Showing papers on "Gas metal arc welding published in 1974"

Cored type electrode welding

Abstract: A cored type arc-welding steel electrode for the welding of 14 gauge to 3/8 inch thick mild steel wherein the ingredients in the core provide a smooth spray arc that is easy to control along with excellent bead appearance, low spatter, and good slag removal. The core ingredients include: calcium oxide, as a necessary compound, in a prefused mix to lower its hygroscopicity; aluminum and magnesium in controlled amounts; and selected fluorides.

Automatic fixed position pipe welding

Abstract: Automatic fixed position pipe welding is carried out by gas-shielded electric arc welding with a novel flux-cored electrode wire having a low-carbon sheel sheath containing a core filling of, by weight, 16-17 percent ferro manganese, 10-11 percent ferro silicon, 1-4 percent manganous oxide, 1/2-1 percent potassium aluminum fluoride, and the balance rutile. The wire exterior is shiny and metallic-appearing, and the wire is configured to have folded-in edges.

Drop transfer in short-circuit welding

Abstract: This paper considers the physical processes which may occur when a liquid weld metal drop comes in contact with a liquid metal pool. Experiments with drops of aqueous KCl solutions and mercury, combined with a theoretical analysis of the effects of surface tension and Lorentz forces, lead to the following conclusions. Drops larger than a critical size, which is a function of the capillary constant and wire diameter, will transfer to the pool and smaller drops will lead to stable menisci. Surface tension alone will complete the interaction in approximately k(M/4πT)1/2 s, where M and T are the drop mass and surface tension in CGS units and k similar 37. An electric current I can result in a repulsive force on drops of radius less than approximately μ0I2/16π2T (MKS units). The magnetic pinch instability can dominate surface tension effects under extreme conditions, and magnetically induced streaming can make otherwise stable menisci unstable. Applied to short-circuiting MIG welding systems, these results show how proper attention to the current and weld metal surface tension can lead to reduced spatter and better process control.

Nuclear fuel elements sealed by electric welding

Abstract: A nuclear-fuel assembly has an end plug and is sealed except for a small diameter axial bore in the plug. A welding electrode of the same material as the plug has an end ground to a point. The tapered end is then inserted into the bore. Before the bore is sealed the assembly is filled with an inert-gas at high pressure. An electric welding current is then directed through the electrode and the plug to seal the bore.

Welding powder for producing wear-resistant layers by build-up welding

Abstract: A welding powder contains a first component selected from the group consisting of molybdenum, tungsten, and a mixture of these two metals and a second component of at least one element selected from the group consisting of oxygen, nitrogen, hydrogen and carbon. The second component of oxygen, nitrogen, hydrogen or carbon is present in the metal of the welding powder partly in an unbound, dissolved state.

Process and apparatus for the performance of arc welding and overlaying, preferably submerged arc

Abstract: Arc welding and overlaying, particularly with strip electrodes, and particularly for overlaying by the submerged arc welding process with strip electrodes, can be regulated as to the distribution of arc energy by using strip electrodes which are run through male and female gears so that the current input of the electrodes is adjusted as to uniformity across the width of the overlay path.

Plasma-MIG arc welding

Abstract: A plasma-MIG welding method and device in which a stream of oxidizing gas, such as argon plus 2% oxygen, is introduced into the plasma arc in the region of the plasma nozzle orifice. This improves the stability of the MIG arc, and higher welding currents can be used, especially with negative polarity on the electrodes and the plasma and MIG arcs.

Apparatus for ultrasonic welding

Abstract: Apparatus for welding a metallic component to a non-metallic component which involves interposing an aluminum layer between metallic and non-metallic components, preheating the metallic component and the aluminum layer, preferably by induction heating, to a temperature of at least 250*C and then subjecting the components to ultrasonic welding.

Flux-coated arc welding electrode

Abstract: Nickel-chromium-silicon steel electrode for arc welding provides maraging stainless steel weld deposits having desirable strength, toughness and corrosion resistance in age-hardened condition. Electrode arc can be shielded with inert gas or with lime-cryolite-titania flux containing specially controlled proportions of manganese.

Method of 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.

