Showing papers on "Arc welding published in 1970"

Consumable electrode arc welding machine

Abstract: A electrode wire feeding device adapted for use in a consumable electrode arc welding machine, wherein the wire feeding device is provided with a lubricant feeder for effecting a smooth movement of such wire in a length of hollow guide tubing connecting between said feeding device and a suitable welding torch. In the lubricant feeder, a solid lubricant is employed which can be finely pulverized under friction in contact with the moving wire, whereby the frictional resistance between the wire and the hollow guide tubing can be substantially reduced.

Electric arc welding gun having a nozzle with a removable metal liner to protect the nozzle from weld splatter

Abstract: The welding gun construction utilizes a nozzle member having an opening for directing an inert gas against the work to be welded. A tubular welding tip is disposed centrally within such opening to guide a welding wire toward the work. A welding arc is drawn between the work and the wire. A tubular metal liner is received within the opening to protect the nozzle member from weld splatter, which comprises molten metal globules thrown up from the welding area. The solidified weld splatter accumulates within the liner, which can be removed and disposed of as needed, before the weld splatter builds up to a thickness sufficient to cause a short circuit between the welding tip and the nozzle member. A new liner is then inserted into the nozzle. The liner is formed with a retaining element whereby the liner is held within the nozzle against accidental dislodgement. Such retaining element may take the form of an oval portion, one or more spring fingers bent outwardly from the liner, or a dimple portion formed by outward deformation of the liner. A pocket or tapered portion may be formed within the nozzle member to retain the outwardly projecting fingers or dimples. The liner may also be arranged for insertion into the nozzle from the rear, and may be retained in the nozzle by an outwardly projecting flange on the rear portion of the liner.

Dual welding wire feed for arc welder

Abstract: This application discloses an electric arc welding system using two welding wires fed through a single torch, with means for driving either wire in either direction The torch, or torch tip, has a wire passage which, at the extremity of the tip, will pass only one of the two wires The two wires are threaded through the torch side-by-side, and with one in a retracted position, the other can be fed from the torch Thus, assuming two wires of different characteristics, a change over from one to the other can be quickly made

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.

Method for arc welding using individual pulse control for material detachment and acceleration

Abstract: A method of arc welding wherein the welding current delivered to the welding electrode is periodically caused to assume a plurality of essentially different amplitude values such that a waveform having at least a main and auxiliary amplitude is provided to the electrode. The main amplitude is provided to fuse and detach material from the end of the electrode while the auxiliary amplitude is used to accelerate the detached material to the weld puddle.

Bonded arc welding flux and liquid binding agent therefor

Abstract: Arc welding flux comprising finely divided flux material and a binding agent, the binding agent comprising finely divided water soluble or water dispersible material of the class consisting of fluorides, mixed fluoride, aluminates, hydroxides and carbonates of the alkali metals, at least one additional material of said class being present when said aluminate is present, said binding agent being present when said aluminate is present, said binding agent being present in quantity at least sufficient to provide adequate bond strength in the welding flux after the flux material, binding agent and water have been intensively mixed, dried and baked at from 650 DEG F

Arc welding apparatus

Abstract: Herein described is electronic circuitry used in an arc welding apparatus which provides continuous melting and etching action for the duration of a weld. This is achieved by providing a polarity reversing circuit comprising an electric current storage medium such as an inductor and a current limiter attached across the welding arc electrode and the workpiece. The current limiter allows a certain amount of current to be drawn from the welding power supply to induce electromagnetic energy into the inductor. The current flowing into the inductor and the current limiter bypasses the welding arc and establishes a magnetic field in the inductor. At the termination of the current from the power supply to the electrode, the current induced in the inductor by its collapsing magnetic field flows through the current limiter and through the electrode in a reverse direction, thus causing periodic polarity reversal at the electrode to perform the etching cycle.

