Showing papers on "Shielding gas published in 1970"

Semiautomatic welding apparatus

Abstract: This invention is a welding apparatus operable to automatically provide an electrode surrounded by a shielding gas for welding through an arc-welding process. More particularly, this invention is a welding apparatus having a welding gun assembly connected through a cable assembly to a quick connector assembly which, in turn, is adapted to be inserted within a supply adapter assembly to transfer gas, welding wire, and electrical power to the welding gun assembly. Additionally, this invention relates to a welding apparatus operable to supply welding wire while having structural features (1) allowing for the ready disconnecting and connecting to a supply source, and (2) to maintain the gun assembly in a cool condition during welding operations; and (3) achieving lightweight features for ease of usage.

Pulsed arc spray welding in a narrow groove

Abstract: A process for multi-layered spray arc welding using a gas shielded consumable electrode which comprises: preparing the welding edge of each of a pair of plate members such that when said members are placed into welding alignment, the combination of their prepared edges will together form an I-shaped or V-shaped welding line groove between said members, placing said plate members into welding alignment so as to form said welding line groove, and spray arc welding said plate members along said welding line groove with consumable electrode in the presence of a shielding gas by passing a welding current having a rectangular waveform through said electrode to said welding line, such that at recurring intervals, a welding arc having a current density of from 100 to 300 amp/mm2 is established between the tip of said consumable electrode and said welding line groove for a period of time of from 0.3 to 5 seconds, and extinguished for a period of time of from 0.2 to 3 seconds, such that when said arc is established, molten metal droplets are transferred to said groove, and when said arc is extinguished, the transfer of molten metal droplets is interrupted.

Welding electrode with lithium shielding metal

Abstract: An electric arc welding electrode comprised principally of an elongated steel member having associated therewith lithium alloyed with or coated over with other low boiling temperature metals plus metals of higher melting temperatures for delaying the boiling action of the low boiling temperature metals. The member may be striated and these metals fill the striations.

Welding gun trigger control circuit

Abstract: A MIG welding gun trigger control circuit in which the welding gun trigger is employed to control the supply of welding gas, welding current, and welding wire feed to the gun, with the arrangement being such that to start the welding the operator presses the trigger to obtain a pre-welding gas purge without welding current or wire feed, and after the pre-welding gas purge is completed, the trigger is released to start the wire feed and provide welding current as well as continue the shielding gas flow. If the arc forms, the operator proceeds and completes the weld without having to hold the trigger switch closed, and when the weld is complete, the operator again presses the trigger switch to stop the wire feed but provide continued gas flow for post-welding purge, this action setting into motion a timer circuit that briefly continues welding current supply for stub burn off. After post-purge, release of the trigger switch shuts off the welding system and re-sets the system for the next welding operation. If the arc fails to form during the start cycle or if the arc or the weld current is broken during the actual weld, the control system automatically shuts itself off.

Art of casting metals

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.

Improvements in or relating to methods and apparatus for the manufacture of composite metal tubing

Abstract: 1,207,675 Making composite metal tubing, welding by fusion INTERNATIONAL COMBUSTION (HOLDINGS) Ltd 14 June, 1968 [16 March, 1967], No 12317/67 Headings B3A and B3R A method of making composite metal tubing comprises cladding by weld deposition either the outer or inner surfaces or both surfaces of a hollow metal ingot and then forming the latter into tubing A hollow mild steel ingot is mounted for rotation about a horizontal axis and a welding head is supported on a carriage for reciprocation either parallel to or along the axis of the ingot The filler wire is applied at an angle of 45 degrees, which angle is suitable for cladding the ingot with overlapping beads of austenitic stainless steel The clad ingot is reduced to tubing by any suitable process and heat treated if necessary The welding head, which is cooled, includes a tube for the filler wire, a purge tube delivering purge gas to the wire feed tube and a shield gas supply tube The shield gas may be argon plus 5% oxygen

Method and apparatus for welding an overlay on a metal base

Abstract: A method and apparatus for welding an overlay on a metal base. The welding apparatus contains a supply of granular flux which feeds through a nozzle and covers the weld. An inert gas is introduced to the flux supply to purge it of air. The gas discharges through the nozzle and assists in protecting the weld. Particularly useful for welding an overlay of a nickel tantalum alloy.