Electrode composition and welding method for arc welding steel

Abstract: A wire electrode for use in arc welding comprising a metal to be deposited on a substrate and further comprising a flux, said flux comprising:

Arc welding process and apparatus

Abstract: An arc welding process and apparatus utilising an electrode and a counter-electrode between which a column of plasma forms. A first unidirectional current source is located between the electrode and the counter-electrode, and a second unidirectional current source is located between the counter-electrode and the member to be welded. These two sources simultaneously pass the two unidirectional currents.

Flux-cored welding wire for gas-shielded electric arc welding

Abstract: A novel flux-cored welding wire for gas-shielded electric arc welding is described characterized by a shiny, metallic-appearing surface on a low carbon steel sheath and containing within its core as essential flux ingredients 6-20% ferro manganese, 6-20% ferro silicon, 1-20% manganous oxide, 1/2-5% of a flouride compound, and the balance rutile. The wire is especially useful in out-of-position welding to produce sound welds combining good strength and high notch toughness at subzero temperatures.

Process for welding aluminum and aluminum alloys in horizontal welding position

Abstract: Aluminum and aluminum alloys are welded in a horizontal welding position in which the base metals to be welded are vertically disposed in abutting relationship with the welding groove opened sidewise by oscillating the tip of the welding electrode in the widthwise direction of the abutted base metals and welding the base metals while maintaining the angle formed by the surface of the molten pool and the electrode on the advancing side thereof greater than 90°. The surface of the molten pool as used herein is defined as one which is parallel to the crater surface of the weld which results upon termination of welding by extinction of the welding arc.

Resistance welding parameter profile for spot welding aluminum

Abstract: As tip force is increased, there is a larger tolerance in the variation of the other welding parameters, i.e., current and weld duration where good weld quality is obtained. Longer weld current duration reduces the tendency to have cracks appearing in the sheet under the electrodes. There is a near linear correlation between welding current and shear strength which is independent of the number of weld cycles and tip force used.

Electron beam, laser beam and plasma arc welding studies

Abstract: This program was undertaken as an initial step in establishing an evaluation framework which would permit a priori selection of advanced welding processes for specific applications. To this end, a direct comparison of laser beam, electron beam and arc welding of Ti-6Al-4V alloy was undertaken. Ti-6Al-4V was selected for use in view of its established welding characteristics and its importance in aerospace applications.

Flux-cored welding wire

Abstract: The flux-cored welding wire is intended to inert-gas shielded fusion welding of titanium and its alloys and includes a metal coating or tubular casting of titanium or its alloys and a powder flux core containing (per cent by weight): BaF2 -- 5 to 10, Fluoride of a rare-earth element -- 18 to 20, CaF2 -- 40 to 50, SrF2 -- the rest, the ratio of the weight content of the powder flux to the total weight content of titanium in the wire being from 0.3:1 to 1:1.

Electric arc fusion welding apparatus

Abstract: A TIG welding arrangement utilizing a high frequency arc starting arrangement with a fuse protected secondary arc gap operable to protect the welding apparatus.

Welding Studies on Arc-Cast Molybdenum

Abstract: Although molybdenum has several metallurgical characteris­ tics that make its fabrication (espe­ cially by welding) difficult, it has some important properties that give it good potential for use in the next gen­ eration of nuclear reactors or in radio- isotope thermoelectric generators. To increase our understanding of the characteristics that have limited the use of molybdenum, a program was undertaken in support of the Molten Salt Breeder Reactor in which very complex prototype components for a chemical processing test stand were fabricated from arc-cast molybdenum by extrusion, machining, welding, and brazing. This paper presents some of the results of the welding development portion of that program. Procedures were developed for clean­ ing and stress-relieving this material before welding and for making helium-leak-tight welds by both the gas tungsten-arc and electron beam processes. A commercial orbiting-arc weld head was modified so that mo­ lybdenum tubing could be field joined

Application of Acoustic Emission to Weld Monitoring.

