Showing papers on "Butt welding published in 1971"

Analysis of thermal elastic-plastic stress and strain during welding by finite element method

Abstract: It is well known that welding thermal stresses and resulting residual stresses influence the strength of welded construction, causing troubles such as brittle fracture, buckling and weld cracking. At the instant of welding, a limited portion of the welded joint is heated up to a very high temperature and cooled down to room temperature. In the thermal cycle which takes place, the temperature distribution changes with time and it affects the mechanical properties of the metals. In order to perform a reliable theoretical analysis, the above mentioned factors should be taken into account. The authors developed a method of theoretical analysis of this problem based on the finite element method, with consideration of the effects of changes in the modulus of elasticity, yield stress and the coefficient of linear thermal expansion of the metal with temperature. They analysed thermal transient stresses induced in a butt weld under a moving electrode and also in a fillet weld in the courses of the first and second beads and obtained various information on thermal stress history in the process of welding. Examples verifying usefulness of the method are cited.

Submerged-arc both-side butt welding method of a square groove

Abstract: A method for submerged-arc welding of a square butt joint from opposite surfaces thereof, by using tandem electrodes. The tandem electrodes are moved at 50 to 120 cm/min, relative to the joint, while passing a current I1 of 1,000 to 2,000 amperes through the leading electrode, while keeping the trailing electrode current I2 to one-fourth to four-fifths of I1 and the arc voltage of the leading electrode at (I1/40)+15 to (I1/40)+35 volts. The welding operations from the opposite surfaces are conducted under similar conditions.

Method for automatic manufacture of metal container bodies,and welding machine for application thereof

Abstract: An apparatus for the automatic continuous, high-speed manufacture of metal containers is disclosed utilizing a welding machine with electrode rolls. The blanks are stacked and rounded and moved toward the welding point on a first conveyor. The rounded blanks are then transferred to a second conveyor operating at the welding speed which is less than the speed of the first conveyor. The apparatus includes means for reducing the speed of the rounded blanks below the welding speed immediately before the transfer from the first to the second conveyor, and to increase their speed above the welding speed immediately after the transfer so as to compensate for the speed reduction before the transfer.

Electric resistance welding machines

Abstract: An electric resistance welding machine has several pairs of active electrodes below the work piece, such as mesh, being welded. Above the work piece a current bridge is provided for each pair of active electrodes, the current bridge being lowered in use so that the work piece is gripped at welding points between the active electrodes and the bridge, the welding current flowing from one active electrode, through the work piece at one welding point, across the current bridge, through the work piece of the other welding point, and back to the other of the pair of active electrodes.

Process and apparatus for submerged arc welding

Abstract: A submerged arc welding process performed on adjacent longitudinal edges of a pipe blank. Two submerged arc welding units are supported on carriages which move on a stationary travel beam over the pipe blank. The welding units start welding at opposite ends of the longitudinal edges and weld toward each other until they meet. At that time one welding unit stops and returns while the second continues forward to overlap the welds while the fused flux remains electrically conductive at the area of overlap. After the second unit merges the welds, it returns.

Apparatus for resistance butt welding of several pipes into extended sections

Abstract: An apparatus for resistance butt welding of several pipes into extended pipe lengths. The apparatus uses a conveyor-type transport device for feeding the pipes to a butt-welding machine, trimmers for the removal of external and internal weld burrs, and skids for delivering single pipes to the transport device.

Multiple electrode resistance welding machine

Abstract: The subject of this invention is a multiple electrode resistance welding machine in which, by a particular configuration of the conductors which connect the power supply to the several welding positions, the DC resistance and the inductance of the circuit between the power supply and each of the welding guns is made constant. Through the use of the novel arrangement of secondary circuit conductors, the total resistance and the inductors in all of the circuits is the same so that the welding current and wave shape is the same in all of the secondary gun circuits and the weld quality at all of the welding points is uniform.

Self-centering clamp for butt-welding tubes

Abstract: Self-centering welding clamp fitted with a rotating drum on which a filler-metal wire supply reel or spool is designed to feed the weld ahead of the electrode, said wire being driven by knurled wheels at a certain speed in one direction or another between an angled coupling connected to the fixed body of the clamp and a flexible sheath embedded inside the rotating drum by means of a system of synchronization between the motor of the drum and that of the knurled wheels in order to permit, in buttwelding two tubes by circular welding, to recharge the weld as desired with filler-metal.

Method of manufacturing large rotatable members by welding

Abstract: A method of producing large rotatable steel parts with circular cross-sections for construction of large machines such as shafts of generators and turbines. In a first stage a welding process is effected under a welding head for production of a weld connection in the central region of a welding gap between the parts. This central weld is subsequently circularly machined and the remaining peripheral groove is widened and formed of V shape. The parts are then welded at the groove, while the parts are rotated, by use of a welding process with a granulated welding flux.