Fatigue Performance Of Friction Stir Butt Welds In A6000 Series Aluminum Alloy

Abstract: Friction stir welding is a novel solid state joining process for making low cost, energy efficient butt welds in aluminum alloy extrusions. The plate edges are clamped against a backing plate and the material is plastically deformed and stirred by a rotating tool moving along the joint line. The resulting weld bead is flush with the surface and exhibits little distortion. The material in the weld and heat affected zone (HAZ) has a fine-grained microstructure and a high tensile strength compared with welds produced by conventional arc welding methods. The present investigation was undertaken to determine the fatigue properties of friction stir welds in 5 mm thick plates in an AA6082 alloy. Extruded plates in the T4 condition were used in the test program. S-N tests in pulsating tension at R = 0.5 were performed on specimens with the weld transverse to the stress direction. Reference tests were made on the base material. Crack growth data were obtained for material in the weld metal, in the HAZ and base material. S-N tests were also made on conventional MIG butt welds from the same batch material to enable a comparison of the two welding methods. The results indicate that the fatigue strength of transverse friction stir welds is approximately 50 percent higher than the fatigue strength of MIG butt welds. The crack growth rates obtained for the weld material were lower than in the base material, probably due to a more fine grained microstructure in the weld region. INTRODUCTION The friction stir welding process has recently been developed as a cost effective alternative to conventional metal inert gas (MIG) and tungsten inert gas (TIG) Transactions on Engineering Sciences vol 8, © 1995 WIT Press, www.witpress.com, ISSN 1743-3533 226 Surface Treatment Effects II welding in aluminum alloys [1]. A major advantage of friction stir welding is that it is a solid state process involving a much lower heat input than that required in conventional arc welding methods. The weld itself and its adjacent narrow heat affected zone both have a very fine-grained microstructure with high mechanical strength. The high tensile strength of the weld material and the favorable geometry would also indicate that friction stir welds could have high levels of fatigue strength. A testing program was implemented to determine the fatigue properties of transverse butt welds of two alloys in the AA6000 series. The data presented in this paper are results from introductory tests on specimens fabricated from extruded plates in AA6082 material in the T4 temper condition. THE FRICTION STIR WELDING PROCESS In friction stir welding the plates to be joined are clamped on a backing plate to prevent movement A cylindrical shouldered tool with a specially profiled pin is rotated at a high speed, see Fig. la. The pin is slowly brought into contact with the joint line, and the material is heated by friction and plasticised in an annular volume around the pin. As the pin is lowered into the plates, soft material is extruded at the surface. Upon further lowering of the pin and movement along the joint line the shoulder face contacts the plate surface and the plasticised material is compressed against the face of the shoulder. The soft material is mashed by the leading face of the pin profile and transported to the trailing face of the pin where it consolidates and cools to form a solid-phase weld. The generation of a friction stir weld has many similarities with extrusion seam welds that form when material is joined in the weld chamber of an extrusion die [2]. The material flow, however, is somewhat different due to the more extensive mechanical mixing of the material from the two plates in the friction stir process. The properties of the weld are closely related to the tool technology. The tool bit shape and material determines the heating, plastic flow and forging pattern. Development of the friction stir welding process has up to now been concentrated mainly on butt and lap joints, however, introductory tests have shown that friction stir welding is suitable for a wide range of joint configurations [4], as shown in Fig. 2. EXPERIMENTAL PROGRAM The specimens were fabricated from AA6082 alloy plate material, in the T4 (as-extruded) condition. The plate thickness was 5 mm. The mechanical properties are listed in Table 1. Transactions on Engineering Sciences vol 8, © 1995 WIT Press, www.witpress.com, ISSN 1743-3533 Surface Treatment Effects II 227 Table 1. Mechanical properties of the AA6082 alloy in T4 temper.

Method of sealing nuclear fuel elements 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.

