抄録
Melting characteristics of mild steel, stainless steel and copper alloy wires, are investigated for pulsed or constant current MIG arc using transistor controlled power supply.
Results obtained are summarized as follows;
(1) Wire melting rate in MIG welding is affected by many factors; effective anode melting potential, length and resistance of the electrode wire extension, heat contents of metal droplets and electric current applied.
(2) Wire melting rate in pulsed MIG welding is found to be independent of pulse frequency, and is expressed as a function of average value and effective value of pulsive current applied. Even if the average current is kept constant, melting rate of electrode wire is possible to increase as the effective value of pulsed current becomes higher.
(3) Heat conteut of metal droplets depends on an anode heating of MIG arc and joule's heating in a segment of the electrode wire travelling from the contact tip to the arc.
