A welding device for gas shielded arc welding includes: a portable welding robot mounted with a welding torch including a nozzle that guides jetting of shielding gas and a contact tip that performs energization on a consumable electrode; a feeding device that supplies the consumable electrode to the welding torch; a welding power source that supplies electric power to the consumable electrode via the contact tip; a gas supply source that supplies the shielding gas to be jetted from a nozzle end; and a control device that controls the portable welding robot. When the welding torch is seen from a side of jetting of the shielding gas, the contact tip is placed in an inside of an opening of the nozzle, the nozzle and the contact tip have a relatively movable structure, and an inner diameter of the nozzle end is within a range of 10-20 mm.

A system and method of welding or additive manufacturing is provided where at least two welding electrodes are provided to and passed through a two separate orifices on a single contact tip and a welding waveform is provided to the electrodes through the contact tip to weld simultaneously with both electrodes, where a bridge droplet is formed between the electrodes and then transferred to the puddle.

In a consumable electrode-type arc welding in which pulse welding and short-circuit welding are alternately repeated, a welding current is controlled such that a welding current immediately before shifting from the pulse welding to the short-circuit welding is lower than a base current in a pulse.

A gas-shielded arc welding method includes feeding a consumable electrode via a welding torch and performing welding while flowing a shielding gas. The welding torch includes a nozzle. An inner diameter of the nozzle is 15 mm or more. A nozzle-base material distance between a tip of the nozzle and a material to be welded is 22 mm or less. A ratio expressed by (the inner diameter of the nozzle/the nozzle-base material distance) is 0.7 or more and 1.9 or less.

A welding system includes a power source configured to generate power and deliver the power to a welding torch. The power is provided in accordance with an electrode negative pulse welding regime that includes a cyclic peak, followed by a stabilization phase, then a return to a background level. The stabilization phase has a generally parabolic current shape, and is performed in a current-closed loop manner until a transition point, where control becomes voltage-closed loop until the background level is reached. Resulting weld performance is improved, with a globular-like transfer mode, reduced shorts and enhanced arc stability.

A welding system includes a power source configured to generate power and deliver the power to a welding torch. The power is provided in accordance with an electrode negative pulse welding regime that includes a cyclic peak, followed by a stabilization phase, then a return to a background level. The stabilization phase has a generally parabolic current shape, and is performed in a current-closed loop manner until a transition point, where control becomes voltage-closed loop until the background level is reached. Resulting weld performance is improved, with a globular-like transfer mode, reduced shorts and enhanced arc stability.

A welding system includes a feeder that advances a self-shielded flux-cored welding electrode toward a weld puddle. A power supply provides a welding output to the electrode to generate an arc, and a controller controls the welding output. The controller controls the power supply to provide a background welding output to the electrode before a shorting event between the electrode and a workpiece is detected. The controller monitors the welding output to detect both the shorting event and the clearance thereof. Upon detecting clearance of the short, the controller automatically switches the welding output to a minimum magnitude fixed current welding output. After the predetermined duration, the controller automatically switches the welding output from the minimum magnitude fixed current welding output back to the background welding output until another shorting event is detected.

An example method of controlling a short circuit welding process includes: setting a heat target for at least a portion of a short state; monitoring output parameters during the short state; calculating a measured heat from the measured output parameters; comparing the measured heat and the heat target; adjusting a pinch current in a subsequent short state in response to at least one comparing from at least one previous short state; and repeating these actions.

A system and method of welding or additive manufacturing is provided where at least two welding electrodes are provided to and passed through a two separate orifices on a single contact tip and a welding waveform is provided to the electrodes through the contact tip to weld simultaneously with both electrodes, where a bridge droplet is formed between the electrodes and then transferred to the puddle.

A welding or additive manufacturing power supply includes output circuitry configured to generate a welding waveform, a current sensor for measuring a welding current generated by the output circuitry, a voltage sensor for measuring an output voltage of the welding waveform, and a controller operatively connected to the output circuitry to control the welding waveform, and operatively connected to the current sensor and the voltage sensor to monitor the welding current and the output voltage. A portion of welding waveform includes a controlled change in current from a first level to a second level different from the first level. The controller is configured to determine a circuit inductance from the output voltage and the controlled change in current, and further determine a change in resistance of a consumable electrode in real time based on the circuit inductance.