Showing papers on "Butt welding published in 1988"

Vibration welding of thermoplastics. Part III: Strength of polycarbonate butt welds

Abstract: In vibration welding of thermoplastics, frictional work done by vibrating two parts under pressure, along their common interface, is used to generate heat to effect a weld. The main process parameters are the weld frequency, the amplitude of the vibratory motion, the weld pressure, and the weld time or weld penetration; The effects of these parameters on weld quality were systematically studied by first butt-welding polycarbonate specimens under controlled conditions over a wide range of process parameters, and by then determining the strengths and ductilities of these welds by tensile tests, A significant result is the apparent existence of a weld-penetration threshold above which high weld strengths are attained, but below which the strength drops off. Under the right conditions, the strengths of polycarbonate butt welds are shown to equal the strength of the virgin polymer.

Vibration welding of thermoplastics. Part IV: Strengths of poly(butylene terephthalate), polyetherimide, and modified polyphenylene oxide butt welds

Abstract: In vibration welding of thermoplastics, frictional work done by vibrating two parts under pressure, along their common interface, is used to generate heat to effect a weld. The main process parameters are the weld frequency, the amplitude of the vibratory motion, the weld pressure, and the weld time or weld penetration.; The effects of these parameters on weld quality were systematically studied by first butt welding thermoplastic specimens under controlled conditions, over a wide range of process parameters, and by then determining the strengths and ductilities of these welds by tensile tests. The three thermoplastics investigated are poly (butylene terephthalate), polyetherimide, and modified polyphenylene oxide. Changes in the weld pressure are shown to have opposite effects on the strengths of polyetherimide and modified polyphenylene oxide welds; Also, the weld frequency is shown to have a significant effect on the weldability of polyetherimide. The weldability data for these three thermoplastics are compared with data for polycarbonate. Under the right conditions, the strengths of butt welds in these materials are shown to equal the strength of the virgin polymer.

Process for the remote-controlled semi-automatic welding of two rotationally symmetrical components

Abstract: Welding is controlled from a control station (14) located at some distance from the welding zone. Before the start of a welding pass, the welding parameters are set by an operator, to whom the values to be given to the parameters as a function of the type of pass are supplied by a memory in which the information relating to the welding is stored. The welding operation is started, after the parameters have been checked as a function of the content of the memory. The welding operation is monitored continuously by the operator by means of a remote screen display of the welding zone. If appropriate, the operator changes some of the welding parameters according to the screen image of the welding zone. These changes are checked by comparison with the content of the memory.

A predicting method of welding residual stress using source of residual stress.

Abstract: In this paper, a predicting method of welding residual stress by using the source of residual stress (inherent strain) is proposed. And the validity of the method is demonstrated by numerical experiments with the aid of the finite element method.Welding residual stress is produced as a result of thermal elasto-plastic behavior. Their source is composed of the thermal strain and/or plastic strain, etc., which is called here inherent strain.Taking a butt welding joint as an example, the sources of residual stress are estimated in different sizes manufactured on the same welding condition. It is found that the distributions of the source of residual stress are almost the same if the sizes of the joint are larger than that of a specific one, which is named a standard size.It is demonstrated that the residual stress produced in the joint of any different sizes can be predicted accurately by elastic analysis using the inherent strain in a standard size of the joint, unless the sizes are too small.

Method and apparatus for cutting welding steel strips

Abstract: An apparatus, for butt-welding steel strips using a laser beam are disclosed, in which opposite ends of preceding and succeeding steel strips fed continuously are cut and the cut end edges thus formed are welded by butt welding using a laser. The cutting and butting at the time of welding are effected with one edge of the preceeding steel strips adjacent to the opposite ends of the succeeding steel strips aligned to be parallel with the center line of travel of the continuous processing line. When effecting the alignment, the preceding or succeeding steel strip is attracted by an electromagnetic chuck on a work table in the continuous processing line and is pulled by the chuck toward a reference block provided with an alignment edge parallel to the center line of travel of the processing line to bring the edge of the sheet into contact with the reference block. The alignment is done in this state. The work table is capable of being moved along the continuous processing line. A revolving table supports the work table.

