高频脉冲变极性焊接电源及电弧压力分析

High-frequency pulse modulated variable polarity welding power and its arc pressure

采用变极性和高频脉冲电路叠加,设计了一套变极性和高频脉冲复合电流输出特性的焊接电源,将高频脉冲电弧特性引入变极性焊接过程。建立电弧压力数学模型,结合具体工艺试验,分析了高频脉冲电流对于变极性焊接电弧特性的改善。结果表明,在相等电流有效值的情况下,电弧压力随脉冲频率的提高而增加,高频脉冲电流频率达到5kHz附近时,弧柱区电弧压力较常规直流电弧提高2倍左右,电弧的挺度和能量密度都有所增加,为进一步研究高频脉冲变极性焊接方法在铝合金焊接中的应用提供了理论依据。

A novel variable polarity welding power with high-frequency pulse modulation is designed by means of superimposed circuit, which can produce arc characteristics of high-frequency pulse welding in variable polarity welding process. Based on mathematic model of arc pressure and process experiment, the high-frequency pulsed current can increase arc pressure in a large scale. In the same root-mean-square welding current, the arc pressure with high-frequency (5 kHz) pulsed current increase to 2 times of the normal tungsten inert-gas welding arc, and it helpful for increasing of arc stiffness and energy density. It also provides theoretical proof for further researches on the high-frequency pulse modulated variable polarity welding.