Showing papers on "Arc welding published in 1971"

Arc-electrode phenomena

Abstract: The paper gives a survey of the most important aspect of arc-electrode processes (excluding externally heated cathodes) which concern engineers in a variety of applications. Although it is not possible to avoid discussion of the basic mechanisms and of the number of conflicting and still unresolved theories for them, the emphasis is, as far as possible, on those characteristics which affect the design and operation of devices or processes in which they occur. There is a brief general description of arc discharges and of important differences between them and glow discharges. After distinguishing between thermionic and nonthermionic cathodes (and commenting on the transitions of emission type which occur with some metals), the main body of the paper deals with nonthermionic cathodes. This begins with some of the chief observational data, such as current density, root splitting, electrode erosion, magnetic deflection, plasma jets and force on the cathode, and goes on to consider some of the important factors which affect cathode processes, including electrode material and surface state, current, gas and its pressure or vacuum. After commenting on zones within the cathode fall, there is a discussion of the many theories which have been put forward to explain the emission mechanism of cold-cathode arcs. It is suggested that no single process is responsible for all conditions, and that transitions in mode can occur, either abruptly or gradually, and the most significant principles and facts which must be taken into account are outlined. There is a short Section describing the main features of arc anodes, and the paper concludes with a discussion of electrode effects in mercury-arc convertors, gas-blast and oil circuit breakers, vacuum switches, arc heaters and plasma torches, arc welding, commutation and arc furnaces.

Apparatus for controlling electric welding processes

Abstract: An apparatus for controlling electric welding processes with consumable electrodes by generating electric pulses of the variation in the welding parameters, the voltage, current or mechanical vibration, in the workpiece. These variations which are characteristic for the melting during welding are picked up, transformed and supplied to a signaling device to furnish a statement on the transfer of the material which the welder uses to correctly guide the electrode.

Combination welding torch

Abstract: A combination welding torch. Adapter means are provided for electric arc welding utilizing a consumable electrode interchangeable with elements for inert gas shielded arc welding utilizing a non-consumable electrode, and connection means are provided for use in the welding torch apparatus, to thereby provide a unitary welding torch usable interchangeably for performance of welding operations.

Automatic arc welding machines

Abstract: Device for performing completely automatic welding operations using fusible or infusible electrode, in accordance with a program directly governed by the path of the electrode, by emission of electric signals corresponding to equal elementary portions of path, such signals being collected by at least one step-by-step motor actuating the programmer. The device is characterized by the fact that the programmer includes means of controlling and adjusting all the welding parameters listed below : welding current strength, current pulsations, wire advance, wire advance pulsations, starting and stopping the unwinding of the wire, the rate of movement of the electrode, variations in such rate, arc fading, the minimum flow of protective gas, adjustment of the position of a torch perpendicularly to the welding wire and parallel to the surfaces to be welded, adjustment of the distance of the torch from the surfaces to be welded, slope of the torch in a plane passing through the welding wire, and slope of the torch in a plane perpendicular to the welding wire. The programmer turns step-by-step under the impulse of the electric signals emitted by the means of moving the torch, so that the angular speed of the programmer is directly proportional to the path travelled by the torch.

Method of and apparatus for welding an end plug onto a nuclear fuel element

Abstract: Welding methods and apparatus for bonding a metallic end plug into an end of a metallic fuel tube or rod for a nuclear reactor. Defects in the weld joint between the fuel tube and end plug are substantially reduced by arc welding in a chamber filled with an inert gas, disposing the welding electrode directly over the joint to be welded, deflecting plasma produced during the welding away from the body of the fuel tube, and directing the plasma into the joint.

Electrical system for automatic arc welding

Abstract: A process and system for welding of the tungsten inert gas (TIG) type is described. A welding torch is mounted on a mechanism which provides for motion of the torch with respect to the work (a pipe being welded) in three different directions. Movement in each direction is electronically controlled so as to obtain preset magnitudes of oscillation of the torch, both vertically and laterally with respect to the work. The vertical oscillation is provided by following the pulsating arc current in accordance with a preselected control function. In addition, the system and process provides for control of substantially all of the parameters affecting the formation of the weld in order to produce improved weldments.

