Showing papers on "Shielding gas published in 1973"

Starting and stabilizing apparatus for a gas-tungsten arc welding system

Abstract: A method and apparatus for starting and stabilizing an arc in the gas-tungsten arc welding system and the like. A plasma flame extending from the tungsten electrode to the work is established by ionizing a portion of the flow of inert gas used for shielding. The gas is ionized by means of an auxiliary arc that is struck between the tungsten electrode and a second metal component of the torch acting as a second electrode. The resulting plasma flame provides a conductive path for starting and stabilizing the main arc struck between the tungsten electrode and the work.

Deep narrow gap welding torch

Abstract: A welding torch adapted for welding deep narrow gaps wherein shielding gas diffusers fit inside the welding groove, a plastic liner is placed deep inside the torch so electric contact between the filler wire and contact tube is close to the exit, and a zirconia oxide insulation prevents torch contact with the gap walls.

Welding torch for underwater welding

Abstract: The invention relates to a welding torch for welding underwater and to a method of underwater welding using the welding torch. A high speed stream of water is directed from a nozzle on the welding torch obliquely onto a member or members to be welded to form a flared-out curtain of water. Gas is injected into the volume enclosed by the curtain of water to create a gaseous atmosphere and welding is carried out in the gaseous atmosphere.

Fluxes and slags in welding

Abstract: The complex welding technology of today demands an understanding of the formulation, manufacture, performance and use of welding fluxes. The volume of fluxes used in covered-electrode, submerged-arc, flux-cored wire, electroslag, brazing and oxyacetylene techniques, has grown to a total of probably over 400 million pounds per year in the United States. The fact that in the U.S. today the covering on coated electrodes averages approximately 25% of the 600 to 700-million pound annual production is an indication of the importance of welding fluxes. The technology leading to proper flux formulation has been little understood. It is hoped that a presentation of some of the principles of welding flux technology will provide an appreciation of improved quality of weld metal obtained through slag/metal reactions. The choice of compounds and the exact formulation in the preparation of a flux will depend upon many factors, including both technical and production economies.

Gas welding cable and gun therefor

Abstract: An arc welding gun, particularly for the use of the so-called MIG and TIG welding processes, in which the gun is constructed from an integral end portion of a welding cable, which is preferably of hollow construction, having a bore therethrough for the passage therethrough of a wire welding electrode or a shielding gas. Where wire electrode is supplied to the cable, a shielding gas may be supplied through an additional conduit external to the electrical conductor or the cable. The gun may be provided with control means, for example a manually actuatable switch, and as the terminal fitting of the welding head assembly is connected directly to the metallic conductor of the cable, all electrical joints are eliminated between the terminal fitting of the gun and the opposite end of the cable, preferably the connector terminal to the welding proper. As the gun utilizes the welding cable as an integral part, thereof, the terminal end portion, if desired, may be flexible permitting various gun configurations.

Grain refinement control in tig arc welding

Abstract: A method for controlling grain size and weld puddle agitation in a tungsten electrode inert gas welding system to produce fine, even grain size and distribution is disclosed In the method the frequency of DC welding voltage pulses supplied to the welding electrode is varied over a preselected frequency range and the arc gas voltage is monitored At some frequency in the preselected range the arc gas voltage will pass through a maximum By maintaining the operating frequency of the system at this value, maximum weld puddle agitation and fine grain structure are produced

Electrode for vertical-up open arc welding using molding shoes

Abstract: A cored-type welding electrode for vertical-up welding using molding shoes to hold the molten metal in position, using an open arc which does not require an externally-supplied shielding gas and which permits very high linear welding speeds. The core materials include a metal fluosilicate capable of breaking down in the heat of the arc to produce: a gas in sufficient volume to shield the arc from the atmosphere and a slag forming ingredient; and, other slag forming ingredients including the metal oxides and the alkali metal fluorides in a critical volume such that the total slag forming ingredients do not exceed six percent of the total electrode weight and the oxides are present in quantities at least greater than the fluorides. The self-shielded electrode further permits the use of active deoxidizers in quantities of under 0.5 percent.

Welding gun chuck assembly

Abstract: A chuck assembly including electrode stickout guide means and gas flow directing nozzle means for use with a welding gun having electrode stickout is provided. The chuck assembly provides gas flow passages for shielding gas and fume extraction, and further provides maximum protection of the chuck assembly components for weld spatter. The guide means are readily interchangeable for use with gasless or gas shielded welding operations.

