A gas shielded arc welding method includes welding a steel sheet with a tensile strength of 780 MPa or more using a shielding gas containing Ar in an amount of 92 vol. % to 99.5 vol. %. In the gas shielded arc welding method, a value calculated from the following expression (1) is 0.20 or more: {v/(D/2).sup.2}10{(100C.sub.Ar)I/v}0.1 . . . (1), where C.sub.Ar represents an Ar content (vol. %) in the shielding gas, D represents an inner diameter (mm) of a nozzle from which the shielding gas is supplied, v represents a welding speed (cm/min), and I represents a welding current (A).

A method of welding a superalloy component includes the following sequential steps. A welding step for welding a cavity using a filler metal in an inert atmosphere, where the cavity is located in the component. A covering step for covering the filler metal and a portion of the component with a weld filler layer in the inert atmosphere. The weld filler layer has a greater ductility than material comprising the component and/or material comprising the filler metal. A second covering step for covering the weld filler layer with a braze material, and subsequently performing a brazing operation. A heat treating step heat treats the component.

Various welding systems including a welding torch assembly are provided. The welding torch assemblies may include a welding torch adapted to be utilized in a welding operation to establish a welding arc between the welding torch and a workpiece. The welding torch assemblies may also include a temperature sensing system integral with the welding torch and adapted to sense a temperature of the workpiece.

A welding or additive manufacturing wire drive system includes a first spindle for a first welding wire spool, a second spindle for a second welding wire spool, a first drive roll, and a second drive roll. One or both of the drive rolls has a circumferential groove. A first welding wire and a second welding wire are located between the first drive roll and the second drive roll in the circumferential groove. The first welding wire contacts the second welding wire between the first drive roll and the second drive roll. The first welding wire further contacts a first sidewall portion of the circumferential groove. The second welding wire further contacts a second sidewall portion of the circumferential groove. Both of the first welding wire and the second welding wire are radially offset from a central portion of the circumferential groove.

A nozzle assembly for a welding torch and a welding torch including said nozzle assembly is provided. The nozzle assembly generally comprises a base defining a distal threaded portion for securing the nozzle assembly to a distal end portion of a conductor tube of the welding torch, the base defining a distal threaded portion and a nose defining a mating threaded portion adapted to engage the distal threaded portion of the base, thereby removably securing the nose to the base. The distal threaded portion may comprise tapered Edison threads or a shell thread design.

A welding system includes a welder configured to output welding power to generate an arc between a welding electrode and a workpiece. The welding system also includes a power pin configured to be coupled to the welder in a first orientation or a second orientation. The power pin is configured to switch the welding power from a first polarity to a second polarity when the power pin is switched from being coupled to the welder in the first orientation to being coupled to the welder in the second orientation.

A welding torch includes a gas lens of a lattice structure that straightens a shielding gas. The welding torch includes a non-consumable electrode, an electrode holder into which the non-consumable electrode is inserted, and a torch body including a sleeve that holds the electrode holder, a flow path forming portion that forms a shielding gas flow path around the sleeve, and a nozzle that forms a shielding gas guiding space around a distal end of the non-consumable electrode, the distal end extending from the electrode holder, in which the gas lens is provided so as to separate the shielding gas flow path from the shielding gas guiding space.

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 a of F-equivalent values is 0.21% or more, oxides of which the total value 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 to 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 apparatus and system for preheating and removing surface oxidation of welding wire using electric arcs one via one or more tungsten electrodes is disclosed. The preheating and cleaning electric arcs may occur between tungsten electrodes, or between one or more tungsten electrodes and welding wire. Electric arc preheating of welding wire allows increased efficiency and deposition rates.

The invention relates to nuclear power and can be used in manufacturing of fuel elements for nuclear reactors. A method of sealing nuclear reactor fuel elements is proposed comprising welding one end of a casing with a first plug, loading the fuel element with fuel, and welding a second plug to another end of the casing. The casing is of a high-chromium ferrite-martensite steel and the plugs are of a ferrite steel. Argon arc welding is carried out at a volume ratio of the materials of the casing and the plugs contributing to formation of the metal of the weld seam which allows formation of a ferrite phase in said metal, wherein the ratio is: V.sub.1/V.sub.20.18, where V.sub.1 is the volume of ferrite material and V.sub.2 is the volume of ferrite-martensite material. Argon arc welding is carried out at a current of 14-20 A, a speed of 12-15 m/h, an arc voltage of 9-10 V and an argon flow rate of 7-8 l/min. This method provides for the desired quality of the welded joins and simplifies the fuel element manufacturing process.