高速CMT焊送丝速度和焊接电流波形参数的优化

在5 m/min的平均送丝速度、1.8 m/min的焊接速度下开展高速CMT焊正交试验，研究焊接工艺参数对焊接过程及焊缝成形的影响，分析高速下焊接过程不稳定的原因. 结果表明，峰值送丝速度、峰值持续时间tp和峰值电流Ip的影响作用依次降低. 焊接工艺参数匹配不合适时(包括焊机的专家参数)，高速焊时频繁发生周期性“粘丝”现象，焊缝成形不均匀、咬边严重. 峰值送丝速度过快、高速下的熔滴后拖和熔池前部金属薄层温度过低是“粘丝”产生的主要原因. 通过合理匹配上述三个参数消除了粘丝并获得良好的焊缝成形.

Optimization of waveform parameters for high speed CMT welding of steel

A series of high speed CMT welding tests were conducted on Q235 steel at a wire feed speed of 5 m/min and a welding speed of 1.8 m/min. The effect of waveform parameters on welding process, weld bead appearance was researched by means of orthogonal test. The causes for unstable welding process at high welding speed were analyzed. The results showed that the wing order: peak wire feed speed, boost current duration (tp) and boost current (Ip). With unsuitable welding parameters (including expert welding parameters in CMT power source), periodic “wire adhesion” phenomenon which led to uneven weld bead appearance and severely undercut occurred frequently in high speed CMT welding. The “wire adhesion” phenomenon was caused by high peak wire feed speed, droplet drag and low temperature of thin liquid metal layer in front of the weld pool. Wire adhesion phenomenon was eliminated and sound weld bead appearance was obtained by properly matching the above three waveform parameters.