Showing papers on "Butt welding published in 1994"

Welding wire verification control system

Abstract: A control system for verifying propriety of welding wire for welding a part includes a spool containing the welding wire mounted to a welding machine. The spool contains an identification label which is automatically readable by a scanner positioned adjacent thereto. A controller is operatively joined to the welding machine for controlling welding start-up and a specified welding operation of the part which requires a specified welding wire. The controller is operatively joined also to the scanner for automatically reading the spool label to identify the welding wire thereon which is compared in the controller with the specified welding wire, with welding start-up of the part being prevented unless the specified welding wire matches the identified welding wire.

Apparatus and method for nondestructive evaluation of butt welds

Abstract: Apparatus and method for nondestructive evaluation of butt welds. The present invention in its broadest form includes an apparatus and method for detecting flaws in butt welds in steel sheets using horizontal shear ultrasonic waves generated on the surface thereof. Observation of reflected waves having amplitude greater than a chosen value signals the presence of significant flaw. To achieve this objective, the present apparatus detects only reflected horizontal shear waves; other modes are electronically removed using bandpass filters, since they occur at different frequencies. The invention may therefore be used in the presence of surface structures such as clamps and the like, and in the presence of surface nonuniformities in the vicinity of the weld, thereby permitting on-line flaw detection steel mill environment without interfering with the line output. The ultrasonic waves are generated and received by a pair of electromagnetic acoustical transducers having magnetic fields which are oriented 40-65 degrees from the direction of the transmitted and received waves.

Spot welding apparatus

Abstract: A spot welding apparatus comprises a welding gun having a pair of opposing welding electrodes either one of which is movable towards the other to apply a pressure onto a work and away from the other to release the pressure, a servomotor attached to the welding gun for adjusting the pressure applied to the work through movement of the movable welding electrode, a servomotor controller for controlling an operation of the servomotor, a welding current regulator for adjusting a value of welding current applied through the opposing electrodes to the work, a weld-interval timer arranged for adjusting at least one weld time interval and weld timing for the welding current and the pressure both applied to the work, and a spot welding controller electronically connected to the servomotor controller, the welding current regulator and the weld-interval timer, for simultaneously and arbitrarily adjusting a welding condition, namely the welding current, the pressure, the weld time interval and the weld timing, during a cycle of spot welding at every welding point on the work or at one specified welding point on the work.

Manufacture of welded tube

Abstract: PURPOSE:To reduce weld defects by taking the arc-welding output of a 2nd consumable electrode type gas shielded arc welding means as a value within a prescribed range at the time of manufacturing a welded tube using a composite heat source which consists of a 1st high-frequency heating means and the 2nd consumable electrode type gas shielded are welding means CONSTITUTION:The arc-welding output P(W) of the 2nd consumable electrode type gas shielded arc welding means is set to a value so as to satisfy the next inequality Otherwise, butt welding is executed by automatically controlling the output so as to be a fixed value within the range of the next inequality which is predetermined based on tube-making speed that is detected during manufacturing the tube and thickness of an open pipe Inequality: 5<=P/(Vt)<=15 Where, V is the tube-making speed (mm/sec) and (t) is the thickness of the open pipe (mm)

Fatigue tests and life prediction of 16 Mn steel butt welds without crack-like defect

Abstract: Fatigue test results of 16 Mn steel butt welds without crack-like defect under both constant and variable amplitude loads are reported and new procedures are used to predict fatigue crack initiation (FCI) life, fatigue crack propagation (FCP) life and total life of the butt welds. The results indicate that the FCI life and FCP life should be calculated separately and the total life is the sum of the FCI life and FCP life. For the butt welds investigated, stress cycles to initiate a crack of engineering size may occupy more than 70 percent of the total life of the butt welds and it is more suitable to express the total life as a power function of the equivalent stress amplitude {ie275-1}. In predicting the FCI life, the expression of FCI life obtained from the test results of notched specimens is used but the effects of microstructure, surface condition, macro- and micro-geometrical discontinuities at weld toe should be taken into account. In predicting the FCP life, the formula developed by Zheng and Hirt is used and the stress ratio is taken as 0.6 to account for the residual stresses effect on the FCP rate. Because overload produced by the maximum load in a load spectrum has no effect on the FCI life of 16 Mn steel and weldment of the steel, according to the procedures outlined in the paper, one can use the FCI life expression mentioned and the linear damage accumulation rule proposed by Miner to predict the FCI life of 16 Mn steel butt welds under variable amplitude loads. A good agreement is achieved between the predicted results and the test data.

