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.

Disclosed herein are embodiments of alloys configured to form a coating with two contrasting physical behaviors: 1) reduced hardness with the end result of an easily machinable coating and 2) high abrasion resistance. Generally low hardness will result in low abrasion resistance. However, embodiments of the alloys described herein are able to maintain a low hardness while exhibiting higher abrasion resistance.

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.

A pressure vessel includes: (a) a cylindrical sidewall having a wall thickness, an inside surface, an outside surface, and the cylindrical sidewall extending between a first end and a second end, wherein one of the first end or the second end includes a sidewall edge that forms part of an outwardly opening weld groove; (b) an end cap constructed to engage the cylindrical sidewall edge, the end cap comprising an end cap edge corresponding to the sidewall edge and that, when combined with the sidewall edge, forms the outwardly opening weld groove; (c) a cylindrically extending backer bar located in support of the outwardly opening weld groove formed by the sidewall edge and the end cap edge; and (d) a weld joint formed in the outwardly opening weld groove and holding the cylindrical sidewall to the end cap. A method for welding a pressure vessel sidewall and end cap together is provided.

A method comprising an arc ignition phase (IP), an arc-stabilizing phase (AP) and a stable arc phase (SP). The arc stabilizing phase comprises an initial sub-phase (IS) comprising the step of feeding at least one hot wire (4, 12) at constant feed speed and a main sub-phase (MS) comprising the steps of feeding said hot wire at constant feed speed and feeding at least one cold wire (22) at constant feed speed. The stable arc phase comprises the steps of continuously adjusting the feed speed of the hot wire and continuously adjusting the feed speed of the cold wire. The invention also relates to a welding apparatus (1) for carrying out the method. The welding apparatus comprises a hot wire feeding means (150), a contact means (2), a cold wire feeding means (35) and a control unit (31). The control unit is adapted to control said hot wire feeding means to feed the hot wire at a constant feed speed during the initial sub-phase, feed the hot wire at a constant feed speed during the main sub-phase and to continuously during the stable arc phase adjust the feed speed of the hot wire. The control unit is adapted to control said cold wire feeding means to feed the cold wire at a constant feed speed during the main sub-phase and continuously during the stable arc phase adjust the cold wire feed speed.

Specific AC welding waveforms are utilized to increase the toughness level of austenitic stainless steel above what is achieved using the same welding consumables using standard DC welding waveforms.

Strip cladding heads having strip pressure limits and strip cladding systems with strip cladding heads having strip pressure limits are disclosed are disclosed. A disclosed example cladding head for a strip cladding system includes a first contact jaw comprising first and second contacts to deliver welding power to a cladding strip that is driven between the first and second contacts, a first contact pressure adjuster to set a first pressure applied by the first and second contacts to the cladding strip, and a first strip lock preventer to limit the first pressure applied by the first and second contacts to the cladding strip to less than a threshold pressure.

Specific AC welding waveforms are utilized to increase the toughness level of austenitic stainless steel above what is achieved using the same welding consumables using standard DC welding waveforms.

A method comprising an arc ignition phase (IP), an arc-stabilizing phase (AP) and a stable arc phase (SP). The arc stabilizing phase comprises an initial sub-phase (IS) comprising the step of feeding at least one hot wire (4, 12) at constant feed speed and a main sub-phase (MS) comprising the steps of feeding said hot wire at constant feed speed and feeding at least one cold wire (22) at constant feed speed. The stable arc phase comprises the steps of continuously adjusting the feed speed of the hot wire and continuously adjusting the feed speed of the cold wire. The invention also relates to a welding apparatus (1) for carrying out the method. The welding apparatus comprises a hot wire feeding means (150), a contact means (2), a cold wire feeding means (35) and a control unit (31). The control unit is adapted to control said hot wire feeding means to feed the hot wire at a constant feed speed during the initial sub-phase, feed the hot wire at a constant feed speed during the main sub-phase and to continuously during the stable arc phase adjust the feed speed of the hot wire. The control unit is adapted to control said cold wire feeding means to feed the cold wire at a constant feed speed during the main sub-phase and continuously during the stable arc phase adjust the cold wire feed speed.