具有稳定熔滴过渡过程的单丝大电流 GMAW(熔化极气体保护焊)焊接方法拥 有其他高效 GMAW 焊接方法不可取代的优势． 通过采集大电流 GMAW 的熔滴过渡高速 摄像和焊接电流电压信号，对比分析了大电流 MIG(熔化极惰性气体保护焊)和 MAG(熔 化极活性气体保护焊)焊接过程中不同的熔滴过渡行为，分析了焊接电流和保护气体成 分对熔滴过渡频率的影响． 结果表明:大电流 MIG 焊接熔滴过渡形式为单一的旋转射流 过渡，且旋转频率随着焊接电流的增大先减小后增大;大电流 MAG 焊接熔滴过渡形式为 摆动和旋转射流混合过渡，且摆动过渡频率会因为液流束与熔池接触短路而增大;外加磁 场能够改变大电流 GMAW 液流束和电弧的旋转方向，减小旋转角度，这一发现为 400 A 以上稳定单丝高效 GMAW 焊接工艺的研发提供了新思路．

Single wire high-current GMAW welding methods with steady metal transfer processes has irreplaceable advan- tages over other high-efficiency GMAW welding methods． Based on the high-speed photography and electric signals se- lecting technology in metal transfer process of GMAW，the differences between MIG and MAG welding were discussed， and the impacts of current or shielding gas constitution on transfer frequency were highlighted． The results indicate that metal transfer style of high-current MIG welding is rotating spray transfer，and the rotating frequency of MIG welding de- crease at first and then increase with the increase of welding current; while in the MAG welding，it becomes a mixing rotating and swing transfer style，and the rotating frequency or swing frequency increases when the flow beam contacts with the weld pool in high current condition． In addition，the external magnetic field can change the rotation direction of large current GMAW flow beam and arc，and reduce the rotation angle． This discovery provides a new idea for the research and development of high efficiency GMAW welding process with single wire over 400A．