A series of welding filler wires with innovative composition design for fusion welding precipitation-hardened lightweight austenitic Fe—Mn—Al—C alloys. The first class of the welding filler wires is composed of 23-34 wt. % Mn, 7.5-11.5 wt. % Al, 1.35-1.95 wt. % C, with the balance being essentially Fe. After fusion welding, there are high-density of nano-sized (˜3-5 nm) (Fe,Mn).sub.3AlC carbides (κ-carbides) uniformly distributed within the austenite dendrite cells in the fusion zone (FZ). The amount of nano-sized (˜6-10 nm) κ-carbides existing within the eutectic regions is significantly increased and the size of the austenite dendrite cells is substantially reduced. The second class of welding filler wires has the composition of 23-34 wt. % Mn, 7.5-11.5 wt. % Al, 1.40-1.95 wt. % C, 0.1-2.5 wt. % Ti, 0.1-3.0 wt. % Nb, 0.1-2.5 wt. % V, with the balance being essentially Fe. The microstructure of the FZ in the as-welded condition results in formation of substantial amount of nano-sized (˜6-10 nm) face-centered-cubic structured ductile Ti-rich Ti-carbides, Nb-rich Nb-carbides and V-rich V-carbides within the eutectic regions. These carbides are extremely hard (2000˜3500 Hv), enhancing hardness of the obtained FZ.

A series of welding filler wires with innovative composition design for fusion welding precipitation-hardened lightweight austenitic Fe—Mn—Al—C alloys. The first class of the welding filler wires is composed of 23-34 wt. % Mn, 7.5-11.5 wt. % Al, 1.35-1.95 wt. % C, with the balance being essentially Fe. After fusion welding, there are high-density of nano-sized (˜3-5 nm) (Fe,Mn).sub.3AlC carbides (κ-carbides) uniformly distributed within the austenite dendrite cells in the fusion zone (FZ). The amount of nano-sized (˜6-10 nm) κ-carbides existing within the eutectic regions is significantly increased and the size of the austenite dendrite cells is substantially reduced. The second class of welding filler wires has the composition of 23-34 wt. % Mn, 7.5-11.5 wt. % Al, 1.40-1.95 wt. % C, 0.1-2.5 wt. % Ti, 0.1-3.0 wt. % Nb, 0.1-2.5 wt. % V, with the balance being essentially Fe. The microstructure of the FZ in the as-welded condition results in formation of substantial amount of nano-sized (˜6-10 nm) face-centered-cubic structured ductile Ti-rich Ti-carbides, Nb-rich Nb-carbides and V-rich V-carbides within the eutectic regions. These carbides are extremely hard (2000˜3500 Hv), enhancing hardness of the obtained FZ.

Provided is a solid wire for gas metal arc welding, which has a small amount of fume during welding and is suitable as a welding material for high Mn steel materials. The wire has a chemical composition containing, in mass %, C: 0.2% to 0.8%, Si: 0.15% to 0.90%, Mn: 17.0% to 28.0%, P: 0.03% or less, S: 0.03% or less, Ni: 0.01% to 10.00%, Cr: 0.4% to 4.0%, Mo: 0.01% to 3.50%, B: less than 0.0010%, and N: 0.12% or less, with the balance consisting of Fe and inevitable impurities. It may contain at least one selected from V, Ti, Nb, Cu, Al, Ca and REM, if necessary. The wire has excellent manufacturability, can significantly suppress the amount of fume generated during gas metal arc welding, and can easily manufacture a weld joint having high strength and excellent impact toughness at cryogenic temperatures.

The present disclosure relates to a welding composition for joining high manganese steel base metals to low carbon steel base metals, as well as systems and methods for the same. The composition includes: carbon in a range of about 0.1 wt % to about 0.4 wt %; manganese in a range of about 15 wt % to about 25 wt %; chromium in a range of about 2.0 wt % to about 8.0 wt %; molybdenum in an amount of ≤ about 2.0 wt %; nickel in an amount of ≤ about 10 wt %; silicon in an amount of ≤ about 0.7 wt %; sulfur in an amount of ≤ about 100 ppm; phosphorus in an amount of ≤ about 200 ppm; and a balance comprising iron. In an embodiment, the composition has an austenitic microstructure.

