钢/铝线冲击焊电流参数对引弧和飞溅的影响

Effect of Current Parameters on Arc Striking and Spatter of Steel and Aluminum Wires during Percussive Welding

利用精密高频逆变冲击焊机进行了钢/铝异种金属线对接冲击焊试验,采集焊接过程的电流信号,并使用高速摄像技术对引弧过程和焊接飞溅进行了研究,分析了焊接电流参数对焊点形貌和抗拉载荷的影响。结果表明,随线圈电流增大,引弧时刻提前,缓升阶梯模式下引弧瞬间电流减小,同时引弧电流上升速度较慢,容易出现引弧失败;三段阶梯模式则不受影响,因为其引弧电流较大,上升速度快,电场较强,能够快速引弧。焊接过程中燃弧间距不足易导致熔滴短路进而爆炸飞溅。增大电磁线圈电流能抑制弹片的回弹幅度,保证燃弧间距,进而减少飞溅的发生。在三段阶梯电流模式下,调整线圈电流为14.5A,减少了焊接过程引弧失败和飞溅现象,获得形貌良好和抗拉载荷稳定的焊点。

The percussive welding experiments of steel and aluminum wires were carried out by using high-frequency inverter power supply.Collecting the welding process current signal and using high-speed photography to study the arc striking process and the welding spatter,and the effects of welding current parameters on the morphology and tensile load of the welding spots were analyzed.The results show that with the increase of the coil current,the arc striking time is advanced,under the slow rising step current mode,the instant current of arc striking decreases,meanwhile the current rising rate is slow,and the failure of arc striking is easy to occur.But the three-stage current mode is not affected,because its arc striking current is large,the rising rate is fast,and the electric field is strong,it can strike the arc quickly.The insufficient arc spacing during welding is more likely to cause short-circuit,explosion and splash of molten droplets.Increasing the current of electromagnetic coil can inhibit amplitude of shrapnel to ensure the arc spacing and reduce the occurrence of splash.Under the three-stage step current mode,adjusting the coil current to 14.5 A can reduce arc failure and spatter in the welding process,and obtain welding spot with good morphology and stable tensile load.