Inert atmosphere tack welder

Abstract: This disclosure relates to spot resistance welding or tack welding of edge portions of sheet material, particularly the welding of seams of containers. Means are provided for effecting gaseous flow around each of a pair of opposed electrodes with the flowing gas being preferably an inert gas and the flow being selectively one of pressure to one electrode and vacuum or partial vacuum to the other or pressure flow to both electrodes. Inert gas flow between the sheet portions being welded is also obtained.

Coated electrode for electric arc welding of steel of various structure

Abstract: The present invention relates to welding coated electrodes and is used for welding steel of various structure. The electrode comprises a rod containing carbon, silicon, manganese, molybdenum, nickel, titanium and iron, and a coating of the fluoric-calcium type.

Method and apparatus for electron beam welding

Abstract: This invention relates to a method of welding low carbon steel using an electron beam. The portion of the workpiece being welded is located in an evacuated welding zone and a deoxidizing metal backup member is disposed in spaced relation to the joint to be welded. During welding, the electron beam vaporizes a portion of the deoxidizing metal and the release of the metal vapor aids in increasing the soundness of the weld.

Parameters Involved in the Spectroscopic Monitoring of Atmospheric Contaminants in the Tungsten Inert Gas Arc Process

Abstract: Tungsten-helium arc atmospheric contaminants spectral monitoring parameters under welding conditions, using rotating circular wedge to oscillate emission lines across exit slits

Improvements in or relating to the Cladding of Metal Surfaces by Fusion Welding

Abstract: 1,188,995. Welding by fusion. INTERNATIONAL COMBUSTION (HOLDINGS) Ltd. 9 May, 1967, No. 21413/67. Heading B3R. Apparatus for cladding a metal surface by fusion welding includes a welding head comprising a housing 37, a guide tube 38 extending from the plane of the open end of the housing for guiding to the housing 37 metal wire which forms a consumable electrode, the tube 38 having an inlet for inert shielding gas preferably adjacent the wire inlet and being disposed at 45-50 degrees to the normal to the plane of the open end. Inert gas is also fed to the housing through one or more tubes 43 and flows through a gauze barrier 45 normally to the weld site. Cooling tubes 46 surround the lower open edge of the housing 37. An electrode contact lip 41 is connected to the end of tube 38. The welding head may be adjustably mounted on a carriage 22, Fig. 1, so as to project into or extend over a tube rotatably mounted in a chuck 5 for cladding purposes, the carriage being adapted to be fed longitudinally by a lead screw 18 so that weld metal is deposited on the tube in a helical path. The feed motion of the carriage and welding head is such that the welding arc is largely directed on to the previously laid weld bead. Two such helical layers are laid; for the first layer the weld point is located slightly after bottom dead centre and for the second layer slightly before.

The Influence of Shield Gas Compositions on the Arc Temperature in Gas-Shielded Metal-Arc Welding

Abstract: The influence of shield gas compositions in argon-nitrogen, argon-oxygen, argon-carbon dioxide and argon-hydrogen systems on the arc temperature was studied by means of the spectral line intensity method.The findings in this work are as follows:1) The arc temperature increases slightly with an increase of welding current.2) The arc temperature does not undergo a noticeable change with arc voltage.3) The arc temperature increases with an increase in nitrogen, oxygen, carbon dioxide and hydrogen additions.The arc temperature in argon-hydrogen gas mixtures is highest, and the one in argon-carbon dioxide gas mixtures is lowest.4) The arc temperature seems to be influenced by electrode materials.

Parameters for Pressurized Inert Gas Metal Arc Welding of Aluminum.

