Showing papers on "Butt welding published in 2003"

Friction Stir Welding Tools and Developments

Abstract: The basic principle of Friction Stir welding (FSW) is described. Certain applications (butt and lap welding) are reviewed, with particular emphasis on probe types currently under development (Flared-Triflute™ probe and an A-Skew™ probe). Both give lap welds of 190% of the plate thickness, an improvement in weld integrity, a reduction in upper plate thinning and an increased welding speed over current practice. Butt welds produced with Whorl™ and MX-Triflute™ frustum-shaped probes that gave acceptable weld quality are also described.

Coded welding consumable

Abstract: Information pertaining to characteristics of consumables such as metal welding electrode wire and shielding gas and which characteristics are useful in connection with adjusting welding parameters in an arc welding process and/or selecting between operating modes in a welding system are encoded on welding wire and/or on other memory components such as bar code labels and tags, RFID cards and tags, IC cards, and Touch Memory buttons, and the memory device is scanned prior to and/or at the point of use of the welding wire or shielding gas for enabling tracking of product distribution, manual and/or automatic selection of an operating mode for the welding system, manual and/or automatic adjustment of welding parameters in a given operating mode, consumables inventory, and the like.

A study on the quality improvement of robotic GMA welding process

Abstract: With the advance of the robotic welding process, procedure optimisation that selects the welding procedure and predicts bead geometry that will be deposited has increased. Amajor concern involving procedure optimisation should define a welding procedure that can be shown to be the best with respect to some standard, and chosen combination of process parameters, which give an acceptable balance between production rate and the scope of defects for a given situation. This paper represents a new algorithm to establish a mathematical model for predicting top-bead width through a neural network and multiple regression methods, to understand relationships between process parameters and top-bead width, and to predict process parameters on top-bead width in robotic gas metal arc (GMA) welding process. Using a series of robotic GMA welding, additional multi-pass butt welds were carried out in order to verify the performance of the multiple regression and neural network models as well as to select the most suitable model. The results show that not only the proposed models can predict the top-bead width with reasonable accuracy and guarantee the uniform weld quality, but also a neural network model could be better than the empirical models.

Joining plastics - can friction stir welding compete?

Abstract: As plastics become candidates for an increasing number of applications, it is important to continue developing processes to join them efficiently. In the past, a few processes have dominated the area. Now a new process, Friction Stir Welding, enters the arena of competition with the established practices. This paper delivers a comparison of several processes for joining plastic materials. Process parameters investigated include machine and tool costs, part preparation, weld rate, joint efficiency, consumables, reproducibility, and process capability. When compared on these bases, Friction Stir Welding stands as an able competitor with established processes.

Effect of wire feed position on laser welding with filler wire

Abstract: The utilization of the laser welding process with filler wire addition is often considered a complicated and difficult process which has too high accuracy demands for a work shop floor. This study shows the effect of some of the most important welding variables to the quality and efficiency of laser welding when welding with filler wire. The material used was a common structural steel St52/37 of 6 mm in thickness. The joint type used was a butt joint. Acceptable weld quality was achieved with most of the tested parameter combinations. The effect of the wire feeding parameters for the acceptable weld quality was smaller than expected. The variations of weld quality caused by the nonoptimized aiming of filler wire can be compensated by the adjustment of the filler wire feed rate and the heat input. The quality of the welds was compared with developed weld quality index. The increase in heat input will make it possible to accept wire feeding to a lower position or from backwards compared to the welding direction. The misalignment of wire in the transverse direction to welding direction and laser beam optical axis causes problems that may lower the quality of the weld. The comparison of the welds with variable air gap widths showed that the weld width is more dependent on the heat input that on the original gap volume.

Towards advanced welding methods for the ITER vacuum vessel sectors

Abstract: The problem of joining the International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) sectors, considering the tolerance requirements of the blanket attachments, and the time required for TIG welding, continues to stimulate EU R&D into power beam welding techniques which can yield fewer passes, less welding time and lower distortion. The previous work on reduced pressure e-beam welding showed that penetration varied with position, fit-up, distance and pressure and single-pass weld control was deemed to be not reliable enough so the work direction changed to an all-e-beam welding procedure where the root weld is carried out with rest-current-control and the fill passes by wire-fill. In addition, a novel method of increasing the possible single-pass weld thickness for overhead positions is investigated demonstrated and now patented. Another solution may be offered with wire-fill NdYAG laser welding, which has demonstrated useable and stable results and proved improved performance over TIG. Preliminary work has shown even further advantages with the introduction of hybrid MIG/Laser welding.