Welding construction for multilayered devices

Abstract: A welding construction for multi-layered device includes a plurality of concentric superposed tubes tightly fitted within one another and secured to one another by welding at the end of their interfaces formed between adjacent superposed tubes. A space is left between such welds and their associated interface in order to prevent stress concentrations and avoid cracking. Lengths of tubing thus formed are then assembled end to end by welding opposed end portions to each other. Welding in two steps enables the checking after each step.

Improvements in or relating to welding

Abstract: 1,236,126 Making valves; welding by pressure TRW Inc 10 July, 1969, No 34782/69 Headings B3A and B3R In butt welding two elements, one element is rotated relatively to the other while the elements are coaxially aligned, the elements are brought into rubbing contact and a welding current is passed through them, the relative rotation being terminated when welding temperature is reached A headed valve stem 10 is held against rotation in an insulated movable clamp 13 and an oppositely arranged headed valve stem 18 is held against rotation in another insulated movable clamp 22 A valve tip 24 to be welded to stem 10 and valve tip 26 to be welded to stem 18 are held between the clamps 13, 22 in a conductive clamp 27 carried in a shaft 28 rotatable in bearings 31, 32 by means of gear teeth 33 An insulating spacer 29 is arranged between the tips 24, 26 In operation the tips 24, 26 are rotated and pressure is applied by rods 43, 44 to move the stems 12, 21 into contact with the tips, current is then supplied by a transformer 39 to the clamps 13, 22 to pass in series through the stems and tips causing resistance heating at the joints and when welding temperature is reached the spindle 28 is braked and current flow stopped After welding the unit may be moved to another position and driven to allow machining of flash possibly after flash annealing In a modification the single spindle 28 is replaced by two spaced spindles which carry a common single tip piece which is welded to the two valve stems using increased pressure for upsetting The assembly is then moved to another station where a cutting wheel fits between the spindles to cut the single tip into two Stems may be welded to heads and the stems may be hollow or of different metal from the valve head

Laser welding and cutting

Abstract: The first part discusses the principles of laser welding, selecting weld parameters, equipment and tooling, material properties and joint design, new CO2 laser for welding, and applications. The second part dealing with cutting, considers apparatus, reflectively, power and power density requirements, single mode and multimode lasers, applications, cutting and drilling with laser alone, and future developments.

アプセット・バット溶接における接合面の酸化介在物の分散・微細化機構

Abstract: Dispersing mechanism of oxide inclusions is studied by investigating the behavior of oxide film inserted artificially at the interface of specimens in the upset butt welding processApplying the concept obtained in the study of flash welding, the authors presume that good mechanical properties can be obtained, if the oxide film which may exist always in the interface, is dispersed by adopting adequate welding conditionsIt is obtained that if the temperature of the weld interface is above a certain value, welded joints with good mechanical properties are obtained under rapid heating and cooling as in this experiment By using the model test pieces with oxide film artificially inserted in the interface, it is made clear that a certain maximum temperature in upset butt welding process is necessary for the dispersion of the oxide film See Figs10, 11 Above mentioned critical maximum temperature is measured to be about 1370°C which coincides with the melting point of FeOAccordingly the mechanism of the dispersion of the oxide film is understood as follows As the coupling force between Fe and O becomes weak in liquid state of oxide, O can diffuse easily from the oxide film layer in the interface, giving many fine oxide particles in the neighborhood and no trace of oxide film in the interfaceIt must be noticed that dispersion takes place at temperatures below the melting point of steel The dispersion has little relation to applied mechanical pressure or the deformation of the test pieces See Figs13, 14

Method and apparatus for controlling a fusion welding process

Abstract: 1,219,865. Welding by fusion. J. I. KAZENNOV, V.A. VINOGRADOV, V. S. POPENKO and L.T. SOLODKIN. 13 March, 1969 No. 13296/69. Headings B3R. [Also in Divisions G1 and G3]. An arc welding process is controlled in accordance with measurements of the weld composition produced by a spectrally sensitive radiation detector. When butt welding dissimilar materials departures of the weld from the joint show as changes in weld composition. In the case of lap joints of dissimilar metals or a butt joint with a dissimilar backing strip, composition changes indicate changes in penetration. In a gas-shielded welding process, Fig. 6, the metals to be welded are placed on a strip 18 having a groove 19 through which is passed an antioxidant gas different from that shielding the welding zone. The concentration of antioxidant gas in the weld atmosphere falls off away from the joint, and provided photo-cells 13, 14, which are connected in a bridge circuit, are symmetrical about the joint the bridge will balance. Imbalance of the bridge actuates a motor, by means of a multivibrator acting as a D.C. to A.C. converter, to return the electrode to the centre of the joint.