Automatic arc-welding method

Abstract: An automatic arc-welding method, which comprises, when welding two objects to be welded together by means of a welding wire along a first groove formed between the objects to be welded on a first side thereof, continuously determining by calculation a target welding current, with which a depth of penetration agrees with a target value thereof, on the basis of the root gap, the material of the welding wire and the like; continuously determining by calculation a target feeding rate of the welding wire, at which an extension length of the welding wire agrees with a target value thereof, on the basis of the welding current, the material of the welding wire and the like; continuously determining by calculation a target welding speed, at which a height of the weld bead agrees with a target value thereof, on the basis of the feeding rate of the welding wire, the material of the welding wire, the root gap and the like; and on the other hand, when welding the objects to be welded together by means of the welding wire along a second groove formed on a second side of the objects to be welded, opposite to the first groove, continuously determining by calculation a target welding current and a target welding speed while taking into consideration the depth of penetration and the weld bead in the first groove; thereby automatically controlling the welding current, the feeding rate of the welding wire and the welding speed on the basis of the respective target values thus determined.

Apparatus for the continuous welding of strips and/or sheets

Abstract: The invention relates to an apparatus for the continuous butt welding of strips and sheets by laser beams. The sheets or strips 1,2 are moved together in abutment and retained in the same level by tension rollers 3,4 on both sides and right and left of the welding gap. On at least one side of the strips or sheets the tension roller 3 comprises a hollow shaft 9,10 and roller shells 13, 14 pivotably mounted thereon. Both the hollow shaft 9,10 and the roller shells 13, 14 are formed with an aperture 18a, 18b through which the laser beam 25 of a welding head 19 disposed inside the hollow shaft 9,10 extends. The welding head 19 is so aligned that the focused laser beams 25 impinges through the apertures 18a, 18b in the hollow shaft 9,10 and the roller shells 13,14 on to the welding gap in the clamped zone of the strips or sheets 1,2.

Development of transition metal joint for steam generator circuit of prototype fast breeder reactor

Abstract: A transition metal joint between type 304 stainless steel and 2·25Cr–1Mo steel, with Alloy 800 as the transition piece, is being developed for application in the steam generator circuit of the 500 MW prototype fast breeder reactor. As part of this programme, the hot cracking susceptibility of Inconel 82/182 and of 16–8–2 welding consumables were compared and the microstructure and mechanical properties of butt welds between type 304 stainless steel and Alloy 800, welded by the two consumables, were studied to select the appropriate welding consumables for this joint. It is recommended that the 16–8–2 consumable should be used for welding this joint because of its lower microfissuring tendency and reduced mismatch in the coefficient of thermal expansion across the joint, although this would mean a slight adverse effect on the elevated temperature mechanical properties. Further, to select the optimum post-weld heat treatment (PWHT) of the joint between Alloy 800 and 2·25Cr–1Mo steel, welded with Inc...

Butt welding method by means of laser beam

Abstract: Two thin plate members preferably made of metallic sheets are prepared and one end surface of at least one of the members is formed so as to have an inwardly curved recess which constitutes a gap when the end surfaces of the members are linearly butted together. A laser beam is irradiated along the butted portion of the members. The gap may have various forms having a predetermined width. The two members to be butt-welded may be substituted by two end portions of a single metallic sheet having a rectangular configuration in the case where a shell portion of a can is formed by the butt-welding operation.

Butt welding method

Abstract: A butt welding method is disclosed, which comprises abutting a pair of steel sheets and welding the abutting surfaces by opposing electrodes while preventing gaps from developing between the widthwise outer portions of said steel sheets by suppressing rotational deformation of the abutting surfaces in the widthwise outer portions thereof.

Control system and method for vibration welding

Abstract: A displacement transducer is used to continuously monitor the distance between two fixtures securing parts to be welded. The signal from the displacement transducer is used to stop the welding process when a desired amount of material has been extruded from the weld. The control strategy will automatically take into account part nonuniformities that normally result in poor welds in welding processes that use time as the control variable.

Method for the electric butt-welding of the two reciprocally contacting ends in the gap region of a laid railway track

Abstract: Method for the electric flash-butt welding of the two reciprocally contacting ends in the joint region of a rail section of a laid railway track (7) by means of a mobile flash-butt welding machine (1) having a transversely and vertically adjustable welding apparatus (15). The welding apparatus comprises two halves which can be displaced relative to one another in the rail longitudinal direction by means of hydraulic cylinders and each have a pair of clamping and welding jaws which can be driven by hydraulic clamping cylinders. The welding apparatus (15) is placed with said pair onto the rail joint or the rail gap, in particular with prior releasing or loosening of the rail-fastenings of the sleepers. The two rail ends (42, 43) are here in each case seized by the electrically/hydraulically driveable pair of clamping and welding jaws and are moved to or from one another by means of a control device according to a welding process programme and are welded together with a closing hydraulic upsetting stroke. Thereafter, if appropriate, the protruding weld upset is removed by again hydraulically driving the pair of clamping and welding jaws of the one apparatus half and of the other apparatus half which is connected to a shearing-cutter device. In the region directly outside or in front of and behind the welding apparatus (15), the two rail ends (42, 43) are additionally seized by in each case at least one further pair of clamping jaws (47, 48), which can be driven via driving cylinders (50) for clamping and displacement, of a rail- drawing or -displacing device (16), in particular for drawing up a long rail section (5) before the actual welding process and/or during the closing upsetting stroke in accordance with the welding process operation.

