Metal Transfer Characteristics in Pulsed GMA Welding(Welding Physics, Process & Instrument)
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Metal transfer characteristics of pulsed current GMA welding of mild steel are investigated by using constant current power source with electrode positive polarity. It is shown that stable zone of welding condition in lower current region is widened by using pulse welding. Melting rate of wire is much increased in the pulse welding and its value is calculated in the same manner used for stationary D.C. current welding. Welding condition under that one droplet is formed in higher current phase and detached in the lower current phase is explored and the welding parameter to realize it is systematically determined. It is shown that the duration and amplitude of peak current together with wire feed rate mainly determine the condition and therefore the drop size. Effects of the change in the duration and amplitude in peak current on the condition of one droplet transfer are also investgated. Increase in duration of peak current phase require increase of wire feed rate. The maximum and the minimum sizes of droplet are almost same respectively in the range of peak current of 300-450A. In pulsed MIG welding the detaching of droplet is not so sharp compared with that in pulsed MAG welding. In this case the fluctuation of arc length is so wide that the stable zone of one droplet transfer could not be found in the higher feed rate of wire.
- Transactions of JWRI
Transactions of JWRI 12 (1), 9-17, 1983-08