Abstract: A shielding gas composition and method of using the shielding gas in gas metal arc welding or flux cored are welding, or composite cored arc welding. The gas is a mixture of argon, helium and carbon dioxide blended to facilitate metal transfer in any position for all the named processes.

Abstract: A low carbon metal-core weld wires for gas shielded welding operations having a low carbon steel sheath with a carbon content not more than approximately 0.008% C. A metal-core composition of the weld wire has little and preferably no fluxing agents, so that the weld deposit produced thereby has no more than occasional slag islands formed thereon. The metal-core composition may have carbon added thereto to improve the mechanical properties of weld deposit produced thereby, and the metal-core composition is between approximately 16% and approximately 20% of a total weight of the metal-core weld wire. The low carbon metal-core weld wire has a relatively low fume generation rate and produces weld deposits with excellent mechanical properties.

Abstract: A soldering iron device has a gas passage formed by enclosing a soldering iron tip 3 of an electric soldering iron with double pipes 6 and 7 to make a nozzle. By providing projections A, B and C in the spacing between said double pipes, the double pipes are prevented from any eccentricity and biasing, and the velocity of an inert gas G to be supplied is made slow to ensure that the gas is jet through the nozzle tip end. Further, engulfing of oxygen in the atmospheric air can be suppressed, whereby it is possible to prevent defective wetting of solder due to high temperature oxidation of the soldering iron tip and to suppress high temperature oxidation of workpieces and flux cored solder alloy and flux, and excellent solderability is obtained.

Abstract: A welding (10) for use with gas metal arc welding wherein the welding head (10) has a diffuser body (16) with an inlet end (28) and an outlet end (38). A welding tip (14) is axially located within the diffuser body (16) and extends axially beyond the outlet end (38). The diffuser body (16) has a gas outlet (37) and a gas inlet (34), and there is at least one gas channel (36) operatively connecting the gas inlet (34) and the gas outlet (37). One or more diffusing lenses (20) are provided between the gas outlet (37) and the outlet end (38).

Abstract: A method for applying a stainless steel weld overlay on a substrate, e.g., a carbon steel or low alloy steel, uses an arc welding process. The process includes welding a stainless steel weld overlay onto the substrate using a shielding gas mixture including greater than 2% nitrogen by volume with balance being an inert gas or a mixture of inert gases. The nitrogen is of a sufficient concentration so as to eliminate solidification cracking in the weld overlay. In addition, the nitrogen may help to eliminate a mismatch in me coefficient of thermal expansion between the weld overlay and the substrate. Furthermore, if the weld overlay comprises only a single layer, the nitrogen concentration in the shielding gas mixture may be less than 2%.

Abstract: The invention relates to a welding apparatus, that includes a welding machine (1), shielding gas unit (4) and a nozzle part (3), that is connected to the welding machine (1). The welding rod (L), that is led to the welding point from the shielding gas unit (4), is arranged to be melted while being protected by the shielding gas in connection with the nozzle part (3) by means of an arc achieved by influence of the supply unit (1b) for welding current. To improve fire safety of the welding occasion, the welding apparatus includes furthermore a coupling arrangement (X), that comprises furthermore organs (X2), that are arranged to interrupt at least supply of welding current to the nozzle part (3) and to lead shielding gas to the point exposed for fire or that is burning through the nozzle part (3) at an essentially increased volume flow rate in respect to the welding occasion.

Abstract: An improved method for welding and passivation forms a chromium oxide passivated film over the welded portion during the welding process. In a shielding step, a backshield gas, preferably argon, is flowed around the welding site. In a welding step, an arc gas, preferably argon with approximately 10% hydrogen and less than 1 ppm moisture content, is flowed through the welding head and a welded joint is formed, for example by high speed tungsten-inert gas (TIG) orbital welding. In the passivation step, a process gas, preferably argon with approximately 30-100 ppm of oxygen and less than 1 ppm moisture content, and preferably less than 1 ppb moisture content, is flowed over the welded portion to form a chromium oxide passivated film on the welded portion. The process gas is passed through a gas purifier prior to being flowed over the welded portion to maintain its moisture level at less than 1 ppb.

