双丝工艺在桥梁U肋焊接中的应用研究

Research on the Application of Double Wire Process in Bridge U-rib Welding

桥梁U肋通常采用多台焊机同时作业的方式进行生产,可选用熔化极气保焊机或埋弧焊机,焊接速度一般约为0.4 m/min。采用Tandem双丝焊接工艺进行试验,在保证焊接质量的前提下,焊接速度可提升至1.2 m/min,极大提高了生产效率。试验发现当多套双丝焊接设备同时焊接至U肋末端时,极易出现电弧磁偏吹的现象,影响了U肋末端的焊接熔深、焊缝成形,造成焊接不良。针对该问题开发了一种抑制电弧磁偏吹的控制方法,该方法主要是在脉冲电流的基值阶段增加第二脉冲电流从而提高电弧的抗干扰能力。第二脉冲的峰值电流、峰值时间和个数影响了抑制电弧偏吹的效果,根据第一脉冲基值维持时间计算出第二脉冲的个数并存储在焊机中,第二脉冲峰值电流和峰值时间根据基值反馈电压的变化量进行实时调整。同时研究了双丝焊接工艺中主机和从机何时触发输出第二脉冲,试验发现主机按照焊机中存储的参数触发输出第二脉冲,从机触发第二脉冲的时刻受主机控制,当主机处于脉冲峰值下降阶段时触发从机输出第二脉冲,焊接效果最好。

Bridge U ribs are usually produced by multiple welding machines at the same time,and the melting pole gas weld‐ing machine or submerged arc welding machine can be selected,and the welding speed is generally about 0.4 m/min.This paper uses Tandem double wire welding process for testing,under the premise of ensuring welding quality,the welding speed can be increased to 1.2 m/min,which greatly improves the production efficiency.The test found that when multiple sets of double-wire welding equipment were welded to the end of the U rib at the same time,the phenomenon of arc mag‐netic bias blowing was very easy to occur,which affected the welding penetration and weld formation at the end of the U rib,resulting in poor welding.To solve this problem,a control method to suppress arc bias blowing was developed,which mainly increases the second pulse current in the base value stage of the pulse current to improve the anti-interference ability of the arc.The peak current,peak time and number of the second pulse affect the effect of suppressing arc bias,and the num‐ber of the second pulse is calculated according to the base value maintenance time of the first pulse and stored in the welding machine,and the peak current and peak time of the second pulse are adjusted in real time according to the change of the base value feedback voltage.At the same time,when the main machine and slave trigger the output of the second pulse in the double wire welding process,the test finds that the main machine triggers the output of the second pulse according to the pa‐rameters stored in the welding machine,and the moment when the slave triggers the second pulse is controlled by the host,and when the host is in the pulse peak decline stage,the slave outputs the second pulse,and the welding effect is the best.