Submerged arc welding torches and systems to resistively preheat electrode wire are disclosed. A disclosed example submerged arc welding torch includes: a first contact tip configured to transfer weld current and preheating current to the wire; a second contact tip configured to conduct the preheating current to the wire; an air-cooled first conductive body portion configured to receive the weld current and to conduct the weld current and the preheating current to the first contact tip; an air-cooled second conductive body portion configured to receive the preheating current and to conduct the preheating current to the second contact tip; and an insulator coupled between the first and second conductive body portions.

Embodiments of welding systems and methods with coordinated dual power outputs supporting a same welding process or a same AC output process are disclosed. One embodiment of a welding system includes an engine and a generator operatively connected to the engine, where the engine is configured to drive the generator to produce electrical input power. The welding system also includes a power supply operatively connected to the generator and having at least one controller. The power supply is configured to convert the electrical input power to form two power outputs that are coordinated with each other, at least in time, via the controller to support a same welding process. The same welding process may be, for example, a hotwire welding process, a tandem metal inert gas (MIG) welding process, or an alternating current (AC) output process.

A contact tip assembly with a preheating tip comprises a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch. The assembly also includes an electrode preheating circuit configured to provide preheating current through a portion of the welding-type electrode via a second contact tip of the welding torch, and a voltage sense circuit to monitor a voltage drop across the two contact tips, and the electrode preheating circuit adjusts at least one of the first current or the preheating current based on the voltage drop.

The disclosed technology generally relates to welding technologies and more particularly to electrode assemblies for arc welding, e.g., submerged arc welding. In one aspect, an electrode assembly for submerged arc welding comprises a contact tip portion and an extension portion arranged serially and configured to feed a consumable electrode therethrough. During welding, the contact tip portion is disposed to be distal to an arcing tip of the consumable electrode and the extension portion is disposed to be proximal to the arcing tip of the consumable electrode. The extension portion is configured to electrically insulate the consumable electrode from a work piece during welding with a solid insulating material surrounding the consumable electrode.

The disclosed technology relates generally to welding technologies and more particularly to electrode assemblies for arc welding, e.g., submerged arc welding. In one aspect, an electrode assembly for submerged arc welding (SAW), the electrode assembly comprising a head portion comprising a contact nozzle and an extension portion removably and serially attached to the contact nozzle and disposed to be proximal to an arcing tip of a consumable electrode relative to the contact nozzle. The extension portion comprises a ceramic sleeve configured to slidingly feed the consumable electrode therethrough, and a pair of metallic sheaths covering opposing ends of the ceramic sleeve.

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.

An apparatus and system for preheating and removing surface oxidation of welding wire using electric arcs one via one or more tungsten electrodes is disclosed. The preheating and cleaning electric arcs may occur between tungsten electrodes, or between one or more tungsten electrodes and welding wire. Electric arc preheating of welding wire allows increased efficiency and deposition rates.

An additive manufacturing machine that includes a wire supply including a wire drive configured to advance a wire at a wire feed rate and a wire heater configured to apply resistive heating to heat the wire. The additive manufacturing machine includes an additive head for emitting a laser beam to weld the wire to a substrate, a sensor configured to detect a weld parameter, and a controller operatively connected to the wire supply, additive head, and sensor. The controller is configured to determine a failure mode of the weld as the laser beam welds the wire to the substrate based at least in part upon the weld parameter. In response to determining the failure mode, the controller is configured to adjust at least one of the wire feed rate, the resistive heating, and a power of the laser beam as the laser beam welds the wire to stabilize the weld.

A system and method for submerged arc welding. The system advances a consumable welding electrode toward a workpiece, and then stops the advancement when the consumable electrode makes contact with the workpiece. The system provides a preheating current level through the consumable welding electrode proximate the workpiece while the consumable welding electrode is in contact with the workpiece during a preheating period of time to preheat the portion of the consumable welding electrode without establishing an arc. The system then retracts the consumable welding electrode from the workpiece and increases the preheating current level to a welding current level over an arc establishment period of time to establish an arc between the consumable welding electrode and the workpiece. The system then begins to form a weld by advancing the consumable welding electrode toward the workpiece again, resulting in melting the consumable welding electrode and depositing molten metal onto the workpiece.

Welding wire preheating systems and methods are disclosed. An example welding method includes: receiving a signal indicative of initiation of welding process; prior to initiating a welding arc based on the received signal, controlling voltage or current applied to a welding electrode to preheat the electrode to a temperature above an ambient temperature but below a melting point of the welding electrode; monitoring feedback voltage to determine a termination of preheating; and terminating preheating prior to initiating the welding arc in accordance with a welding protocol.