Abstract: The invention relates to an electric arc welding torch comprising a torch body having an electrode holder (3) and a nozzle (4), said nozzle (4) being formed with at least one nozzle partition (2) having an internal surface (2a) and an external surface (2b), characterized in that at least one supplemental partition (8) extends along at least one portion of the internal surface (2a) and/or external surface (2b) of the nozzle partition (2), in that one of said partitions (2, 8) is electrically conductive and in that the other of said partitions (2, 8) is electrically insulating and the use of such a torch in an electric arc welding or cutting process under a protective gas, particularly a TIG, MIG or MAG welding process.

Abstract: A shielding gas mixture for gas-metal arc welding of austenitic stainless steel is provided in which the gas mixture comprises from about 2 to about 5% carbon dioxide, from about 1 to about 4% nitrogen, and the balance being argon. Also, a process for welding austenitic stainless steel is provided by forming an electric arc between a nonconsumable electrode and the workpiece and in which the gas mixture is used.

Abstract: A welding nozzle contains a plurality of orifices through which a shielding gas is directed. The shielding gas is routed by an inner member to flow directly onto the weld area in an axial direction through the inner member and in a radial direction through the plurality of orifices. The welding nozzle causes the shielding gas to completely surround the weld area and optimizes weld quality. This welding nozzle is particularly suited for use with a gas stream shielded arc welding device.

Abstract: A backpressure controlling device for welding purge gas comprising a vertically oriented cylindrical housing, a water outlet at the bottom of the housing and a water outlet in the wall of the housing and spaced up from the bottom of the housing, the water outlets defining a water volume space in the housing, a gas inlet tube and a concentric gas outlet tube surrounding the gas inlet tube, the gas inlet tube being adjustably positioned in the housing and having a length such that one end thereof extends below the water inlet and the other end thereof extending out of the housing for connection to a pipeline carrying purge gas, the gas outlet tube being secured to a spacer wall spaced from the upper end of the housing and extending to a point above the water outlet and communicating with the exterior of the housing through openings in the wall of the housing above the spacer wall, the housing being of a size such that the volume of the space above the water inlet is at least about one and one-half times as grea

Abstract: A protective gas shroud for welding is provided by: positioning an article into a chamber having an opening at the top to permit welding of the article; introducing argon into the body of the chamber to act as a protective gas shroud for the article during welding; introducing helium into the open top of the chamber to assist in maintaining a protective gas shroud around the article during welding; and welding the article within the protective gas shroud.

Abstract: A hybrid welding apparatus for subjecting a base metal to gas-shielded arc welding and laser welding comprises a laser generator for emitting a laser beam and a condenser optical system for condensing the laser beam to laser weld the base metal. The condenser optical system includes a plurality of lenses, each having a hole portion in the center thereof. A tubular supply holder for supplying a welding wire is passed through these respective hole portions of the lenses and located substantially coaxially with the axis of the condenser optical system. The laser beam and welding wire to be applied to the base metal are arranged coaxially, so that laser-welding and arc-shielded welding can be simultaneously performed with a wide angle between the welding head and a bevel of the base metal, thereby deepening penetration of the weld at an increased welding speed.

Abstract: An apparatus for underwater welding has a housing and a diverter. The diverter is inside the housing and has an outer sheath and an inner sheath. A gap between the housing and diverter passes a screening fluid to form an outer screening jet that prevents water from flowing into a weld site near the electrode. The inner sheath forms a pair of channels in the inner diverter. One channel passes a shielding fluid that shields the weld site. The other channel forms an exhaust line for venting the weld site during welding.

Abstract: An electric welding device for welding a fastening element (4) having a through-duct (17) on a workpiece is proposed. The welding device comprises a conveying and holding system (1) having a guide member (2) with a guide duct (3). The fastening element (4) is supplied to the guide duct and is held in one of its ends during the welding process. Within the guide duct there is arranged a loading member (6) which is capable of moving to and fro in the longitudinal direction thereof and has a head (7) which can be brought to rest on the fastening element (4). The loading member has a duct (9) with an inlet (10) and an outlet (11) formed on the head (7). A gas supply duct (12) opens into the guide duct (3). The loading member (6) closes the gas supply duct (12) in a first position. In a second position, the loading member (6) connects the inlet (11) to the gas supply duct (12) so a gas flows to the welding position during the welding process.

Abstract: MIG welding apparatus includes a torch body; a machine barrel extending forwardly of the torch body; a contact tip extending forwardly from the machine barrel; and a pair of gas supply tubes extending along and substantially parallel to the contact tip, enabling reduction in the weld prep angle to about three degrees.

