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 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 contact device for a welding apparatus is disclosed. The contact device for feeding current to at least a first welding wire and a second welding wire. The contact device including first and second contact jaws. The first and second contact jaws including a slot formed therein to provide the first and second contact jaws with improved flexibility to individually and independently flex about the first and second welding wires to ensure proper contact is maintained between the contact jaws and the welding wire.

A contact device for feeding current to one or more welding wires in a welding apparatus includes a split tip nozzle having first and second diametrically opposed slots formed therein and a biasing means for supplying an adjustable biasing force to first and second split tips to bias the first and second split tips together to ensure that a desired contact between the split tip nozzle and the one or more welding wires is maintained throughout the lifecycle of the nozzle. The biasing force may be applied by any means including, for example, a compression ring, interaction of tapered surfaces between the tube and the split tip nozzle, a compression or cylinder spring pre-mounted on the first and second split tips, a tensioning screw, etc.

For producing a welded ring, a band having a length corresponding to the circumference of the ring is bent to form a ring and its two ends are welded together. The band ends to be welded together have an offset in the circumferential direction of the ring, the offset lying in the plane of the band. The welding is performed form both lateral edges of the ring from the outside up to the offset. This avoids an overlapping weld of a welding quality that is different at the centre of the ring from that at the edges.

Regulating the feed speed of multiple strips during electroslag strip cladding includes guiding a first strip and a second strip towards a work piece. A current is transferred to at least one of the first strip and the second strip to create a molten slag pool on the work piece sufficient for initiation of a cladding phase. A welding parameter associated with the cladding phase is measured and the first strip is fed towards the molten slag pool at a first variable feed speed based on the measuring of the welding parameter. The second strip is fed towards the molten slag pool at a second variable feed speed that is different from the first variable speed, but dynamically determined based on the first variable feed speed.

The invention relates to a method for submerged arc welding comprising the steps of guiding a first hot wire (4; 4a, 4b) towards a work piece and guiding a cold wire (22; 22a, 22b) at a variable feed speed. The method further comprises the steps of continuously measuring, during a welding phase, at least a first active welding parameter related to at least said first hot wire (4; 4a, 4b) adjusting the cold wire (22; 22a, 22b) feed speed in dependence on at least first active welding parameter variations, to maintain high welding stability and high weld quality. The invention also relates to a system (9) for carrying out the method. The system (9) comprises hot wire feeding means (150) for feeding a first hot wire (4; 4a, 4b) towards a work piece and cold wire feeding means (35) for feeding a cold wire (22; 22a, 22b) at a variable cold wire (22; 22a, 22b) feed speed and a control unit (31) for controlling the second wire feeding means (35). The system (9) also comprises measuring means (27) adapted to continuously measure at least a first active welding parameter related to said first hot wire (4; 4a, 4b). The control unit (31) determines target values for the cold wire (22; 22a, 22b) feed speed, each target value corresponding to a first active welding parameter value and controls said second wire feeding means (35) to adjust said cold wire (22; 22a, 22b) feed speed to said target values.

Embodiments of additive manufacturing systems are disclosed. In one embodiment, an additive manufacturing system includes an array of multiple electrodes for sequentially depositing material layer-by-layer to form a three-dimensional (3D) part. The system includes a power source to provide electrical power for establishing a welding arc for each electrode. The system includes a drive roll to drive each electrode. The system also includes a controller to operate the system at a first deposition rate to form first resolution contour portions of a layer of the part. The controller also operates the system at a second deposition rate to form second resolution fill portions of the layer of the part. The system provides variable width deposition at the second deposition rate using a variable number of the electrodes. The first deposition rate is lower than the second deposition rate, and the first resolution is higher than the second resolution.

The invention relates to an electric arc-welding welding head comprising a contact device and one or more wire feeder units, the contact device encompassing an electrode assembly, the electrode assembly comprising at least two fusible continuously-fed wire electrodes arranged in a contact device. An electrically insulated duct is provided for electric insulation of at least one of the electrodes so that the electrode is electrically insulated from other electrodes in the electrode assembly. The invention also relates to an electric arc-welding contact device and an electric arc-welding welding head assembly.

A contact device for a welding apparatus is disclosed. The contact device is for providing current to a first welding wire and a second welding wire. The contact device includes first and second contact jaws. The first and second contact jaws include a plurality of longitudinally extending grooves formed therein that form passageways for the welding wires. The welding wires can be positioned in a first configuration in which they are spaced apart and in a second configuration in which they are next to and contact each other.