Method for assembling the terminal portion of a motor vehicle wheel axle support-member, and the terminal portion produced by this method

Abstract: The method enables certain components such as two half-shells (3), a hub (5) and flange (7) to be assembled for the purpose of forming a wheel axle terminal (1) and consists essentially of the following operations in succession: - positioning one of the half-shells (3) on the other so that their respective edges (11 and 13) and respective semicylindrical end portions (12) mate in order to form a cylindrical seat (4); - welding said half-shells (3) together along edges (11 and 13); - inserting said hub (5) into the cylindrical seat (4) and welding the axial ends of this latter to the seat (4) by circumferential butt welds; - positioning the flange (7) on an end portion (6) of the hub (5) which emerges from the seat (4), and welding the axial end of said portion (6) circumferentially by a butt weld to the flange (7).

Transport arrangement for the welding-wire feed on welding equipment

Abstract: The invention deals with the control of the welding-wire feed on welding equipment. In order to deliver the welding wire (2) at constant force even in the face of unfavourable actions of force and avoid tensile or compressive stresses, the welding wire (2) is guided between a pushing drive (3) and a pulling drive (6) through a yielding part (4) and a curved tube (8). The tube tension is assisted by a spring (11). The yielding part (4, 9) is coupled to a control member (13) which measures the yielding travel of the yielding part (4, 9) when compressive or tensile stresses develop at the welding wire (2) and feeds it to a control system for compensation via speed control of the first drive (3). In this way, even very soft and thin welding wires (2), for example made of tin, aluminium or the like, can be delivered without problem.

Electric welding device for automatically welding heating spiral fittings together

Abstract: In an electric welding device for automatically welding heating spiral fittings made of plastic, a scanner (3) for fitting data is connected via a converter (4) with an input of a controller (8) in connection, which via a power stage (13), the welding power for a welding duration controls. To achieve the optimum welding factor of the scanner (3) and the converter (4) for the scanning of target welding operation data of the fitting (1) are arranged. A further input (at 12) of the controller (8) is connected to switching circuits (computer 11) which generate signals of the actual welding operation from the detected welding capacity and from the actual welding time.

Cathode ray tube having implosion band with raised tabs and method

Abstract: An implosion band for a cathode ray tube has a plurality of raised tabs distributed about the periphery of the rearward edge of the band to accommodate attachment of additional tube components such as degaussing coils. The tabs are formed by: punching narrow slots in a strip of band material, near a longitudinal edge of the strip; forming the strip into a hoop by butt welding the ends of the strip; and stretching the hoop into a rectangular band while at the same time displacing outwardly the band material between the slot and the edge of the band to form the tabs.

Laser welding equipment

Abstract: PURPOSE:To perform the butt welding with a complicated shape by providing a laser projection part to rotate with an optical axis as a center and arranging a filler feeder to its rotational part to feed a filler from the front of a weld beam. CONSTITUTION:A holder 7 is supported by a fixed flange 10 and besides, the laser projection part 1 to rotate the optical axis 12 as a center by a motor 11 with a speed reducer is provided and the filler feeder 3 is arranged to the holder 7 via a supporting body 15. After a member W to be welded is set on a table 2, the table 2 is controlled to move according to a program and an arithmetic processing part 22 controls the rotation of the holder 7. The holder 7 is rotated so that a filler wire F of the feeder 3 is always fed from the front of the weld bead B by this method. Accordingly, even in case of the abutting surface with the complicated shape such as a curve, a bent curve, etc., the stable butt welding can be performed.

Heat treatment for welding zone

Abstract: PURPOSE:To improve toughness in a weld zone and also to relieve residual welding stress, by subjecting a heat-transfer pipe of a heat exchanger and a hub of a pipe plate to butt welding and then applying heat treatment to the weld zone under specific conditions. CONSTITUTION:The heat-transfer pipe 2, composed of high-Cr steel containing, as principal components, 8.0-10.0wt.% Cr and 0.8-1.2wt.% Mo, of a heat exchanger and the hub 3a of a pipe plate 3 composed of high-Cr steel are allowed to abut each other and subjected to inert-gas tungsten-arc welding by the use of filler metal. Subsequently, the weld zone 4 is rapidly heated up to a temp. in a temp. region of the Ac3 transformation point or above, 900-960 deg.C, from the inside by means of a high-frequency heater 6, and the outside is cooled rapidly down to ordinary temp. by passing water 10. Further, high-frequency heaters 6, 7, 8 are electrified, and a residual welding stress zone 9 including the weld zone 4 is heated from the inside up to 700-760 deg.C and then cooled slowly. In this way, a coarse-grain zone in the weld zone 4 is refined and formed into a stable tempered martensite structure, so that toughness is improved and residual welding stress is relieved.

