Abstract: A method of operating a welding power supply during a welding process in which an electric arc between a consumable electrode and a work piece is generated while feeding the consumable electrode and moving the arc in relation to the work piece along a welding track, wherein a transition between a DC power output of the welding power supply and an AC power output of the welding power supply, or vice versa, is made without interruption of the welding process.

Abstract: A welding fixture for securing workpieces during welding. The welding fixture may include a movable gantry that is configured to span over the workpieces. The welding fixture may further include a plurality of pressure units that are suspended from the gantry and that are configured to controllably apply a force to the workpieces during welding. The gantry may be moved over the workpieces in a welding direction while pressure units maintain a force on the workpieces and while welding heads that are positioned behind the pressure units weld the workpieces together.

Abstract: A method of operating a welding power supply (20) during a welding process in which an electric arc (95) between a consumable electrode (94) and a work piece (102) is generated while feeding the consumable electrode (94) and moving the arc (95) in relation to the work piece (102) along a welding track (103), wherein a transition between a DC power output of the welding power supply and an AC power output of the welding power supply, or vice versa, is made without interruption of the welding process.

Abstract: Support device (20) meant to bear in supporting fashion on one or more work pieces in connection with friction stir welding, comprising: A holder unit (30), a first support wheel (40) which can be rotated relative to the holder unit about a first rotational axis (R1), and a second support wheel (50) which can be rotated relative to the holder unit around a second rotational axis (R2) which is parallel to the said first rotational axis, a support body (60) connected with the holder unit which is situated between support wheels and exhibits a support surface (61) turned outward, and an endless flexible metal belt (21), which runs in a loop over the outer peripheral surfaces (41, 51) of the support wheels, and is in sliding contact with the support surface of the support device, wherein the support devices are shaped to provide support as they bear on one or more work pieces with the outer peripheral surfaces of the support wheel, and with the support surface of the support body resting against the work piece

Abstract: A welding device and method for powder welding. The welding device includes at least a first container for fluxing agent in powder form, which first container includes an outlet with an outlet direction arranged for outflow of powder. The welding device further includes a first member for inlet of heated gas into the first container. The welding method includes arranging powder in the first container. Gas is heated and is allowed to pass into the first container for heating of the powder. The powder is then deposited on a welding area.

Abstract: Backing arrangement for supporting a welded seam extending on a curved path which is formed between two curved work pieces by friction stir welding with a welding tool separate from the backing arrangement, which backing arrangement comprises a backing body which is intended to bear upon the work pieces opposite said welding tool to assume at least a part of the compression force that is exerted by the welding tool against the work pieces to keep the material plasticized during the welding operation in the area of the welded seam The backing body is equipped with a shoulder which exhibits a bottom surface turned outward, via which the backing body is equipped to bear on the work pieces. A driving mechanism is situated to rotate and/or oscillate the shoulder so that the bottom surface of the shoulder can thereby be made to carry out a rotating and/or oscillating motion against the work pieces for creating fictional heat in them.

Abstract: A twin wire welding apparatus including a first contact tube for guiding a first consumable electrode toward a weld puddle and transferring welding current to the first consumable electrode, a second contact tube for guiding a second consumable electrode toward said weld puddle and transferring welding current to the second consumable electrode, and a single power source connected to said first and second contact tubes for providing the same potential to said two consumable electrodes, and a method for operating such an apparatus.

Abstract: An arc electric welding head comprising a first contact device housing a first duct for feeding a first electrode and providing electrical contact between a first power source and said first electrode, a second contact device housing a second duct for feeding a second electrode and providing electrical contact between a second power source and said second electrode, said first and second contact devices being electrically insulated from each other, said first and second ducts being parallel.

Abstract: Backing arrangement (2) for supporting a welded seam extending on a curved path which is formed between two curved work pieces by friction stir welding with a welding tool separate from the backing arrangement, which backing arrangement comprises a backing body (20) which is intended to bear upon the work pieces opposite said welding tool to assume at least a part of the compression force that is exerted by the welding tool against the work pieces to keep the material plasticized during the welding operation in the area of the welded seam. The backing body is equipped with a shoulder (21) which exhibits a bottom surface (22) turned outward, via which the backing body is equipped to bear on the work pieces. A driving mechanism (50) is situated to rotate and/or oscillate the shoulder so that the bottom surface of the shoulder can thereby be made to carry out a rotating and/or oscillating motion against the work pieces for creating fictional heat in them.

Abstract: An electric arc welding method is provided, wherein an electrode assembly comprises at least two fusible continuous electrodes acting on a workpiece for generating a weld pool via electric arcs, wherein the at least two electrodes are arranged in sequential order relative to a welding direction and laterally separated relative to each other, wherein steps are performed of monitoring at least one stability parameter (Stab_par) for each electrode of the electrode assembly; determining if one electrode of the electrode assembly violates a stability criterion (Crit); separating at least temporarily the one electrode violating the stability criterion (Crit) from one or more adjacent electrodes when a violation of the stability criterion (Crit) of the one electrode is detected.

