The invention relates generally to welding and, more specifically, to welding wires for arc welding, such as Gas Metal Arc Welding (GMAW) or Flux Core Arc Welding (FCAW). In one embodiment, a tubular welding wire for joining steel workpieces via arc welding includes a steel sheath disposed around a core. The core includes iron powder, iron titanium powder, silico-manganese powder, iron silicon powder, iron sulfide, graphite, rare earth compound, and a frit. The frit includes a Group I or Group II compound, silicon dioxide, and titanium dioxide. The graphite and the frit together comprise less than 10% of the core by weight.

An aluminum alloy brazing sheet, a manufacturing method therefor, and a manufacturing method for an automotive heat exchanger. The aluminum alloy brazing sheet includes an aluminum alloy core material, a first brazing material that is clad to one surface of the core material, and a second brazing material that is clad to the other surface of the core material. The core material, the first brazing material, and the second brazing material each include a respective prescribed aluminum alloy. A count of an Al—Si—Fe intermetallic compound having an equivalent circle diameter of 0.5 to 80.0 μm in the second brazing material is less than or equal to 2,000 particles per mm.sup.2.

The invention concerns a brazing sheet comprising a core layer (5) and a braze cladding, said core layer (5) being aluminium or an aluminium alloy, said braze cladding comprising (a) a flux composite layer (2), which flux composite layer comprises a matrix of aluminium or an aluminium alloy, said matrix containing flux particles; (b) at least one filler alloy layer (1) not containing flux particles; and, (c) an aluminium or aluminium alloy layer (3) not containing flux particles, said layer forming the outermost surface of at least one side of the brazing sheet, wherein the flux composite layer (a) is positioned between said filler alloy layer (b) and said aluminium or aluminium alloy layer (c). The invention further concerns a method for its manufacturing, a cladding plate, use of the brazing sheet and a brazed heat exchanger.

A flux for submerged arc welding is a sintered flux and is for use in high speed welding. In the flux, the following relationships of contents in mass percent are satisfied: CaF.sub.2: 10.0% to 20.0%, MgO: 8.0% to 15.0%, a sum of Na.sub.2O and K.sub.2O: 2.1% to 3.5%, MnO: 1.5% to 5.0%, FeO: 0.5% to 5.0%, SiO.sub.2: 10.0% to 20.0%, Al.sub.2O.sub.3: 13.0% to 28.0%, and TiO.sub.2: 13.0% to 28.0%. In addition, the following relationships are further satisfied: 65≤(MgO+SiO.sub.2+Al.sub.2O.sub.3+TiO.sub.2)≤75, and 0.5≤(Al.sub.2O.sub.3/TiO.sub.2)≤2.0.

A method for the manufacture of a welded joint including the following successive steps: I. The provision of at least two metallic substrates wherein at least one metallic substrate is a steel substrate, and II. The welding of the at least two metallic substrates with a welding head while, simultaneously, applying on the at least two metallic substrates, ahead of the welding head, a welding flux including a titanate and a nanoparticulate oxide selected from the group consisting of TiO.sub.2, SiO.sub.2, ZrO.sub.2, Y.sub.2O.sub.3, Al.sub.2O.sub.3, MoO.sub.3, CrO.sub.3, CeO.sub.2, La.sub.2O.sub.3 and mixtures thereof.

The invention concerns a flux for brazing, a process for brazing metal parts employing said flux, a flux composition containing said flux, aluminum parts coated with said flux or said flux composition, a process for brazing and a brazed metal object obtainable by said brazing process. The flux is high in KAlF.sub.4 and low in K.sub.3AlF.sub.6.

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 of F-equivalent values is 0.21% or more, oxides of which the total value of amounts ranges from 0.30% to 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 0.20%. An amount of iron powder ranges from 0% to less than 10.0%. A Y-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 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%. A chemical composition excluding the fluorides, the oxides, the CaO, the carbonates, and the iron powder is within a predetermined range. Ceq ranges from 0.10% to 0.44%.

A coating composition for a heat exchanger tube including vanadium (V), a flux, and a binder, wherein the vanadium is included in an amount of 28 to 38 parts by weight with respect to 100 parts by weight of the composition, and a coating method of a heat exchanger tube using the same are provided.

A braze tape (12) useful with superalloy materials. In one embodiment, the tape includes a layer (14) containing superalloy powder (22) in a binder (24), and a layer (16) containing boron and silicon free braze material powder (32) in a binder, joined together by a layer (18) of double-sided adhesive fluorocarbon polymer tape, such as a double-sided adhesive polytetrafluoroethylene or Teflon tape (46).

A flux-cored wire for arc welding of a duplex stainless steel includes a stainless-steel sheath filled with a flux and contains, with respect to the total mass of the wire, predetermined amounts of Cr, Ni, Mo, N, Mn, and Si, in which letting a Ti alloy content in terms of Ti be [Ti] and letting an Al alloy content in terms of Al be [Al], [Ti] and [Al] are predetermined values, and in which parameter A expressed as A=[Ti]+2[Al] satisfies a predetermined value, and the balance is composed of Fe, a slag-forming component, and incidental impurities.