Hard facing welding device - with several electrodes

Abstract: The metal carbide weld facing device comprises >=2 welding electrodes, which are offset relative to each other, both in and transverse to the direction of welding. The electrode heads are pref. mounted on a trolley. Straight line, slightly overlapping, pendulum or sliding overlapping seams may be produced, in the latter case a reciprocating mechanism being employed for the welding heads. The machine permits the fast application of hard facing on flat surfaces.

Improvements relating to the explosive welding of tubular members

Abstract: 1,220,171. Welding by pressure. H. VAN DER HORST. 29 Jan., 1968 [27 Jan., 1967], No. 4424/68. Heading B3R. In welding tubular parts the surfaces to be welded are arranged to overlap with a wedgeshaped space therebetween and an explosive is ignited about the surfaces. In butt welding two tubes 1, 2, Fig. 1, the adjacent ends are tapered to leave a space a therebetween, a strip 3 of explosive and a detonator 4 are arranged about the tubes with an expandable mandrel within the tubes and the explosive is ignited to weld the tubes. The ends of the tubes in a modification are not tapered, but one is expanded to overlap the other with a tapering space therebetween. A mandrel is employed within the tubes. In another embodiment a sleeve 12, 13, Fig. 3, is arranged about the abutting ends of tubes 10, 11, the sleeve being shaped to form an angle with each tube end and explosive 14 with detonator 15 is arranged on the sleeve. Tubes of aluminium, copper &c. may be joined and may be of different diameters. A clamping cushion of rubber may be arranged beneath the explosive. The explosive layer is preferably ignited by a strip of explosive having a low detonation velocity and forming an angle to the length of the layer.

Investigation of welding thermal strains in marine steels

Abstract: The stress-strain-temperature response of metal plates during welding is discussed and current efforts to analyze the phenomena are outlined. Transient strain and temperature data obtained from welding experiments on HY-80, HY-130, low carbon and maraging steels are presented. The experiments were designed to approximate ship structural weldments including thick-section, multi-pass butt welds. The experimental data are compared to analytical predictions obtained from computer programs developed for the National Aeronautics and Space Administration. Results indicate that the programs can be used to analyze complex structural weldments applicable to ship and submarine fabrication. It was also found that the effects of thick-section, multi-pass welding are more pronounced in the early passes and tend to level off as deposited weld metal increases. The transient strain response of both thin and thick section plates was found to be predominantly longitudinal except in the immediate area of the welding arc itself. The maximum mechanical strains observed on plates of varying strength levels were found to be roughly proportional to the inverse of the base plate yield strength. Finally, the strain plots of the two highest strength steels were characterized by unusual secondary tensile peaks which may be linked to phase transformations in the heat affected zone during cool-down. Several recommendations are made concerning further investigations aimed at developing the NASA programs and subsequent experiments into shipyard design and production tools.

Bonded joints and non-destructive testing: Problems in methods for the control of quality of butt welds made by the friction, cold pressure and flash welding processes

Abstract: Traditionally ndt of fusion welded joints for critical weldments is conducted during the final stages of fabrication on the basis of 100% inspection. The Author has long maintained (and it may be regarded by some as self-evident) that ndt serves industry better in circumstances where it can be used to monitor quality during production thus avoiding the production of expensive scrap. Unfortunately ndt methods, with few exceptions, cannot be considered particularly useful in either role when it comes to the control of quality of friction, pressure and flash welds. In this article an attempt is made to explain why this is so and why it is necessary to resort to sampling techniques and destructive tests to assess quality on the basis of circumstantial evidence. Recent trends have been towards the monitoring of process parameters in two of these processes and some measure of success has been achieved.

