A system and method for welding. In some embodiments, the system includes a tungsten electrode, an electrode position actuator, and a processing circuit. The processing circuit may be configured to detect contact between the tungsten electrode and a weld puddle, and, in response to detecting contact between the tungsten electrode and the weld puddle, to control the electrode position actuator to move the tungsten electrode out of contact with the weld puddle.

According to an aspect of the present invention, there is provided a flux-cored wire including a steel sheath and a flux that fills the steel sheath. The flux contains fluorides of which a total value α of F-equivalent values is 0.21% or more, oxides of which the total value β of amounts ranges from 0.30% to less than 3.50%, and carbonates of which a total value of amounts ranges from 0% to 3.50%. An amount of CaO ranges from 0% to less than 0.20%. An amount of iron powder ranges from 0% to less than 10.0%. A X-value is 5.0% or less. The amount of CaF.sub.2 is less than 0.50%. The amount of Ti oxides ranges from 0.10% to less than 2.50%. A ratio of α to β ranges from 0.10 to 4.00. A total value of amounts of MgCO.sub.3, Na.sub.2CO.sub.3, and LiCO.sub.3 ranges from 0% to 3.00%. Other chemical composition is within a predetermined range. Ceq ranges from 0.45% to 1.20%.

An example welding system includes: a downdraft table having: a work surface; and a suction source configured to create a negative pressure through at least one of the work surface or a second surface adjacent to the work surface; and a positive pressure source configured to direct a positive pressure airflow around at least a portion of a periphery of the downdraft table.

A method of joining a first metal and a second metal is described. The first metal comprises Pb in an amount of at least 50 wt. % by weight of the first metal. The method comprises fusing the first metal and the second metal using non-consumable electrode arc welding.

The present disclosure is directed to a system and method for obtaining a desirable shielding gas flow in a welding device. The system includes a user interface configured for a user to input the size of the nozzle, a processor that is configured to calculate a desirable flow rate of shielding gas based at least in part on the input nozzle size, and a flow regulator that is configured to control the flow of the shielding gas in order to obtain the desirable flow rate.

A irradiation welding apparatus including an irradiation welding generator having at least one irradiation welding head configured to apply an irradiation treatment to end contact surfaces of a first profile and a second profile to join the first profile and the second profile, where the at least one irradiation welding head forms a planar cross-sectional shape in an x-y directional plane relative to the irradiation welding generator.

A method for using a plasma torch includes delivering a plasma gas through a plasma gas flow channel of a plasma torch while ionizing the plasma gas to produce a plasma arc that extends between the electrode and the workpiece. Additionally, shield fluid is delivered through a shield flow channel at a first pressure. A piercing operation to produce a pierce hole in the workpiece using the plasma arc is initiated while the shield fluid is delivered through the shield flow channel at the first pressure. After conducting the piercing operation for an amount of time, the shield fluid is delivered to the shield flow channel at a second pressure that is higher than the first pressure. Subsequent to the piercing operation, performing a cutting operation that forms a cut in the workpiece that originates at and extends away from a boundary of the pierce hole.

A non-consumable electrode arc-welding method is provided for causing a welding machine to output or stop a welding current in accordance with at least an ON state and an OFF state of a start signal. In the method, a start signal is switched between an ON state and an OFF state, thereby controlling the on/off operation of the welding machine. Further, an operation mode instruction signal is switched between a normal mode and an interval mode, thereby controlling the operation mode of the welding machine. When the operation mode instruction signal indicates the interval mode and also the start signal is in the ON state, the welding current is outputted in a welding current output period. Then, the output of the welding current is suspended in a welding current interval period successively following the welding current output period.

A welding method includes feeding a welding electrode axially from a welding torch, moving the welding electrode radially in a desired pattern with respect to a central axis of the welding torch by a motion control assembly within the welding torch, transmitting from control circuitry a signal corresponding to a position of the welding electrode relative to a weld joint or weld pool, advancing the welding torch or a workpiece to establish a weld, and transferring material from the welding electrode to a first location in an area of the weld pool. The welding electrode moves radially while feeding the welding electrode from the welding torch, the material from the welding electrode is transferred to the first location during a first cycle of the desired pattern, and the first location is controlled based at least in part on the signal.

A weld is formed in a workpiece such as a pipeline by first activating a melting device, such as a laser, to form a molten weld pool in the workpiece and then activating a welding device, such as a GMAW torch, to initiate a weld in the weld pool. The weld therefore incorporates the weld pool homogeneously. Relative movement between the activated welding device and the workpiece continues and completes the weld while the melting device remains deactivated.