Systems for multi-wire submerged arc welding including a flux-cored wire electrode comprising an internal flux, the internal flux comprising about 5% to about 70% of a carbonate compound and less than 25% of calcium fluoride (CaF.sub.2) by weight of the flux; an external flux for submerged arc welding, are provided such that, after a submerged arc welding process, the systems provide a weld metal comprising nitrogen in an amount of less than 100 ppm. Methods of performing multi-wire submerged arc welding using a flux-cored electrode and an external flux are also described.

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). In one embodiment, a tubular welding wire includes a sheath and a core. The tubular welding wire includes less than approximately 0.4% manganese metal or alloy by weight, and the tubular welding wire is configured to form a weld deposit having less than approximately 0.5% manganese by weight.

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). In one embodiment, a tubular welding wire includes a sheath and a core. The tubular welding wire includes less than approximately 0.4% manganese metal or alloy by weight, and the tubular welding wire is configured to form a weld deposit having less than approximately 0.5% manganese by weight.

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). In one embodiment, a tubular welding wire includes a sheath and a core. The tubular welding wire is configured to form a weld deposit on a structural steel workpiece, wherein the weld deposit includes less than approximately 2.5% manganese by weight.

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). In one embodiment, a tubular welding wire includes a sheath and a core. The tubular welding wire is configured to form a weld deposit on a structural steel workpiece, wherein the weld deposit includes less than approximately 2.5% manganese by weight.

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%.

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 gas shielded arc welding may contain, based on total mass of the wire: Fe: 78 mass % or more; TiO.sub.2: 4 mass % to 13 mass %; Mn: 1.0 mass % to 2.4 mass %; Cr: 1.0 mass % to 3.0 mass %; Mo: 0.2 mass % to 1.2 mass %; Si: 0.1 mass % to 0.8 mass %; Mg: 0.1 mass % to 1.0 mass %; fluoride (F conversion value): 0.05 mass % to 0.25 mass %; C: 0.01 mass % to 0.10 mass %; V: 0.003 mass % to 0.020 mass %; Nb: 0.003 mass % to 0.020 mass %; and B: less than 100 ppm (including 0 ppm). The contents of Mn, C, and V based on total mass of the wire may satisfy a relationship of 28Mn/(390C+2370V)0.82.

A flux-cored wire for gas shielded arc welding may contain, based on total mass of the wire: Fe: 78 mass % or more; TiO.sub.2: 4 mass % to 13 mass %; Mn: 1.0 mass % to 2.4 mass %; Cr: 1.0 mass % to 3.0 mass %; Mo: 0.2 mass % to 1.2 mass %; Si: 0.1 mass % to 0.8 mass %; Mg: 0.1 mass % to 1.0 mass %; fluoride (F conversion value): 0.05 mass % to 0.25 mass %; C: 0.01 mass % to 0.10 mass %; V: 0.003 mass % to 0.020 mass %; Nb: 0.003 mass % to 0.020 mass %; and B: less than 100 ppm (including 0 ppm). The contents of Mn, C, and V based on total mass of the wire may satisfy a relationship of 28Mn/(390C+2370V)0.82.

The present disclosure relates to tubular welding electrodes that have a metallic sheath surrounding a granular core, wherein the metallic sheath comprises a metal matrix composite (MMC) that includes a ceramic material and aluminum or an aluminum alloy. The ceramic material may be in the form of microparticles or nanoparticles. The present disclosure also relates to method for making such tubular welding electrodes.