Abstract: A method and device for welding pipe onto a piping network at a joint comprising introducing an inert purging gas under pressure at a substantially constant flow rate at one end of the pipe away from the weld joint, providing a flow restriction at the end of the piping network away from the weld joint, diverting a minor portion of the inert purging gas flowing through the piping network into and through a constant back pressure maintaining device for maintaining a substantially constant back pressure on the inert purging gas in the piping network during the welding, whereby any changes in back pressure occurring in the piping network cause a greater or lesser amount of the inert purging gas to flow through the constant back pressure maintaining device, thereby enabling production of precise and highly reproducible welds with an orbital welder.

Abstract: A gas injection disc is provided which includes an outer ring and a tubular modular insert which slips into the outer ring. The outer ring is provided with an inner bore, a ring-shaped plenum located around the inner bore, an outer gas sealing surface around the plenum, and two gas feed paths extending from the periphery of the outer ring to the plenum. The gas feed paths are each provided with a gas feed attachment for coupling gas supply tubes thereto. The insert is provided with a plurality of radially aligned injectant holes, an inner gas sealing surface, and an axial bore. The insert is seated in the inner bore of the outer ring such that the inner and outer gas sealing surface face each other with a small gap provided therebetween which enables the insertion of the insert into the inner bore. The insert thereby substantially encloses the plenum, and the injectant holes are aligned with the plenum to receive injectant gases and direct the injectant gases into the axial bore of the insert.

Abstract: An alloy comprising nickel, chromium, molybdenum, manganese, nitrogen and on in amounts such that a weld metal formed therefrom is austenitic, wherein nitrogen is present in a concentration of from about 0.1 to about 0.2% of the alloy in weight percent. The weld metals prepared from the alloys of the present invention possess superior properties as compared to other stainless steels. These properties include inter alia a superior tearing modulus, fracture toughness, and yield strength, even at cryogenic temperatures.The present invention further provides a method for welding a metal part which is intended for exposure to cryogenic temperatures comprising welding the metal part using a welding electrode comprising nickel, chromium, molybdenum, manganese, nitrogen and iron in amounts such that a weld metal formed therefrom is austenitic, wherein nitrogen is present in the electrode in a concentration of from about 0.1 to about 0.2% of the electrode in weight percent.

Abstract: Automatic orbital welding system for welding conduit sections. The system may include a weld head having a clamping assembly for aligning the conduit sections. The weld head may include an electrode for applying heat to the conduit sections. Inert purge gas is preferably passed through the conduit sections while the orbital weld is formed to exclude contaminants from the weld area. A purge assembly is preferably connected to one of the conduit sections. The purge assembly preferably includes a purge restrictor having a valve disposed therein to allow the pressure within the conduit sections to be precisely controlled within a predetermined range during welding to promote the formation of a suitable weld.

Abstract: The present invention provides a system for supplying a high-pressure medium gas suitable for processing a semiconductor to be processed by heating under isostatic pressure in a short cycle.The system includes a gas holder containing a high-pressure medium gas, a compressor for pressurizing the high-pressure medium gas supplied from the gas holder, a high-pressure vessel having a heater, an accumulator for storing the high-pressure medium gas pressurized by the compressor, a first evacuation unit for evacuating the inside of a pipeline for the high-pressure medium gas, a vacuum casing for holding the opening of the high-pressure vessel in a vacuum, a second evacuation unit for evacuating the inside of the vacuum casing, and a valve unit for connecting the high-pressure vessel and the accumulator so that series connection and parallel connection can be switched on the outlet side of the compressor.

Abstract: A filler material guide nozzle assembly for feeding fusible filler metal wire or other metal forms into reduced-width, high-aspect-ratio (ratio of depth to width) metallic joints with control and stability of the filler metal position as it enters the molten pool area. The filler material guide nozzle assembly is designed with a thin but stiff non-circular cross-sectional shape, with its width dimension significantly greater than its thickness dimension, and can be utilized in very reduced-width welded or otherwise fused joints to provide the accuracy and stability required for reliable filler material addition. During use with welding, brazing and similar processes, the outlet end of the nozzle is located within the joint near the bottom, close to the area to be fused. The width dimension of the nozzle apparatus is oriented parallel to the depth of the weld joint, and the thickness dimension is oriented perpendicular to the depth of the joint.

