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 submerged arc welding apparatus includes a first wire feeder feeding a first hot wire towards a work piece; a first contact tube transferring current to the first hot wire for arc generation to create a weld puddle; a second wire feeder feeding a cold wire at a variable feed speed towards the weld puddle; one or more sensors configured to continuously measure, during a welding phase, at least a first active welding parameter related to at least the first hot wire; and a control unit. The control unit is configured to determine different target values for the variable feed speed of the cold wire based on different values of the at least a first active welding parameter such that a different target value for the variable feed speed of the cold wire is determined according to a different value of the at least a first active welding parameter.

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.

Provided is a welding robot mechanism that has: a welding robot having a touch sensing function; a welding power source for supplying welding power to the welding robot; and a control unit for controlling the welding robot, wherein the welding power source has a welding power source communication unit that receives detection signals with regard to control of the welding robot and the touch sensing, and transmits the detection signals outward. The control unit is linked to the welding power source communication unit via a serial bus communication wire. The detection signals comprise a mass of data including a detection data group designated as a first group and a detection data group designated as a second group, and is configured to read the detection data group designated as the first group in a shorter cycle than that for the detection data group designated as the second group. The detection data group designated as the first group includes a detection signal obtained by the touch sensing.

Systems, methods, and apparatus to preheat welding wire for low hydrogen welding are disclosed. An example apparatus to reduce hydrogen associated with a consumable welding electrode includes: a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch; an electrode preheating circuit configured to provide preheating current through a first portion of the welding-type electrode between a wire feeder supplying the welding-type electrode and at least one of the first contact tip or a second contact tip of the welding torch.

Systems, methods, and apparatus to heat welding wire for low hydrogen welding are disclosed. An example method includes drawing a supply material through a die to form a wire; and applying electrical current to a portion of the wire to reduce a hydrogen content of the wire.

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.

A welding torch includes first to third wire passages, a wire detection space, and a wire detecting device. The first wire passage has a first wire inlet port allowing a first welding wire to enter thereto and a first wire outlet port allowing the first welding wire to be output therefrom. The second wire passage has a second wire inlet port allowing a second welding wire to enter thereto and a second wire outlet port allowing the second welding wire to be output therefrom. The third wire passage has a third wire inlet port allowing a portion of the first welding wire output from the first wire outlet port and a portion of the second welding wire output from the second wire outlet port to enter thereto, and a third wire outlet port allowing the portion of the first welding wire and the portion of the second welding wire to be output therefrom. The wire detection space is connected to the first and second wire outlet ports and the third wire inlet port. The wire detection space allows the portions of the first and second welding wire to pass through the wire detection space. The wire detecting device is configured to detect the portion of the first welding wire and the portion of the second welding wire in the wire detection space. The welding torch can switch between the welding wires with a simple structure.

A a multiple welding method having an improved starting process in which the control unit of the guide electrode starts welding-wire advancing of the guide electrode and sends a synchronization signal to the control unit of the trailing electrode when the guide electrode has moved a certain distance or for a certain time. The control unit of the trailing electrode starts welding-wire advancing of the trailing electrode in dependence on the received synchronization signal before the guide electrode touches the workpiece.