Simultaneous temperature measurements on laser welded seams with at least two pyrometers in relation to monitoring process parameters and weld quality

Abstract: In laser butt welding of metal sheets, in particular sheets of unequal thicknesses, the temperature is measured at two points behind the liquid-solid interface. From combination of the two readings obtained a series of process data can be derived whereby the welding process can be monitored.

Plural member binding device and automatic welding system for the device

Abstract: PURPOSE: To use a welding equipment suitable for a welding operation and to automatically weld plural members by assembling an assembling part supplied through a part supplying device with an assembling device and welding the plural parts with a welding equipment in order to bind them as one body CONSTITUTION: The device is composed of a punching device 12 consisting of a transportable hydraulic puncher, a step supplying device 22 having a function to supply a step material 20 and a function to insert the material 20 into a frame material 10, a running stand 7 mounting the punching device 12 and the step supplying device 22, a frame material fixing device 9 of a hydraulic stock vice structure to clamp two frame materials 10, a welding positioner 14 to clamp and hold an object to be welded in a welding attitude, and a hexa- axial articulated robot Therefore, a product can be produced, the plural members can be bound by welding and made into the part binding welding structure, and the finished article can be obtained by starting from supplying the part and welding the plural members COPYRIGHT: (C)1995,JPO

Numerical and experimental study of residual deformations due to double-J multi-pass butt-welding of a pipe-flange joint

Abstract: Numerical and experimental study of residual deformations due to double-J multi-pass butt-welding of a pipe-flange joint

Ultrasonic butt welding of aluminum, copper and steel plate specimens

Abstract: Characteristics of ultrasonic butt welding of the same and of different metal plates are studied. The ultrasonic vibration source used has eight 15-kHz bolt-clamped Langevin-type lead-zircon-titanate (PZT) transducers of 60 mm diameter and is driven by a 50-kW static induction thyristor power amplifier. Welding specimens of aluminum, copper and steel plates of 6 mm thickness are successfully joined end-to-end with weld strength almost equal to that of an aluminum specimen. The input power required for aluminum, aluminum and copper, and aluminum and steel plates are about 5 kW/cm2, 5.5 kW/cm2 and 3.5 kW/cm2, respectively. The measured temperature rise at the specimen side surface and elongation of the welded specimen during a tensile test correspond to weld strength. The hardness distributions along the weldment of welded specimens are measured and the maximum temperature rise in an aluminum welding specimen is estimated to be over 480°C from the reduction of hardness at a welding specimen surface.

Quality assurance of electrically weldable joining elements

Abstract: A data exchange process between a thermoplastic, electrically weldable joining element and a data-processing welding device assures and inspects its quality. The electrically weldable joining element has an integrated, bi-directional data carrier (2) that supplies all relevant and welding-specific data (12) that are relevant to the welding and specific to the production model to the data carrier (4) in the welding device and thus ensures an optimum welding of the element. The data carrier (4) of the welding device supplies all device- and laying-specific data (34, 42) to the data carrier (2) of the joining element, so that retraceability is ensured at any later moment.

