Showing papers on "Butt welding published in 1996"

Joining of aluminium based metal matrix composites

Abstract: Metal matrix composites (MMCs) are becoming more popular as structural materials, and joining them is, therefore, of paramount importance. As these new materials become available, it is necessary to define and optimise joining techniques, and a thorough understanding of each process is required. A number of joining processes have been addressed, namely: fusion welding (tungsten and metal inert gas welding, electron and laser beam welding, resistance, capacitor discharge, and plasma welding), solid state bonding (diffusion bonding, friction and magnetically impelled arc butt welding), brazing, and adhesive bonding. The advantages and disadvantages of each technique are discussed with respect to weld-parent material microstructure and the mechanical properties of the bond. Recommendations are subsequently made as to the most appropriate method for bonding aluminium based MMCs.

Laser welding apparatus employing a tilting mechanism and seam follower

Abstract: In general, the present invention pertains to an apparatus and control system for working sheet material employs a tilting mechanism which automatically tilts a head about a theoretical point disposed upon the sheet material. In another aspect of the present invention, the head is defined as a laser head and the pivot point corresponds with the laser beam focal point. A further aspect of the present invention provides a seam tracking device and control system which automatically adjust a welding head height relative to the sheet material as a datum rather than relative to a gantry or other structure supporting the welding head. In yet another aspect of the present invention, an optical seam tracking device is employed to automatically tilt the welding head along differing rotational planes. In still another aspect of the present invention, various axial slides are employed in combination with a gantry. A further aspect of the present invention uses a seam tracking device and microprocessor to track a welding seam and move a welding head predetermined amounts due to sensed pre-weld gap widths. Another aspect of the present invention uses an automated tilting mechanism for creating a tailored blank butt weld between dissimilar materials. A method of operating the present invention is also provided.

Laser welding apparatus employing a tilting mechanism

Abstract: An apparatus for working material employs a tilting mechanism which tilts a head about a theoretical point disposed upon the sheet material. The welding or cutting head is defined as a laser head and the pivot point corresponds with the laser beam focal point. The laser head projects a laser beam directly upon the sheet material without the use of redirecting steerable mirrors. At least a pair of tilting mechanisms are employed to tilt the welding or cutting head along differing rotational planes. Various axial slides are employed in combination with a gantry. A laser vision system tracks a welding seam and a pre-weld gap. The tilting mechanism creates a tailored blank butt weld between dissimilar materials. A method of operating the present invention is also provided.

Method for joining two parts of different kinds by heterogeneous butt welding, and uses thereof

Abstract: An end portion of each of two parts (10, 11) is machined and the machined end portions of the parts (10, 11) are arranged in facing positions to form a welding bevel (13) extending in a longitudinal direction between the parts (10, 11), whereafter a filler metal is deposited into the welding bevel (13). The welding bevel is a narrow bevel with side walls at an aperture angle of no more than 5° relative to the longitudinal central plane of the bevel (13). A nickel alloy comprising 18-32 % of chromium is deposited into the welding bevel. The method is particularly suitable for joining a pressurised water nuclear reactor vessel tubing and an austenitic stainless steel primary circuit pipe.

Method and installation for laser welding a spacer grid of a fuel assembly for a nuclear reactor, and device for welding via the interior of a grid

Abstract: A laser-beam welding device forming part of a set of at least four welding devices (13a, 13b, 13c, 13d) is introduced into each of the cells of a set of at least four cells (36a, 36b, 36c, 36d), along the axis of the cell in such a way that the welding laser beam (38a, 38b, 38c, 38d) of the welding device is aligned with an edge of the cell (36a, 36b, 36c, 36d). A laser-beam weld is simultaneously produced along at least a part of the length of an edge of each of the cells (36a, 36b, 36c, 36d) of the set of cells and relative displacement between the grid (35) and the welding devices (13a, 13b, 13c, 13d) is carried out in order to introduce the welding devices into at least four new cells of the grid which are arranged in a square. The invention also relates to a device for welding a grid via the interior of the cells of the grid and to an installation for fast welding of a grid.

