TIG电弧辅助MIG焊非接触引弧的参数适应性
Parametric adaptability of TIG arc-induced non-contact MIG arc ignition

为了深入了解钨极惰性气体保护（tungsten inert gas，TIG）电弧辅助熔化极惰性气体保护（metal inert gas，MIG）焊实现非接触引弧的特点，以及此种新型引弧方式对MIG焊接参数变化的适应性，该文通过TIG-MIG复合焊的大量引弧试验，利用电信号与电弧图像同步采集系统对此进行了试验研究。试验结果表明：先引燃的TIG电弧不仅能使MIG焊快速可靠地实现非接触引弧，而且能使MIG焊在较低的电压和电流条件下进入稳定的熔滴自由过渡，形成的焊缝规则且无飞溅附着；当MIG焊的初始送丝速度、焊枪倾角、保护气体流量以及焊丝末端直径在一个较大的范围内变化时，MIG焊在TIG电弧的辅助下均能够实现非接触引弧；根据焊丝末端直径匹配合适的初始送丝速度，即使焊丝末端带有较大尺寸的小球，MIG焊在非接触引弧过程中也不会产生焊接飞溅。
Abstract：A series of arc ignition experiments using tungsten inert gas-metal inert gas (TIG-MIG) hybrid welding was conducted for various MIG welding parameters with simultaneous measurements of the arc voltage, the welding current and images of the TIG-MIG hybrid welding arc. These experiments studied the characteristics of the TIG arc-induced non-contact MIG arc ignition and its adaptability to the various MIG welding parameters. The results show that the initial TIG arc not only quickly enables the MIG welding to achieve non-contact arc ignition but also enables the MIG welding to enter a stable droplet-free transfer mode with a relatively low arc voltage and welding current. The weld appearance is more uniform than the conventional MIG welding with no spatter. The initial wire feed speed, welding torch inclination angle, shield gas flow rate and welding wire end diameter for the MIG welding could be varied over relatively wide ranges with non-contact arc ignition of the MIG welding when ignited by the TIG arc. If the initial wire feed speed is properly matched to the welding wire end diameter, no spatter is produced during the non-contact MIG arc ignition process even with large residual droplet on the end of the welding wire.