Device for feeding tubes end to end into a butt welding machine

Abstract: 1,236,605. Welding by pressure. PRVNI BRNENSKA STROJIRNA, ZAVODY KLEMENTS GOTTWALDA NARODNI PODNIK. 17 Sept., 1968, No. 44137/68. Heading B3R. A device for feeding tubes to be welded end to end into a butt welding machine comprises two pairs of rollers, all of which are parallel and mounted one pair on one side of the machine and one on the other so that the tubes may be fed in a direction normal to the rollers, each roller being mounted on a frame and the frames for each pair of rollers being pivoted together, each pair of frames being connected to a lifting jack 3, 4 and tube traversing jacks 6, 7 being mounted one on one frame of each pair and associated with pivoting stops to effect movement of rakes on the rollers in a direction parallel to the rollers. For welding end to end tube lengths for superheaters or water heaters a pair of rectangular elongated frames 1 pivoted about a shaft 19 is provided on one side of the butt welder and another similar pair is provided on the other side. The frames which each carry a driven roller 2 are connected in pairs to pneumatic jacks 3, 4 through adjustable rods 5 and one of each pair of frames carries a pneumatic jack 6, (7) for moving tubes on the frames in a direction parallel to the rollers 2. A rack is provided on the end of the piston-rod of the jack 6 (7) and engages with a gear on a member 10 rotatably mounted on a sleeve. With the pistonrod advanced the sleeve is engaged by a spring pressed detent and when the rod is retracted the member 10 is firstly caused to rotate into a vertical position and then by engagement of the end of the piston rod with the sleeve is caused to be retracted with rod to move rearwardly. In operation a tube is placed on each pair of frames, the tubes are fed into the butt welder by the rollers 2 and welded. After welding the frames are rotated by the jacks 3, 4 to raise the welded tubes from the welder, the tubes are moved rearwardly by the jacks 6, 7 and the frames are lowered for the next tubes to be welded.

Adjustable gate for butt welding machine

Abstract: A multiple upset pressure welding apparatus particularly adapted for cold welding wire ends together. The mechanism includes pairs of dies that are supported for relative movement toward and away from each other with the dies of the pairs also being relatively movable toward and away from each other. Gates or restraining devices are juxtaposed to each of the pairs of dies for permitting movement of the wires toward each other during the welding process and for precluding reverse movement of the wires when the pairs of dies are retracted. The restraining gates are adjustable so as to accommodate different size wires and to permit gripping of the wires adjacent the respective dies.

Improvements in or relating to a method of making a rolling bearing cage and to a combination including such a cage

Abstract: 1,243,302. Making bearings. SVENSKA KULLAGERFABRIKEN A.B. 12 May, 1969, No. 24117/69. Heading F2A. [Also in Division B3] A rolling bearing cage is made by forming pockets 2 in a plane metal strip 1, surface treating the strip so as to be resistant to wear, cutting the strip to the required length and, after inserting rolling elements 8 into their pockets and inserting the cage into a bearing race 10, joining the ends of the strip to form the cage. The ends of the strip may be joined by resistance butt welding the ends having first been chamfered to accommodate protuberances (17, Fig. 4, not shown) produced during welding. The surface treating of the strip may provide a surface which is electrically resistive to facilitate the welding. Notches (14, Fig. 2, not shown) are provided for connection to a current source and to accommodate clamps during welding.

Root work on butt welding

Abstract: The component to be welded at right angles to the two workpieces butts is shaped with a depression and filled with welding powder. It is held in place at the seam so that when arc welding takes place, the welding powder melts and welds the roots of the butts, and as it is contained within the depression, the third component is welded in place at right angles.

Design Considerations in Inertia Welding of Turbocharger and Gas Turbine Components

Abstract: This paper begins with a statement of the acceptance and use of inertia welding in the gas turbine field. A short explanation of the inertia welding process follows. Categories of welds discussed are solid inertia butt welds; tubular inertia butt welds; and angular-annular inertia butt welds. An example of the first category is a bimetallic engine valve. The second category is typified by steel shafts joined to superalloy rotors for turbines. The joining of wrought superalloy disks to cast superalloy blade rings to produce a composite wheel comes into the third category. The effect of welding parameters on strength and microstructure, as well as design and process changes required for inertia welding are related. In conclusion, basic considerations for utilization of inertia welding are expressed.Copyright © 1971 by ASME

Butt welding thin plate strips

Abstract: A bolt with an angled face is placed at the end of the seam to be welded between the 05 mm thick plates When the welding head reaches the end of the seam the head is deflected and the molten metal allowed to continue under its own volition to complete the seam The weld is not damaged by molten metal being dispersed at the end of the weld

Method of flash butt welding of articles

Abstract: A method of flash welding of two elongated parts secured in clamps which consists in essence in that elastic energy is stored in one of the parts to be welded and in a welding machine element connecting two clamps in which said part is secured, and the energy thus stored is employed to bring together the parts to be welded during the welding procedure.

Resistance butt welding machine

Abstract: A machine for (the) resistance butt welding of articles, such as pipes, (featuring) having a welding transformer and two pipe clamps, and an additional pipe clamp located at a distance from one of the (available) first two clamps, (the rigid attachment of the extreme clamps to) a common shaft made up of two (halves as well as rigid fixation of the) lengths joined and secured rigidly to the extreme pipe clamps, a casing of an actuating cylinder rigidly fixed to the intermediate clamp and (of the cylinder piston -) to said shaft.