Abstract: Metal deposition rate is increased with reduced energy input in pulsed arc welding with a consumable electrode and a shielding gas mixture of argon, helium and carbon dioxide, the helium content being in the range from about 16% to about 25% and the carbon dioxide content being from about 1% to 4%. The component gases are stored in separate containers until the welding operation during which precisely metered flows of each are entrained by a metering valve and directed to the weld region. Consistently finished welds are produced, on stainless steel, low alloy steels and nickel based alloys as well as other weldable ferrous metals, including during out of position welding operations.

Abstract: Power delivered to the welding arc from a constant current rapid response power supply is controllable to maximize arc stability particularly in out-of-position welding operations. A first control modulates the output current from the power supply between a high value close to the maximum output value and a minimum value just sufficient to maintain the welding arc. The modulation is effected at a given frequency appropriately adjusted in accordance with the electrode material and diameter to maintain optimum spray metal transfer in the welding arc. A further control is effected by pulse width modulating the output from the power supply in accord with a set-in current programmed signal which is compared with a current feedback signal or, alternatively, a set in voltage programmed signal which is compared with a voltage feedback signal. This latter control provides for operation of the power supply in a constant current control mode or alternatively, a constant voltage control mode.

Abstract: A gas-shielded, metal-arc, pulse welding process which comprises establishing an arc with a consumable metal electrode in a gas-shielded environment. A direct current in the range of from about 15 to 80 amps is applied to the electrode and pulsated at a frequency of from about 5000 to 25,000 pulses per second to a first maximum amplitude of from 100 to 125% of the minimum current required to produce a spray transfer of metal from the electrode. The pulsating current applied to the electrode is cyclically increased at a frequency of from about 90 to 400 cycles per second to a second maximum amplitude of from about 150 to 600% of the minimum current required to produce a spray transfer of metal from the electrode and is maintained at the second maximum amplitude for a time within the range of from 5 to 50% of each cycle. The process is particularly applicable to automatic welding processes wherein the weld must be accomplished out-of-position.