Abstract: Narrow groove welding is accomplished with a welding apparatus containing an improved gas lens made of a sintered bronze material. The sintered bronze material requires the use of a higher gas supply pressure than is commonly used, but it results in a higher volume of laminar gas flow, thereby facilitating deep narrow groove welds. The sintered gas lens does not require the use of a skirt below the lens to maintain a column of laminar gas flow, thereby making it possible to mount a light source below the lens directly within the flow of cover gas and away from the line of view of the operator.

Abstract: A welding apparatus and shield are provided for safely and effectively welding metal structures. The shield includes a translucent body having an oblique end surface which, in part, extends beyond the end of a gas nozzle of an arc welding apparatus. The operator may safely view the arc plasma generated between the nozzle and a workpiece through a relatively flat portion of the shield. The shield substantially covers the arc plasma while in use, protecting the operator as well as bystanders.

Abstract: A shielding gas pre-flow time control system for a gas metal arc welder for generating an arc simultaneously with the turning on of a torch switch for directing a torch to a normal position while maintaining a sufficient pre-flow time of shielding gas for more than one (1) second. The gas metal arc welder includes a welding power source, a wire feeding device and a welding torch in which, when the torch switch is firstly turned on, only the shielding gas solenoid valve is activated to cause the shielding gas solenoid valve is actuated to cause the shielding gas to be pre-flowed. When the switch is secondly turned on, during the pre-flow time, the wire feeding device is operated and simultaneously a voltage is applied to the wire being fed and an arc is generated so as to start the welding. When the torch switch is turned off, wire feeding device is stopped, the shielding gas feed is stopped and the welding arc is stopped, all at the same time.

Abstract: A method of metal-inert-gas arc welding which reduces spatter in the welding process, wherein a liquid (8), preferably a hydrocarbon, is dispersed in the inert gas during the welding process. At a weld site (2), the use of the liquid (8) dispersed in the gas prevents any spatter formed from adhering to any surface adjacent the welding hand piece (3). The liquid may be dispersed in the gas by passing the gas through the liquid in a container (7) located between the gas supply (12, 13) and the welding hand piece (3), or may be injected into the gas as a vapor or free mist.

Abstract: A weld spring clip used to tack weld two pipes together using a tungsten inert gas welder and a shield gas includes a reflector that can be inserted within a weld seam using a handle. The reflector, which is attached to an arm and a handle, is positioned beneath the desired weld site on the interior of the pipes. The handle biases the clip in place on the pipe at the seam, and a point on the end of the reflector assists in aligning the reflector at the seam. In position, the reflector reflects the shield gas toward the interior of the weld site. By reflecting the shield gas, oxidation along the interior surface of the weld site is prevented, and the need for a back gas is eliminated.

Abstract: In arc welding of aluminum using an inert gas, such as argon or a mixture of argon and helium, 80 to 250 ppm of a mixture of N.sub.2 and N.sub.2 O is added to the inert gas to improve the welding process and the welding result.

Abstract: A backside shield assembly for use during plasma arc welding. Two elongated closed boxes are supported in a selected spaced apart distance suitable for positioning the boxes on opposite sides of the backside of a weld line. Each box includes an inlet tube for an inert gas that generates a first side of the box and communicates with an elongated tube running along the inner surface of the first side. Perforations are provided in the elongated tubes. The balance of the interior of each box contains a flow diffusing material. The second box side, opposite the first side, is perforated. In use, the assembly is placed inside a conventional welding chill bar channel with the boxes on opposite sides of a weld line. The second surface is spaced slightly from the panel to be welded. An inert gas is directed through the inlet tubes, elongated tube perforations, diffusing material and out through the second side perforations.

Abstract: A welding system for superhigh purity gas supply system, capable of removing easily and completely the metals deposited, during the installation of the superhigh purity gas pipe system, on the outer surfaces of the portions of the pipes which are closed to the portions to be welded thereof and on the inner portions of these pipes, and capable of setting up a superhigh purity gas supply system in a short period of time.

