Provided is a welding method using a special torch and a flux cored wire, in which the special torch has a suction nozzle between the contact tip and the shield nozzle, and the flux cored wire has a flux filled inside the steel outer casing, and a seam portion where both ends of a metal in a width direction of the steel outer casing are butted or overlapped in a longitudinal direction of the flux cored wire.

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%.

Provided herein is a stop-off material for a brazing process. The stop-off material includes a solvent, a thickener, and magnesium oxide. About 5 weight percent to about 60 weight percent of the stop-off material comprises the magnesium oxide. The stop-off material is configured to be removed from a surface after heating and via air pressure.

A purpose of the present invention is to provide a flux-cored wire that excels in slag removability and weldability, and is capable of high-efficiency operation without the risk of reheat cracking and makes it possible to obtain a welding bead with high corrosion resistance even when used in equipment operating at high temperature for a long time. The present invention relates to a flux-cored wire for gas-shielded arc welding that is used for welding using a specific shielding gas having a high Ar ratio, includes substantially no As, Sb, Pb and Bi, has slag component and alloy component compositions satisfying predetermined conditions, and satisfies the relationship {(3??O.sub.2?)+?CO.sub.2?+(0.0085?A.sup.2)?(0.19?A)}?20.0 (where A={?Cr?+(4.3??Nb?)}).

A wire including, in terms of % by mass with respect to a total mass of the wire, as a total in a steel outer skin and a flux, 0.03 to 0.08% of C, 0.1 to 0.6% of Si, 1.2 to 2.5% of Mn, 0.01 to 0.5% of Cu, 0.5 to 1.5% of Ni, 0.05 to 0.5% of Ti, 0.002 to 0.015% of B, and 0.05% or less of Al, and further including, in the flux, 4 to 8% in terms of TiO.sub.2, 0.1 to 0.6% of in terms of SiO.sub.2, 0.02 to 0.3% in terms of Al.sub.2O.sub.3, 0.1 to 0.8% of Mg, 0.05 to 0.3% in terms of F, 0.05 to 0.3% in terms of Na and K in a fluorine compound, 0.05 to 0.2% of Na.sub.2O and K.sub.2O, and 0.2% or less in terms of ZrO.sub.2.

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). A disclosed tubular welding wire has a sheath and a core, and the tubular welding wire includes an organic stabilizer component, a rare earth component, and a corrosion resistant component comprising one or more of: nickel, chromium, and copper.

The present invention accurately distinguishes a soldering material less likely to oxidize. A Cu core ball has a Cu ball having a predetermined size, and a solder layer coating the Cu ball. The Cu ball provides a space between a semiconductor package and a printed circuit board. The Cu core ball has the soldering material having lightness greater than or equal to 62.5 in L*a*b* color space subsequent to a heating storage test performed for 72 hours in a temperature-controlled bath at 150 C. with a temperature of 25 C. and 40% humidity, and the soldering material, prior to the heating storage test, having lightness greater than or equal to 65 in the L*a*b* color space and yellowness less than or equal to 7.0 in the L*a*b* color space.

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%.

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.

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.