Showing papers on "Shielding gas published in 1969"

Arc welding gun

Abstract: A high current capacity arc welding gun for gas-shielded, continuous feed, consumable electrode arc welding processes. Features include: a unique handle cooled by convection air flow; an improved head assembly having a unique electrical insulating ion impervious shield for preventing destructive arcing to the gas nozzle, an improved shielding gas flow path through the head assembly which additionally cooperates with the ion impervious shield to prevent gas nozzle arcing, a unique current contact tip which attaches to the head assembly by a novel curved wedge clamping concept and which is produced by an improved, versatile, and inexpensive method of manufacture that increases the copper density and refines the grain structure in the current contact tip for greater life; an improved gooseneck lining for longer life and reduced friction; a heat protected control switch assembly of rugged construction and unique trigger operation; and an improved welding cable connection assembly.

Arc welding process and electrode for stainless steel

Abstract: There is disclosed an arc welding process for stainless steel and a flux-cored electrode particularly useful therein. In one embodiment, means are provided for limiting the moisture content of the electrode as applied to the workpiece. In another embodiment the electrode is formulated of components having relatively low moisture absorptivity.

Plasma-generating method and means

Abstract: An inert gas welding torch is used to create plasma by directing one or more discrete high velocity jet gas streams into a welding arc between the electrode and the workpiece. The plasma stream is controllable with regard to energy content or location by varying the amount or direction of the inert gas flow. The plasma stream is insensitive to variations of arc length, and permits abnormally high current densities in the electrode. When used with consumable electrodes, the invention is useful for casting as well as for deep welding heavy plate materials in a single pass.

Spatter and heat shield for welding gun

Abstract: A heat and spatter shield for an arc-welding gun of the type used for applying gas-shielded consumable-electrode arc-welding processes. A shield element insulated from the welding current circuit is attachable to the arc-welding gun so as to be disposed at the downstream end of the current contact tip and extend beyond the downstream opening of the gas nozzle so as to shield the downstream opening of the gas nozzle from metal spatter ejected from the welding operation and from direct heat radiation from the welding arc. At least the core of the shield element is composed of a heat-resistant nonelectrically conductive material. The shield element is disposed in the gas stream and arranged to provide an airfoil effect contributing to formation of the proper flow configuration of the shielding gas. Cylindrical and spherical-type shield elements are disclosed. Various means are disclosed for attaching the shield element to the arc-welding gun.

Method and apparatus for underwater arc welding

Abstract: According to the method of this invention water is kept away from the arc in underwater arc welding by means of a gas under a pressure greater than that of the water and, preferably, the wire-feeding unit, welding gun, and electrode wire of the gas shielded, metal arc-welding apparatus to be used under water are enclosed in airtight and watertight containers. The air connecting conduits and tubing carrying the electrode wire and shielding gas are similarly enclosed in airtight and watertight conduits. The containers and conduits are then internally pressurized with a shield gas to prevent the entry of water. The welding gun nozzle is enclosed within coaxially disposed tubular sections such that the electrode wire may be surrounded by either one or two annular gas streams under pressure which serve to shield it effectively from the surrounding water. Welding then takes place in a pocket of shielding gas to permit underwater welds of a quality previously obtainable only in atmospheric conditions.

Preheating and welding method

Abstract: A fusion welding method for steel exceeding 0.4 percent carbon content where all such steel in the article which is integral with the weld surfaces is heated above the upper transformation temperature resulting in a superior weld and a sound article absent localized areas of martensite and other detrimental characteristics. Preheating, simultaneous heating, and/or post heating is employed and when an article is preheated, surfaces to be welded are maintained relatively cold to minimize oxidation. Surfaces to be welded are freshly exposed immediately prior to welding and in an extremely rapid sequence of operations and when preheating is employed; surface exposure, preheating and welding steps are carried out in rapid sequence to minimize oxidation. Surfaces are provided with V-shaped configurations novel to resistance upset butt welding.

Composite electrode for consumable electrode arc welding process

Abstract: A consumable composite electrode of infinite length for use in an automatic arc-welding of steel without shielding gas and the like shielding means comprising a steel sheath and a powdery mixture filled within the sheath and having a specific composition which contributes to the arc-welding of the steel workpiece

Consumable welding rod for welding chromium steels and the resultant welds

Abstract: The consumable welding rods contain titanium and niobium in amounts such that a weld formed by melting the rod contains titanium niobium in an amount corresponding to the expression 2Ti+ Nb (6-14)C wherein Ti, Nb and C are the proportion of titanium, niobium and carbon in said weld metal. The proportion of titanium and niobium in the welding rod is determined by estimating the total quantity of carbon in the weld metal, the quantities of carbon, titanium and niobium lost by oxidation during welding and the variations in the quantities of titanium and niobium in the weld metal resulting from the welding process.