Abstract: A weld shield apparatus provides an atmosphere of inert gas within a conduit in an underbead region where an external weld joint is to be produced. The weld shield apparatus includes a diffuser structure having a convex exterior surface that is defined by a wall structure, the convex exterior surface is shaped to fit within the conduit and to be separated from an inner wall of the conduit by a clearance space. The diffuser wall structure is comprised of a porous material which enables gas communication between an inlet to the diffuser and the convex exterior surface. A seal is positioned immediately upstream from the diffuser structure and is positioned to engage the inner walls of the conduit so as to prevent the passage of gas in an upstream direction. A source of gas is coupled to the inlet to the diffuser structure and enables inert gas to pass through the porous material and to flow in a laminar manner, via the clearance space, past the underbead region and into the downstream region of the conduit.

Abstract: An arrangement for butt-welding cylindrical sections of large, thin-wall tanks includes a rotatable mandrel with side-by-side sets of radial position adjusters. Each set of adjusters bears on one of the tank sections adjacent the seam, to prevent the sections from sagging out-of-round. The mandrel rotates relative to the welder, so that a continuous seam is formed. A purge chamber is fixed in position behind the seam at the weld head, and is flushed with inert gas. The purge chamber includes a two-sided structure which is contiguous with the cylindrical sections and a circumferential vane to form an open-ended tube-like structure, through which the radial position adjusters pass as the mandrel and cylindrical workpiece sections rotate. The tube-like structure is formed into a chamber by a plurality of movable gates which are controlled to maintain a seal while allowing adjusters to progress through the purge chamber.

Abstract: A pulsed arc welding apparatus includes a consumable electrode wire which is fed toward a workpiece at a wire feeding rate, a power supply for supplying a welding current to the wire to produce a droplet at the end of the wire by the heat of arc, a pulse form setting part for setting a pulse form of the welding current supplied by the power supply, based on a peak current and a pulse duration, an optimum pulse determining part for determining a peak current and a pulse duration for each of pulses of the welding current based on an average current and for supplying the peak current and the pulse duration to the pulse form setting part so that each respective peak current and each respective pulse duration of the welding current supplied to the wire have a minimum value needed to transfer a droplet from the wire to the workpiece for each pulse at a rate synchronous with the wire feeding rate, and an average current setting part for setting the average current based on the wire feeding rate and for supplying the

Abstract: A TIG welding system for controlling the weld shape for the seal welding of a small pressurization hole in the end plug of nuclear fuel rods. The controlled shape of the seal weld enables improved ultrasonic detection capabilities. The system achieves the desired weld shape by controlling the pressure differential between the interior and exterior volumes of the fuel rod. The weld box pressure is decreased in accordance with Boyle's law while the weld material for sealing the hole is molten. The system uses an output from the weld electronics as an input to a programmable logic controller ("PLC"). After a programmed time delay, the PLC outputs a signal to a solenoid valve to open a "ballast" volume. The expansion of gas from the weld box into the ballast volume causes a sudden drop in pressure to a level below the pressure inside the fuel rod. As a result of this pressure differential, the molten weld material forms a concave weld upon solidification.

Abstract: The present invention is a method for welding difficult-to-weld metal components as illustrated in the welding of a receiver for a weapon. The method reduces net distortion by a number of techniques, including: (1) cooling the weld with Carbon Dioxide (CO.sub.2) preheated with the welding torch tip; (2) use of not more than approximately 4% oxygen in the shield gas to enable hotter, faster welding; (3) the use of a reduced voltage and wire feed rate at the end of a weld to avoid cracking; (4) the intentional use of distortion to reduce net distortion; and (5) sequencing of welds to reduce distortion. Distortion can be introduced in the stamped parts as they are made or when placed in a fixture for welding that, when welded, have less distortion than before. Distortion can also be countered by welding parts in a sequence where a subsequent weld reduces the distortion of a previous weld.

Abstract: This invention is of a Cr--Mo steel pipe of a wall thickness of 13 mm or less, containing C: 0.03-0.10 wt %, Si: 0.50-1.00 wt %, Mn: 0.30-0.60 wt %, P.ltoreq.0.007 wt %, S.ltoreq.0.020 wt %, Cr: 1.00-1.50 wt %, Mo: 0.45-0.65 wt %, Al: 0.002-0.010 wt % and N: 0.002-0.010 wt % and the remainder consisting of Fe and unavoidable impurities for which preheating and postheating treatments for the prevention of weld cracking and stress corrosion cracking can be effectively omitted, said steel pipe of this invention being suitable for steam piping applications such as STPA23 used in power generation plants, etc.

