Abstract: The invention relates to a process for the arc welding of at least one metal workpiece to a matrix comprising at least one brazed zone, the braze of which contains copper and phosphorus, in which (a) at least one layer of an alloy containing copper and more than 1% tin by weight is deposited on at least one part of the brazed zone and (b) the metal workpiece is welded to the said at least one layer of copper/tin alloy deposited in step (a). The invention relates to a process for manufacturing a brazed copper heat exchanger using the at least one layer of copper/tin alloy. The brazed copper heat exchanger may be used in the cryogenic separation of gases.

Abstract: A method and an apparatus for a hybrid laser beam and electric arc welding process. A laser beam, an electric arc, a shielding gas and a consumable welding wire are used to create a weld on a steel work piece by melting the welding wire. The weld contains 30 to 1000 ppm titanium by weight, at least 0.7% manganese by weight, 50 to 1000 ppm oxygen by weight, and less than 10% nickel. The welding wire is either solid welding wire or cored welding wire, and may contain, in varying percentages: titanium, manganese, iron, nickel, boron, molybdenum, carbon or chromium.

Abstract: Hybrid welding process employing a laser beam combined with an electric arc, with a supply of consumable welding wire and shielding gas, in which the said wire is melted by the said laser beam and/or the said electric arc so as to produce a weld on at least one steel workpiece to be welded, characterized in that the said weld contains 30 to 1000 ppm titanium by weight, at least 0.7% manganese by weight, 50 to 1000 ppm oxygen by weight and less than 10% nickel. Welding wire that can be used in this process.

Abstract: The invention concerns a method for arc-welding of at least a metal workpiece (1) on a matrix (2) comprising at least a brazed zone (3) whereof the brazing contains copper and phosphorus, which comprises the following steps: (a) producing on at least part of the brazed zone (3), a deposition of at least a layer (5, 6, 7) of pure copper or of a copper alloy for which the phosphorus solubility limit is between about 0.1 and 3.5% at solidification temperature; and (b) welding the metal workpiece (1) on said at least one copper layer (5, 6, 7) deposited in step (a). The invention also concerns a method for making a brazed heat exchanger using such a welding process. The invention further concerns the resulting heat exchangers and their use in cryogenic gas separation, in particular air separation in a cryogenic separating unit.

Abstract: The invention relates to a process for the arc welding of at least one metal workpiece (1) to a matrix (2) comprising at least one brazed zone (3), the braze of which contains copper and phosphorus, in which (a) at least one layer (5, 6, 7) of an alloy containing copper and more than 1% tin by weight is deposited on at least one part of the brazed zone (3) and (b) the metal workpiece (1) is welded to the said at least one layer (5, 6, 7) of copper/tin alloy deposited in step (a). Process for manufacturing a brazed copper heat exchanger, in which such a welding process is carried out. Exchangers thus obtained and their use in the cryogenic separation of gases, particularly air gases, in a cryogenic separation unit.

Abstract: Process for manufacturing a welded pipe from a metal strip having two longitudinal edges approximately parallel to each other, which are brought together so as to come approximately into contact with each other and thus form an unwelded pre-tube, the pre-tube then being welded in order to join the edges together. The two edges are welded together to obtain a welded metal pipe by using, approximately simultaneously, at least one laser beam and at least one electric arc, that is to say using a hybrid arc/laser, preferably plasma/laser, welding process. This process can be used to produce weld seams of rectilinear, helicoidal or spiraled shape.

Abstract: The invention concerns a method for welding one or several metal components to be assembled by producing at least one weld joint on said metal components to be welded, said weld joint being obtained by using a laser beam and at least an electric arc, which consists in generating said laser beam using a power-diode laser device. The invention also concerns an installation for implementing the welding method. The invention is useful for welding abutted flanks designed to constitute at least part of a motor vehicle body component.

