电弧-锁眼-焊池系统中力场和热场的动态变化，分析了其行为机理。