Abstract: An apparatus and method for purging reactive gases from the vicinity of a molten weld during the welding process, having particular application to the welding of industrial process piping systems and pipelines, especially stainless steel and other alloy pipelines. A system is disclosed for boosting purging speed and efficiency by providing a multidirectional flow of purging gas adjacent to the interior walls of the pipe sections being joined. The rate of purge gas flow is automatically adjusted in response to changing gas pressures in the vicinity of the progressing weld.

Abstract: An apparatus for providing a gas shield includes two radially adjustable walls disposed in spaced relation to each other along a substantially common central axis, each wall including a plurality of radially oriented wall segments defining a substantially flat, round wall having a circumference; a wedge structure for radially displacing the plurality of radially oriented wall segments between an expanded position wherein the circumference of each wall is expanded and a withdrawn position wherein the circumference of each wall is withdrawn; and a conduit for introducing a shield gas into a space defined between the two radially adjustable walls.

Abstract: A process to avoid or limit corrosion at the junction of two piping comprising devices welded together, said piping comprising devices being adapted to flow corrosive gases through them, said process comprising the steps of:a) providing a first piping comprising device and connecting it to an inert gas source;b) purging it with an inert gas comprising substantially not more than 10 ppb of an oxidizing gas selected from the group consisting of oxygen, carbon dioxide, water vapor or mixtures thereof, said inert gas flowing from a first opening to a second opening of said piping comprising device;c) providing a second pipe comprising device in flow communication with the first one, while continuing to purge the first piping comprising device;d) welding the two piping comprising devices, said welding being carried out under an inert gas atmosphere; ande) repeating steps c and d if necessary.

Abstract: An open faced trailing weld shield for constraining an inert gas to a welding puddle area and a solidifying weld area of a joint of abutting metal members that are reactive in the atmosphere at an elevated temperature while permitting viewing of such weld areas as a welding torch to which the shield is attached traverses the joint in a welding operation and permitting viewing of such weld areas to monitor the weld procedure and changing weld parameters as may be required. The shield includes a U-shaped tube member having closed end leg portions and a plurality of spaced downwardly opening aperture. A frame member closely surrounds the U-shaped tube member and is provided with a flared downwardly extending opening so that an inert gas that is introduced into the tube member flows downwardly to shield the weld puddle and the solidifying weld area until it has cooled sufficiently to be nonreactive with the atmosphere.

Abstract: A gas shielding apparatus for shielding a weld with a gaseous substance. The gas shielding apparatus includes a shroud body mountable to a torch body having a first plenum for producing a primary shield stream and a first delivery structure for delivering the gaseous substance to the first plenum. The shroud body has a second plenum defining a secondary shield stream substantially surrounding the primary shield stream. A trailer shield portion extends laterally from the shroud body and has a second plenum for producing a trailer shield stream. The apparatus also includes a second delivery structure for delivering measured amounts of the gaseous substance from the first delivery structure to the second plenum and the third plenum. The second delivery structure is coupled to the first delivery structure upstream from the primary plenum when the shroud body is mounted to the torch body.

Abstract: Devices for monitoring, calibrating and maintaining a manufacturing robot. The first device comprises a reference pin mounted to a first member and a reference aperture located on a second adjacent member wherein the reference pin is inserted into the reference aperture when the two members are at their zero reference location. A second device checks tip alignment by periodically passing the welding tip of a welding torch through a V-shaped notch in a gauging block. The gauging block is electrically conductive and if the tip contacts the sidewalls of the V-shaped notch an electrical circuit is completed signalling the robot controller of tip misalignment. A third device comprises a shielding gas monitor having a closed tube to which the welding torch is applied for expelling shielding gas into the tube. The tube is in fluid communication with a flow gauge that measures gas flow and signals the controller if gas flow is insufficient.

Abstract: An apparatus and method for purging reactive gases from the vicinity of a molten weld during the welding process, having particular application to the welding of industrial process piping systems and pipelines, especially stainless steel and other alloy pipelines. A system is disclosed for boosting purging speed and efficiency by providing a multidirectional flow of purging gas adjacent to the interior walls of the pipe sections being joined. The rate of purge gas flow is automatically adjusted in response to changing gas pressures in the vicinity of the progressing weld.