Abstract: 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).

Abstract: A welding device applies weld material between two work pieces such that the work pieces are connected mechanically with one another. The welding device includes a welding head and a central element. The welding head performs a welding action during transport thereof along an operating direction between the work pieces. Two primary sensor members are arranged on the central element upstream of the welding head relative to the operating direction. The sensor members register geometric properties of a spacing between the work pieces in which spacing the weld material is to be applied. Each sensor member is configured to maintain contact with a respective wall of the two work pieces adjoining the spacing while allowing variation of lateral distances between the central element and the adjoining wall. This is accomplished by the sensor members being pivotally attached to the central element via at least one pivoting axis oriented essentially perpendicular to the operating direction.

Abstract: Support device (20) meant to bear in supporting fashion on one or more work pieces in connection with friction stir welding, comprising: A holder unit (30), a first support wheel (40) which can be rotated relative to the holder unit about a first rotational axis (R1), and a second support wheel (50) which can be rotated relative to the holder unit around a second rotational axis (R2) which is parallel to the said first rotational axis, a support body (60) connected with the holder unit which is situated between support wheels and exhibits a support surface (61) turned outward, and an endless flexible metal belt (21), which runs in a loop over the outer peripheral surfaces (41, 51) of the support wheels, and is in sliding contact with the support surface of the support device, wherein the support devices are shaped to provide support as they bear on one or more work pieces with the outer peripheral surfaces of the support wheel, and with the support surface of the support body resting against the work piece

Abstract: A contact tip (1) for gas metal-arc welding comprising: A body (3) of a metal material with a tubular base portion (4) and two or more fingers (5a, 5b) extending in the axial direction from a front end of the base portion; At least one wire-feed conduit (7) extending axially through the body, in which a welding wire is to be received and fed; slots (10a, 10b) arranged between the fingers in order to space these apart, and A spring means (11) surrounding the fingers and exerting a radially acting spring force on the fingers of such strength that the fingers, when cool, are kept spaced apart, such that no pressure will be exerted on the casing surface of a welding wire introduced in the wire-feed conduit, and when heated to a temperature above the softening temperature of the metal material, are compressed by the spring force radially inward in order to exert pressure on the casing surface of a welding wire received in the wire-feed conduit.

Abstract: A welding arrangement and a welding process for forming a weld seam between two edge portions, wherein the edge portions form a Y joint having a root portion and a bevel portion, said root portion being welded by a hybrid laser electric arc welding process including directing a laser beam and an electric arc in a single interaction zone of plasma and molten metal. A hybrid laser electric arc welding head and welding submerged arc welding head are arranged on a common carrier structure for welding the Y joint.

Abstract: A welding method for gas metal arc welding is provided with continuous electrode feeding and control for short arc welding and/or spray arc welding and also short pulsing in which the control cyclically alternates between short pulsing and short arc or spray arc welding, and time for carrying out the respective control being programmed by a user. A welding power source and software for carrying out this method are also provided.

Abstract: A welding device for powder welding is described, which comprises a welding head for transportation of at least one welding electrode to a welding area, and a powder transportation device for transportation of powder from a container to the welding area. The powder transportation device comprises at least a first pipe which at a first end has an opening which is arranged to be placed in the container in order to transport fluxing agent from the container. The powder transportation device comprises at least a first ejector which is connected to the second end of the first pipe and which is arranged to transport powder from the container via the first pipe using pressurized gas.

Abstract: A welding device applies weld material between two work pieces (P1, P2) so as to connect the work pieces (P1, P2) mechanically with one another. The welding device has a welding head (110) and a probe head (120). The welding head (110) performs a welding action in respect of the work pieces (P1, P2) during transport of the welding device along an operating direction (OD) in a welding plane (WP); and the probe head (120), which is arranged upstream of the welding head (110) relative to the operating direction (OD), measures a set of geometric properties of a gap (G) between the work pieces (P1, P2). Thus, the welding head (110) can be properly positioned to attain a desired application of the weld material in the gap (G).

Abstract: The invention relates to a twin wire welding apparatus (1) including a first contact tube (2) for guiding a first consumable electrode (4) toward a weld puddle (6) and transferring welding current to the first consumable electrode (4), a second contact tube (10) for guiding a second consumable electrode (12) toward said weld puddle (6) and transferring welding current to the second consumable electrode (12), and a single power source (16) connected to said first and second contact tubes (2,10) for providing the same potential to said two consumable electrodes (4,12), and to a method for operating such an apparatus.