Abstract: Hybrid welding process using a laser beam and an electric arc to produce a weld bead. The electric arc is established between an electrode connected to a first pole of a current source and at least one workpiece to be welded and connected to a second pole of a current source via at least one electrically conducting earth contactor in contact with the workpiece to be welded. To obtain effective welding, a contact is made between the earth contactor and the workpiece to be welded laterally and/or upstream of the point of impingement of the electric arc on the workpiece(s) to be welded, and considering the direction of formation of the welded joint, so as to balance the forces associated with the induced electromagnetic field acting on the puddle of liquid metal.

Abstract: Hybrid welding process and unit for welding metal workpieces, such as tailored blanks, by using a laser beam and an electric arc, preferably a plasma arc, in which process, after a welded joint has been produced, the laser beam is sent and/or deflected into radiation absorption means, such as an absorption cavity, allowing the radiation of the said beam to be absorbed. The beam continues to be deflected during the welding stop phase after producing one welded joint and before starting to weld a second welded joint. The process and the unit of the invention are particularly suitable for the mass production of workpieces for the motor-vehicle industry, such as tailored blanks that can be used to manufacture, for example, motor-vehicle body components, or for the mass production of pipes.

Abstract: A flux-cored wire for welding shielded by a flow of gas, in particular of the rutile or slag-free type, composed of an outer metal sheath and a central core comprising filling elements, and an MAG gas-shielded welding process using such a flux-cored wire for producing a welded joint on a steel construction, such as an offshore platform or a storage tank. The welded joint obtained has improved impact strength and proved toughness, and contains less than 65 ppm nitrogen, from 300 ppm to 0.12% carbon, from 0.01% to 0.6% silicon, from 0.9% to 1.9% manganese, from 20 ppm to 0.08% titanium, from 1 ppm to 80 ppm boron, from 5 ppm to 150 ppm alumin from 10 ppm to 0.02% niobium and from 10 ppm to 0.02% vanadium.

Abstract: A method of multicasting data from a sender to first, second and third receivers through a network including first and second routers, the method comprising transmitting a data packet from said sender to said first, second and third receivers, detecting at said first, second and third receivers whether said data packet is properly received, transmitting a first reception information signal from said first receiver to said first router by a first path, transmitting a second reception information signal from said second receiver to said first router by a second path, determining, at said first router, in dependence upon said first and second reception information signals, whether said first and second receivers require re-transmission of said data packet and, if so, transmitting information relating to said first and second detection information signals to said second router, determining, at said second router, whether said third receiver requires re-transmission of said data packet and, if not, instructing sai

Abstract: Process for welding one or more metal workpieces to be joined together by producing at least one welded joint between the edges to be welded of the said metal workpiece or workpieces, the said welded joint being obtained by using at least one laser beam and at least one electric arc, in which process, during welding of the joint, at least one part of the welding zone comprising at least one part of said welded joint is shielded during the operation with at least one shielding atmosphere formed by a gas mixture consisting of argon and/or helium with a content greater than or equal to 70% by volume; and at least one additional compound chosen from H2, O2, CO2 and N2 with a content of 0 to 30% by volume.

Abstract: Process for manufacturing a welded pipe from a metal strip having two longitudinal edges approximately parallel to each other, which are brought together so as to come approximately into contact with each other and thus form an unwelded pre-tube, the pre-tube then being welded in order to join the said edges together. The two edges are welded together to obtain a welded metal pipe by using, approximately simultaneously, at least one laser beam and at least one electric arc, that is to say using a hybrid arc/laser, preferably plasma/laser, welding process. This process can be used to produce weld seams of rectilinear, helicoidal or spiralled shape.

Abstract: Hybrid welding process using a laser beam and an electric arc to produce a weld bead. The electric arc is established between an electrode connected to a first pole of a current source and at least one workpiece to be welded and connected to a second pole of a current source via at least one electrically conducting earth contactor in contact with the workpiece to be welded. To obtain effective welding, a contact is made between the earth contactor and the workpiece to be welded laterally and/or upstream of the point of impingement of the electric arc on the workpiece(s) to be welded, and considering the direction of formation of the welded joint, so as to balance the forces associated with the induced electromagnetic field acting on the puddle of liquid metal.

