The characteristics of weld bead formation and droplet transfer in pulsed gas metal arc weld (GMAW) with different arc lengths were studied by changing the base current time in this work. The results showed that it was easier to cause short circuits and spatters with a short arc. However, the deviation between the deepest point of penetration and the center of bead will be aggravated with the increase of arc length. In addition, more than 90% “one drop per pulse” (ODPP) transfer mode can be obtained when the pulse parameters were selected properly. However, the short arc trended to rise the proportion of “multiple drops per pulse” (MDPP), and the long arc trended towards increasing the proportion of “one drop per multiple pulses” (ODMP). Additionally, with the growth of the arc in the projected transfer zone, the penetration tended to become shallower because of the increase of arc heat dissipation, the fall of arc energy density, and droplet impact force. Overall, the strategy of choosing suitable arc length of pulsed GMAW was summarized: in order to obtain high-quality bead formation and weld joints, a shorter arc in the projected transfer zone was recommended.

中文翻译：

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基于基准电流时间的电弧长度调节对脉冲GMAW中焊缝形成和熔滴转移的影响

通过改变基本电流时间，研究了不同电弧长度的脉冲气体保护金属电弧焊（GMAW）中焊缝的形成和熔滴转移的特性。结果表明，更容易引起短路和带有短电弧的飞溅。但是，随着电弧长度的增加，最深的穿透点和焊缝中心之间的偏差会加剧。此外，如果正确选择脉冲参数，可以获得超过90％的“每脉冲一滴”（ODPP）传输模式。然而，短电弧趋于增加“每脉冲多滴”（MDPP）的比例，而长电弧趋于增加“每多个脉冲一滴”（ODMP）的比例。此外，随着弧形在预计传输区域的增长，由于电弧散热的增加，电弧能量密度的下降和熔滴冲击力的影响，熔深趋于变浅。总体而言，总结了选择合适的脉冲GMAW电弧长度的策略：为了获得高质量的焊缝形成和焊缝，建议在投影传输区中使用较短的电弧。