Tungsten inert gas arc striking device

Abstract: A tungsten inert gas arc striking device for welding stainless steels and nonferrous metals, e.g., aluminum is provided, in which when striking an arc or restriking the arc, the charge stored in a capacitor is momentarily discharged through a discharge switch and a coupling coil to produce a kick voltage and this kick voltage is then superimposed on a welding current to effect the arc striking or restriking. Thus, welds of high quality can be produced and the occurrence of radio interferences can also be eliminated.

The Non-Stationary Metal Vapour Arc

Abstract: Abstract The motion is depicted as a sequence of steps of a finite residence time. The spot motion affects essentially only the energy characteristics Te which in comparison to the stationary characteristics Tes are shifted to smaller values. Hereby the critical currents I0, I1 are raised in comparison to the corresponding stationary limits I0s, I1s. Particularly attractive are the phenomena found in connection with the dependence of the spot velocity ʋ on the spot current I. If the spot velocity increases with the spot current stronger than ʋ ∞ I1/2 then the E-diagram reveals the existence of an upper limit lu for the spot current. This result can be used to explain qualitatively the experimentally observed phenomena of "spot multiplicity" and “spot extinction”. Quantitative conclusions are obstructed by the lack of knowledge about the velocity dependence on the spot current, ʋ(I). Experimental and theoretical studies to provide a better understanding of the physical background and the analytical laws describing the motion of the cathode spots are urgently needed.

Process for out-of-position welding

Abstract: This invention concerns automatic and semi-automatic welding by means of an electric arc under a protective atmosphere of a gas, using a continuous metallic tubular flux core-type electrode with a particular composition of the core. The fluxing ingredients produce a slag of unusually high viscosity at, and just below, welding temperatures.

Welding method and materials

Abstract: Methods and materials for submerged arc welding for obtaining a high toughness welded metal containing titanium and boron by using a flux cored wire composed of a steel sheath and a core containing titanium and boron with the addition of a metal fluoride.

Method and apparatus for projecting materials into an arc discharge

Abstract: An improved method for energizing reactive materials by means of an arc discharge is provided by interposing a stream of shielding gas between the cathode producing the arc and the reactive material. An apparatus for so interposing a shielding gas includes a conical shroud around the cathode defining therebetween an annular passage for admitting a shielding gas stream.

Electrode and flux combination for submerged arc welding

Abstract: In order to apply the submerged arc method of welding to a medium-carbon, Ni-Cr-Mo-V steel, and obtain a weld deposit which can be heat treated to provide a yield strength of 160-180 ksi along with a reduction in area of at least 25 percent and an impact resistance of at least 15 ft/lbs. at -40*F, an electrode wire having no more than 0.04 percent of silicon is utilized with a neutral welding flux having a residual percentage of manganese and from 1.5-3.0 percent of silicon to insure the proper deoxidation of the molten electrode. The flux also includes about 0.30 percent carbon for replacing that portion thereof lost from the electrode wire during the formation of the weld deposit.

Method of welding metals under water

Abstract: The underwater welding of metal surfaces using a plasma arc, wherein the plasma arc, plasma gas and weld part are sealed with a layer of water glass.

Weld rod containing manganese

Abstract: A cored wire welding electrode for welding cast iron having an outer sheath made of nickel or a nickel-iron alloy and a powedered core composition containing copresent metallic magnesium and graphite and slag-forming ingredients along with special amounts of manganese. The electrode is particularly useful for open arc welding wherein a high strength weld deposit is required.

Method of submerged arc welding of high tension steel workpieces

Abstract: Submerged arc welding of high tension steel workpieces by using bonded flux capable of generating at least 7 percent by weight of carbon dioxide gas during welding operation and producing slag with a basicity B L of not smaller than 1.0, in conjunction with a welding wire capable of providing alloying elements to weld metal, so as to produce weld metal having a high toughness and a high crack-resistivity.

Cleaning welding burners - using blasts of air and parting agent-air mixt

Abstract: Process is carried out after a delay to allow a weld seam to cool and comprises passing an air stream at high speed through the burner; immediately afterwards, passing a parting agent-air mixt. blast; and then, briefly, passing a shielding gas stream to displace the air in the burner. The process is simple and rapid, and the air stream aids burner cooling so that water cooling is not reqd. The process is controlled by time switches.

