MAG焊旋转喷射过渡熔滴运动形态的相关分析

熔滴旋转喷射过渡ＭＡＧ焊是用于钢结构的一种高效焊接方法，在窄间隙焊和角焊缝时还可以克服焊接时侧壁的熔剑不良等缺陷。本文用高速摄影方法拍摄了Ａｒ＋Ｏ２保护气体时旋转喷射过渡的熔滴过渡形态，建立了液尖－液流束运动的相关分析模型，并由此分析讨论了熔滴运动的动态变化过程和旋转参数。结果表明，用本文提出的“相关分析”方法，可以确定液尖与液流束运动的主从关系。在脉冲旋转喷射过渡期间，液尖、液流束均绕焊丝轴线做

Interrelation Analysis of Droplets Moving Morphology of Rotating Spray Transfer in MAG Welding

MAG welding with the droplet rotating spray transfer is a high efficiency welding method used in steel structures. It can also avoid some defects,such as the lack of fusion,when used in narrow gap welds and fillet welds. In this paper, the transfer morphology of the droplets was obtained by means of the high speed camera during MAG welding with Ar+O₂ shielding gas when rotating spray transfer was formed. An interrelation analysis model of the molten metal tip and the liquid metal stream was proposed, and the droplet movement and the corresponding rotating parameters were analyzed with the proposed model. It is shown that the interrelation analysis method suggested in this paper can be used to determine the initiative-passive relation between the molten metal tip and the liquid metal stream. During the pulsed rotating spray transfer, the tip and the stream moved around the wire''s axis, but their rotating speeds were not exactly the same. The rotating radius of the stream was related with the deflection angle of the tip. Besides, it is observed that the movement of the tip played a leading role in the moving system composed of the tip, the stream and the cathode spot, and the cathode spot played a dragging role for the tip and the stream. The unequilibrium forces that acted on the anode spot were the main causes to affect the droplets'' rotating spray transfer.