Laser Sound Generation in a Weld Pool

Abstract: A welding machine requires three additional basic components for truly automated operation: sensors which detect physical properties of the weld; a model of the welding process which relates the controllable welding parameters, current, voltage, welding speed, etc., to the physical properties of the weld; and a control system which takes the signals from the sensors and converts them into a form which can be used for feedback control of the welding machine [1]. As part of a larger program to investigate all aspects of this problem, this study is concerned with the development of ultrasonic sensors to detect the physical properties of the weld.

Ultrasonic butt welding of aluminium, anticorrosive aluminium and copper plate specimens

Abstract: Ultrasonic butt welding of thick metal plate specimens is studied. Welding specimens used are aluminium, anticorrosive aluminium, and copper plates of 6-mm thickness. These welding specimens are successfully joined end to end with specimen strength of about 100 MPa (pure aluminium) or 250 MPa (anticorrosive aluminium) using 26-kHz or 19-kHz butt welding equipment. An ultrasonic vibration source of 19 kHz uses eight bolt-clamped Langevin-type PZT transducers of 50-mm diameter. The power required for joining aluminium, anticorrosive aluminium specimens, and anticorrosive aluminium to copper specimens is found to be 1-3 kW/cm/sup 2/, 6-8 kW/cm/sup 2/, and 7-9 kW/cm/sup 2/, respectively. >

Butt welding machine

Abstract: PURPOSE:To make re-clamping for making a feed margin up to a cut line a specified amount according to a sheet metal thickness unnecessary at the time of welding by selectively using multiple pairs of shear heads having different shear edge thicknesses corresponding to different sheet metal thicknesses. CONSTITUTION:Shear heads 6 and 7 of a double rotary shear device 5 on an outgoing side are respectively arranged on the front and rear parts of a ship bottom-shaped frame 10 supported to be movable in a seesaw manner on a movable table 8 moving back and forth from a line side between an electrode clamp device 2 on an incoming side and an electrode clamp device 5 on an outgoing side. A double rotary shear device on the incoming side is formed also in a similar manner. When for instance a thin sheet of a coiled sheet thickness of 1.0t to 2.3t is cut, the shear head 6 is used. And when a thick sheet of 2.3t to 4.5t is cut, the shear head 6 is lowered by means of an elevator cylinder 9, the shear head 7 is raised and a feed margin is set according to the sheet thickness so that a cycle time is shortened.

The influence of weld metal properties, weld geometry and applied load on weld system performance

Abstract: : Alloy development programs have significantly increased the ductility of steels available for ship structures. Design decisions regarding the optimum use of these alloys often reflect limitations imposed by weld performance considerations and available analytical methods. In this investigation, a sufficiently general analytical methodology, based on the distribution of strain energy density, is applied to the computational prediction of weld performance and fracture. Fracture at a material point coincides with a critical strain energy density value associated with the continuum fracture toughness of the material. The critical strain energy density value for each component of the weld metal, heat affected zone and base metal system are obtained from uniaxial tension test data. The role of weld crown, weld metal strength and applied load to butt welded panel performance are examined parametrically. The results suggest that particular combinations of these parameters may offer significant advantages in weld performance.

Measurement of fine interval

Abstract: PURPOSE:To measure the width of a fine interval accurately, by making a parallel luminous flux from a projector section irradiate material to be measured so as to generate a reflected light at right angles to the longitudinal direction of the fine interval. CONSTITUTION:When a welding line is detected at a butt weld part 6 of a plate 5 to be welded such as steel plate, a strip-like luminous flux LB is projected to give a slit image which crosses the welding line at right angles. Then, the reflected light FL of the luminous flux LB irradiating the plate 5 being welded is picked up by a means such as CCD camera. A projection system and a light receiving system are so arranged that the projection axis of the projection system is intersected at right angles with the light receiving axis of the light receiving system on the plate 5 being welded. In this manner, the brightness distribution of image signals obtained by image pickup is binarized using an optimum threshold and is subjected to an addition processing of '1' level following the binarization for each of the scanning lines in the directions of respective scanning line. After the addition processing, a new threshold is determined from a signal distribution newly gained to detect both edges of the weld part 6. Thus, the gap width and the welding line are calculated from the edge positions thus obtained.

