Kobe Steel, Ltd.

Naoki Mukai

Reiichi Suzuki

Tokuji Maruyama

Shun Izutani

Takashi Yashima

The present invention relates to a flux-cored wire for positive polarity gas-shielded arc welding use, in which a flux contains a metal powder and also contains BaFand SrFand AlFand/or CaFas fluorides wherein the content of BaFis 1.0 to 4.5%, the content of SrFis 2.0% or less, the content of CaFis 0.45% or less and the content of AlFis 0.70% or less, at least one of metal elements constituting the flux and the fluorides is a strong deoxidizing metal element having a specified standard formation Gibbs energy, and the content of each of an oxide and a carbonate in the flux is 0.5% or less.

Flux-cored wire, welding method, and weld metal

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┘)+└CO┘+(0.0085×A)−(0.19×A)}≤20.0 (where A={└Cr┘+(4.3×└Nb┘)}).

Flux-cored wire for gas-shielded arc welding and welding method

A welding torch for arc welding in a shielding gas atmosphere, includes: a contact tip for feeding a welding wire; a suction nozzle surrounding the welding wire, and sucking a gas from a space between the suction nozzle and the welding wire; and a shielding gas supply nozzle provided on the outer periphery of the suction nozzle, and supplying the shielding gas toward a welded portion from a space between the shielding gas supply nozzle and the suction nozzle. The welding torch satisfies '7&#x2264;Ltk&#x2264;17 and 0&#x2264;Lts&#x2264;18', where Lts [mm] is a distance between the tip of the contact tip and the tip of the shielding gas supply nozzle, and Ltk [mm] is a distance between the tip of the contact tip and the tip of the suction nozzle.

Welding torch

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.

Growing community of inventors

Fujisawa, Japan

Naoki Mukai