A dual-torch welding system is disclosed. In one embodiment, the welding system includes a pair of torches positioned in an other than opposing arrangement to weld a substantially circular component therebetween, and a means for rotating the substantially circular component and the pair of torches relative to one another, allowing welding of the substantially circular component by the pair of torches.

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 method for joining two metallic, tubular joining members to one another, the method including arranging two metallic, tubular joining members with respect to one another in an overlapping or end-face manner, and joining the joining members by material bond along a joining zone of the joining members. In the joining, a chain of joining spots extending in the circumferential direction of the joining members is produced in the joining zone, wherein successive joining spots in the chain overlap, wherein, in the joining, the joining spots are produced by means of TIG pulse welding with an arc time of up to 100 ms, preferably of up to 50 ms, wherein an arc of a welding pulse of the TIG pulse welding is extinguished after the arc time has been reached. A corresponding welding apparatus is also described.

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.

A method and related system and apparatus for refurbishing worn rail transit rails to a desired refurbished rail surface profile substantially similar to the surface profile of a newly-manufactured rail, comprising: depositing a first line of fill material along a lower-inside section to be refurbished; in N1 successive iterations thereafter, progressing circumferentially from the lower-inside section to be refurbished to an upper-outside section to be refurbished, depositing an n+1.sup.th line of fill material adjacent an n.sup.th line of fill material wherein the n.sup.th line of fill material substantially provides a flow barrier against the n+1.sup.th line of fill material flowing past the n.sup.th line of fill material.

Systems and methods are provided for utilizing in-line wire feeders. A welding-type system may include an in-line wire feeder device configured to feed electrode wire from a wire source. The in-line wire feeder device may include an in-line wire feeding mechanism, may be a physically separate component from both of a second wire feeder device and a welding-type torch, and may be connected in series with the second wire feeder device. The in-line wire feeder device may control feeding of the electrode wire from a wire source, with the controlling including causing the second wire feeder device to feed the electrode wire from the wire source until the electrode wire reaches the in-line wire feeding mechanism, and then afterwards deactivating at least a feeding function of the second wire feeder device, and causing the in-line wire feeding mechanism to take over feeding of the electrode wire from the wire source.

Method for compensating an interfering influence on a welding current, provided by a welding power source (4) for welding a workpiece (3), from another welding power source (4), comprising the steps of: (a) providing (SA) a compensation voltage (U.sub.Komp), which is calculated on the basis of a welding current progression provided by the other welding power source (4); (b) subtracting (SB) the compensation voltage (U.sub.Komp) from a measured voltage (U.sub.Mess), measured by a voltage measurement unit (8) of the welding power source (4), so as to determine a corrected measured voltage (U.sub.Mess); and (c) regulating (SC) the welding current generated by the welding power source (4) as a function of the corrected measured voltage (U.sub.Mess).

Two welding wires whose current values are individually variable are placed along a groove of steel plates, and two operations are repeated, the first operation including: passing substantially the same current through both welding wires; generating a cathode spot in front of a molten pool by one welding wire's arc on a welding-direction forward side; and cleaning the steel plates' surfaces by the arc, and the second operation including: passing a pulse current having a higher value than that of the welding wire through the other welding wire, so that a cathode spot is generated in the molten pool by each welding wire's arc to newly form a molten pool; and advancing both welding wires in the welding direction to move the cathode spot to the newly-formed molten pool, and at the same time performing welding within an area where oxides on the steel plates' surfaces are removed.

The disclosed technology generally relates to welding, and more particularly to a consumable welding wire for metal arc welding, and a method and a system for metal arc welding using the consumable welding wire. In one aspect, a method of arc welding includes providing a welding wire comprising one or more alkaline earth metal elements. The method additionally includes applying power to the welding wire to generate a plasma arc sufficient to melt the welding wire. The method further includes depositing molten droplets formed by melting the welding wire onto a workpiece at a high deposition rate while regulating to maintain a substantially constant power delivered to the plasma arc.