Abstract: In order to increase the short-circuit transfer frequency and reduce the welding spatter, the influence of axial magnetic field on short-circuit transfer was investigated by applying DC and alternating axial magnetic field respectively. The high-speed camera, current and voltage signals and the short-circuit transfer force of droplets under the action of magnetic field were analyzed as well. All results show that the short circuit transition frequency reaches the maximum when the DC magnetic field excitation current takes 4 A. When the AC magnetic field excitation current becomes 9A and the magnetic field frequency reaches 100 Hz, the short circuit transition frequency reaches the maximum, which is basically consistent with the fluctuation frequency of the current-voltage waveform. Appropriate application of magnetic field parameters can effectively promote the necking and disconnection of the liquid bridge, increase the short circuit transition frequency and reduce the spatter.

Key words: short circuit transition, metal argon arc welding, axial magnetic field, force analysis