脉冲PAW+缆式七丝焊丝MIG复合焊是一种高效、优质、低耗的新型焊接工艺。焊接时七根焊丝与等离子弧共同作用于熔池。缆式焊丝送进时端部电弧旋转耦合，与脉冲等离子弧的周期性涨缩共同作用形成独特的电弧形态，增强了熔池的流动性，但丝极间电弧相互干扰，影响因素众多，动态行为复杂，其电弧物理作用机制仍不明确。本研究采用数值模拟和试验验证相结合的方法，依据脉冲PAW+缆式七丝焊丝MIG复合焊工艺特点，开展其电弧耦合行为、熔滴过渡与熔池振荡及流体行为的研究，获得焊接规范参数对焊接电弧耦合行为、熔滴过渡和熔池振荡及流体行为的影响规律，继而开展PAW脉冲调制研究，实现对变厚度截面焊接工件的稳定焊接，确立“焊接规范参数-电弧耦合行为-小孔和熔池形态-焊缝成形”之间的相关性。本项目能促进对脉冲PAW+缆式七丝焊丝MIG复合焊接动态过程的全面系统理解，丰富和发展焊接传热传质理论，具有重要的科学意义和实际价值。

Pulse PAW-MIG hybrid welding with cable-type seven wires is a innovative welding process, which has an efficient, high quality and low cost. Seven wires and plasma arc are both acted to the weld pool during welding process. Arc are rotating and coupling at wire tip when the cable type wire is feed, which are acting together with periodic contraction and expansion arc of pulse plasma arc. This unique arc shape can increases the fluidity of molten pool. However, mutual interference exists between the MIG arc and plasma arc. Too many process parameters are existed, and can effect the stability of the arc. The dynamic behavior is very complex. So far, its action physics mechanism remains still unclear. In this project, numerical simulation and experimental verification method are combined. According to process characteristics of the pulse PAW-MIG hybrid welding with cable-type seven wires, the coupled arc behavior, droplet transfer and weld pool oscillation and fluid behavior are studied. The influence rule of welding parameters on the coupled arc behavior, droplet transfer and weld pool oscillation and fluid behavior can be obtain. After that, pulse modulation technique is carried out to weld variable thickness workpiece stablely. The correlation among "welding specification parameters - coupled arc behavior - keyhole and the shape of weld pool – weld formation " is determined. This project can promote comprehensive understanding of the dynamic process of pulse PAW-MIG hybrid welding with cable-type seven wires, and can enrich and develop the physical mechanism of welding heat transfer and mass transfer. Therefore, this research has important scientific significance and practical value.