Abstract: This study was designed to establish the significance of various process parameters in Pressurized Inert Gas Metal Arc (PIGMA) welding. Specifically, the effects of arc voltage, filler metal speed, travel speed, and chamber pressure were determined. The measured responses were arc mode and stability, weld appearance, soundness, area, width, penetration, reinforcement, and depth-towidth ratio. Using predetermined combinations of parameters, bead-on-plate welds were made on an 8 in. diameter by 1 in. wall Type 1100 aluminum cylinder. The filler metal was 0.030 in. diameter Type 718 aluminum alloy. The welding was performed in a pressure chamber with the cylinder in the horizontal-rolled position. After welding, the welds were X-rayed and visually and metallographically examined. For purposes of analysis, the raw data of each response were treated using a multiple regression analysis technique. By this technique, the variability in ratings due to each independent variable and to lower order interactions was determined. Calculated ratings were obtained for each combination of parameters. The results of the study were derived using the trends of the calculated ratings. Findings are briefly described below: Chamber pressure, in general, when increased, acts to reduce weld appearance, weld width, and arc stability and increases the depth-to-width ratio. Increased pressure shortens the arc and changes the transfer mode to short circuiting. Arc voltage, when increased from 22 to 28 v, exhibits relatively minor influence on weld soundness and appearance but did increase weld penetration and area. Travel speed, when increased from 60 to 120 ipm, decreased weld penetration, width, and cross-sectional area. ELDON D. BRANDON is with the Rocky F la t s Division. The Dow Chemical Co., Golden. Colo. P a p e r presented a t the AWS 51st Annual Meeting held in Cleveland. Ohio, dur ing J u n e 8-12, 1970. Filler metal feed speed, was the most significant factor affecting weld appearance, soundness, reinforcement, penetration, width, area, and depth-to-width ratio. The best appearing and soundest welds occurred at lower filler metal feed rates. As would be expected, the size of the weld increased with filler metal feed rate. Using criteria of acceptable appearance and soundness, the maximum depthto-width ratio (1.2:1) was obtained at 29 v. 800 ipm filler metal feed speed. 70 ipm travel, and 82 psi absolute pressure. Introduction Pressurized Inert Gas Metal Arc or PIGMA welding is a relatively new technique being used at the Rocky Flats Plant to reduce weld-metal porosity to extremely low levels when other techniques fail. Other desirable conditions, such as a narrower, more Fig. 1—Welding chamber and fixture used for PIGMA welding study Fig. 2—Close-up of torch/filler metal feeder assembly concentrated arc profile, have been realized. The PIGMA process is essentially the same as gas metal-arc welding except that the torch and workpiece are enclosed within a pressure chamber. For welding, the chamber is pressurized to some elevated pressure in the range of 20 to 100 psia. The chamber may or may not be evacuated before being pressurized. Inert gas is normally used to backfill the chamber after evacuation. However, compressed air may be used if an inert atmosphere is not required. After the desired pressure is reached, the welding proceeds in the normal manner except, of course, the operation must be carried out by remote control. The basic process and equipment have been described in more detail by Barker.* The current program was designed to establish the significance of various process parameters in PIGMA welding. Several response variables were measured to find their relationships to the basic welding parameters. Also, a wide range of variable levels was used. Thus, a set of limits was established wherein acceptable welds could be made. Experimental Materials The selected base metal, type 1100 a l u m i n u m , was c y l i n d r i c a l , 8.28 in. outside diameter by 1 in. wall by 13 in. long. 1100 aluminum is a 99% purity alloy containing very small amounts of copper, silicon, and iron. The filler metal was a 0.030 in. diameter 718 aluminum alloy. This alloy consists of 12% silicon, the balance aluminum. Before welding, the cylinder was » Barker . R.. "PIGMA Welding—A Methold for Reducing Weld Poros i ty , " Welding Journa l , 44 (1), Research Suppl. , l-s to 6-s (1965). 510-s ; N O V E M B E R 1970 Table 1—Summary of Pressurized Inert Gas Metal Arc Welding Procedure Process Base Metal Filler metal Preweld cleaning (base metal) Joint configuration Temperature control Welding position Polarity Shielding gas (torch) Chamber gas Power supply

A Method of Arc Welding with Alternating Current.

