The invention discloses a
gas metal arc welding method and a
gas metal arc welding system, and belongs to the field of
gas metal arc welding control. Constant wire feed is adopted, the wire feed rate ranges from 1.5 to 18m / min, a
welding source outputs
pulse current, and the average value of the
pulse current is preset according to the wire feed rate before
welding and is kept unchanged in the
welding process; the
arc voltage Ug is given before welding, a feedback value Uf of the
arc voltage is sampled in real time in the
welding process, and
delta I is equal to the absolute value of k(Uf-Ug), wherein
delta I is regulation current, and k is a proportionality coefficient and ranges from 10 to 100; when the feedback value Uf of the
arc voltage increases,
delta I is subtracted from the
peak value Ip of the
pulse current, and the basic value current Ib is added to delta I to keep the arc
voltage stable; and when the feedback value Uf of the arc
voltage decreases, the adjusting process is reversed. By the
high frequency pulse current, the average value and the effective value of the current are obviously different, so that on the premise that the heat input of a
base metal the heating of a solder wire is not changed basically, the heating of a solder wire is changed, the
melting rate of the solder wire is adjusted and the
arc length is adjusted.