Abstract: A shield protects the back side of a molten and solidifying weld on a structure being welded from the deleterious effects of ambient gases, such as oxygen and nitrogen. The shield is in the form of a continuous tubular chamber surrounding an open central area, allowing clear viewing of the weld. The chamber is bounded by two spaced skins and inner and outer walls extending between the skins. An inert gas can be introduced into the chamber under pressure. One skin is generally planar and perforated, allowing the gas to exit the chamber. In use, the chamber is secured to a welding device for movement therewith, with the central opening opposite the weld head and the perforated skin adjacent to the panel being welded. As welding proceeds, an inert gas is fed into the chamber and escapes through the perforations and passes into the central area, preventing entry of ambient air which would contaminate the weld during welding and solidification of the weld.

Abstract: The present invention relates to a method of producing a protective gas consisting of 0.0010-0.100 percent by volume nitric-oxide, 0-90 percent by volume helium, 0-5 percent by volume hydrogen, 0-50 percent by volume carbon dioxide, and the remainder argon. The invention also relates to a gas mixture for producing the productive gas. The method of producing the protective gas is characterized by dissolving nitric oxide in condensed argon to a concentration of 0.0010-0.100 percent by volume, calculated on gas phase, vaporizing the resultant solution and mixing remaining constituents in the vaporized solution in such proportions as to obtain a protective gas of the predetermined composition. The gas mixture used for producing the protective gas is characterized in that it consists of 0.0010-0.100 percent by volume nitric oxide in condensed argon, calculated on gas phase, and is preferably held under an overpressure.

Abstract: An improved method and apparatus for shielding inert gas from seeping out of metal pipes in a welding application wherein a high-temperature resistant purge strap is placed around the weld gap and the pipe ends. Advantageously, the purge strap is equipped with a window to allow the welder access to the pipe ends. Dams may be inserted into each pipe near the end to be welded, the purge strap placed about the pipes covering the end of each, and inert gas pumped into the pipes, displacing the air within the pipes. A weld bead is laid into the gap and the purge strap is shifted around the circumference of the pipes to allow completion of the weld. The purge strap device is also disclosed.

Abstract: The invention relates to a process for the electric welding of two weld parts by the flow of electric current through a welding point and the use of fluid such as an inert or protective gas to inhibit or prevent or eliminate oxidation at the welding point. The fluid is supplied through a continuous bore in one weld part and is directed toward the welding point, so that the fluid sweeps over the welding point radially from the bore. The fluid may be an inert gas such as argon or nitrogen, optionally mixed with carbon dioxide; alternatively the fluid may be aqueous liquid, the water being vaporized in the region of the welding point.

Abstract: Surface-treated metallic workpieces such as zinc-plated steel plates are welded with high quality while they are being held in intimate contact with each other. An auxiliary gas including an oxygen gas is ejected from a space (7) around an electrode (1) through a nozzle (8) to a welding point (9) on overlapping surface-treated metallic workpieces such as zinc-plated steel plates (3a, 3b). When the zinc-plated steel plates (3a, 3b) are welded in the atmosphere of the auxiliary gas, the surface layers of zinc and oxygen react with each other, producing a solid oxide such as zinc oxide or zinc peroxide. Therefore, a gas such as a zinc vapor is prevented from being produced between the overlapping zinc-plated steel plates (3a, 3b). The welded joint is of high quality without blowholes which would otherwise blow away molten steel.

Abstract: A shielding gas for flux cored arc welding. The specific gas combination is intended to promote significantly lower fume emission levels while providing equivalent or better welding performance.

Abstract: An automatic welding apparatus and an automatic milling apparatus for machining welding grooves in order to weld a three-dimensional surface such as a ball tank or the like are disclosed. A welding wire spool is accommodated within a case and a cover to prevent the welding wire from being oxidized and from being contaminated with foreign materials. The automatic milling apparatus is installed to form welding grooves on the both sides of the objects to be welded, in the case where a welding is performed on a three-dimensional curved surface. A guide roller having a handle is installed to control the machining depth of the grooves, and an idling type nylon guide roller is installed in closed contact with the shaft of a cutter, thereby adjusting the distance between the rail and the groove, and adjusting the deviations of the depth of the grooves, which are caused by the machining inaccuracies due to the deviations of the three-dimensional curvature.