A brazing composition contains 1 part by mass or more and 10 parts by mass or less of Zn powder, 1 part by mass or more and 5 parts by mass or less of Si powder, 3 parts by mass or more and 10 parts by mass or less of KAlF flux, 1 part by mass or more and 3 parts by mass or less of (meth)acrylic resin, wherein the mass ratio (Zn/Si) of Zn powder relative to Si powder is 1 or more and 5 or less.

Disclosed is a flux composition for use in brazing of an aluminum alloy material and includes a flux component [A] containing KAlF.sub.4; and a fluoride [B] containing an element other than Group 1 elements and Group 2 elements and containing no potassium (K). Also disclosed is a brazing sheet which includes an aluminum alloy core; a filler material lying on or over at least one side of the core; and a flux layer lying on or over one side of the filler material and including the flux composition.

A flux-cored wire for gas-shielded arc welding, including, in terms of mass % relative to a total mass of the wire, in the total of the steel outer sheath and the flux, C: 0.03 to 0.08%, Si: 0.1 to 0.6%, Mn: 1.5 to 2.8%, Cu: 0.01 to 0.5%, Ni: 0.35 to 0.98%, Ti: 0.05 to 0.25%, and B: 0.002 to 0.015%, Al: 0.05% or less, and including, in the flux, TiO.sub.2 conversion value: 3 to 8%, Al.sub.2O.sub.3 conversion value: 0.1 to 0.6%, SiO.sub.2 conversion value: 0.2 to 1.0%, ZrO.sub.2 conversion value: 0.20 to 0.65%, Mg: 0.2 to 0.8%, F conversion value: 0.05 to 0.25%, Na conversion value: 0.02 to 0.10%, and K conversion value: 0.05 to 0.20%.

A tube for a heat exchanger including a tube structure made of lightweight metal alloy and having an inner surface and an outer surface. The tube further includes: a first layer of material on the outer surface of the tube structure, the first layer having different chemical composition than the tube structure, a second layer of material on the first layer of material, the second layer having different chemical composition than the tube structure and the first layer. The first layer includes metallic material having a lower galvanic potential than the tube structure. The first layer includes the deposition of zinc particles within the first layer. The deposition of zinc is not less than 3 g/m.sup.2 and not more than 7 g/m.sup.2. The second layer includes an aluminum silicon compound. The deposition of aluminum silicon compound within the second layer is not less than 14 g/m.sup.2 and not more than 16 g/m.sup.2.

An ultra high-strength flux-cored arc welded joint having excellent impact toughness comprises: 0.01 wt % to 0.06 wt % of carbon (C), 0.1 wt % to 0.5 wt % of silicon (Si), 1.5 wt % to 3.0 wt % of manganese (Mn), 2.5 wt % to 3.5 wt % of nickel (Ni), 0.5 wt % to 1.0 wt % of molybdenum (Mo), 0.4 wt % to 1.0 wt % of copper (Cu), 0.4 wt % to 1.0 wt % of chromium (Cr), 0.01 wt % to 0.1 wt % of titanium (Ti), 0.003 wt % to 0.007 wt % of boron (B), 0.001 wt % to 0.006 wt % of nitrogen (N), 0.02 wt % (excluding 0) or less of phosphorus (P), 0.01 wt % (excluding 0) or less of sulfur (S), 0.03 wt % to 0.07 wt % of oxygen (O), and remaining iron (Fe) as well as unavoidable impurities.

The invention described herein pertains generally to boric acid free flux composition wherein in some embodiments, a phthalocyanine pigment is used to effect a color change at activation temperature.

The present invention concerns a process for the manufacture of flux compositions, flux compositions obtainable by the process according to the invention, aluminum or aluminum alloy parts at least partially coated with the flux composition manufactured by the process, and a brazing process and brazed metal object obtainable by said process.

One or more techniques and/or systems are disclosed for an agglomerated welding flux that can comprise, as expressed in % by weight of flux: 25 to 35% MgO, 20 to 28% CaF.sub.2, 15 to 22% Al.sub.2O.sub.3, 12 to 17% SiO.sub.2, and 0,2 to 0,4% carbon (% by weight). The carbon can be introduced using at least one metallic compound contained in the flux. Further disclosed is a process for submerged-arc welding of at least one workpiece made of austenitic stainless steel, using the described flux. Additionally disclosed is a welded joint that can comprise 17 to 20% Cr, 5 to 8,5% Mn, and 14 to 18% Ni, which can be obtained using the described process.

A brazing sheet used for brazing aluminum in an inert gas atmosphere or vacuum is formed by arranging a brazing material on one side or both sides of a core material made of pure aluminum or aluminum alloy, and performing cladding with an intermediate material interposed between the core material and the brazing material. The brazing material includes 6% to 13% of Si and the balance being Al and inevitable impurities. The intermediate material includes 0.01% to 1.5% of Bi, at least one of 0.05% or more of Li, 0.05% or more of Be, 0.05% or more of Ba, and 0.05% or more of Ca, and the balance being Al and inevitable impurities. By promptly supplying Bi and Li, Be, Ca, and/or Mg into the brazing material during brazing heating, these elements are eluted in the molten brazing material, embrittling the oxide film on the surface of the brazing material.

A braze gel includes a braze powder, a braze binder, and a viscosity reducer. The braze gel has a gel viscosity sufficiently low to permit dip coating of a component with the braze gel to apply a braze coating of the braze gel to the component. A brazing process includes applying the braze gel to a portion of a component. The brazing process also includes drying the braze gel to form a braze coating on the component to form a braze-coated component. A brazing article includes a component and a braze coating over a portion of the component. The component may have structural features having a spacing of less than about 5 mm and a depth of at least about 1 mm, which may be honeycomb cells. The component may be a turbine component.