摘   要:等离子弧焊和激光焊及电子束焊并称为高能束焊接，由于其能量密度极高，焊接质量好，应用的范围也越来越广泛。为了进一步提高焊接效率，可采用缆式焊丝送丝来提高熔敷率，相比单丝焊，焊接效率更高。熔滴过渡的方式、频率对焊接过程的影响非常大，因此深入探讨缆式焊丝填充时熔滴过渡的行为及其影响因素，对提高焊接效率具有深远的理论指导意义。

填丝等离子弧焊工艺试验表明，焊接电流对电弧能量密度影响最大，进而影响焊丝的熔化与过渡。随着焊接电流和送丝速度的增加，熔滴过渡频率增大，熔滴尺寸逐渐减小。焊接电流分别为50A、100A、150A、200A时，熔滴过渡周期逐渐缩短，以缆式焊丝填充、送丝速度为0.35m/min为例，过渡周期分别为0.93s、0.67s、0.42s、0.29s。当送丝速度分别为0.3m/min、0.35m/min、0.4m/min、0.45m/min时，以缆式焊丝填充、焊接电流为100A为例，熔滴过渡周期分别为1.02s、0.67s、0.54s、0.42s。

利用FLUENT模拟软件，建立三维数学模型，对熔滴进行受力分析，在不同焊接参数下对单丝填充等离子弧焊熔滴过渡进行了数值模拟表明，送丝速度为0.35m/min时熔滴过渡周期为0.23s，送丝速度为0.4m/min时熔滴过渡周期为0.18s，模拟值与试验值吻合度高。

通过对比缆式焊丝填充和单丝填充等离子弧焊熔滴过渡行为，在相同的送丝速度和焊接电流下，缆式焊丝填充时熔滴过渡频率明显低于单丝填充熔滴过渡频率，熔滴尺寸更大，过渡相对稳定，焊接效率更高。

关键词：缆式焊丝；熔滴过渡；等离子弧焊

Abstract: Plasma arc welding and laser welding and electron beam welding are called high energy beam welding. Because of their high energy density and good welding quality, the application range is more and more extensive. In order to further improve the welding efficiency, cable welding wire can be used to improve the welding rate, compared to single wire welding, welding quality better. We all know that the way of droplet transfer, the frequency of the impact of the welding process is very large, so in-depth discussion of cable welding wire filling droplet transition behavior and its influencing factors, to improve the welding efficiency has far-reaching theoretical significance.

The plasma arc welding process shows that the welding current has the greatest influence on the arc energy density, which affects the melting and transition of the welding wire. With the increase of welding current and wire feeding speed, the droplet transfer frequency increases and the droplet size gradually decreases. When the welding current is 50A, 100A, 150A and 200A respectively, the droplet transfer cycle is shortened and the cable welding speed is 0.35m / min. The transition period is 0.93s, 0.67s, 0.42s, 0.29s. When the wire feeding speed is 0.3m / min, 0.35m / min, 0.4m / min and 0.45m / min, the welding current is 100A as the example, the droplet transfer period is 1.02s, 0.67 S, 0.54s, 0.42s.

The numerical simulation of the droplet transfer of the single filament filled plasma arc welding under different welding parameters was carried out by using the FLUENT simulation software to establish the three-dimensional mathematical model. The results showed that when the wire feeding speed was 0.35m / min, The transition period is 0.23s, the droplet transfer cycle is 0.18s when the wire feed speed is 0.4m / min, and the simulation value is in good agreement with the experimental value.

The droplet transfer frequency was significantly lower than that of the monofilament filling droplet during the same wire feed speed and welding current. The frequency of the droplet was much lower than that of the monofilament filling droplet in the same wire feeding speed and welding current. Drop size is larger, the transition is relatively stable, welding efficiency is higher.