Butt welding method for resin clad steel sheet

Abstract: PURPOSE:To provide a weld zone excellent in conveyability and workability by heating the butting side end faces of resin clad steel sheets to pyrolyze or carbonize resins, opening the ends to remove foreign matters, joining surface steel sheets together to process these into a single sheet and then, performing but welding thereon. CONSTITUTION:The ends of the resin clad steel sheets 1 are heated up to the temperature in which the resins 2 are pyrolyzed or carbonized by a burner, etc. When the ends are heated, these are opened and the resins 2 are pyrolyzed or carbonized, hence the majority thereof is removed and a part remains between the surface steel plates. These remaining foreign substances of a carbide, pyrolyzed material, etc., are removed by pickling or a mechanical means. The surface steel shuts which are opened are welded together and processed into the single sheet.

Welding method using high density energy beam, and its device

Abstract: PURPOSE: To improve the welding precision by constantly matching the positional relationship between parts to be welded when temporarily spot-welded works at prescribed intervals are finally and continuously welded, and suppressing the rise of the joined parts during the temporary welding. CONSTITUTION: The actual position of a temporarily welded part X of a work W1 (W2) which is temporarily welded using the laser beam by a temporary welding station 1 is detected based on the data from a camera 18 and an analyzing instrument 19, and the final welding line is set as the part to be permanently welded based on the locus obtained by successively connecting these temporarily welded parts X. A control unit 24 to control so that a welding robot 22 may scan the laser beam irradiated from a torch 20 along this final welding line through a working device 23 is provided on a final welding station 13.

Welding equipment for joining steel sheets

Abstract: PURPOSE:To efficiently raise the temperature of a part requiring preheating and also to perform continuous operation. CONSTITUTION:In the steel sheet joining welding equipment having preheating equipment of steel sheets 1 and 2 when the steel sheets 1 and 2 on right and left are joined together by butt welding utilizing a laser beam, plasma, etc., a back bar 11 is abutted via an insulating member from the lower part of a butt weld zone 3 of the steel sheets 1 and 2 and coils 12b to generate an induced current to heat the steel sheets 1 and 2 surround the insulating member and the back bar 11 and are located at the lower parts of the steel sheets 1 and 2 on right and left, respectively. Consequently, the temperature of the weld zone is raised efficiently by a proximity effect of the induced current and burning of the coils 12b by the beam of laser, plasma, etc., is avoided.

Effect of Lack of Penetration on the Fatigue Strength of High Strength Steel Butt Weld

Abstract: Fatigue tests are performed to evaluate the fatigue strength of high strength steel containing partial penetration butt weld and full penetration butt weld. The influence of the unwelded ligament (Lack of Penetration) in the partial penetration welds on the fatigue life is analyzed for various LOP sizes. For full penetration welds, the fatigue crack initiated at the weld toe and propagated to the HAZ. For partial penetration welds, however, the fatigue cracks initiated at the LOP section and propagated to the weld metal (or weld toe) for the considered LOP sizes (from 2mm to 4mm) reducing the fatigue strength. Consequently, the increament of the LOP size yield in the fatigue life degradation by some extent.

Method for repairing damaged airfoils of turbine engines

Abstract: The invention relates to a method of repairing aerofoils (6), damaged in the head or edge area, of turbine engines. To this end, first of all damaged areas, except for an undamaged aerofoil stub, are cut off essentially transversely to the longitudinal extent of the aerofoil or at an angle to the front or rear edge of the aerofoil or roughly in a semicircular shape around the damaged aerofoil area to form a straight or roughly semicircular repair surface (31). The repair surface of the aerofoil stub is then prepared for butt welding. After that, a repair plate (7) of constant thickness, exceeding the maximum profile height of the aerofoil by more than 50%, is tack welded in an abutting position to the repair surface (31) with an end face (30) adapted to the repair surface, and the aerofoil stub and the repair plate (7) are welded by means of butt welding. Finally, the welding seam and the repair plate (7) are removed down to the profile contour of the aerofoil stub and to the desired aerofoil profile. This method is preferably used for the repair of aerofoils of integral rotors of turbine engines, in particular for aerofoils of integral compressor rotors.