Studies on Ultrasonic Butt Welding Using 19 kHz Vibration Systems

Abstract: Ultrasonic butt welding by 19 kHz vibration frequency systems is studied. Welding specimens used are aluminum and anticorrosive aluminum plates of 6 mm thickness. These welding specimens are successfully joined end to end with specimen strength of about 100 MPa (pure aluminum) or 250 MPa (anticorrosive aluminum) using 19 kHz butt welding equipment. An ultrasonic vibration source uses eight bolt-clamped Langevin type PZT transducers of 50 mm diameter. Required power for joining aluminum and anticorrosive aluminum specimens is respectively 1–3 kW/cm2 and 6–8 kW/cm2.

Method and apparatus of relative positioning and longitudinal movement between reeled-pot and butt welding equipment

Abstract: In order to hold the longitudinal edges (12, 14) of a can body (10) which are to be butt-welded together contiguous with one another on the way to a welding apparatus (52), the can body (10) is moved past a magnet (40) by means of which the longitudinal edges (12, 14) are magnetized with opposite polarity. The two poles (NS, SN) of the magnet (40) each have a supporting surface (42, 44) for a conveyor belt (36) which conveys can bodies (10) one behind the other from a guide member (22) to the welding apparatus (52).

Clamp for welding

Abstract: The utility model relates to a clamp for the steel bar welding, which is especially suitable for the welding of steel bars used in the construction The existing butt welding method is not popularized because of the low work efficiency In the utility model, two steel bars are positioned and clamped by installing one spanner on one jaw; the spanner is used for screwing the cam down; the sleeve barrel of a supporting plate is arranged under the jaw; the inside of the sleeve barrel is provided with a spring slide block, which can drive one supporting plate and one jaw to move along the groove of the sleeve barrel under the action of the spring hydraulic cylinder Thereby, the two steel bars are pressed tightly, and the strength after welding is increased The clamp for welding has the advantages of simple structure, light weight, simple operation, high work efficiency and good concentricity of the two steel bars after welding, which can be used for the welding of pipes

Method of flash-butt resistance welding of a batch of like parts in pairs

Abstract: A method of flash-butt resistance welding of a batch of like parts in pairs consists in that during flashing off of workpieces (1,2) they are brought apart or together depending on the resulting resistance obtained by comparison of the actual resistance between the workpieces (1,2) being welded with the specific short-circuit impedance of the welding circuit, which is determined during the upsetting of the preceeding pair of workpieces (1,2) after the welding current reaches a constant level.

Wheel for automobile

Abstract: PURPOSE:To improve durability and to realize light weight by using the steel plate of dissimilar cross section as the stock for disk and assembling the disk in ununiform thickness and the rim roll-forming a cylindrical body by press- fitting them. CONSTITUTION:A thin steel coil 21 with dissimilar cross sectional part having different thickness in the width and rolling directions manufactured by rolling in the rolling roll with uneven die is cut in specific size to make a blank 22 for disk. After forming a center hole 23, etc., on this blank 22 the disk 26 having a hat part, pad part and spoke flange part is manufactured at press forming stage. On the other hand, a rim is made a blank 32 by cutting a hot rolled coil 31 in specific length and after forming it in cylindrical shape at coiling stage a cylindrical body 33 is made at butt welding stage. After removing burrs at trimming stage, it is formed in the rim shape having a necessary rim flange part, beat sheet part and well part and a valve hole is further punched to manufacture a rim 34. These disk 26 and rim 34 are assembled by press-fitting at pressure fit stage and integrated at welding stage to form a wheel 40.

Nozzle for laser welding using filter wire

Abstract: PURPOSE:To ensure the laser welding by arranging a filler wire guide made of a high melting point member to the tip part of a nozzle for the laser welding. CONSTITUTION:A filler wire feed nozzle 4 is supported by a supporting body 5 independently of a torch 3 and the guide 9 with respect to the filler wire F is provided to the tip of the nozzle 1 for the laser welding. On this occasion, the guide 9 is constituted of a couple of side plates 10a and 10b and guide piece 11 made of high melting point material such as ceramics, etc. At the time of performing the butt welding of members 3a and 2b to be welded, the filler wire F is fed from the filler wire feed nozzle 4 via the guide 9. Accordingly, the wire F can be fed to a working point with high accuracy and since the member of the guide 9 is made of the high melting point material, the damage and wear at the time of working are reduced. The laser welding can be surely performed by this method.