| With the development of the society, the field of high-efficient welding has become an important direction of welding subject. In order to improve the welding speed greatly, twin-wire or multi-wire gas metal arc welding technologies are adopted to maintain the heat input unchanged in order to improve welding speed. Multi-wire welding technology could overcome the disadvantage of single-electrode high speed welding, because more liquid metal are deposited into the weld pool. The welding efficiency is improved with higher melting speed and deposition efficiency. However, the arc interference induced by the electromagnetic force occurred during the multi-wire welding process may lead to the welding process became unstable, and so on.In this paper, triple-wire automatic welding systems, data acquisition and analysis systems, and high-speed camera system has established a complete set of triple-wire GMAW welding test platform. Analysis the triple-wire GMAW welding process, the electrical signal, the arc shape, the morphology of the metal transfer,focus on the multi-wire welding arc interference ,and the analysis of multi-wire welding point changes.Increasing the T-arc in the single-wire welding (M-arc) process,acquisiting double-arc signals, taking M-arc droplet transfer and arc shape, calculated M-arc arc parameters ( length, width, area) and wire dry extension using Labview, Measuring M-arcwire feed speed changes using tachometer. After analysis of the wire increases, M-arc shape, droplet shape, wire dry extension changes. And research center in a single wire arc (M-arc) welding process stability, while increasing the L-arc and T-arc, comparative analysis of the effect of M-arc droplet on L-arc and T-arc arc. In the single-wire welding process, arc showing the basic cone.With the current increases, the arc brightness is also larger, in the current up to 300A, the arc more stable, showing a more complete bell-shaped. In the single-wire welding, as the current increases, the metal transfer from the big drop to the exclusion of transition changes in the current reaches a certain value, the formation of potential arc transition. According to the minimum-voltage-principle, subject to an additional heat source in heating, expansion of the arc will make the electric field strength E to keep the minimum, so, in a single wire (M-arc) welding process stability, increased a arc, M arc increases the arc length and area. Since the heating effect of the adjacent arc, making the M-arc thermal resistance decreases, the corresponding reduced wire dry extension, double-welded wire to the steady state, M arc welding point has changed.In addition, a single wire (M-arc) welding process stability, increased L-arc and T-arc arc,to achieve three wire welding, the distribution of three-wire current and voltage stability of the arc, in the three wire (L , M, T) arc current distribution, welding stability IL> IT than IL <IT. When the Triple-wire current and voltage is the same, broken arc obvious. The arc in the guide and follow the arc current is constant, with the middle of the arc current increases, the middle arc metal transfer from the big drop to the exclusion of transition, and then to the semi-submersible submarine arc-arc transition and transformation; and there a critical value of M arc current IM0, when the IM <IM0, increasing IM, raised pool gradually move from near the root of L-arc to M-arc;When IM> IM0, the raised pool gathering area disappear.Finally, the study of the energy conditions in the same line, a single, double, three wire welding seam forming and welding efficiency. Found that odd and even three-wire, weld coefficient increased gradually, over a high coefficient decreases; at the same speed conditions, the line the greater the energy, the smaller form factor of the weld; remain single, double, triple-wire welding speed of 1:2:3, single, double, three-wire weld coefficient increases, more than a high coefficient decreases, the welding efficiency increases. |
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