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%.

A flux-cored wire for carbon dioxide gas shielded arc welding including, in terms of % by mass with respect to a total mass of the wire, 0.03 to 0.08% of C, 0.2 to 0.7% of Si, 1.4 to 3.0% of Mn, 0.01 to 0.5% of Cu, 0.8 to 3.0% of Ni, 0.05 to 0.5% of Ti, 0.002 to 0.015% of B, 0.05% or less of Al, 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.

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?)}).

The invention relates to a method of forming a coating or of three-dimensional structural elements on substrate surfaces which is/are formed by TiAl. Said coating/Said three-dimensional structural elements is/are manufactured by laser build-up welding. The procedure is followed in the method in accordance with the invention that titanium and aluminum are supplied into the region of influence of at least one laser beam in wire and/or band form in a pure or alloyed form in each case as a single wire or a single band. They are melted by the thermal input and in this respect the materials are mixed with one another. The coating or three-dimensional structural elements are thereby formed with TiAl on the substrate surface.

Provided is a flux-cored wire for gas-shielded arc welding that contains, per wire total mass, specific amounts of C, Mn, TiO.sub.2 and specific amounts or less of P and S, and contains, in the flux, a specific amount of Ni per wire total mass. The Ni has a ratio (1/2) of 0.50-1.00 when 1 (mass %) is the content per wire total mass of particles having a size of 106 m or less and 2 (mass %) is the content per wire total mass of particles having a size exceeding 106 m.

Provided is a flux-cored wire for gas-shielded arc welding that contains specific amounts of C, Mn, TiO.sub.2, and Ni and specific amounts or less of P and S. The TiO.sub.2 has a ratio (1/2) of 0.90-1.50 when 1 (mass %) is the content per wire total mass of particles having a size of 106 m or smaller and 2 (mass %) is the content per wire total mass of particles having a size exceeding 106 m.

The present invention relates to a flux cored wire and the method and apparatus for manufacturing the same. The flux cored wire in accordance with the present invention can prevent the flux filled inside strip from leaking out and the moisture in the atmosphere from penetrating into the flux. The method of the present invention also does not require longer processing time. For this, the flux cored wire in accordance with the present invention is comprised of: an inner tubular body formed with flat strip by curling up the side edges of the strip into a tubular body having a seam and filed with flux inside; and an outer tubular body formed with flat strip by curling up the side edges of the strip into a tubular body having a seam and wrapping around the inner tubular body in tight contact.

Brazing alloy wire formed from a composite comprising a sheath of at least one ductile first phase and a core comprising particles of a different composition to the sheath, in which: the sheath has an annealing temperature in degrees K the particles have a melting point at least 20% above the annealing temperature of the sheath the particles have a size distribution in which 25% by weight or less comprise particles less than 25 m in size the particles are discrete.

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.