This steel sheet has a base steel sheet, a coated portion, and an exposed portion, the shape of the end edge side of the steel sheet and the end portion on the outer side of the base steel sheet is a protruded curve represented by a curvature radius R1 and R1 is 5 μm or more.

A wire for gas-shielded arc welding includes, based on a total mass of the wire: C: 0.01 mass % or more and 0.10 mass % or less, Si: 0.05 mass % or more and 0.55 mass % or less, Mn: 1.60 mass % or more and 2.40 mass % or less, Ti: 0.05 mass % or more and 0.25 mass % or less, Cu: 0.01 mass % or more and 0.30 mass % or less, S: 0.001 mass % or more and 0.020 mass % or less, N: 0.0045 mass % or more and 0.0150 mass % or less, Al: 0.10 mass % or less, and P: 0.025 mass % or less, with the remainder being Fe and inevitable impurities. In the wire, the following relationship is satisfied: 0.1≤[Ti]/[Si]≤3.0, where [Si] is the content of Si (mass %) and [Ti] is the content of Ti (mass %).

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.

An electric resistance welded steel pipe for a torsion beam, in which a base metal portion includes, in terms of % by mass, 0.04 to 0.12% of C, 0.03 to 1.20% of Si, 0.30 to 2.50% of Mn, 0.08 to 0.24% of Ti, 0.005 to 0.500% of Al, 0.01 to 0.06% of Nb, and 0.0005 to 0.0100% of N, a balance including Fe and impurities, wherein V.sub.c90, defined by the following Formulae (i) and (ii), is 200 or more, a mass ratio of Ti content to C content is from 0.85 to 5.00, an areal ratio of ferrite is 80% or more, an average crystal grain size of ferrite crystal grains is 10 μm or less, and an average aspect ratio of ferrite crystal grains is 2.0 or less, in a metallographic microstructure of a central portion in a wall thickness direction of the base metal portion;
log V.sub.c90=2.94−0.75(βa−1)  Formula (i);
βa=2.7C+0.4Si+Mn+0.45Ni+0.8Cr+Mo  Formula (ii).

Provided is a steel material for high heat input welding having excellent welding heat affected zone low-temperature toughness at −55° C. in the case that the steel material is welded by high heat input welding with a heat input of more than 80 kJ/cm. The steel material may be used in low-temperature storage tanks, for example. The steel material for high heat input welding includes, in mass %, C: 0.04 to 0.09%, Si: 0.15 to 0.25%, Mn: 1.40 to 2.00%, P: 0.015% or less, S: 0.0005 to 0.0040%, Al: 0.030 to 0.080%, Ti: 0.005 to 0.025%, B: 0.0003 to 0.0020%, Ca: 0.0005 to 0.0030%, N: 0.0030 to 0.0060%, O: 0.0040% or less, Nb: 0.005% or less, and Mo: 0.005% or less, the balance being Fe and incidental impurities.

A wire for gas-shielded arc welding includes, based on a total mass of the wire: C: 0.01 mass % or more and 0.10 mass % or less, Si: 0.05 mass % or more and 0.55 mass % or less, Mn: 1.60 mass % or more and 2.40 mass % or less, Ti: 0.05 mass % or more and 0.25 mass % or less, Cu: 0.01 mass % or more and 0.30 mass % or less, S: 0.001 mass % or more and 0.020 mass % or less, N: 0.0045 mass % or more and 0.0150 mass % or less, Al: 0.10 mass % or less, and P: 0.025 mass % or less, with the remainder being Fe and inevitable impurities. In the wire, the following relationship is satisfied: 0.1≤[Ti]/[Si]≤3.0, where [Si] is the content of Si (mass %) and [Ti] is the content of Ti (mass %).