A method and a device for fusion welding one or more steel sheets made of press-hardenable steel, preferably manganese-boron steel; are disclosed. In the method, the fusion welding is performed by supplying filler wire into a molten bath generated a laser beam. In order to improve the hardenability of the weld seam, regardless of whether the steel sheets to be welded to one another are steel sheets of identical or different material quality, the filler wire is coated with graphite particles prior to fusion welding and the filler wire coated in this manner is introduced directly into the molten bath in such a way that the tip of the filler wire melts in the molten bath, the graphite particles are mixed with a waxy or liquid carrier medium to be applied to the filler wire, and the mixture is applied in the form of a coating to the filler wire. The method and the corresponding device are distinguished by a high productivity and a relatively low energy consumption. The method can be implemented with a relatively low equipment outlay.

A tubular welding electrode for arc welding that has improved crack resistance comprises a steel sheath disposed around a granular powder flux fill core. The granular powder flux fill core comprises magnesium oxide and a sulfur source such as iron sulfide.

The present application describes an article having a first metal component joined to a second metal component by a metallurgic joint of presintered powdered metal interposed between contiguous surfaces of the first metal component and the second metal component. The present application also describes a composition for use in a brazing process comprising a presintered powdered metal. The present application also describes a process for brazing including the following steps: presintering a powdered metal; adding the presintered powdered metal to a first and second metal component; and heating the combination of the first and second metal components containing the presintered powdered metal until the powdered metal melts and joins the metal components to form a metallurgic joint.

Provided are an austenitic steel having excellent machinability and ultra-low temperature toughness in a weld heat-affected zone including 15 wt % to 35 wt % of manganese (Mn), carbon (C) satisfying 23.6C+Mn28 and 33.5CMn23, 5 wt % or less (excluding 0 wt %) of copper (Cu), chromium (Cr) satisfying 28.5C+4.4Cr57 (excluding 0 wt %), and iron (Fe) as well as other unavoidable impurities as a remainder, wherein a Charpy impact value of a weld heat-affected zone at 196 C. is 41 J or more, and a method of manufacturing the steel. According to the present invention, a low-cost ultra-low temperature steel may be obtained, a stable austenite phase may be formed at low temperature, carbide formation may be effectively suppressed, and a structural steel having excellent machinability and ultra-low temperature toughness in a weld heat-affected zone may be provided.

A steel sheet for the manufacture of a press hardened part is provided, having a composition of: 0.15%C%0.22%, 3.5%Mn<4.2%, 0.001%Si%1.5%, 0.020%Al0.9%, 0.001%Cr1%, 0.001%Mo0.3%, 0.001%Ti0.040%, 0.0003%B0.004%, 0.001%Nb0.060%, 0.001%N0.009%, 0.0005%S0.003%, 0.001%P0.020%. A microstructure has less than 50% ferrite, 1% to 20% retained austenite, cementite, such that the surface density of cementite particles larger than 60 nm is lower than 107/mm.sup.2, and a complement of bainite and/or martensite, the retained austenite having an average Mn content of at least 1.1*Mn %. Press-hardened steel part obtained by hot forming the steel sheet, and manufacturing methods thereof.

An arc welding method includes performing welding by using a gas and a solid wire. The gas contains Ar. The solid wire includes a steel core wire and a copper plating film formed on a surface of the steel core wire, and the copper plating film has an average grain diameter of 600 nm or less.

A metal cored wire for submerged arc welding, the wire comprising a steel sheath with a core comprising powders of: carbon in a range of about 0.3 wt. % to about 1.2 wt. %; silicon in a range of about 0.1 wt. % to about 3.0 wt. %; manganese in a range of about 9.0 wt. % to about 30 wt. %; chromium in an amount less than about 8 wt. %; nickel in an amount less than about 6 wt. %; molybdenum in an amount less than about 6 wt. %; tungsten in an amount less than about 5 wt. %; copper in an amount less than about 4 wt. %; niobium in an amount less than about 2 wt. %; vanadium in an amount less than about 2 wt. %; titanium in an amount less than about 2 wt. %; nitrogen in an amount less than about 0.4 wt. %; boron in an amount less than about 1 wt. %; at least one of: (i) sulfur in an amount less than about 0.3 wt. %; (ii) phosphorous in an amount less than about 0.03 wt. %; or a combination thereof; and the balance with iron.

Welding compositions for high manganese steel base metals, the composition comprising: carbon in a range of about 0.4 wt % to about 0.8 wt %; manganese in a range of about 18 wt % to about 24 wt %; chromium in an amount of about 6 wt %; molybdenum in an amount of about <4 wt %; nickel in an amount of about <5 wt %; silicon in an amount of about 0.4 wt % to about 1.0 wt %; sulfur in an amount of about <200 ppm; phosphorus in an amount of about <200 ppm; and the balance comprising iron.

Systems and methods for low-manganese welding alloys are disclosed. An example arc welding consumable that forms a weld deposit on a steel workpiece during an arc welding operation, wherein the welding consumable comprises: less than 0.4 wt % manganese; strengthening agents selected from the group consisting of nickel, cobalt, copper, carbon, molybdenum, chromium, vanadium, silicon, and boron; and grain control agents selected from the group consisting of niobium, tantalum, titanium, zirconium, and boron, wherein the grain control agents comprise greater than 0.06 wt % and less than 0.6 wt % of the welding consumable, wherein the weld deposit comprises a tensile strength greater than or equal to 70 ksi, a yield strength greater than or equal to 58 ksi, a ductility, as measured by percent elongation, that is at least 22%, and a Charpy V-notch toughness greater than or equal to 20 ft-lbs at 20 F., and wherein the welding consumable provides a manganese fume generation rate less than 0.01 grams per minute during the arc welding operation.

One embodiment of the present invention provides a carbon filament wire for laser welding of a steel sheet having an aluminum-based coating layer, a laser welding method of a steel sheet having an aluminum-based coating layer by using same, and a welded product produced by same, the carbon filament wire comprising: a resin matrix; and two or more carbon filaments provided inside the resin matrix.