Electrode for arc welding in air

Abstract: An electrode for electric arc welding in air containing alkali metal composites which comprise an alkali metal oxide in combination with one or more metal compounds of acidic or amphoteric nature, preferably iron oxide, manganese oxide, aluminum oxide or silicon dioxide. The alkali metal composite is less hygroscopic than the alkali metal compound it contains and is capable of being reduced to elemental alkali metal in the welding arc by reducing agents contained in the electrode. The alkali metal composite is provided in sufficient quantity so that the alkali metal obtained therefrom reduces the nitrogen content of the weld metal sufficiently to suppress nitrogen boil in the weld metal. Certain metal oxides and fluorides, preferably oxides of silicon, calcium, or aluminum and fluorides of calcium, barium, lithium or sodium are moisture barrier materials and may be included in the alkali metal composite to further enhance its resistance to absorption of moisture from the air.

Magnetic control of arc environment

Abstract: Control means for the arc of an automatic DC electric welding device comprising an electromagnet with its magnetic poles aligned perpendicular to the arc and the seam to be welded and providing a preselected and optimized magnetized environment for the arc. A Hall-effect probe is located immediately ahead of the welding arc to detect the magnitude and direction of the effect on the magnetic environment of detrimental magnetic fields in the immediate vicinity of the welding operation. The Hall-effect probe is connected through a detector circuit and a control circuit to the power supply for the electromagnet. Upon detection of the magnitude and direction of the effect of a detrimental magnetic field by the Hall-effect probe, appropriate adjustment is made of the power supplied to the electromagnet through the detector and control circuits, enabling the electromagnet to nullify the effect of the detrimental field on the preselected magnetic environment.

Lithium containing welding electrode

Abstract: An electrode for electric arc welding in air and a method of using same. The electrode contains lithium compounds and agents to reduce these compounds to elemental lithium in the welding arc. Lithium is added to the welding rods preferably in the form of lithium fluoride and/or lithium silicates, while the reducing agents are preferably calcium, aluminum and magnesium, and are preferably added in the form of intermetallic compounds of calcium and aluminum, and calcium and magnesium. A quench material to de-stabilize or quench the lithium-containing arc plasma and give it a higher voltage gradient may also be used. Satisfactory quench ingredients include carbohydrates; sugar (sucrose), because of its ready availability and lost cost, is preferred.

Control apparatus for short-circuit arc welding

Abstract: An apparatus for controlling the feeding of the welding electrode in short circuit metal transfer arc welding which employs a feeding speed detecting circuit. The feeding speed varies according to variations in the period of shortcircuiting between the electrode and the workpiece and the time during which a welding arc is generated.

Device for feeding a consumable wire electrode to an arc welding torch

Abstract: A device for feeding a consumable wire electrode to an arc welding torch from a wire reel through a flexible conduit tube by means of two wire feeding means of the push and pull types. The wire feeding means of the push type is driven by a motor having a substantially constant torque characteristic, while the wire feeding means of the pull type is driven by a motor having a substantially constant speed characteristic. Specifically, the driving motor for the feeding means of the pull type takes the form of a compressed-air driven motor which, by regulating the flow rate of exhaust air, has a desired constant speed characteristic.

Current control for pulse arc welding

Abstract: A pulse arc welding method and device for maintaining a pulse current at a constant value, which said current is periodically superimposed with DC welding current, even when the power source voltage or arc voltage has changed, through the interposition of a pulse current detector and pulse current control equipment, and to feed back the output thereof to the pulse current control equipment through the detection of the pulse current by the pulse current detector.

Production of an improved non-austenitic steel weld deposit

Abstract: A method of producing an improved non-austenitic steel weld deposit characterized by superior toughness in the Charpy V-notch impact test by melting a covered ferrous low hydrogen arc welding electrode consisting of a current conductive core and a limefluoride coating, which method consists of proportioning the core and coating components containing metallic and oxide forms of the basic metals of the group consisting of lithium, sodium, potassium, cesium, magnesium, calcium, strontium and barium and of the acid metals of the group consisting of aluminum and silicon so that when all components are melted together under the influence of an electric arc they produce a weld metal deposit and a welding slag with a basicity or mole ratio of oxide of basic metal to oxide of acid metal of at least 2.2 and restricting the sources of metallic and oxide forms of titanium in the core and coating components so that the weld metal deposit contains less than 0.07 percent titanium.

