气体熔池耦合活性TIG焊接方法是一种新型的活性焊接方法, 该方法采用内外两层气体进行TIG焊, 内层惰性气体保护熔池金属和钨电极, 外层气体引入活性元素O, 使焊缝熔深增加, 并通过调节内外喷嘴的相对位置, 简单方便地调节外层活性气体与熔池表面的耦合度, 实现对焊缝成形和焊缝性能的控制。 外层气体的引入对焊接电弧有着重要的影响, 因此针对气体熔池耦合活性TIG电弧, 采用Boltzmann作图法分析了外层气体为O2时不同耦合度下电弧等离子体的温度分布, 在此基础上研究了电弧电压和电弧形貌的变化规律。 结果表明, 与普通TIG电弧对比, 气体熔池耦合活性TIG焊时, 外层气体引入氧可使电弧略有收缩, 电弧中心温度升高, 同时电弧电压上升; 与内外层气体都为Ar的情况相比, 外层采用O2对电弧的收缩作用更明显。 当耦合度从0增加到2时, 电弧中心温度和电弧电压都略有上升。 在气体熔池耦合活性TIG焊中电弧收缩不明显, 进行不锈钢焊接时熔深显著增加的主要机理不是电弧收缩。

In the present paper, Boltzmann plot method was applied to analyze the temperature distributions of the arc plasma when the gas pool coupled activating TIG welding was at different coupling degrees with the outer gas being O2. Based on this study of temperature distributions, the changing regularities of arc voltage and arc appearance were studied. The result shows that compared with traditional TIG welding, the introduction of O2 makes the welding arc constricted slightly, the temperature of the arc center build up, and the arc voltage increase. When argon being the inner gas, oxygen serving as the outer gas instead of argon makes the arc constricted more obviously. When the coupling degree increases from 0 to 2, the temperature of the arc center and the arc voltage both increase slightly. In the gas pool coupled activating TIG welding the arc is constricted not obviously, and the reason why the weld penetration is improved dramatically in the welding of stainless steel is not arc constriction.