Laser edge welding member and its welding method

Abstract: PROBLEM TO BE SOLVED: To enhance productivity by forming a weld zone in which plural superposed parts formed on the end face of a weld joint are connected and alternately crossed and thereby laser-welding the superposed part in one welding operation. SOLUTION: While a laser welding machine 9 is moved along a welding line, it is also moved in the width direction of a weld joint 4 in the manner of continuously and alternately crossing a first and a second superposed part 6, 7 formed on the end face of the weld joint 4. Then, a laser beam is emitted from the laser welding machine 9, heating the end face of the weld joint 4 to form a weld zone 8. Thus, the superposed part is surely welded, with the formation of welding defects effectively eliminated.

Method of welding electrically conductive metal profiles

Abstract: A method of flash/butt welding an aluminum bicycle wheel rim, in which an aluminum sleeve having a dielectric anodized hardcoat surface finish is inserted into the center of the rim in order to support the interior walls of the rim during the welding process, is disclosed. The walls of a wheel rim or other similar metal profile defines an inner space in a tubular section of the rim. The sleeve is partially inserted into a first end of the rim and partially inserted into a second end of the rim. During the welding process, an electric current flows across a small space or gap between the two ends. The electric current melts the ends, at which time the two ends are pressed together in order to forge them into a single piece. The metal sleeve supports the inner walls of the profile in order to prevent collapse of the wall during welding. Due to the dielectric coating, the sleeve does not affect the welding circuit.

Method and apparatus for butt welding together sheet blanks

Abstract: An apparatus is disclosed for positioning, clamping and welding together proximal edge portions of two sheet blanks. The apparatus incorporates a high energy laser and sheet clamping mechanism used to clamp each sheet blank in place between an associated electromagnet and ferromagnetic clamping shoes. The shoes are positioned above a corresponding electromagnet and are vertically movable theretowards on the activation of the electromagnet. In use, the sheets are held in place with the respective sheet blanks sandwiched between the associated electromagnets and shoes with the proximal edge portions of the sheets abutting. The high energy laser is movably provided in the apparatus to move an emitted laser beam along a predetermined path over the abutting proximal edge portions to perform welding operations.

Process for butt welding two metal blanks and a motor vehicle part obtained by said process

Abstract: Process for butt welding two metal blanks(1,2) of which the first blank is of steel and the second blank is of a metal having a melting temperature lower by more than 400° C. than the melting temperature of the steel. The process includes positioning the two metal blanks (1,2) so that they contact each other in the region of their lateral faces to be butted together, maintaining the two metal blanks in contact, directing onto one of the principal faces of the metal blank (1) a high energy density bean (5) which passes through the first metal blank (1) and of which the focusing point is situated at a given distance from the joint plane (3) so as to generate in the region of the joint plane (3) a temperature equal to the melting temperature of the second metal blank (2) to within 10%, and displacing the high energy density beam (5). This process is applicable to the welding of two metal blanks of which one is of steel and the other is of aluminium or aluminium alloy for producing a motor vehicle part, in particular a body and structural part.

Method for repairing gas turbine blade, its repairing device, and gas turbine blade

Abstract: PROBLEM TO BE SOLVED: To facilitate the automatic welding by cutting a deteriorated tip part of a gas turbine rotor blade, finishing the surface, and performing the welding by cladding. SOLUTION: A gas turbine rotor blade 1 having a deteriorated part 2 at the tip part is repaired by the welding by cladding. The tip part including the deteriorated part is cut or ground to the prescribed shape. A surface 4 to be welded by cladding is of the constant shape. Because the shape is constant, the welding conditions such as the welding current, the welding voltage and the arc length can be easily set, and the heat input can be easily controlled. Every rotor blade 1 can be executed under the constant welding conditions, and when the set condition is once inputted, a large number of rotor blades 1 can be repaired under the same condition, and the time of execution can be greatly reduced. The quality of a weld zone 5 by cladding is not dispersed for each rotor blade 1, but is uniform. The sound weld zone 5 by cladding free from any defective welding can be formed.