Abstract: : The report discusses the feasibility of applying acoustic emission to real-time monitoring of gas metal arc welding. A state-of-the-art survey indicated that investigators had some success with detecting cracks, porosity, and slag inclusion during the welding of steels by monitoring acoustic emission. The presence of cracks was most easily detected in gas tungsten arc welding of stainless steels. Slag inclusions associated with roped bead in submerged arc welding can also be detected by acoustic emission. In the present work, cracks were introduced in a restrained weldment by hydrogen additions to the shielding gas. Selective filtering was used to increase the signal-to-noise ratio. Results show that the acoustic emission rate from cracks is much higher than that from the welding arc noise. A real-time weld monitor for detection of cracks in steel is therefore technically feasible. However, when porosity was introduced, the acoustic emission rate was about the same order as that from the welding arc noise. Thus, porosity could not be detected by the acoustic emission in a real-time weld monitoring situation.

Water Curtain Type Underwater CO2 Arc Welding by Using Flux Cored Wire (The first report)

Abstract: We have proposed the water curtain type underwater CO2 arc welding as a method of underwater welding. With this method we could make nozzle-to-work distance longer than 2-3 times compared with that for conventional underwater CO2 arc welding because of good shielding effects.But, in case of welding with solid wires, welding speed was limited up to 30 cm/min. For the purpose of solution to this trouble, we tried single pass butt welding on mild steel at 0.3 m underwater by using flux cored wires.Results obtained are as follows:1) At high speed welding 120 cm/min as underwater welding, we succeeded to get good welds without blowholes and cracks.2) The welds obtained from this method have excellent mechanical properties at bending test and tensile test.3) Maximum hardness in welds was Hv 300.4) This method had a weak point of poor visibility in the cause of melting of flux and slag into the water.

Refractory electrode arc welding torch - for welding the interior of small bore tubes

Abstract: Welding torch (I) has a bore contg. a refractory electrode, and an electrode holder (II) projecting from (I) is arranged so that in use it can be inserted into the bore of a tube with the electrode in close proximity to the joint and can be rotated in the tube to finish the weld. (II) has a passage for the supply of an inert protective gas for the electrode area, and a high thermal conductivity core in contact with the electrode and a heat sink in the body of (I). The heat sink and/or the core has an extended specific surface e.g. ribs, channels or grooves over which the inert gas is passed and they are pref. Cu.

Welding arc gap ionization device

Abstract: An alpha emitting isotope is positioned near the tip of a TIG welding electrode so that the alpha radiation can provide an ionized path between the electrode and the workpiece.

Gas-metal reactions and porosity in the inert gas arc welding of copper

Abstract: A study has been made of the effects of welding and material variables on the occurrence of porosity in tungsten inert gas arc welding of copper. The experiments were based on a statistical design and variables included, welding current, welding speed, arc atmosphere composition, inert gas flow rate, weld preparation, and base material. The extent of weld metal porosity was assessed by density measurement and its morphology by X-ray radiography and metallography. In conjunction with this the copper-steam reaction has been investigated under conditions of controlled atmosphere arc melting. The welding experiments have shown that the extent of steam porosity is increased by increased water vapour content of the arc atmosphere, increased oxygen content of the base material and decreased welding speed. The arc melting experiments have shown that the steam reaction occurs in the body of the weld pool and proceeds to an apparent equi1ibrium state appropriate to to its temperature, the hydrogen and oxygen being supplied by the dissociation of water vapour in the arc atmosphere. It has been shown conclusively that nitrogen porosity can occur in the tungsten inert gas arc welding of copper and that this porosity can be eliminated by using filler wires containing small amounts of aluminum and titanium. Since it has been shown to be much more difficult to produce sound butt welds than melt runs it has been concluded that the porosity associated with joint fit up is due to nitrogen entrained into tho arc atmosphere. Clearly atmospheric entrainment would also, to a much lesser extent, involve water vapour. From a practical welding point of view it has thus been postulated that use of a filler wire containing small amounts of aluminum and/or titanium would eliminate both forms of porosity since these elements are both strongJy deoxidising and denitriding.

Welding high-strength aluminum alloys

Abstract: Handbook has been published which integrates results of 19 research programs involving welding of high-strength aluminum alloys. Book introduces metallurgy and properties of aluminum alloys by discussing commercial alloys and heat treatments. Several current welding processes are reviewed such as gas tungsten-arc welding and gas metal-arc welding.