Investigation into the underwater laser welding of steel

Abstract: An investigation was undertaken using a 1.2 kW carbon dioxide laser for underwater butt welding of BS 4360 43A and 50D steel, in order to assess the quality of the welds and to achieve an understanding of the laser/water/material interaction. Using a high‐speed camera, the temporal behavior of the melt pool and “plasma” dynamics surrounded by an aqueous environment were monitored. Experiments were undertaken to characterize the attenuation of the laser beam in the water as a function of various focal length optics and depth of water. The effect of energy input conditions on the weld bead appearance and mechanical properties were also examined. The interaction of the laser beam with water produced a wave‐guiding mechanism in which the focused beam instantaneously vaporizes the water and directs the beam on to the workpiece. The underwater weld beads exhibited sound microstructures over a range of weld energy inputs, mainly due to the formation of a “dry region” during welding. Metallurgical analysis of the welds showed a slight increase in hardness, though other post‐weld mechanical strengths were similar to in‐air results.

Method of controlling heat input in electric resistance welded tube

Abstract: PURPOSE: To obtain a product with a superior welded quality by performing proper heat input control in a non-stationary state of a mill. CONSTITUTION: An on-line image pickup is made on an area in the neighborhood of a welding point of an electric resistance welded tube by means of a camera 11 installed so as to monitor such area ; the position of the welding point is detected by binarizing the brightness level of the obtained picture; and on the basis of the deviation between this present welding point and a preset reference welding point, a heat input voltage is controlled for the welding machine so as to make this deviation zero.

Grid welding fixture for a spacer grid

Abstract: A modular grid welding fixture for a spacer grid that facilitates full grid laser welding of a spacer grid in one setup. The modular design allows for partial implementation of each weld type. A base plate is used for mounting to the positioning/rotational plate of the welding system. A removable sub-plate received in the base plate is used to position the grid strips for proper location for welding. A top fixture plate is aligned with the base plate and provides for mounting of a second sub-plate if required. Side plates with spring loaded pressure pads that are hinged to the top fixture plate apply uniform pressure to the outer grid strips during processing. The base plate, top plate, side plate, and pressure pads are provided with a plurality of through holes to allow access of the laser beam for welding. Corner clips are used to insure contact of the overlapping sections of the outer grid strips for proper corner welding.

Process for pre- or post-treatment of components welding seam to be executed resp. executed

Abstract: Process comprises treatment of ferrous and non-ferrous workpieces either before or after welding, in partic., laser-beam welding. Accordingly either mechanical vibrations are introduced into the material in front of the advancing weld seam to increase the strength of the material or they are introduced into the material after the welding process to influence the solidification kinetics of the material. The appts. incorporates a punch (8) which is mounted on a heavy mass (10) in a guide unit (3) either in front or behind the welding head (13, 6). The punch contacting appropriate surface areas of the workpiece is brought into motion by means of a piezoelectric oscillator.

Weld head, welding equipment and welding method

Abstract: PURPOSE:To perform highly clean welding by arranging annular members rotatably with columnar metallic members to be butt-welded as a center and fixing plural discharge electrodes toward the columnar metallic members on the annular members. CONSTITUTION:The annular members 102 and 102' are rotated by a gear 105 and pipes 103 and 103' are subjected to butt welding while the electrodes 101 and 101' fixed on the annnular member 102 and 102' are rotated. The annular members 102 and 102' and the pipes 103 and 103' are covered by outer frames 104 and 104' and shielding gas is introduced into the inside in advance. Since the pipes 103 and 103' are welded at the same time at plural places, shrinkage in accordance with melting at the early stage of welding is evened off at the cross sections of the pipes 103 and 103' and a gap is not generated on a butt part. Thus, particles in a welding atmosphere are prevented from mixing in and welding free from strain can be performed.