Method and apparatus for automatic arc welding in a vertical position

Abstract: A method of arc welding in a vertical direction and an arc-welding machine for automatically performing the steps of the same are provided. According to the arc welding method of the invention, the advancement of a consumable electrode wire is accelerated and the welding voltage of the welding torch is increased as the torch crosses the centerline of a generally vertically extending weaving pattern it is caused to follow during a welding operation. After passing the centerline, the voltage is decreased to its original level, as it is on the return stroke also. This method is further improved by increasing the welding current of the torch slightly after increasing the welding voltage and further by decelerating or stopping the weaving motion at both sides and at the center of the weaving path of the wire. The apparatus for automatically carrying out this arc welding method comprises, in conjunction with an advancing consumable electrode wire and a welding torch adapted to follow a weaving path in a generally vertical direction, means for changing certain of the welding conditions, such as the advancing speed of the metal wire, the welding voltage and current, the weaving speed, and means for aligning the centerline of the weaving path or width to the welding centerline of a base metal.

Flexible welding rod having organically bound core and protective sheath

Abstract: Primarily intended for arc welding, the cord consists of a core formed of a mineral powder which is mixed with an organic binder and contains at least the constituents of a welding flux, the core being encased in a flexible protective sheath of organic material.

Inert gas shielded arc welding torches

Abstract: This invention describes an inert gas shielded electric arc welding torch for butt-welding tubes or tubular members of a wide range of outside diameters. The torch comprises a number of trolleys which are linked together and are spaced around the periphery of one tube. At least one trolley is provided with drive means and at least one trolley is produced with a welding head for making the butt-weld. All trolleys are constrained to follow a desired path by engagement with a track fitted around at least one tube. The torch is adjustable to suit differing sizes of tube or tubular member by altering the number of trolleys and/or by adjusting the spacing between them.

Electrical welding machine having amperage control transformer

Abstract: An arc welding unit operable on single or multiple phase alternating current and including for each phase a basic control device including a three-legged magnetic core. A primary leg includes a portion of the secondary, or output, winding, the remainder of which is wound on a secondary leg of the core. Flux through the secondary leg is controlled by regulating the duty cycle of the saturation current through a control winding on the third leg of the core, and flux-induced emf in the secondary winding due to current flow through the control winding is essentially eliminated because the secondary is formed on both the primary and secondary legs.

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.

Welding by electron bombardment

Abstract: Electron beam welding apparatus wherein means are provided for welding a joint sealed by a sheet of foil and thereafter depositing a plastic product on the weld head to prevent contamination.

Method for arc welding with overlapped band electrodes

Abstract: An improved arc-welding process and apparatus for producing welded seams by means of band or flat strip electrodes. The apparatus of the invention uses at least two band or flat strip electrodes which overlap at least partially. The aformentioned flat strip electrodes are then welded by means of arc-welding in a common welding bath.

Non-consumable electrode configuration having increased arc starting capabilities

Abstract: There is disclosed a non-consumable electrode for electric arc welding in a highly controlled inert atmosphere. In order to improve the initiating characteristics the rod-shaped electrode has at least one longitudinal edge starting from the end of the rod facing the arc, the edge angle of at least one of said edges being acute.

Thermionic insulated arc welding gun

Abstract: Improved means of insulating that portion of an air cooled arc welding gun which extends between the handle portion and the head portion to prevent thermionic emission dense enough to establish the conductance of welding current between it and the weldment, improved means for enclosing the welding current circuit suspended within the handle of the gun within a tube composed of insulating material to reduce the amount of heat radiated from the circuit within the handle, and improved means for suspending a highly heated welding current circuit within the handle to provide space between the wall of the handle bore and the suspended heated circuit for the circulation of cooling air therethrough. Also disclosed is the method of making the improved structure.

A Study of the Effectiveness of Four Instructional Techniques of Teaching ARC Welding at the University Level

Abstract: The problem was to study the effectiveness of four instructional techniques of teaching arc welding at the university level.