Abstract: Hybrid welding process and unit for welding metal workpieces, such as tailored blanks, by using a laser beam and an electric arc, preferably a plasma arc, in which process, after a welded joint has been produced, the laser beam is sent and/or deflected into radiation absorption means, such as an absorption cavity, allowing the radiation of the said beam to be absorbed. The beam continues to be deflected during the welding stop phase after producing one welded joint and before starting to weld a second welded joint. The process and the unit of the invention are particularly suitable for the mass production of workpieces for the motor-vehicle industry, such as tailored blanks that can be used to manufacture, for example, motor-vehicle body components, or for the mass production of pipes.

Abstract: A flux-cored wire for welding shielded by a flow of gas, in particular of the rutile or slag-free type, composed of an outer metal sheath and a central core comprising filling elements, and an MAG gas-shielded welding process using such a flux-cored wire for producing a welded joint on a steel construction, such as an offshore platform or a storage tank. The welded joint obtained has improved impact strength and improved toughness, and contains less than 65 ppm nitrogen, from 300 ppm to 0.12% carbon, from 0.01% to 0.06% silicon, from 0.9% to 1.9% manganese, from 20 ppm to 0.08% titanium, from 1 ppm to 80 ppm boron, from 5 ppm to 150 ppm aluminum, from 10 ppm to 0.02% niobium and from 10 ppm to 0.02% vanadium.

Abstract: A flux-cored wire for welding shielded by a flow of gas, in particular of the rutile or slag-free type, composed of an outer metal sheath and a central core comprising filling elements, and an MAG gas-shielded welding process using such a flux-cored wire for producing a welded joint on a steel construction, such as an offshore platform or a storage tank. The welded joint obtained has improved impact strength and improved toughness, and contains less than 65 ppm nitrogen, from 300 ppm to 0.12% carbon, from 0.01% to 0.6% silicon, from 0.9% to 1.9% manganese, from 20 ppm to 0.08% titanium, from 1 ppm to 80 ppm boron, from 5 ppm to 150 ppm alumin from 10 ppm to 0.02% niobium and from 10 ppm to 0.02% vanadium.

Abstract: A flux-cored wire for welding shielded by a flow of gas, in particular of the rutile or slag-free type, composed of an outer metal sheath and a central core comprising filling elements, and an MAG gas-shielded welding process using such a flux-cored wire for producing a welded joint on a steel construction, such as an offshore platform or a storage tank. The welded joint obtained has improved impact strength and improved toughness, and contains less than 65 ppm nitrogen, from 300 ppm to 0.12% carbon, from 0.01% to 0.6% silicon, from 0.9% to 1.9% manganese, from 20 ppm to 0.08% titanium, from 1 ppm to 80 ppm boron, from 5 ppm to 150 ppm aluminum, from 10 ppm to 0.02% niobium and from 10 ppm to 0.02% vanadium.

Abstract: A device and a method of manufacturing a metal tube made from a metal sheet with two substantially straight and parallel longitudinal edges, in which method the two longitudinal edges of the metal sheet are welded together using a welding method employing at least one electric arc between at least one electrode (Ei) and the metal sheet in contact with at least one ground lead (PMi), in which the plane of each ground lead (PMi) is positioned a distance (e.sub.i) of between -5 mm and +25 mm with respect to the plane of each corresponding electrode (Ei), the positive direction being the direction of relative travel of the metal sheet with respect to the at least one electrode (Ei).

Abstract: The characteristics of a weld made by electron beam welding are improved by introducing into the region of the pieces to be welded, which is subjected to remelting during welding, a material which is obtained by applying an arc welding process, or a process for remelting under slag, to a mild or slightly alloyed steel. The introduction of the material into the region of the weld increases the production of acicular ferrite which increases the tensile strength of the weld. The material may be introduced by providing a deposit of it over part or the whole of the surface of one or both of the pieces to be welded, by introducing a mass of it between the surfaces to be welded or as a filler wire.