等离子弧−MIG焊丝振荡式复合焊接工艺

PAW−MIG wire oscillating hybrid welding technology

针对现有的等离子弧-MIG复合焊接过程中的双弧排斥问题,基于MIG焊丝位移规律性改变提出了一种新型的MIG焊丝振荡与等离子弧共熔池的复合焊接工艺.通过调节MIG焊丝电机转速(振荡频率)和振荡振幅进行了焊接工艺试验.结果表明,随着电机转速(振荡频率0~41 Hz)的增加,等离子弧与MIG电弧排斥减弱,耦合趋势增大.尤其是电机转速为2000 r/min(振荡频率33 Hz)时,共熔池复合焊接效果较好;MIG焊炬振荡振幅为1 mm时,电弧形状最为稳定,但振荡频率和振荡振幅过大均不利于焊接过程稳定性;MIG焊炬振荡提高了熔滴过渡频率,使焊丝尖部呈现小熔滴过渡,减小了焊接飞溅.对接试验力学性能测试表明,抗拉强度、抗弯强度均随振荡频率的提高呈现先增大后减小趋势,分析认为MIG焊炬振荡具有一定搅拌熔池的作用,有效提高了焊接接头的力学性能.

In order to solve the problem of double arc repulsion in the existing PAW−MIG hybrid welding process,a new welding process based on the regular change of MIG wire displacement was proposed,which combined MIG wire oscillation with plasma arc in common weld pool.The welding process test was carried out by adjusting the rotation(oscillation frequency)and amplitude of MIG welding wire motor.The results show that with the increase of rotational speed(oscillation frequency),the repulsion between plasma arc and MIG arc decreases and the coupling trend increases.Especially when the rotational speed is 2000 r/min(oscillation frequency 33 Hz),the common weld pool effect is obvious.When the amplitude of MIG torch is 1 mm,the arc shape is the most stable.When the oscillation frequency and amplitude are too large,it is not conducive to the stability of welding process.The oscillation speeds up the droplet transition frequency so that the tip of the welding wire presents a small droplet transition and reduces the welding splash.The mechanical properties of the butt test show that the tensile strength and bending strength increase first and then decrease with the increase of the oscillation frequency.The oscillation enhances the stirring ability of the molten pool metal and effectively improves the mechanical properties of the welded joint.