Shielding gas pressure actuated pipe-welding device

Abstract: An internal pipe-welding device having a carriage, an internal pipe clamp, a rotating welding nozzle which is pivotally mounted and biased away from its welding position, a pressure responsive means connected to the welding nozzle and adapted to move the welding nozzle to welding position responsive to the supply of shielding gas through a single service lead supplying the welding potential, the motive power for feeding electrode and the shielding gas. The pivoting of the welding nozzle also pivots a contact button which makes contact to supply electricity for welding to the welding nozzle only when the nozzle is in welding position.

Method of arc welding for hard facing

Abstract: In welding for providing a metallic work with hard facing, in which an electric arc is maintained between a consumable tape electrode and said metallic work, the arc being submerged in powder of flux, while the surface of said metallic work is being gradually coated with the molten electrode material; the improvement comprises the application of a magnetic field during the welding process to eliminate the malignant effect of a circular magnetic field around the electrode caused by the welding current and thereby to obtain a uniformly coated surface.

Method of plasma treatment of metals

Abstract: A method is provided for plasma treatment of metals without removing the material from the treatment area (for example, welding, surfaceremelting, surfacing and the like) by a transfer plasma arc burning between the plasmatron electrode and the metal being treated, one of the electrode areas of the arc being located on said metal. The method consists in that the plasma treatment is carried out in a layer of flux and plasma is produced from a gas mixture comprising components having considerably different values of heat conductivity at arc temperatures. The component with the relatively high heat conductivity is hydrogen, helium or nitrogen, and the component with the relatively low heat conductively is neon, argon, xenon, krypton or nitrogen.

Protective gas for arc welding

Abstract: A protective gas for the arc welding of materials such as highalloyed ferritic chrome steel, austenitic chrome-nickel steel and chrome-nickel-molybdenum steel includes a mixture of argon and nitrogen with the nitrogen content being 1 to 20 percent and preferably 5 to 10 percent by volume. An addition of more than trace amounts and up to 10 percent by volume of oxygen is also proposed. An advantageous form of the gas contains 5 percent by volume of nitrogen and 3 percent by volume of oxygen.

Protective gas welding process

Abstract: 1,250,572. Welding by fusion. MESSER GRIESHEIM G.m.b.H. 15 Jan., 1969 [14 Feb., 1968], No. 2444/69. Heading B3R. In gas-shielded consumable wire-electrode welding, the shielding gas is a mixture of argon and more than 10% and not more than 25%, by volume, oxygen, the wire electrodes used contain at least 1A0% Mn, by weight, and at least 0A4% Si, by weight, as deoxidizing components. The gas may additionally contain nitrogen (e.g. up to 1 %, by volume) and carbon dioxide as impurities. Example Mn, Si contents of the electrodes are 1A0% Mn, 0A4% Si; 1A6% Mn, 1A1% Si, by weight, the higher contents being used with higher oxygen content in the gas. The electrodes may additionally contain at least one further deoxidizing component selected from Ti, Cr, Al and the rare earths.

Devices for use in the gas-shielded welding of tubes

Abstract: 1,138,685 Welding by fusion STD SERVICES Ltd 17 Nov, 1966 [9 Nov, 1965], No 47404/65 Heading B3R A device supplying shielding gas to the inside of tubes being gas shielded arc welded comprises a supply pipe 15 having a port 22 through which the gas escapes and a pair of brushes 17, 18 mounted on the pipe 15 on opposite sides of the port 22 and each having bristles 21 engaging the wall of a tube 11 being welded Such a device may be used to argon shielded arc weld the longitudinal seam of a tube 10 Argon is fed through the pipe 15 As the weld passes the zone 12 it is water-cooled The device may be used in butt-welding tubes even if of different internal diameters The bristles are of heat resistant resilient material such as stainless steel The brush exposed to least heat may have nylon, copper or brass bristles The internal gas pressure may be sufficient for the gas to support the weld metal

Gas-shielded consumable electrode arc welding

Abstract: In gas-shielded arc welding with a fusible electrode which is pushed by a motor-driven wire advancing mechanism towards the workpiece through a guide and contact member serving to transmit the welding current to the electrode, said guide and contact member being surrounded by a shielding gas nozzle electrically insulated from said guide and contact member, the insulation resistance between said guide and contact member and said shielding gas nozzle is monitored to provide an output signal when said resistance is lower than a predetermined magnitude.