Abstract: 1,188,027. Welding by fusion. ORDENA TRUDOVOGO KRASNOGO ZNAMENI INSTITUT ELEKTROSVARKI IMENI E.O. PATONA. 28 June, 1967, No. 29747/67. Heading B3R. [Also in Division H2] A method of alternating current arc welding comprises the superimposition of pulses of current B of the same polarity as the arc current at the ends of the half cycles A of the arc current i. If desired the pulses of current are superimposed on the negative half waves of the arc current; furthermore, additional current pulses may be superimposed on the arc current either at the beginning or at the middle of the half waves or both. Thus the stability of the arc is enhanced and the transfer of metal controlled. Arc current to an electrode 5 and workpiece 6 is provided from an A.C. source 1 by way of a transformer 3 and a variable inductor 4. Current pulses are provided by a circuit which includes a capacitor 10 charged by way of a diode 9 from the secondary winding 14 of a transformer 8. The pulses superimposed on the arc current are provided by discharging the capacitor 10 across the arc 7, the discharge being effected by triggering a controlled rectifier 11 at the appropriate time or times, the triggering impulses being provided by a phase shifting circuit which includes the components 15-22. A switch 23 is provided to disable the phase shifting circuit. The welding may be automatic or semiautomatic using consumable or non-consumable electrodes. Shielding gas may include argon (e.g. for stainless steel) and carbon dioxide.

Flux for welding titanium and its alloys

Abstract: 1,208,916. Welding by fusion. INSTITUT ELEKTROSVARKI IMENI E O. PATONA. 27 Dec., 1967, No. 58642/67. Heading B3R. [Also in Division C7] A flux for welding Ti and its alloys contains by weight: CaF 2 .. .. .. 77A5-99A5% Simple sodium halide .. . 0A5-2A0% e.g. NaF and NaCl. The flux may also contain 5-21% BaCl 2 and is used in automatic argon arc welding at a welding rate of 40-60 m./hr.

Method of Manufacturing Thin-Walled Tubular Structures.

Abstract: 1,194,163 Welding by fusion KABELUND METALLWERKE GUTEHOFFNUNGSHUTTE AG 3 Sept, 1968 [14 Sept, 1967], No 41776/68 Heading B3R [Also in Division H1] A tube or cable sheath is longitudinally lap welded by gas shielded arc welding the overlapped margins of a formed strip 2 In making a cable a strip of paper is laid on the core prior to welding the sheath A layer 7 of thermoplastic polymer is extruded on to the welded sheath Tubes or sheaths of copper of thickness up to 0A5 mm may be so welded The shielding gas may be argon

Apparatus for Controlling a Consumable-Electrode Welding Installation

Abstract: 1,188,169. Welding by fusion. ORDENA TRUDOVOGO KRASNOGO ZNAMENI INSTITUT ELEKTROSVARKI IMENI E.O. PATONA. 18 July, 1967, No. 33003/67. Heading B3R. [Also in Division H2] In a control circuit for arc welding, an electrode feed motor 1 is connected to the welding supply 16 by contacts 26 of a contactor 6, the release of the contactor 6 is delayed until after the arc ceases, control means regulating the welding supply 16 and the feed motor 1 comprise a control relay 12 connected by a starting switch to the welding supply 16, and normally open contacts 13 of the control relay 12 are located in the circuit of the contactor 6. Actuation of a switch 24, Fig. 1, and the start switch 9, connects the control relay 12 to a separately excited D.C. generator 16 and energizes contactor 6. Thereupon the generator 16 is connected in parallel to the shielding gas valve 5, the electrode 25 and the feed motor 1 and the arc strikes. Where the shielding gas is carbon dioxide, a gas preheater 19 is used. To reduce the welding current, start switch 9 is released to de-energize relay 12, to shunt a resistor 4 in the shunt circuit of the feed motor 1 to reduce the feed rate and to insert resistance in the field of the generator 16 to reduce the welding voltage. To stop welding, a switch 20 is actuated to short circuit the feed motor armature and to disconnect the contactor 6. The arc burns back and extinguishes and after a delay of 1-2 seconds produced by a condenser 7, the contactor 6 returns the circuit to normal. In a modification, Fig. 2, the release of the start button 32 reduces the welding current by releasing the control relay 12 as before and a relay 27 energizes to hold the contactor 6. To stop welding, the start button 32 is again operated. Relay 12 operates and is followed by a relay 28 which shunts the armature of the feed motor and disconnects the contactor 6. In a further modification, Fig. 3 (not shown), the reduction of welding current is effected directly by relay 27 which is energized directly by release of the start button. Reference has been directed by the Comptroller to Specification, 1,090,118.