Study of gas tungsten arc welding procedures for tantalum alloy T-111 (Ta-8 W-2Hf) plate

Abstract: Methods of eliminating or reducing underbread cracking in multipass GTA welds in thick T-111 plate were studied. Single V butt welds prepared using experimental filler metal compositions and standard weld procedures resulted in only moderate success in reducing underbread cracking. Subsequent procedural changes incorporating manual welding, slower weld speeds, and three or fewer fill passes resulted in crack-free single V welds only when the filler metal was free of hafnium. The double V joint design with successive fill passes on opposite sides of the joint produced excellent welds. The quality of each weld was determined metallographically since the cracking, when present, was very slight and undetectable using standard NDT techniques. Tensile and bend tests were performed on selected weldments. The inherent filler metal strength and the joint geometry determined the strength of the weldment. Hardness and electron beam microprobe traverses were made on selected specimens with the result that significant filler metal-base metal dilution as well as hafnium segregation was detected. A tentative explanation of T-111 plate underbread cracking is presented based on the intrinsic effects of hafnium in the weldment.

Weld additive for electric-arc deposit welding

Abstract: A welding additive for incorporation into electric-arc welding rod, e.g. of the coated or core type, contains chromium carbide with superstoichiometric quantities of carbon in the lattice of the chromium carbide to ensure a carbon content of 15 to 25 percent by weight. Preferably the additive is a low-melting hypereuctectoid of Cr3 C2 and elemental carbon. The additive improves the wear resistance and frictional characteristics of a deposit weld by imparting to its characteristics which have hitherto been associated only with high-carbon deposites of autogenous welding.

Lead battery welding apparatus

Abstract: A welding method for fusing lead components together in a lead-containing electrochemical cell is disclosed together with apparatus for carrying out the method. The method includes forming an ingot-like mold around the lead components to be welded, the walls of the mold being comprised of a material having a high softening point, good thermal conductivity and arc-erosion resistance. Arc welding of the components utilizing an inert-gas-shield nonconsumable electrode, e.g., tungsten, is accomplished by passing the electrode over a weldable surface formed by the lead components in an oscillating path at a controlled speed and welding current to permit the lead components to melt and flow into the ingot-like mold while simultaneously controlling heat transfer through the adjacent mold walls. The resultant weld is of low internal impedance and is relatively thick for increased oxidation and corrosion resistance during operation of the battery.

Composite metal thermostatic element

Abstract: A method for welding alloys of high manganese content to avoid the development of weld flash is shown to comprise the steps of resistance welding the manganese alloy under conditions of temperature and pressure which are adequate for forcibly expelling manganese oxide from the surface of the alloy. The resistance welding is performed while a thin layer of tin is disposed at the weld location, the tin being melted but remaining fluid without significant vaporization thereof at the welding temperature for restraining expelled manganese oxide at the extremities of the weld location to prevent the formation of weld flash.

The Effect of Ambient Pressure on the Nitrogen Content of Mild Steel Welds

Abstract: To know the effect of ambient pressure on the nitrogen content of weld metal, mild steel specimens were welded using an iron electrode wire in air, N2, Ar-N2, and N2-O2 atmospheres at pressures between 1 atm and 9 atm.The changes in the shape of penetration and the arc phenomena due to the ambient pressure were also investigated.The main results obtained by this study are summarized as follows;1) In nitrogen welding atmosphere, the nitrogen content of weld metal increased gradually with the increase of the ambient pressure. The absorption of nitrogen does not obey the Sieverts' law.2) In air welding atmopshere, the nitrogen content of weld metal does not increase continuously with the ambient pressure, but it drops rather at pressures between 4 and 6 atm.3) In Ar-N2 welding atmosphere, the nitrogen content of weld metal increased with the partial pressure of nitrogen in the atmosphere of 1 to 6 atm pressure. The nitrogen content of weld metal made in the atmosphere of higher pressure is lower as compared with the one in the atmosphere of lower pressure at same partial pressure of nitrogen.4) In N2-O2 welding atmosphere, the enhancement of nitrogen absorption by steel welds due to the coexistence of oxygen is observed at higher pressures of welding atmosphere too. The oxygen precent of N2-O2 atmospheres, in which the maximum nitrogen content is to be expected, is lower at higher pressures of welding atmosphere.

Effect of the thermal cycle in welding on the structure and phase composition of the heat-affected zone in maraging steel

Abstract: 1. The increase of grain size during welding depends on the cooling rate and on the time the metal remains at temperatures above the α→γ transformation temperature. 2. Cooling from α→γ transformation temperatures at a low rate leads to an increase in the amount of retained austenite and some reduction of hardness in the heat-affected zone.