Butt welding appts. for joining edges of metal parts, esp. metal strip - comprising clamping arrangement, welding head, esp. laser welding head, and seam cover on underside to prevent weld protrusion

Abstract: Butt welding appts. for joining the edges of metal parts, esp. the butting edges of metal strip, comprising a clamping arrangement for holding the edges to be joined and a welding head, esp. laser welding head, above the welding seam, and having a seam cover (9) on the underside of the seam, at least in the weld area (8), to prevent weld protrusion. The seam cover is formed as a rotary disc (9) or cover shoe (10) of cast iron, steel, copper, titanium or ceramic material or has a suitable coating. The seam cover (9, 10) is cooled by means of cooling channels (12). USE/ADVANTAGE - For butt welding thin metal sheets, esp. the butting edges of metal strip. Allows thin sheets and strip of metals of low melting point and low melt viscosity to be butt welded without weld protrusion on the underside.

Welding method for high purity ferritic stainless steel

Abstract: PURPOSE:To produce a vessel of high quality with high reliability by performing plasma welding on a first layer from an unwetted part to form penetration bead on the wetted part side and performing TIG welding on a second layer an austenitic stainless steel filler rod. CONSTITUTION:When one side butt welding of the high purity ferritic stainless steel vessel is performed, a square groove or or a single-V groove is formed on high purity ferritic stainless steel base metals 1. Plasma welding is performed there as the first layer 3 from the unwetted part 9 side and the penetration bead 5 is formed on the wetted part 8 side. The second layer 4 is then subjected to TIG welding by the austenitic tsainless steel filler rod. Further, TIG fusion welding without filler metal is performed from the wetted part 8 side. In addition, TIG welding with the filler rod of stainless steel of similar composition is performed from the wetted part 8 side. Consequently, the welding time is reduced and welding efficiency can be improved.

Detection of Weld Line And Automatic Seam Tracking By Ultrasonic Sensing Robot For Underwater Wet Welding

Abstract: An underwater wet welding robot with an ultrasonic sensor was developed to detect the weld line and to track the weld line automatically. The robot can move the welding torch toward X and Y directions and the ultrasonic sensor can oscillate along the X direction. As the ultrasonic sensor, an immersion type probe of 9.0 mm in diameter was used. The frequency of the ultrasonic wave is 5.0 MHz. The spot size of the ultrasonic beam is approximately 2 mm at a water distance of 50 mm. As the result of the detecting experiment of weld line by the ultrasonic method, there was no problem in the case of as-received steel plate. However, when the surface condition of the base metal is poor, the robot sometimes makes misjudgment. In the tracking test of the butt weld line of steel plates, which has the angle of 30{degree} to the Y-axis, the tracking error was about 0.5 mm. As the result of the experiments, it was made clear that the robot system is effective on the automatic seam tracking of underwater wet welding.

Method of automatically adjusting welding conditions for an arc welding robot

Abstract: A method, such that, using known data, a relationship between a target welding current and a welding current command to be instructed to a welding machine to achieve the target welding current is estimated by a linear formula. Then, a welding current command corresponding to a welding current to be achieved is obtained according to the linear formula, and is actually supplied to the welding machine to carry out a welding operation. An actual welding current is fed back from the welding machine, and this actual welding current and the welding current command associated therewith are stored as one set of data. This process is repeated using different welding current command values, and the resulting sets of data each including the combination of a corresponding welding current command and actual welding current are stored. Based on a plurality of sets of data thus obtained, a linear relational formula, representing the relationship between the actual welding current (target welding current) and the current command, is derived for each of a plurality of welding current ranges.

Hoop joining welding method

Abstract: PURPOSE:To provide the hoop joining welding method of short welding time, not requiring bead treatment after welding, not generating burn through, etc., not limiting welding condition of material, plate thickness, etc., capable of automating and easily welding CONSTITUTION:The rear end part 11 of preceding hoop and the front end part 12 of succeeding hoop are uncoiled from an uncoiler 1, mutually corresponding oblique welding faces are formed in a welding face forming process 20, successively, the faces to be welded are butted in a seam welding process 30. Subsequently, excessive edge part is cut in a post welding treatment process 40, the hoop completed seam welding is obtained. The welded face of both end parts 11, 12 are respectively formed to oblique shape in the plate width and thickness directions corresponding each other.