Plasma arc welding method and apparatus

Abstract: Disclosed is a method and apparatus for minimizing the double arcing phenomena often associated with plasma arc torches. The invention is characterized in that by moving the shielding gas rapidly across the face of the torch tip at an angle to the plasma arc, the double arcing phenomena is minimized or eliminated.

Welding of reactive metals

Abstract: A method of forming welded seams between two plates or work pieces of titanium by which the weld is made at the juncture of the two plates by a shielded arc welding burner. The heat generated during the welding operation in the quasi stationary temperature weld is removed by means of fluid forcefully applied against an area of the titanium plates or work pieces on the side opposite to that where the welding is taking place so as not to reach the welding area and thereby to effect cooling to a temperature below the critical range.

Extended electrode welding technique

Abstract: : The patent relates to arc welding of relatively thick close square butt steel joints wherein the welding operation is confined to a narrow deep groove or gap and is carried out in a gaseous atmosphere.

Method of the arc welding and deposition of metals in vacuum

Abstract: A method of the arc welding and deposition of metals in vacuum by means of a consumable electrode, in which for the purpose of providing the stable arcing process between the electrode wire and the workpiece, the arc is stabilized by shielding the current-carrying parts of one of the electrodes with the aid of a metal envelope having a charge corresponding to the charge of the other electrode.

Nitrogen Content and Porosity of Titanium Weld Metal

Abstract: Effects of the nitrogen partial pressures in the welding atmospheres of several gas mixtures and welding conditions on the nitrogen content and porosity of titanium weld metals were systematically studied.The important conclusions obtained are as follows;1. Titanium weld metals absorb large amounts of nitrogen in arc welding in atmospheres with rich nitrogen.2. The nitrogen content of titanium weld metals decrease with an increasing welding current as in other metals.3. The existence of an oxidizing gas in arc atmospheres does not contribute to the enhancement of nitrogen absorption into titanium weld metals.4. Nitrogen absorbed causes porosity of welds.

Effect of Addition of Nitrogen of Oxygen in Shielded Gas on Porosity of MIG Aluminum Weld Metal

Abstract: For the purpose of decreasing blowholes in aluminum weld metal, this experiment was carried out under the shielding gas of argon mixed with nitrogen and/or oxygen.Results obtained are as follows:-1) Blowholes in aluminum deposited metal by MIG welding can be decreased by adding nitrogen and/or oxygen to supplied argon gas. Minimum porosity is obtained respectively for mixing ratios of argon 50%+nitrogen 50%, argon 98.5%+oxygen 6.5% (bead on plate) and argon 98.5%+oxygen 1.5% (I-butt weld).2) In case of argon and oxygen shielding gas, same spray transfer is observed by oscillogram as in the case of argon only, but under argon-nitrogen shielding gas metal transfer changes to short circuit type.

Improvements in Electric Arc Welding with a Protective Gas Shield

Abstract: 1,161,011 Welding by fusion Y BROYARD, R GUETET and R NAUTRE 18 July, 1966 [21 July, 1965], No 32105/66 Heading B3R In gas shielded metal arc welding, the shielding gas rotates around the consumable electrode 6 as the gas exits through the nozzle 4 The gas rotates in an anti-clockwise direction when viewed in the direction opposed to the axial flow direction of the gas The rotation of the gas is produced by introducing the gas through a tangential inlet 13, or a series of guide vanes In a modification, an outer stream of gas, eg air, surrounds and rotates in the same direction as the shielding gas It is stated that with the positive side of the supply connected to a ferrous electrode, electrons from the rotating ionised stream of shielding gas move towards the electrode and are injected into the arc to increase the arc current

