Showing papers on "Welding published in 1972"

Laminated non-woven sheet

Abstract: A LAMINATED NON-WOVEN SHEET IS MADE FROM NON-WOVEN MATS OF MELT-BROWN THERMOPLASTIC POLYMER FIBERS. THE NON-WOVEN SHEETS MAY BE PRODUCED BY EITHER POINT WELDING OR USING ADHESIVES TO LAMINATE AT LEAST ONE NON-WOVEN MAT HAVING A HIGH STRIP TENSILE STRENGTH TO AT LEAST ON NON-WOVEN MAT HAVING A HIGH TEAR RESISTANCE SO THAT THE SHEETS HAVE BOTH HIGH STRIP TENSILE STRENGTH AND HIGH TEAR RESISTANCE. D R A W I N G

Deep penetration welding with high-power CO 2 lasers

Abstract: Experiments performed over the past year have involved the use of near-diffraction-limited lasers at power levels up to 20 kW for welding applications. This is a substantially higher power level than used in all previously reported experiments. As a result of the higher powers, significantly deeper penetration has been achieved. The optical cavity for the lasers used in these tests was an unstable oscillator, producing a near-diffraction-limited output with an obscuration of approximately 50 percent. The measured penetration for these tests is in reasonably good agreement with established correlations for vacuum electron beam welding data, indicating a strong similarity between the two types of welding. It is shown that a power of 2-4 kW is needed to produce thermally efficient welds in low-thermal-diffusivity plate materials such as 1/2-in stainless steel, and that higher powers are needed for the more highly conducting metals.

Mechanism of ripple formation during weld solidification

Abstract: The formation of ripples on the surfaces of GTA spot and seam weld surfaces in thin metal sheet was investigated by high speed motion pictures. The ripples are observed to form solely due to oscillation of the weld pool during solidification; no other mechanism for ripple formation was found. Weld pools were melted through thin metal sheets while a high speed camera observed the melting and solidification events on the bottom surface of the pool opposite the arc. When welding power is supplied from storage batteries, the weld pool surface shows virtually no oscillation while the arc is on. Shutting off of this arc suddenly releases the plasma pressure which was stretching the pool surfaces, setting the pool into oscillation like a struck drumskin. Solidification during this oscillation results in rippled surfaces. When a single phase full-wave rectified conventional dc welding power supply is used, the pool surface is observed to oscillate at 120 hertz. When this arc is shut off, the pool changes oscillation frequency in a fraction of a second from the frequency imposed by the pulsating plasma pressure to its own natural frequency. Pool oscillation periods after the arc is shut off are measured on the film strips. If the pool is considered to be a stretched membrane with surface tension providing the stretching force, a theoretical surface tension can be calculated from the oscillation period, pool mass and pool geometry. Agreement of the calculated surface tension values with published surface tension values for several metals demonstrates that the stretched membrane model adequately describes the pool oscillations. By counting the number of pool oscillations in the films and counting the number of ripples on solidified spot welds afterwards, a one-to-one correlation is established between ripples and pool oscillations. When a seam weld is made using storage batteries as the welding random disturbances of the pool surface are observed. Each disturbance leaves a few ripples before it damps out.

Method for short circuit metal transfer arc welding

Abstract: The method and system of the present invention minimizes weld spatter through control of the short circuit current and through control over the short circuit and arc time intervals.

Apparatus for ultrasonic welding of sheet materials

Abstract: An apparatus for joining sheets of thermoplastic material by ultrasonic vibration welding in which the welds are formed between the working surface of an ultrasonic resonator and opposing surfaces of anvils arranged in a changing pattern; means are disclosed for modifying the total energy transmitted by the resonator to the portions of the sheet material between the resonator and anvils so that the amount of energy is greater for a higher total surface area and less for a lower total surface area of the opposing surfaces of the anvils.

Hot Cracking of Austenitic Steel Weld Metal

Abstract: It is well known that a small amount of ferrite in austenitic stainless steel weld metal is very effective for the prevention of hot cracking. But the reason seems to be not quite clear. This experiment was carried out to know the relation between the solidification phases, sulphur microsegregation and hot cracking susceptibility of Ni-Cr alloyed steels. Because it has been confirmed by previous experiment that γ iron crust of primary solidification phase through the peritectic reaction of Fe-Ni system is very responsible to the hot cracking of 3.5% nickel alloyed steel weld metal. Circular groove hot cracking test specimens were prepared by three series of Ni-Cr alloyed cast steels, which contain about 0.15% sulphur. The groove of specimen was welded by TIG and MIG welding. The experimental results obtained are as follows;(a) The weld metals which crystallize as primary γ iron are much more sensitive to hot cracking than those which crystallize as primary α iron and transform to γ iron. This result concides with the tendency of sulphur microsegreagation of weld metals, which was detected by EPMA.(b) The hot cracking susceptibility of Ni-Cr alloyed steel weld metals relates to the boundary line of primary γ or α solidification surfaces, while the ferrite amount of weld metal at the room tenperature by Schaeffler diagram seems to have no direct relation with the susceptibility.

