A self-shielded flux-cored welding wire with a special protective slag coating formed in situ and a manufacture method thereof. The self-shielded flux-cored welding wire includes a low-carbon steel belt and a flux core powder, the flux core powder is filled in the low-carbon steel belt, the flux core powder includes the following ingredients in percentage by mass: 60-80% glass powder, 2-8% zirconium oxide powder, 0.05-0.85% graphene powder, 2-8% potassium carbonate sodium powder, 1-3% potassium titanate powder, 2-5% rutile powder, 1-5% corundum powder, 1-3% sodium fluorosilicate powder, and the balance of iron powder, and a weight of the flux core powder accounts for 13-25% of a total weight of the welding wire.

A flux-cored wire for gas-shielded arc welding has a steel outer sheath filled with a flux. The flux-cored wire includes specific amounts, relative to a total mass of the wire, of TiO.sub.2, at least one of Si, an Si oxide and an Si compound, C, Mn, Mo, Ni, at least one of metal Mg and an Mg alloy, an F compound, a K compound, an Na compound, B and a B compound, and Fe, respectively. A total content of each of Ti and a Ti alloy, metal Al and an Al alloy, and V is restricted to the specific range, respectively. A content of Ti is also restricted to the specific range relative to the total mass of the steel outer sheath.

A flux-cored wire for are welding of a duplex stainless steel includes a stainless-steel sheath filled with a flux and contains, with respect to the total mass of the wire, predetermined amounts of Cr, Ni, Mo, N, Mn, and Si, in which letting a Ti alloy content in terms of Ti be [Ti] and letting an Al alloy content in terms of Al be [Al], [Ti] and [Al] are predetermined values, and in which parameter A expressed as A=[Ti]+2×[Al] satisfies a predetermined value, and the balance is composed of Fe, a slag-forming component, and incidental impurities.

[Object] There is provided a flux-cored wire capable of obtaining a weld metal having excellent low temperature toughness and improving welding efficiency, in which preheating performed for preventing cold cracking can be omitted or simplified. [Means for Solving Problems] The flux-cored wire includes one or more of CaF.sub.2, BaF.sub.2, SrF.sub.2, MgF.sub.2, and LiF and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire, one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide are included in the flux-cored wire, and when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire, a ratio of an amount of the CaF.sub.2 with respect to the α is 0.90 or more, and a ratio of the α with respect to the β is 3.0 or more and 15.0 or less.

The invention provides an ignition flux for arc stud welding, including at least 30 wt % of an active agent, with the active agent selected from a group consisting of SiO.sub.2 and TiO.sub.2. As such, the electric arc can be easily created and smoothly formed. The invention further provides an arc stud welding method utilizing such ignition flux. As such, the fastener and the metal workpiece can be tightly connected together without the need of inserting an ignition tip into the welding portion of a fastener.

The present invention provides a flux-cored welding wire comprising a shell having a tubular cavity, which accommodates flux. The shell is made of 400 series stainless steels. The deposited metal formed after the welding using the flux-cored welding wire of the present invention has more uniform chemical compositions. Because the loss of chromium during the transition to the deposited metal is less than 0.1%, recourses is saved and welding cost is reduced. The filling ratio of the flux-cored welding wire of the present invention is 5%-25% (preferably 10%-20%). As a result, not only the stability of the compositions in the flux is increased, but also the disadvantages to the manufacture process caused by high filling ratio are avoided. The flux-cored welding wire of the present invention will not be rusty even after it is exposed to the air for a long time.

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.

A pre-coated steel substrate wherein the coating including at least one titanate and at least one nanoparticle; a method for the manufacture of an assembly; a method for the manufacture of a coated steel substrate and a coated substrate substrate. It is particularly well suited for construction, shipbuilding and offshore industries.

A solder includes a Sn alloy phase and a particle. The particle has a higher Young's modulus than the Sn alloy phase. The particle has a lower linear expansion coefficient than the Sn alloy phase. An electronic component includes a metal terminal joined thereto with the solder.

A Ni-based alloy flux cored wire includes a Ni-based alloy outer sheath and a flux with which the Ni-based alloy outer sheath is filled, and includes, per a total mass of the wire, Ni: 45 mass % to 75 mass %, Cr: 20 mass % or less, Mo: 10 mass % to 20 mass %, Fe: 10.0 mass % or less, TiO.sub.2: 3 mass % to 11 mass %, Ca: 0.01 mass % to 2.0 mass %, F: 1.0 mass % or less (including 0 mass %), and Nb: less than 0.5 mass % (including 0 mass %).