【摘要】 采用不同直流脉冲匹配的tandem焊枪实现了12 mm厚Q235钢共熔池打底焊接，并利用高速图像(HSI)和实时电信号对焊接过程进行实时动态检测，研究了焊接速度对焊缝成形、焊接电弧形态和焊接过程稳定性的影响。结果表明，焊接速度主要对焊缝成形和焊接过程稳定性造成影响，对电弧形态的影响不大。随着焊接速度的增加，电弧稳定性先增大后减小，在焊接速度为40 mm/s时，背部自由成形最佳。不同焊接速度下，主丝电弧都保持较高的挺度，几乎不发生偏移，从丝电弧形态在单个脉冲周期内通过产生9°～15°的规律性摆动，促进熔池中部金属向侧壁流动，减小熔池后端金属的累积，从而消除焊缝表面的驼峰和起脊缺陷，提升了整体光洁度。主丝的焊接稳定性整体高于从丝，当焊接速度为40 mm/s时，两电弧稳定性最好。更多还原

【Abstract】 The 12 mm thick Q235 steel eutectic pool backing welding is realized by using tandem welding torches matched with different DC pulse frequencies. High-speed image(HSI) and real-time electrical signals are used to monitor the welding process in real time. The effects of welding speed on weld formation, arc morphology and welding process stability are studied. The results show that the welding speed mainly affects the weld forming and welding process stability, but has little influence on the arc morphology. With the increase of welding speed, the arc stability increases first and then decreases. When the welding speed reaches 40 mm/s, the best back free forming is achieved. At different welding speeds, the leading wire arc maintains a high stiffness and hardly deviates. The trailing wire arc forms a regular swing of 9°-15° in a single pulse cycle, which promotes the metal in the middle of the molten pool to move to the side. The molten flow reduces the metal accumulation at the rear of the molten pool, thereby eliminating hump and ridge defects on the weld surface and improving the overall finish. The welding stability of the leading wire is generally higher than that of the trailing wire. When the welding speed is 40 mm/s, the stability of the arcs is the best.更多还原