A stainless-steel welding wire for use in manufacture of an LNG tank is described. From the welding wire, it is possible to obtain a weld metal having excellent tensile strength and impact value because the contents of Ni, Mn, Mo, and Cr in the welding wire are adjusted. The welding wire can be applied to welding of all of 9% nickel steel, high manganese steel, and stainless-steel materials by adjusting the content relationship of Ni, Mn, Mo, and Cr, and has the effect of obtaining a weld metal with excellent ultra-low temperature toughness in the weld zone.

A stainless-steel welding wire for use in manufacture of an LNG tank is described. From the welding wire, it is possible to obtain a weld metal having excellent tensile strength and impact value because the contents of Ni, Mn, Mo, and Cr in the welding wire are adjusted. The welding wire can be applied to welding of all of 9% nickel steel, high manganese steel, and stainless-steel materials by adjusting the content relationship of Ni, Mn, Mo, and Cr, and has the effect of obtaining a weld metal with excellent ultra-low temperature toughness in the weld zone.

An apparatus and system for preheating and removing surface oxidation of welding wire using electric arcs one via one or more tungsten electrodes is disclosed. The preheating and cleaning electric arcs may occur between tungsten electrodes, or between one or more tungsten electrodes and welding wire. Electric arc preheating of welding wire allows increased efficiency and deposition rates.

An additive manufacturing apparatus forms layers with a material that is molten to produce a formed object. The additive manufacturing apparatus includes a CMT power supply that supplies as a power supply current to heat a wire that is the material fed to a workpiece, to the material; a laser oscillator that produces as a beam source a laser beam that is a beam with which the workpiece is irradiated; and a head drive unit that shifts as a drive unit a feed position for the material on the workpiece and an irradiation position for the beam on the workpiece. The additive manufacturing apparatus shifts the feed position and the irradiation position, with the irradiation position leading in a moving path for the feed position in spaced relation to the feed position.

An additive manufacturing apparatus forms layers with a material that is molten to produce a formed object. The additive manufacturing apparatus includes a CMT power supply that supplies as a power supply current to heat a wire that is the material fed to a workpiece, to the material; a laser oscillator that produces as a beam source a laser beam that is a beam with which the workpiece is irradiated; and a head drive unit that shifts as a drive unit a feed position for the material on the workpiece and an irradiation position for the beam on the workpiece. The additive manufacturing apparatus shifts the feed position and the irradiation position, with the irradiation position leading in a moving path for the feed position in spaced relation to the feed position.

Systems are disclosed relating to a mobile device mounted to a welding helmet such that a wearer of the welding helmet can see a display of the mobile device when wearing the welding helmet. In some examples, the mobile device is mounted such that a camera of the mobile device is unobscured and positioned at approximately eye level, facing the same way the wearer's eyes are facing. In some examples, the simulated training environment may be presented to the user via the display screen of the mobile device, using images captured by the camera of the mobile device, when the mobile device is so mounted to the welding helmet.

A method of connecting together two unit elements (2, 4) of an undersea fluid transport pipe that is subjected to fatigue, by welding together two metallic or bi-metallic unit pipe elements that have been put into abutment via their respective free ends (2a, 4a), the welding being done by making three distinct weld beads (6, 8, 10), with a last weld bead (8) being deposited between two lateral first weld beads (6, 10), and being followed directly by controlled sanding of the weld beads in order to apply compression stresses on them.

A method of connecting together two unit elements (2, 4) of an undersea fluid transport pipe that is subjected to fatigue, by welding together two metallic or bi-metallic unit pipe elements that have been put into abutment via their respective free ends (2a, 4a), the welding being done by making three distinct weld beads (6, 8, 10), with a last weld bead (8) being deposited between two lateral first weld beads (6, 10), and being followed directly by controlled sanding of the weld beads in order to apply compression stresses on them.

A device for wire-arc additive manufacturing, including a welding torch configured to generate an arc for generating a weld pool on a surface of a workpiece, and a wire feeder configured to feed a wire towards the weld pool to generate a weld seam on said surface. According to the present invention, the device comprises a nozzle (6) configured to discharge CO.sub.2 snow onto a surface of a workpiece for cleaning the surface before generating said weld seam on said surface, wherein the nozzle is rigidly connected to the welding torch.

A device for wire-arc additive manufacturing, including a welding torch configured to generate an arc for generating a weld pool on a surface of a workpiece, and a wire feeder configured to feed a wire towards the weld pool to generate a weld seam on said surface. According to the present invention, the device comprises a nozzle (6) configured to discharge CO.sub.2 snow onto a surface of a workpiece for cleaning the surface before generating said weld seam on said surface, wherein the nozzle is rigidly connected to the welding torch.