Method of arc welding

Abstract: A method of arc welding is disclosed in which a consumable electrode of predetermined composition and the same composition in granular or powdered form are fed separately to the weld area, so that variations in the amount of consumable electrode and granular or powdered composition are of no consequence, and the composition of the deposit will always remain constant The necessity for careful control of the ratio of feed is thus eliminated, and, moreover, the pool of molten material under the arc is substantially cooler than that of the pool in other or conventional submerged arc welding methods, with the result that there is less dilution of the pool by the base or substrate

Direct-current arc welder

Abstract: A direct-current arc welder comprising a transformer having its primary winding connected to an AC power source, controlled rectifier elements respectively connected between the secondary winding of said transformer and a welding circuit including an electrode and a workpiece and series circuits respectively consisting of non-controlled rectifier elements and a currentlimiting element and each being connected across the anode and cathode of said each controlled rectifier element, whereby the DC power necessary to maintain an arc between the electrode and the workpiece is supplied to said welding circuit through said controlled rectifier elements, while the DC power required to regenerate the arc after extinction is supplied to said welding circuit through said series circuits consisting of said noncontrolled rectifier elements and said current-limiting element.

Welding paste for resistance welding copper parts

Abstract: A WELDING PASTE FOR JOING COPPER PARTS BY RESISTANCE WELDING BY COATING SUCH PARTS TO BE JOINED AT THE POINTS PRIOR TO WELDING WITH THE PASTE CONTAINING A MIXTURE OF POWDERED SILVER OR POWDERED SILVER AND A SOLDERING FLUX.

Machine for producing resistance welded trimetallic contacts

Abstract: A machine for making trimetal contacts having a body of relatively low cost metal, such as copper, and contact surfaces of an expensive metal such as silver, the machine including a plate rotatable in a vertical plane carrying a plurality of matrices spaced equally about its circumference, and means to position each matrix successively to a plurality of work stations, a first work station to receive the end of a copper wire to a predetermined depth in the matrix at that work station, the matrix cooperating with a first stationary guide-forming countershear means through which the copper wire is fed, to shear the end of the copper wire to form the body of a workpiece, and to carry the severed piece to a second work station when the rotatable plate is indexed to the next station where the end of the short workpiece body is contacted by the end of a silver wire in a first welding chamber where an electric welding current is passed through the contacting surfaces to weld the silver wire to the copper workpiece. The silver wire is then advanced until the weld, and a predetermined length of silver wire enters the matrix which cooperates with a second stationary guide-forming countershear means to shear the silver wire adjacent the weld as the matrix is moved to carry the workpiece to the next successive work station where the second end of the copper body of the now bimetal workpiece is contacted by a second silver wire in a welding chamber positioned on the other side of the rotatable plate from said first welding chamber and the silver wire is welded to the copper of the workpiece, the second silver wire is then advanced into the matrix a predetermined distance and the matrix, in cooperation with a third fixed guide, shears the second silver wire as the plate carries the workpiece forward to a final station where the now trimetal workpiece is simultaneously shaped by upsetting, and ejected from the matrix.

Arc welding apparatus

Abstract: Upon initiating a welding operation, a relay is operated to connect two electric sources of alternating current in parallel circuit relationship through a contactor to fuse a welding electrode away from a workpiece striking an arc between them. Then another relay is operated to keep one of the sources disabled while the operation proceeds with the other source. Upon short circuiting, the contactor is operated to repeat the above process.

Gas-shielded arc-welding system

Abstract: The invention relates to a gas-shielded arc-welding system in which the welding arc is struck and/or stabilized by a highfrequency discharge which takes place between a welding electrode and the workpiece. The matching of the high-frequency voltage source to the high-frequency discharge is improved and the welding torch is simplified by using a first coaxial cable of a length equal to a quarter wavelength of the high-frequency voltage and a second coaxial cable connected to a point of the first coaxial cable in a manner such that the sum of the lengths of the two cables up to the welding electrode is equal to one half wavelength of the high-frequency voltage or to an integral multiple thereof.

One sided arc welding

Abstract: Arc welding of a seam between two workpieces backed by a rail, the temp. of which is measured to establish whether the weld has penetrated to the edge of the workpieces in contact with the rail. Spec., the rail has temp. sensors and can be moved at the same rate as a mobile wire electrode directed at the free side of the workpieces, so that the temp. sensors are always directly below the electrode.