Gas-shielded Arc Spot Welding

Abstract: 1,155,488. Welding by fusion. AIR REDUCTION CO. Inc. 29 Aug., 1967 [6 Sept., 1966], No. 39449/67. Heading B3R. Gas shielded metal arc spot welding apparatus has a device for clamping the workpieces together adjacent the weld zone. A cylinder 29, mounted on a handle 35 or a fixed support, carries a C-shaped frame 20 formed in two parts 21, 22 adjustably interconnected. A consumable electrode 55 is fed by a remote device through the rod 48 of the piston 37 of the cylinder 29 to a contact tube 91 forming part of a welding head threaded into a block 60 which is a press taper fit in the end of the piston-rod 48. Gas, e.g. (argon or helium with, if desired, oxygen, or carbon dioxide) is fed through an inlet 62 in the block 60 to a two-part gas nozzle 80 having gas exit slots 82 and formed of chromium-plated brass. The nozzle 80 may be water cooled and is threaded to an insulating sleeve 76 secured by a screw 78 on the body 71 of the welding head. Current leads 67, 70 connect the welding supply via the block 60 to the contact tube 91 and via the frame 20 to a backing member 24 connected by a spherical coupling to the frame. During welding the piston 37 clamps the workpieces between the gas nozzle 80 and the backing member 24. In a modification, the electrode feeding device is mounted on the cylinder 29. The backing member, Fig. 6b, may be formed with a recess of circular or square section which is filled with weld metal to provide a reinforcing projection. A control device provided with four timers acting sequentially in response to actuation of a switch 36 causes air to be supplied to the cylinder to clamp the workpieces, and shielding gas and the electrode to be fed. The arc strikes when the electrode contacts the work and is terminated by burning back when the electrode feed is stopped. The gas flow and clamping pressure is maintained until the weld solidifies. The control device may be set to produce automatically a second weld at the same spot.

Experiments on Soft-Vacuum Electron Beam Welding

Abstract: A soft-vacuum electron beam welder, welding pressure of which could be arbitrarily varied in the range from hard vacuum (10-4 Torr) to soft vacuum (1 Torr), was made experimentally.With this equipment, experiments with respect to shape of fusion zone in soft vacuum and influences of environment gas on weld bead were carried out using such metals as AISI 304 stainless steel, 2S-aluminum, 75S-, 52S- and Z5A-aluminum alloys, copper, brass, titanium and ziroconium.In case of small working distance, weld penetration depth begins to decrease at an air pressure of 10-2-10-1 Torr to a smaller value at 1 Torr by 15-35 per cent of that in hard vacuum. This rate of decrease does not depend on welding speed, but on kind of material. On the other hand the bead width hardly varies with an increasing environment gas pressure.There are two effects of environment gas on weld bead, that is, ability to suppress change of chemical composition resulting from evaporation of volatile elements and gas contamination effect on weld especially in reactive metals. The latter effect can be prevented by using argon as environment gas.

Improvements in or relating to Welding Thermocouples

Abstract: 1,162,137 Welding by fusion; making thermocouples UNITED KINGDOM ATOMIC ENERGY AUTHORITY 21 Oct, 1966 [4 Nov, 1965], No 46871/65 Headings B3A and B3R [Also in Divisions H2 and H5] In welding the casing 7 of a thermocouple 1 by the heating effect of electrons derived from a plasma arc generator 3; the sealing of the casing 7 stops current flowing through a circuit ineluding a wire 6 of the thermocouple and the arc plasma and this is detected and automatically causes the welding to be stopped Six thermocouples are mounted in one end of a glass enclosure 2 connected through a buffer volume 10 to a vacuum pump 11 The plasma arc generator 3 using argon is located at the other end of the enclosure 2 and the plasma is directed towards a steel deflector 4 having a concave end 5 Flow of electrons to the workpieces is controlled by the voltage applied to them The wires 6 are connected in turn through switch 36 to a battery 44 which provides a preheating current and charges a condenser 42 which provides the welding current The casings 7 are welded by connecting them in turn by a switch 37 to a generator 46 producing a steadily increasing voltage A checking circuit from a source 47 through a wire 6 and the plasma to the anode 12 of the plasma generator 3 is broken when the end of the casing closes due to fusion, whereupon a trip device 48 disconnects the generator 46 after a predetermined delay The thermocouple cables are prepared for welding by drilling out the magnesium oxide insulation and the wires 6 to a depth of 1 mm, removing a further 05 mm of the oxide insulation and bending the wires towards each other The plasma arc generator consists of an insulating block 21, Fig 2, mounting a conductive insert 25 carrying a tungsten cathode 14 An annular silver anode 12 is held by a threaded boss 13 against an alumina sleeve 20 surrounding the cathode 14 Cooling water inlet and outlet pipes 18, 19 are provided and argon is fed through a tube 27 A starting electrode is located downstream of the anode 12