旁路分流双面电弧焊耦合电弧形态及电弧压力测量

建立旁路分流MIG-TIG双面电弧焊接试验系统,利用高速摄像机拍摄电弧形态,采用"小孔快速起弧法"测量施加旁路分流前后的电弧压力分布.结果表明,施加旁路分流后,由于洛仑兹力的作用,耦合电弧的体积膨胀,电弧形态由原来的发散状变为"钟罩"形,沿弧长方向电弧截面直径变化梯度减小.与单独MIG焊电弧相比,由于耦合电弧形状的改变,导致耦合电弧压力整体显著降低,电弧中心的压力峰值仅为单独MIG焊电弧的29.4%,压力分布更加均匀,使得焊缝成形均匀美观,接头质量明显改善.

Couplingarc shape and pressure of bypass-current double-sided arc welding

An experimental system of bypass-current MIG-TIG double-sided arc welding was established. A highspeed camera was used to monitor the arc shape, and "orifice-igniting" method was developed to measure the distribution of arc pressure with and without bypass current. Results showed that after the bypass current being added, the coupling arc expands in volume to be bell-shaped and decreases in gradient of arc diameter along the arc length under the action of Lorentz force. Compared with the single MIG arc, the pressure of coupling arc decreases overall and distributes more uniformly. In the arc center, the coupling arc pressure was only 29.4% of the single arc, which leads to uniform weld appearance and improves the welding quality.