Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Hirohisa Watanabe

Hitoshi Ishida

Tetsunao Ikeda

Hiroshi Sugahara

Yushi Sawada

Hiroaki Kawamoto

Ken Yamashita

Shun Izutani

Yoshitomi Okazaki

Masaki Shimamoto

Shigenobu Namba

Koichi Hosoi

Naoki Mukai

Hiroshi Shintate

Hiraoki Kawamoto

Yukinobu Natsume

It is an object to provide a stainless steel flux-cored wire in which the amount of hexavalent chromium in fume can be reduced while maintaining the weldability excellent. The stainless steel flux-cored wire contains, as percentage to the total mass of the wire: Cr: 11-30 mass %; metal Si, Si oxide and Si compound: 0.5-4.0 mass % in total in terms of Si [Si]; fluorine compound: 0.01-1.0 mass % in terms of F [F]; TiO: 1.5 mass % or above; ZrO+AlO: 3.2 mass % or below; Na compound, K compound and Li compound: 0.50 mass % or below in total of each of an amount in terms of Na [Na], an amount in terms of K [K] and an amount in terms of Li [Li]; and satisfies {([Na]+[K]+[Li])&#xd7;[Cr]}/([Si]+4.7&#xd7;[F])&#x2264;10, where [Cr] represents Cr content.

Stainless steel flux-cored wire

The contents of Cr, Fe, Mn, Ti, Si, Cu, N, Al, C, Mg, Mo, B, Zr, and Nb+Ta in a Ni-base alloy weld metal are properly specified and the contents of Co, P, and S in incidental impurities are controlled. In particular, a weld metal having high cracking resistance is formed by specifying the Mn content in a proper range and restricting the contents of B and Zr at low levels. Regarding a Ni-base alloy covered electrode, by specifying the contents of a slag-forming agent, a metal fluoride, and a carbonate serving as flux components in proper ranges and controlling the contents of Mn, Nb+Ta, and Fe in a flux, good welding workability is achieved and a weld metal having good bead appearance is formed.

Ni-base alloy weld metal and Ni-base alloy covered electrode

In a stainless steel flux cored wire comprising a stainless steel shell and a flux filling the shell, the amount of Si contained in the entire wire is 2.5% by mass or higher, preferably 3.0% by mass or higher in terms of SiO, and the amount of at least one compound selected from the group consisting of polytetrafluoroethylene, graphite fluoride and perfluoropolyether contained in the flux is 0.005 to 0.10% by mass of the total mass of the wire in terms of F, preferably 0.020% by mass or higher. By employing such a constitution, in welding of Cr&#x2014;Ni-based and Cr-based stainless steels and other materials, fume generation and hexavalent chromium leaching can be significantly reduced, and excellent welding workability can be provided.

Stainless steel flux cored wire

A weld metal contains Cr: 28.0% to 31.5% by mass, Fe: 7.0% to 11.0% by mass, Nb and Ta: 1.5% to 2.5% by mass in total, C: 0.015% to 0.040% by mass, Mn: 0.5% to 4.0% by mass, N: 0.005% to 0.080% by mass, Si: 0.70% by mass or less (and more than 0%), Al: 0.50% by mass or less, Ti: 0.50% by mass or less, Mo: 0.50% by mass or less, Cu: 0.50% by mass or less, B: 0.0010% by mass or less, Zr: 0.0010% by mass or less, Co: 0.10% by mass or less, P: 0.015% by mass or less, and S: 0.015% by mass or less, the remainder being Ni and incidental impurities.

Ni-base alloy weld metal, strip electrode, and welding method

A flux-cored wire for stainless steel arc welding including an outer sheath made of stainless steel and flux filled up in the outer sheath contains, as percentage to the total mass of the wire, Cr: 22.0-30.0 mass %, Ni: 6.0-12.0 mass %, Mo: 2.0-5.0 mass %, N: 0.20-0.35 mass %, TiO: 4.0-9.0 mass %, SiO: 0.1-2.0 mass %, ZrO: 0.5-4.0 mass %, total of LiO, NaO and KO: 0.50-1.50 mass %, metal fluoride in terms of fluorine amount: 0.10-0.90 mass %, and rare earth element component: 0.10-1.00 mass %, limits C to 0.04 mass % or below, W to 4.0 mass % or below, Cu to 2.0 mass % or below, BiOto 0.01 mass % or below, and limits oxides other than the above to 3.0 mass % or below. With such a composition, it is possible to obtain a weld bead which is excellent in the weldability in welding in all attitudes and is more excellent in the low temperature toughness while keeping excellent pitting corrosion resistance in arc welding of duplex stainless steel and the like.

Flux-cored wire for stainless steel arc welding

An object of the present invention is to provide a Ni base alloy solid wire for welding, which has excellent cracking resistance to ductility dip cracking in weld metal, can increase the tensile strength of the weld metal to not less than the tensile strength of the base material, and has excellent weldability. The present invention provides a solid wire which has a composition containing Cr: 27.0 to 31.5 mass %, Ti: 0.50 to 0.90 mass %, Nb: 0.40 to 0.70 mass %, Ta: 0.10 to 0.30 mass %, C: 0.010 to 0.030 mass %, and Fe: 5.0 to 11.0 mass %, and is regulated to Al: 0.10 mass % or less, N: 0.020 mass % or less, Zr 0.005 mass % or less, P:0.010 mass % or less, S: 0.0050 mass % or less, Si: 0.50 mass % or less, and Mn: 1.00 mass % or less, with the balance including Ni and inevitable impurities.

Ni base alloy solid wire for welding

A weld metal of a high-strength Cr&#x2014;Mo steel formed by shielded metal arc welding contains: 0.04 to 0.10% by mass C, 0.15 to 0.5% by mass Si, 0.5 to 1.0% by mass Mn, 2.00 to 3.25% by mass Cr, 0.9 to 1.2% by mass Mo, 0.01 to 0.03% by mass Nb, 0.2 to 0.7% by mass V, 0.003% by mass or below and above 0% by mass B, 0.02 to 0.05% by mass O, and the balance of Fe and inevitable impurities. A residual extracted by electrolytic extraction from only an unaffected zone of the weld metal contains precipitated Cr in a Cr content below 0.3% by mass, and precipitated Nb in a Nb content of 0.005% by mass or above.

Weld metal of high-strength Cr-Mo steel

A flux-cored wire for stainless steel arc welding having flux filled up in an outer metal sheath made of stainless steel, comprises: as percentage to total weight of the wire, TiO 5.5 through 10.0 mass %, SiO 1.5 through 3.0 mass %, Al O 0.5 through 1.5 mass %, and fluorine compound (by a value expressed in terms of fluorine) 0.10 through 0.15 mass %, and an amount of ZrO is limited to no more than 0.1 mass %, and it has a flux rate of 25 through 45%, and a total amount of slag forming ingredient is 8 through 14 mass % as a percentage to total weight of the wire, and thereby to provide excellent welding workability especially in welding of a thin sheet stainless steel.

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Fujisawa, Japan

Hirohisa Watanabe