Automatic welding equipment for inner surface cladding steel tube

Abstract: PROBLEM TO BE SOLVED: To perform the butt welding of the inner surface cladding steel tube from an inside surface while selecting a welding material for a base material and the welding material for a clad sheet. SOLUTION: A cylindrical casing 8 is fixed on a truck 7 movable in the inner surface cladding steel tube 1. A rotating shaft 14 is freely rotatably supported in the casing 8. The rotating shaft 14 is revolved by a motor 20 on the truck 7. On the casing 8, a frame 9 equipped with a clamp mechanism 10 is provided. A welding head part 22 with welding machine 24, two wire reels 27, 28, and two wire feeding devices 31, 32 mounted on a head rotating shaft 23, is mounted on the rotating shaft 14. Two kinds of wires 33, 34 are wound on the wire reels 27, 28, and they are selected by changing the direction of rotation of the welding head part 22. COPYRIGHT: (C)1997,JPO

Welded connections in thin cold-formed rectangular hollow sections

Abstract: Publisher Summary This chapter describes welded connection tests, which were performed on C450L0 Rectangular Hollow Sections (RHS). The thickness of the RHS sections varied from 1.6 mm to 3.0 mm. Butt welds, transverse fillet welds and longitudinal fillet welds were tested, and the test results are compared with existing Australian and American design formulae. The test results are also compared with the proposed design rules for welds in RHS members derived from the previous research project on C350L0 RHS members. The reliability analysis method is used to calibrate the existing and proposed design rules. Tests are performed on welds in C350L0 RHS members and proposed design rules are given for butt welds, transverse fillet welds and longitudinal fillet welds. The cold-formed Square Hollow Sections (SHS) and RHS sections used in the tests were supplied by Tube makers of Australia Limited. These sections were manufactured by a unique cold forming process, including in-line galvanizing so that the complete penetration butt weld of C350L0 tubes may be designed in accordance with the tension member rule in AISI- 1991 (AISI, 1991) with a capacity (resistance) factor of 0.95 or the tension member rule in AS4100-1990 with a capacity (resistance) factor of 0.90.

Tig welding equipment

Abstract: PROBLEM TO BE SOLVED: To provide the stable arc by driving a first slide under the arc voltage in the TIG welding, and driving a second slide by the output of a gap sensor to automatically adjust the height of a torch and the position of a shield box SOLUTION: A first slide 7 is fitted to a tip of a manipulator arm 6 of a TIG welding equipment, and an upper comer part of a U-shaped frame 16 is fitted to a movable part of the slide 7 parallel to the axis A base end of a torch 1 is fitted to the center of a lower horizontal frame of the U-shaped frame 16, a second slide 8 is provided on a lower corner part of the U-shaped frame 16, and a gap sensor 5 is provided on a side surface of a shield box 2 In the butt welding of a thick-walled tube 3, a first control driving device 25 is subjected to the arc voltage of a tungsten electrode 9, and the first slide 7 is driven and controlled so that the voltage is the prescribed value The gap sensor 5 detects the distance between the shield box 2 and the thick-walled tube The second control and drive device drives and controls the second slide 8 so that the distance is the prescribed value COPYRIGHT: (C)1997,JPO

Automatic butt welding equipment

Abstract: PROBLEM TO BE SOLVED: To provide a function for properly controlling welding conditions in accordance with change in a groove shape and a welding line, to cope with a universal shape of a work having a curved/inclined surface, and also to enhance welding productivity SOLUTION: An automatic welding equipment 2 is guided by the rail 3 attached nearly parallelly to the welding line 11 of a work 1, and is made to travel on the curved surface of the work, with high-speed rotary arc welding performed by a preceding welding torch, and simultaneously with the second layer welded by a succeeding welding torch In this case, change in a groove condition and in a welding line inclination are detected by a laser sensor and an inclination sensor in real time during the welding, so that the optimum control is carried out by outputting the optimum welding conditions according to the preset groove shape, root gap, and the front/rear and left/right inclinations