Arc welding electrode and process for stainless steel

Abstract: There is disclosed an arc welding process for stainless steel and a flux-cored electrode particularly useful therein which is formulated of components having relatively low moisture absorptivity.

Shielded arc welding with austenitic stainless steel

Abstract: An austenitic stainless steel which is suitable for use as a filler metal in gas shielded arc welding and a gas shielded arc welding process employing said steel as a filler metal. The steel consists essentially of, in weight percent, up to 0.1 percent carbon, 7.5 - 16.0 percent manganese, up to 1.0 percent silicon, 17.5 - 26.0 percent chromium, 5.0 - 17.0 percent nickel, 0.75 4.0 percent molybdenum, 0.2 - 0.38 percent nitrogen, balance iron and incidental impurities, and is additionally limited as follows: 1. The ratio of austenitizing elements to ferritizing elements is greater than 1 in accordance with the following expression:

Tungsten inert gas welding control unit with a filler metal feeding means

Abstract: A welding control device for controlling the voltage, current and gas flow rate for a gas tungsten arc welder type welding unit. A motor driven rheostat current decay control is provided to prevent abrupt weld cut-off. The remote console unit comprises a current preset means, a gas control, a voltmeter and ammeter to maintain the voltage and current as well as a filler metal feeding means. The metal filler means is located on and attached to the forward portion of the two button decay control switch.

Automatic oscillating arc welding method and apparatus

Abstract: Method of operating an apparatus for automatic arc welding with the welding head oscillating to form figure eight patterns, such oscillating motion being carried out by compounding, on an oscillating motion compounding shaft, two reciprocating motions in different directions, which is converted into one original rotation, such compounding and conversion being done in one and the same apparatus.

Arc-welding electrode

Abstract: An underwater electrode comprising generally cylindrical hollow-elongate electrically conducting substrate coated with an insulating material that is self-extinguishing when ignited by an arc. The coating is of a thickness and strength so that it burns away as the substrate is consumed forming a slight cone-shaped protective extension at the end of the substrate where the arc is struck to a workpiece. A preferred coating is a pre-catalyzed thermosettable epoxy resin placed on an uncoated substrate.

Electric arc welding process

Abstract: An electric arc welding process for welding together sheets of unalloyed or low alloyed structural steel utilizes a consumable wire electrode under shielded gas and is characterized in that the welding is conducted with a voltage of 25 to 40 V at a current density of 300-400 A/mm2 wire electrode cross-section with the wire electrode having a diameter of about 0.8-1.2 mm and the shielded gas containing at least some CO2.

An Investigation Into the Factors Contributing to Welding of Contact Electrodes in High Vaccum

Abstract: The effect of a vacuum environment on welding of Cu-Bi (0.3%) electrical contacts has been investigated. The experiments have been planned in order to differentiate between the effects of cold welding, diffusion welding and percussion welding. Cold welding has no affect on newly prepared electrodes, but after the electrodes have been arced appreciably a small residual cold weld force is experienced. The diffusion weld strength is strongly dependent upon the contact force, the electrode temperature and the time in contact. The strongest weld forces are measured in the percussion weld experiment where the electrodes experience a high current prestrike arc as they close. It is also found in this study that the weld force decreases rapidly after the electrode faces are exposed to the residual gases in the vacuum. These results are discussed in terms of the chemisorption of residual gases and the real area of electrical contact. The effects of the change in nature of the electrode surfaces are discussed and a satisfactory qualitative explanation of the results is reached.

Short-circuit inert gas consumable electrode process using additions of 10-14% nitrogen

Abstract: A gas shielded consumable electrode welding process for welding of materials such as 9 percent nickel steels and nitrogen stainless steels with relatively inexpensive stainless steel wire which includes utilizing a shielding gas of 10-14 percent nitrogen balance argon, helium or mixtures thereof, and a short-circuit arc deposition as the arcing process.