Welding power source

Abstract: Metal arc welding apparatus, primarily intended for short-circuit welding, including a first D.C. power supply for maintaining an arc between a consumable electrode and a workpiece and a control circuit responsive to a short-circuit detector for coupling a second D.C. power supply, substantially without inductance, to the welding circuit after a delay. Preferably a further detector senses the impending rupture of the short-circuit and the control circuit acts to reduce the current before the rupture takes place.

Process and apparatus for triple-electrode mig welding using short-circuit and spray-arc deposition

Abstract: A triple-electrode MIG welding process for the butt welding of I-grooves in flat position which comprises arranging three electrodes at the apices of a triangle, two of the electrodes preceding with a short-arc characteristic and one following said two with a spray-arc characteristic, and causing the two preceding electrodes to weld the groove walls by fillet welding while causing the following one electrode to weld and fill up the space between the beads formed by fillet welding, so that one weld layer is formed by three passes.

Trans-Varestraint試験法による溶接金属の凝固割れ感受性の研究(1) 一般構造用材料に対する検討

Abstract: In fusion welding of constructional ferrous and non-ferrous materials solidification cracking frequently occurs in the weld metal when a great deal of distortion and shrinkage takes place in the parent and weld metals due to a local rapid weld heat cycle. The occurrence of this solidification cracking, which is a kind of hot cracking, often gives rise to serious problems for some constructional materials from a view-point of weldability.Meanwhile those constructional materials including commercially pure metals have a brittleness temperature range during solidification whose ductility is very low to cracking.The properties in the solidification brittleness range such as temperature difference, minimum ductility and shape of ductility curve depend upon the kind and amount of impurities or alloying elements in the materials. Increasing the temperature interval and decreasing the minimum ductility are considered to increase the susceptibility of solidification cracking for the material in general.Unfortunately, however, there are few reports, so far, concerning the properties in the solidification brittleness range during welding of the constructional materials in spite of their close relation to solidification cracking.In this report authors have firstly investigated the nominal susceptibility of solidification cracking during TIG arc bead-on-plate welding for various constructional materials of carbon steels, low alloy high tensile strength steels, austenitic stainless steels, aluminum and aluminum alloys and brass, using the Trans-Varestraint Tester which was modified from the original Varestraint. Secondly, utilizing the relationship between the maximum crack length occurring in the center of weld metal with the Trans-Varestraint Test and the temperature distribution during welding which was actually measured, the properties of the solidification brittleness range have been investigated for the weld metals of the materials.Lastly, authors have proposed new indices, the critical strain rate for temperature drop (CST), which reasonably evaluates the solidification crack susceptibility of material during welding and the critical strain rate to time (CSS), which is easy to measured and is substituted for (CST) under a limited condition.

Apparatus for controlling electrode oscillation

Abstract: A welding apparatus wherein the welding electrode is moved transversely in oscillating motion across the weld path, the electrode to be capable of dwelling at either the fore or aft point of maximum displacement of the transverse movement path, the voltage between the electrode and the workpiece is automatically maintained constant by means of an automatic voltage control mechanism.

Some microstructural features of the welds in butt-welded polyethylene and polybutene-1 pipes

Abstract: Microstructural features characterizing butt welds in polyethylene and polybutene-1 pipes have been studied using scanning electron and transmission optical microscopy. The microstructures are explained on the basis of temperature gradients measured in the region of the welds and the flow of molten material during welding.

Self-shielding cored wire to weld cast iron

Abstract: A cored wire welding electrode for welding cast iron having an outer sheath made of nickel or a nickel-iron alloy and a powdered core composition containing copresent metallic magnesium and graphite and slag-forming and alloying ingredients. The electrode is particularly useful for open-arc welding of cast iron to itself and to compatible metals.

Laser Welding of Gold Alloys

Abstract: A neodymium glass laser was used to produce weld joints between test pieces of four different casting gold alloys. The mechanical properties of the welds were determined and their microstructures were evaluated. The results of this study indicate that laser welding of dental casting gold alloys is metallurgically feasible.