The effect of residual stresses on fatigue of butt joints

Abstract: In this paper, a theoretical analysis of the effect of residual stresses on the fatigue behavior of welded butt joints was developed by using linear elastic fracture mechanics (LEFM), superposition principle and finite element approaches. Various configurations of residual stresses in welded butt joints were considered and corresponding residual stress intensity factors were calculated by using Bueckner`s and Kanazawa`s weight functions for an edge and a central through-thickness crack in finite plate, respectively. Newman-Raju`s empirical equation was also used for surface cracks. Fatigue life of butt joint welds subjected to various stress-induced treatments was calculated by using Paris`s law with the effective range of stress intensity factor for zero-to-tensile loading (R = 0) and compared with the available experimental data. It was also found that the effect of a low level of compressive residual stress (less than 62 MPa) in terms of the fatigue strength improvement is of the same order as the effect of a postweld thermal stress relieving process. The contribution of hardness of the treated material to the improvement of fatigue life is obvious at a high level of compressive residual stresses.

Supersonic testing method for butt welding seam of narrow-bore tube

Abstract: An ultrasonic inspection method for welded butt seam of small-diameter tubes alternative use of annular locating scanning and axial reciprocating scanning, use of blind hole as standard reflector, and use of locating loop as locator of probe, so eliminating shape reflection interference, increasing analog characteristics and sensitivty and facilitating commutation between two inspection modes. Its advantages include increasing sensitivity by 6-10 dB and inspection power by 1-1.4 time, and no need of complex calculations.

Machine and method for working butt weld seams on band

Abstract: A machine for working the butt weld seam of a band belt, preferably having a toothed edge, includes various stations disposed successively along a feed path. The stations are a milling device, a grinding device, two ridge milling devices and a band advance device. In the milling device the welding beads are milled off on both broad sides of the band belt to form flat bases which are subsequently surface-ground in the grinding device. The succeeding milling device removes the ridge on the back of the band belt and the other milling device removes the ridge in the toothed space. The milling device for the toothed edge comprises a sensing element which is guided along a tooth of a template corresponding to the tooth space contour or another tooth space of the same band belt. The machine operates automatically under program control and achieves, without impairment of the welding seam, clean-right-angled plane faces, accurate to the required dimensions on the band belt, as well as a removal of the ridges on the narrow faces of the band belt, without damaging the saw tooth.

Laser welding of Al55-Zn coated steel sheet

Abstract: A study has been made of the procedures used for the lap and butt welding of 0.62 and 1.16 mm thickness steel sheets coated with Al55-Zn alloy, using laser-beam technology. The main problems arise in lap welding as a result of zinc evaporation from the coating. The vapour pressures of this element lead to cratering and blistering of the welds which are visible from the external surface and imply severe weld defects. An efficient solution to this problem consists in leaving a gap between the internal faces, thus allowing the zinc vapours to escape. Excessive gaps, however, lead to the molten metal collapse and to lack of penetration. In the present work, acceptable results were obtained with a maximum interface separation of 0.1 mm. This allows excellent continuity of the joints, without cracks, pores or non-metallic inclusions and with moderate hardnesses, thus demonstrating the good laser weldability of the coated material. A difficulty arises, however, in relation to the coating in zones close to the weld. In these high-temperature zones the coating is lost, and in the immediately adjacent areas the coating microstructure and phases are altered, as was shown by scanning electron microscope analyses.

Method and equipment for two sided butt welding of thick metal plate

Abstract: PROBLEM TO BE SOLVED: To improve whole working efficiency by saving the preparation time and the post-preparation time in performing butt-welding of a thick metal plate. SOLUTION: In performing the butt welding of thick metal plates 21, 22 by the gas shielded consumable electrode welding method, the rear side is welded by moving a preceding consumable welding electrode group 30 in a lower groove, the front side is welded by moving a succeeding consumable welding electrode group 40 in an upper groove, and the succeeding consumable welding electrode group 40 is moved in the same direction with a delay of the prescribed time to continuously performing the front side welding and the rear side welding. COPYRIGHT: (C)1997,JPO

Method and apparatus for the seam welding of containers

Abstract: For butt welding or lap welding container bodies, each body is guided between an outer current-carrying electrode roller and an inner roller. According to the invention the inner roller is movably mounted and exerts an opposing pressure to the rigidly mounted outer roller. This results in improved weld quality.