Local vacuum chamber forming method in electron beam welding and electron beam welding equipment for strip continuous treatment

Abstract: PURPOSE:To provide the local vacuum chamber forming method and electron beam welding equipment in electron beam welding capable of sealing between two strips of different strip thickness/strip width an a vacuum welding chamber is enabled and holding a strip very near weld line. CONSTITUTION:The vacuum welding chamber 5 to execute electron beam welding consists of an upper vacuum vessel 3 which is provided with preliminary evacuation chambers 6-9 which extend along weld line so as to enclose periphery of weld zone of strip 1, 2 and are at least one in the trip width and longitudinal direction, and elastic sealing material 10, 10' between chambers 6-9 and opens its lower side and a lower vacuum vessel 4 which is symmetrical to the upper vessel and opens its upper side. In butt welding the strips 1, 2, the gas flowed in from the strip end gap part, which is formed at sandwiching the strips 1, 2 with the upper vacuum vessel 3 and lower vacuum vessel 4, is sucked by one preliminary evacuation chamber at least, vacuum zone is formed around weld zone and then welding is executed.

Butt welding method for thin wall tube and the like

Abstract: PURPOSE: To enable stable butt welding by maintaining at high precision the out-of-roundness, flatness, etc., of the butt end face in each opening in a thin wall tube and the like. CONSTITUTION: Flaring working is performed on the end part of the butt welding side of a tube 1; then, the end face of the flaring part 1A is trued up vertically to the center line of the tube with the out-of-roundness held and with the end faces of the flaring part 1A facing each other; the flaring parts 1A are held by each taper chuck 8 and abutted on each other; and the abutted part is welded from outside while the end faces are held in contact with each other. COPYRIGHT: (C)1996,JPO

Method of welding at least two metal sheets having different thicknesses.

Abstract: of EP0583995The subject of the invention is a method of butt welding at least two metal sheets (1, 2) having different thicknesses, these being greater than 3 mm. The method consists in producing a bevel (3) on one of the main faces of the thicker metal sheet (1) in order to bring the thickness of its side face (4), intended to be butt joined to a side face (5) of the thinner metal sheet (2), to a value e1 lying between the thickness E of the thicker metal sheet (1) and the thickness e of the thinner metal sheet (2), in bringing the metal sheets (1, 2) into contact by their side faces (4, 5) to be butt joined and in producing a welded joint at the butt-joined side faces (4, 5) by localised melting of the metal sheets by means of a laser beam.

Welding control system

Abstract: To control and reset an electro-welding appts., with at least two electrodes, during operation a preset number of welds are made in succession using constant welding parameters. The welding parameters and/or the electrode surface geometry are adjusted by a step until welding splashes start to appear. The welding parameters and/or the electrode surface geometry adjustments are reversed slightly, followed by the preset number of welds. Also claimed is an appts. with an electronic unit to detect welding splashes with reliable evaluation, to generate a signal for the welding control to adjust the welding parameters and/or the electrode surface geometry.

Apparatus for butt welding of thermoplastic pipes

Abstract: A butt welder has several clamps (9,10,11,12) and guides (8,16) to keep the pipes and heater support (28, 29) parallel and coaxial. A heating element (20) in a carrier (23) can be swung about a parallel axis (A2) and has a locking device (32) with a release (33) activated at the end of the heating cycle. The clamps (9,10 and 11,12) are connected to guide pins (42 and 46) which slide in slots (48,49) in guide plates (27). The heater supports (28,29) are attached to the guide plates (47) so that the heater (20) can move according to the free movement available between the guide pins (42,46) within the slots (48,49). The release (33) is attached to the heating element carrier (23).