Effect of nitrogen addition to shield gas on mechanical properties of MIG welds of aluminum alloys

Abstract: It was reported in the previous papers that crystal grains of MIG welds of aluminum alloys were refined and welding cracks were decreased by the addition of nitrogen to shield gas.In this paper, effects of nitrogen addition to shield gas on mechanical properties and blowholes of welds are examined.The following results were obtained.(1) Nitrogen addition had no effects on mechanical properties of welds of 5083 alloy.(2) Mechanical properties of Al-Zn-Mg alloys were improved by nitrogen addition. (3) Inclusions formed in weld metal by nitrogen addition had little effects on its mechnical properties.(4) Nitrogen in shield gas did not always decrease blowholes of welds, though it is reported to decrease the blowholes in some literature.

The Collection and use of the Blow Gases from Steel Production

Abstract: 1,180,637. Recovering combustible gas. FOSTER WHEELER Ltd. 6 Sept., 1968 [8 Sept., 1967], No. 41169/67. Heading C5E. In a process for collecting the hot blow gases from a steel converter, in which a shielding gas is directed at the joint between the top of the converter and a collection conduit, the shielding gas is CO 2 or steam. The hot gases pass from the conduit to heat exchangers (which raise steam), carbon monoxide shift reactor and CO 2 - removal plant, and the steam or CO 2 for the shielding gas may be supplied from these sources. Thus control of the quantities of shielding gas used enables the product gas to be used for making H 2 , CO, or a methanol synthesis gas.

Welded bonding of aluminium and copper

Abstract: System designed to bond aluminium and copper in a permanent condition, particularly for locomotive conductors which gives not only a better performance than pressure bonding or other conventional methods, but also means that conductors can be made largely of aluminium with economy on the use of expensive copper. On the surface of the copper, or its alloy, a silver solder (e.g. LAg 25 cd) is laid using tungsten inert gas welding or gas welding. Then a layer of Al Si 12 is applied, using tungsten inert gas welding through alternating current, on the silver solder. Then through tungsten inert gas welding the aluminium is bonded to the copper clad surface with a filler material such as Al Mg 5, Al 99.5 or Al Si 12. The resulting bond is permanent, and has a better performance than pressure bonding, screwing, soldering or other methods.

Welding Head with Hydraulic Position Regulation

Abstract: 1,183,141. Welding by fusion. COMMISSARIAT A L'ENERGIE ATOMIQUE. 1 Jan., 1968 [17 Jan., 1967], No. 139/68. Heading B3R. [Also in Division G3] A welding head for, e.g., non-consumable electrode gas-shielded arc welding comprises a rear section, which is intended to be introduced and locked into position within a cavity inside which a weld is to be made arounda circular path 16, and a front section 4 intended to be set in rotation from the exterior of the cavity, e.g. by a motor, the welding head having an hydraulic control system comprising a servo-valve 6 actuable from the exterior of the cavity, a double-acting piston 9 driven by the servo-valve when actuated and secured to a support 10 mounting a welding torch 5, the welding head also comprising a link-arm 11 operable from the rear section and slidable in guides 12 secured to the support 10, the arrangement being such that the torch is capable of moving along its axis under the action of the piston and of performing oscillatory movement under the action of the link arm whereby the electrode is maintained at a constant distance from the weld. The servovalve is actuated by a current which is a function of the voltage V-V 0 , where V 0 is a reference voltage from a control potentiometer and V is the voltage from a variable potentiometer 17 operated by movement of a rack 20, attached to the support 10. Holes 19 in a shield member 13 direct shielding gas at the weld. The rear section (Fig. 1, not shown) is locked in position by balls (3) and expandable pads (2). Movement of the member 10 may be monitored by an endoscope (7) connected to a television camera. The head may be used for welding pressure tubes to the end-shields of a nuclear reactor tank.

Nitrogen Content and Porosity of Aluminum Weld Metal

Abstract: Effect of nitrogen partial pressures in the welding atmospheres of several gas mixtures on the nitrogen content of aluminum weld metals was systematically studied.The important conclusions are as follows;1. Aluminum weld metals absorb a large quantity of nitrogen in the welding atmospheres containing nitrogen.2. The nitrogen contents of weld metals increase with increasing arc voltage and decrease with increasing welding current.3. Anomalous nitrogen absorption by weld metal is observed at low atmospheric pressures.4. The existence of an oxidizing gas in arc atmospheres does not contribute to the enhancement of nitrogen absorption by aluminum weld metals.