Method of making a bearing system having entrained wear-resistant particles

Abstract: A rock bit bearing system is provided by filling a groove in the bearing pin of the bit with a deposit including a multiplicity of tungsten carbide particles in a high temperature resistant metal matrix. The tungsten carbide particles are introduced into the deposit using a welding rod that combines the tungsten carbide particles with hard metal welding rod materials. Some of these chemicals may result in a corrosive drilling fluid. The drill cuttings, the materials encountered in the earth formations, barites added for fluid weight control, and the chemical composition of the drilling fluid combine to create a corrosive and abrasive drilling environment. The bit is subjected to a wide range of fluid pressures during the drilling operation. When the bit is at the surface, it is of course only subjected to atmospheric pressure; however, when lowered into the well bore, it will be exposed to very high fluid pressure because of the head of the fluid in the well bore. In view of the circumstances explained above, it can be appreciated that a bearing system for a rotary rock bit must include exceptional performance characteristics and a limited geometrical configuration. Since the entire drill string must be withdrawn to replace the bit when it fails, it is highly desirable to have the bearing system operate for an extended period of time.

Means for welding plastic pipe joints to plastic pipes

Abstract: A plastic pipe joint, integrally composed of a saddle-shaped foot plate and a pipe stub, is welded to the outer surface of a pipe by melting the concave surface of the foot plate and the entire periphery of the pipe along a cylindrical zone whose axial length is somewhat larger than the foot plate. The pipe joint is seated on the pipe surface by means of its foot plate and the plastic allowed to cool until the adjacent melted parts fuse and form a welding joint. Melting of the entire periphery of the pipe within the axial zone avoids later stresses at the welding joint.

Method of constructing a battery connector

Abstract: A method is disclosed for producing through-the-partition battery intercell electrical connections. Flat surfaced connector lugs are placed on each side of a battery partition wall, adjacent an aperture. The connector lugs are each cold formed by a pair of opposed electrodes under the application of high shear force sufficient to extrude the lugs into the aperture until they meet. The high initial shear force on the electrodes then is reduced to a lower secondary shear force, and an electrical welding current is then applied. The welding current is increased as the metal-to-metal contact of the opposed connector lugs increases until the welded connector lugs fills the aperture with metal. The welding current then ceases and the welded connector lugs are allowed to cool while still under the lower secondary shear force. The electrodes are removed from connection and the battery casing, containing liquid-tight intercell battery connections, is ready for further manufacturing or assembling steps.

Method of welding together two thermoplastic workpieces by high frequency vibratory energy

Abstract: For welding together by vibratory energy (sonic or ultrasonic frequency) two workpiece portions which are in abutting contact, an energy concentrating element is disposed between the juxtaposed surfaces to be welded. The energy concentrating element promotes the build-up of dissipated energy to quickly provide molten material which flows and upon solidification produces a fused joint.

Vibratory welding apparatus

Abstract: A vibratory welding apparatus specifically adapted for welding metal includes a resonator one wavelength long at the frequency of the sound transmitted therethrough and is supported from a stationary support by a set of support members which engage the resonator at two of its antinodal regions of longitudinal motion. The members are designed to yield in the direction of resonator motion but to provide rigidity in the direction normal to such motion.

Printed circuit board method and apparatus

Abstract: A method for the low cost production of printed circuits with both soldered-in component leads and welded wire connections, which includes applying a sheet of highly weldable material such as stainless steel to an insulative board, plating a layer of highly solderable material such as copper over the stainless steel, applying a first resist pattern and then a first etchant such as ferric chloride that etches both copper and stainless steel to form a predetermined printed circuit pattern, and then applying a second resist pattern and a second etchant such as chromic acid which etches only the copper to leave exposed regions of the stainless steel. Components can be wave soldered in place, and the solder will not adhere to the stainless steel so that wires can later be welded to the exposed stainless steel weld regions. More uniform welding can be obtained by applying an underlayer of copper to the insulative substrate under the stainless steel layer, so that there is a low resistance path to all weld regions.

Manufacture of electrical metallic tubing

Abstract: Electrical metallic tubing is manufactured from galvanized steel strip by forming the strip into tubular shape, welding the edges together and replacing the zinc lost in welding by gas or arc metallizing the weld zone first with aluminum and then with zinc.