Method for arc welding of sheet member and welding stud therefor

Abstract: PROBLEM TO BE SOLVED: To prevent the burn through of a base material in a time of arc welding mutual sheets and to easily check the welding strength. SOLUTION: A stud 4 having a projecting face on the top end part 4a and an intermediate part 4c formed in a prescribed strength is attached on an electrode 5 of an arc welding machine. Then, the top end part 4a of the stud 4 is welded against the separated sheets 1, 2. In this time, the parts to be welded of the steel sheets 1, 2 and the front face part of the projecting face are welded. Further, the clearance of the steel sheets 1, 2 is buried with a non-molten part of the projecting face. Further, the stud 4 is separated at the intermediate part 4c. In this time, due to the strength of the intermediate part 4c being set as same or some lower as a requiring welding strength, whether the welding strength of the top end part 4a and the steel sheets 1, 2 is obtained with the requiring strength or not is judged correctly. COPYRIGHT: (C)1997,JPO

Method and device for butt welding of tube

Abstract: PURPOSE: To provide the butt welding method and fully automatic welding equipment capable of securing appropriate penetration over whole circumference of tube at the time of the first layer welding in tube butt welding. CONSTITUTION: By inserting an insert ring into groove root part and adjusting a root flat length (f) and root face length (e) among groove shape, appropriate penetration is secured. In butt welding of tube, the penetration having the same height and projecting shape as the inner face of tube is always formed over whole circumference of tube. By this method, fully automatic welding of tube is made possible.

Laser welding method

Abstract: PURPOSE: To form a satisfactory weld bead in a butt welding part, in butt- welding plates with different thickness by a laser beam, to prevent generation of welding defects and to surely butt-weld both plates even in the presence of an abutting gap. CONSTITUTION: A thin plate 1 and a thick plate 2 are arranged in an abutting state and irradiated with a laser beam L. In this case, the laser beam L is moved reciprocally in the direction crossing the the butt-welding part 5 at an amplitude W and made weaving. In addition, the optical axis LC1 in the center of the amplitude of the laser beam L is inclined at an angle θ from the abutting center 25 to the thick plate 2 side. Even if an abutting gap is developed at the butt-welding part 5 between the thin plate 1 and the thick plate 2, the lase beam L is prevented from passing the abutting gap because of the irradiation in the inclined and weaving state, thereby melting the edge of the thin plate 1 and the thick plate 2 and enabling a sure smooth butt- welding.

Continuous rolling method of cast billets

Abstract: A continuous rolling method includes the steps of: de-scaling billets sent directly from a continuous casting machine; continuously welding the billets using a travelling flash butt welder; grinding a burr on a welded part of the billets to remove the burr using a travelling grinding machine; heating the billets to an elevated temperature using an induction heater; and conducting continuous rolling. The travelling flash butt welder and the travelling grinding machine are separately movable along a running line of the billets, and are moved together during flash butt welding. The flash butt welding is carried out while the flash butt welder and the grinding machine travel a specified stroke for welding. The travelling grinding machine and the travelling flash butt welder are moved together to meet the welded part of each of the billets, and the travelling flash butt welder is returned to a waiting position after the flash butt welding is completed. The burr on the welded part of each of the billets is removed while the travelling grinding machine independently changes travelling direction and travels a specified stroke, after the welded part arrives at a specified position.

Method for monitoring a welding machine, method for regulating the welding machine and device for carrying out the method

Abstract: A welding machine produces a spot-welded joint between two components to be welded together by at least one electrode being in contact with one of the components, by passing a welding current through the components during a welding period, and measuring a thermo-electrical voltage between the electrode and the components outside the welding period. A method for monitoring the welding machine on the basis of the thermo-electrical voltage includes determining a monitoring variable from the thermo-electrical voltage and comparing the monitoring variable with a reference variable of the welding machine. The method can be used for regulating a welding machine, especially for producing a plurality of spot-welded joints. A device for carrying out the method includes at least one measuring instrument, in particular a voltage meter, disposed between the components to be welded together and the electrode. An evaluation and regulating device is connected downstream of said measuring instrument.