A welding or additive manufacturing wire drive system includes a first spindle for a first welding wire spool, a second spindle for a second welding wire spool, a first drive roll, and a second drive roll. One or both of the drive rolls has a circumferential groove. A first welding wire and a second welding wire are located between the first drive roll and the second drive roll in the circumferential groove. The first welding wire contacts the second welding wire between the first drive roll and the second drive roll. The first welding wire further contacts a first sidewall portion of the circumferential groove. The second welding wire further contacts a second sidewall portion of the circumferential groove. Both of the first welding wire and the second welding wire are radially offset from a central portion of the circumferential groove.

A welding or additive manufacturing wire drive system includes a first drive roll having a first annular groove, a second drive roll having a second annular groove, a first welding wire located between the drive rolls in the annular grooves, and a second welding wire located between the drive rolls in the annular grooves. A biasing member biases the first drive roll toward the second drive roll to force the first welding wire to contact the second welding wire. The first welding wire contacts each of a first sidewall portion of the first annular groove, a first sidewall portion of the second annular groove, and the second welding wire. The second welding wire contacts each of a second sidewall portion of the first annular groove, a second sidewall portion of the second annular groove, and the first welding wire. The drive rolls rotate in opposite directions thereby moving the welding wires through the wire drive system.

The present application relates to an arc welding arrangement and an electric arc welding method to be used with the arc welding arrangement. The arc welding arrangement comprising a first power source, a first electrode connected to say first power source, and a second electrode, said first electrode being adapted to generate a weld pool via a first electric arc present within a first arc region. The second electrode is operated at welding parameters adapted to ensure that excess energy from at least said first electrode is required to maintain said second arc ignited. The method comprises the step of feeding said second electrode so that it is allowed to consume excess energy from said first electrode to maintain said second arc ignited.

A solid object is rotated in the central pool of molten metal that is formed by using an arc to melt a continuously fed metal wire and depositing the melted wire between the facing edges of two base metals to be joined. The stirring generated by the rotation in the pool moves hotter metal in the central region to its boundary adjacent to the facing edges. This stirring generated movement of molten metal is expected to better heat the facing edges so that the molten metal can better fuse with the facing edges. The stirring generated fluid flow within the molten pool also changes the solidification of the molten metal and the formation of the resultant grains.

A solid-bowl centrifuge screw with a screw flight is provided. The screw flight has at least a first welding layer on a base body of the solid-bowl centrifuge and at least a second welding layer on the first welding layer. Thus, plural welding layers are disposed successively on one another and are applied by shaping build-up welding.

A welding or additive manufacturing contact tip includes an electrically-conductive body extending from a proximal end of the body to a distal end of the body. The body forms a first bore terminating at a first exit orifice at a distal end face of the body, and a second bore terminating at a second exit orifice at the distal end face of the body. The first and second exit orifices are separated from each other by a distance configured to facilitate formation of a bridge droplet between a first wire electrode delivered through the first bore and a second wire electrode delivered through the second bore during a deposition operation.

A method for producing an additively manufactured object includes melting and solidifying a filler metal by use of an arc, and depositing and forming a plurality of layers of molten beads to produce a built-up object, and the method includes: shaping the molten bead of a previous layer; and monitoring a temperature of the molten bead of the previous layer. Shaping of the molten bead of a next layer is started when the temperature of the molten bead of the previous layer is equal to or lower than an allowable interpass temperature.

A welding or additive manufacturing contact tip includes an electrically-conductive body extending from a proximal end of the body to a distal end of the body. The body forms a first bore terminating at a first exit orifice at a distal end face of the body, and a second bore terminating at a second exit orifice at the distal end face of the body. The first and second exit orifices are separated from each other by a distance configured to facilitate formation of a bridge droplet between a first wire electrode delivered through the first bore and a second wire electrode delivered through the second bore during a deposition operation.

A multiple welding method using at least two consumable electrodes which enables stable welding processes at the electrodes and also less heat input into the parent material compared with the multiple pulse welding method. At each of the at least two electrodes a welding process includes a short-circuit welding phase and a hot-welding phase with higher heat input into the parent material relative to the short-circuit welding phase, the short-circuit welding phase and the hot-welding phase periodically alternating, and for the short-circuit welding phases of the welding processes of the at least two electrodes to be temporally synchronized on the basis of at least one defined first synchronization event per short-circuit welding phase.

A hybrid welding apparatus selectively switches between MAG welding and TIG welding. The apparatus includes a control device (1), which includes a welding output unit (10) for outputting a welding voltage and a welding current. When MAG welding is selected, the positive terminal of the welding output unit (10) is connected to a MAG welding torch (2), and the negative terminal is connected to a welding base material (4). Meanwhile, when TIG welding is selected, the positive terminal of the welding output unit (10) is connected to the welding base material, and the negative terminal is connected to a TIG welding torch (3).