Integrated circuit device employing metal frame means with preformed conductor means

Abstract: Wire bonding is eliminated in the assembly of microelectronic devices, by a process involving the direct bonding of circuit electrodes to an unsupported metallic sheet-frame member having a plurality of inwardly extending leads. A single-step vibratory pressure welding technique is employed for the simultaneous bonding of all leads to a semiconductor integrated circuit chip. Lateral confinement of the leads during the bonding steps causes a buckling action to introduce a small but critical loop in each lead to ensure clearance between the lead fingers and the perimeter of the semiconductor chip, whereby electrical shorting is avoided. The loop also provides a structural flexibility in the leads, which tends to protect the bonding sites from excessive stresses. Subsequently, the first frame member including the bonded circuit is attached, preferably by resistance welding, to a second lead frame member of heavier gage and increased dimensions, suitable for connection with external circuitry. Excess portions of the first frame member are then removed, providing a completed assembly for packaging; e.g., plastic encapsulation or hermetic sealing, as in a ceramic-glass flat package.

Apparatus and method for welding joints between metal shapes

Abstract: A traveling electric arc welding apparatus using gas shielded consumable wire electrode, comprises a welding head mounted on a traveling carriage. The mounting means provide for angular shifting of the head about two different axes. Both such axes are in or near and closely parallel to the plane of the weld; e.g., in welding pipeline girth joints one axis lying as nearly as convenient in the plane of the weld is also as nearly as convenient tangential to the weld circle and thus passes near or, if desired, through the locus of the arc. The direction of feeding electrode material with respect to the weld plane is accurately set by movement about this first axis. The other axis is perpendicular to the first and lies generally in the weld plane. Means are provided for accurately aligning and setting the welding head laterally with respect to the plane of the joint; i.e., along the axis of the work in the case of a pipeline joint, by shifting the head about the second axis. Other positioning means are provided to adjust, pre-set and fix the distance or spacing of the welding nozzle from the noint. Means which can be inactivated, if desired, are included for oscillating the head back and forth across the weld path as for filling a wider gap or for capping. Quick release means permit raising the head from the work and returning it to a precisely determined working position.

Stainless steel with high resistance against corrosion and welding cracks

Abstract: Stainless steel with high resistance against corrosion and welding cracks, consisting of carbon, silicon, manganese, nickel, chromium, copper and the remainder of iron with an inevitable amount of impurity. The contents of the aforesaid ingredient elements of the stainless steel are so related with each other that the value of the following austenite/ferrite ratio is kept equal to or less than 1.06. The stainless steel may contain a limited amount of molybdenum, niobium, titanium, and tantalum, with a modified austenite/ferrite ratio. The stainless steel is advantageously used to make heat exchangers in processes employing automatic tungsten inert gas arc welding techniques.

Welding wire driving and straightening device

Abstract: A device for driving and straightening welding wire comprising a supply reel and a driving and straightening mechanism having two pairs of transport rollers and one straightening roller which is arranged between the transport rollers. The shaft of the straightening roller is located on the side of the common tangential plane of the transport rollers facing the supply reel. The straightening roller is adjustable both in its axial direction and in a plane at right angles to the axial direction. The device is particularly suitable for straightening welding wires to be supplied at high speed in plasma-MIG welding processes.

Method of making an explosively welded scarf joint

Abstract: A method of obtaining a bond joint between thin metal members without the addition of a bonding agent. The method yields bond strengths comparable to the parent metal. It comprises overlapping the materials at the edges and bonding them by explosive welding while also making use of the explosive force to shape the materials into an essentially planar configuration.

Welding tip for plastic welding gun

Abstract: A welding tip for plastic welding guns having a hollow body member arranged for removable attachment to a hot air welding gun. The body member supports a guide tube for slidably receiving plastic welding rod. The guide tube supports a pair of plates which in turn support a pressure roller. The body member directs hot air from the hot air welding gun to a lower end of the tip and the arrangement is such that a lower end of a welding rod in the guide tube is softened for deposit in a weld seam. The tip structure is of metal or other heat absorbing material for distributing heat to the guide tube to preheat the welding rod. The pressure roller has a concaved peripheral surface portion for rolling out a smooth weld with the correct pressure.

Device for directing the movement of welding electrode along the butt of joining parts

Abstract: A device for correcting the position of a welding electrode relative to the joint of parts being welded and to keep in axial relationship the weld seam and the joint, while the seam width is adjusted at the same time. The device has two photoelectric sensors indicating the position of the joint and the seam, and follow-up and control units associated with the sensors. In the course of welding, as the joint moves relative to the electrode, a control signal is generated which aligns the welding electrode with the joint of the parts being welded. In case of industrial interferences, the resulting displacement of the seam axis relative to the joint is corrected by a seam control system. The device is capable of maintaining a constant width of the seam in the course of welding.