脉冲频率对三丝间接电弧焊稳定性的影响

Effect of pulse frequency on the stability of triple-wire indirect arc welding

三丝间接电弧焊是一种新的焊接方法,焊接过程中工件不连接电源,主丝连接焊接电源正极,两边丝分别连接两焊接电源的负极,电弧建立在主丝与两边丝之间.焊丝熔化后主丝与边丝导电距离的变化以及焊丝形成的多条熔滴过渡路径均对建立稳定的焊接过程提出了挑战.文中通过调控脉冲频率,分析了脉冲频率对电弧特性、熔滴过渡路径以及焊接电压和焊接电流分布的影响.结果表明,脉冲频率对三丝间接电弧焊的稳定性影响较大,当脉冲频率大于100 Hz时,才能建立稳定的间接电弧;随着脉冲频率的增加,熔滴过渡路径的数量减少,更有利于形成均一的焊道;随着脉冲频率的增加,焊接电压和焊接电流变异系数减小,焊接电流和焊接电压的波动程度减小,三丝间接电弧焊的稳定性提高.

Triple-wire indirect arc welding is a new welding method.During the welding process,the workpiece is not connected to the power source,the main wire is connected to the positive electrode of the welding power source,and the two side wires are connected to the negative electrode of the two welding power sources respectively.The arc is establishedbetween the main wire and the two side wires.The melting of the welding wire leads to the change of the conductive distance between the main wire and the side wire,and the multiple droplet transfer paths formed by the welding wire which pose a challenge to establishing a stable welding process.In this paper,by adjusting the pulse frequency,the influence of pulse frequency on arc characteristics,droplet transfer path,welding voltage and welding current distribution is analyzed.The results show that the pulse frequency has a greater impact on the stability of triple-wire indirect arc welding.When the pulse frequency is greater than 100 Hz,a stable indirect arc can be established.As the pulse frequency increases,the droplet transfer path decreases,which is more conducive to forming a uniform weld bead.As the increase of pulse frequency,the variation coefficient of welding voltage and welding current decreases,the fluctuation degree of welding current and welding voltage decreases,and the stability of three-wire indirect arc welding improves.