Direct current arc welder

Abstract: In a direct current arc welder comprising a phase control circuit for controlling the triggering phase of at least one controlled rectifier element to convert alternating current into direct current which is in turn supplied to a welding electrode and a workpiece to be welded and a feedback circuit for negativefeeding a portion of the direct current thus converted back to the phase control circuit thereby to control the welder output, a gain compensating circuit for compensating the gain of a control circuit in response to the value of said direct current output of the welder to maintain said gain at a substantially constant value no matter what level the value of said direct current output may be.

Alternating current arc power source having opposite polarity ignition pulse

Abstract: An alternating current arc welding having an alternating voltage power source for feeding energy to the welding arc and having a means for coupling, in series with the power source, a relatively high voltage impulse during the time the alternating voltage increases in absolute value so that the arc is re-ignited at the same phase angle during each half cycle.

Arc welding gun unitized gas hose and electrical control cord

Abstract: A unitized shielding gas hose and electrical control cord conduit including a resilient elongate tubular gas hose and a pair of elongate control wires extending within the gas hose. The control wires are twisted together in the gas hose alternately in right and left-hand twist directions to be free to untwist and extend when the conduit is stretched and tend to rewind when the stretch force is removed. Means are also disclosed forming a seal between the control wires and the wall of the gas hose at the entry of the control wires into the gas hose and at the exit of the control wires from the gas hose.

Effect of Welding Atmospheres and Welding Polarity on the Nitrogen Content of Weld Metals

Abstract: Mild steel and stainless steel were welded in controlled arc atmospheres.Effect of nitrogen partial pressures in the welding atmospheres of N2, N2-Ar, N2-O2, Air, N2-CO2 or N2-H2 and welding polarity on the nitrogen content of weld metals was systematically studied.The main results obtained are summarized as follows:1. The nitrogen content of weld metals made in neutral or reducing atmospheres such as N2-Ar or N2-H2 increases with the increase of the partial pressure of nitrogen.2. The co-existence of oxidizing gas with N2 in the arc atmosphere increases greatly the nitrogen content of weld metals.3. Anomalous absorption of nitrogen was observed at low pressures of the arc atmospheres.4. The nitrogen content of mild steel weld metals made in N2, N2-Ar, or N2-H2 welding atmospheres is not influenced by welding polarity, while the nitrogen content of stainless steeel weld metals made with DCSP is more than that with DCRP.5. In oxidizing atmospheres such as N2-O2 or N2-CO2, weld metals absorb much more nitrogen with DCRP than with DCSP.

Anti-hygroscopic arc welding coated electrode and the process for producing the same

Abstract: AN ANTI-HYGROSCOPIC ARC WELDING COATED ELECTRODE CONTAINS, AS A BINDER FOR THE COATING MATERIAL OF THE ELECTRODE, A GLASS POWDER HAVING A SOFTENING POINT OF FROM 350* TO 550*C., WHICH MELTS AND COVERS THE GRAINS OF THE COATING MATERIAL, WHEN HEATED TO A TEMPERATURE ABOVE THE SAID SOFTENING POOOINT, SO AS TO FORM VITREOUS FILMS THEREAROUND.

Welding brass alloys to brass or steel with - nickel alloy welding materials

Abstract: Pressure-resistant solder crack free welding of brass with 55-85 (55-65)% Cu, particularly Muntz metal, with brass or steel takes place using arc discharge under protective gas. Welding material used consists of Ni alloy containing >85, advantageously >90% Ni; Ni-Cu alloy containing 65-71% Ni or an Al bronze containing 77% Cu, 7-8% Al, 8-10% Mn, 2.5-3.5% Fe and 2.5-3% Ni. Welding pref. takes place with 80-150 (110-140). A basic current, 260-340 (270-300). A total current, 28-32 (28-30) V basic voltage, 30-36 (32-34) V overall voltage and 80-160 Hz frequency. Pref. a 2-3 mm thick reinforcing layer of Ni alloy with over 85% Ni or Ni-Cu alloy with 65-71% Ni is previously applied, by short arc welding, to steel article edge to be welded.