Laser beam welding of thermoplastics

Abstract: Current product development showing an ever shrinking physical volume is asking for new, reliable joining technologies. Laser beam technologies conceal innovative solutions to overcome limitations of conventional joining technologies. Laser beam welding of thermoplastics offers several process technical advantages. The joining energy is fed contact-less into the joining area, avoiding mechanical stress and thermal load to the joining partners. The energy is supplied spatially (seam width on the order of 100 μm) and timely (interaction time on the order of ms) very well defined. Different process strategies are possible leading to flexibility, product adapted irradiation, short process times and high quality weld seams as well as to high integration abilities and automation potentials. During the joining process no vibration, no thermal stress, no particle release takes place. Therefore, destruction of mechanically and electronically highly sensitive components, such as microelectronics, is avoided. The work place pollution is neglectable compared to other joining technologies, such as gluing (fume) or ultrasonic welding (noise, pieces of fluff). Not only micro-components can be welded in a reproducible way but also macro-components while obtaining a hermetic sealing with good optical appearance. In this publication firstly, an overview concerning process technical basis, aspects and challenges is given. Next, results concerning laser penetration welding of polymers using high power diode lasers are presented, while comparing contour and simultaneous welding by experimental results and the on-line process monitoring.

Experiments on the induction welding of thermoplastics

Abstract: In induction welding of thermoplastics, induction heating of a gasket, made of a ferromagnetic-powder-filled bonding material and placed at the interface of thermoplastic parts to be joined, is used to melt the interface; subsequent solidification of the melt results in a weld. Tensile tests on induction butt-welds of polycarbonate (PC), poly(butylene terephthalate) (PBT), and polypropylene (PP) are used to characterize achievable weld strengths, and microscopy is used to correlate weld strength with the morphology of failure surfaces. In PC, PBT, and PP relative weld strengths as high as 48%, 43%, and 55% of the respective strengths of PC, PBT, and PP have been demonstrated. Relative weld strengths on the order of 20% have been demonstrated in PC-to-PBT welds.

Deformation prediction and quality evaluation of the gas metal arc welding butt weld

Abstract: The control of distortion and the overall quality are the main targets in the design and manufacturing of sound welds. In this paper a numerical approach is presented in order to support th...

A study on the numerical analysis of magnetic flux density by a solenoid for magnetically impelled arc butt welding

Abstract: The magnetically impelled arc butt (MIAB) welding process uses a rotating arc as its heat source and is known as an efficient method for pipe butt welding. The arc in the gap of the pipe butt joints is rotated along the circumferential weld line by the electromagnetic force resulting from the interaction of the arc current and the magnetic field in the gap. The electromagnetic force is determined by the magnetic flux density in the gap, the arc current and the arc length (i.e. gap size). In particular, the radial magnetic flux density is an important factor in arc rotation and weld quality.This paper proposes a two-dimensional finite element model for the analysis of magnetic flux density distributions in the MIAB welding process. The magnetic flux density is mainly dependent on the gap size between two pipes, the position of the exciting coil that generates the magnetic field, the exciting current in the coil, and the relative permeability of the pipes. Thus, the relations between the magnetic fl...

Ultrasonic-welding apparatus, optical sensor and rotation sensor for the ultrasonic-welding apparatus

Abstract: To provide the ultrasonic-welding apparatus, which can attain the above-mentioned requirement, and which can automatically achieve both measurement of the face-deflection the work piece after welding and the welding of work pieces, such as a reel for a magnetic tape, there is provided an ultrasonic-welding apparatus comprising; a cradle, onto which two work pieces of to be welded and welded to are mounted in piles, and which can rotate around the axis vertical to the welding surface of the work piece of to be welded; a welding hone, which carries out welding using a supersonic in the condition of having sandwiched the two work pieces between the cradle; and a transmission-type laser sensor which measures the fixed part of the work pieces after welding by irradiation of the laser light which runs parallel to the welding surface, and the transmission-type laser sensor measures the fixed part of the work piece after welding, which is rotating on the cradle, in the condition that the welding hone is apart from the work piece after welding.

Microstructure of copper-AISI type 304L electron beam welded alloy

Abstract: Heterogeneous butt welding of copper and AISI type 304L stainless steel was carried out using the electron beam process Examination by scanning and transmission electron microscopy has indicated the possibility of obtaining joints free of cracks and porosity Energy dispersive microanalysis of the weld bead cross-section has demonstrated the presence of non-equilibrium phases The results show that the binary Cu-Fe equilibrium diagram is unable to predict the weld microstructure even at the moderate cooling and solidification rates expected under the present welding conditions The feasibility of the Cu-304L electron beam welding process is therefore hindered by the problem of microstructural stability of the joint because of possible phase transitions during the service life of welded components

Composite welding method of laser welding and arc welding

Abstract: PROBLEM TO BE SOLVED: To provide a butt welding method by composite welding of arc welding and laser welding where the control of the intervals between bevel roots can stably and securely be performed, and an excellent weld zone having satisfactory penetration and free from welding defects can be obtained on butt welding for a thick steel plate under the condition of a long welding margin and butt welding for a large-sized structure such as seam welding for a large-sized UO steel tube. SOLUTION: In the butt welding method by composite welding of laser welding and gas-shielded arc welding, the material to be welded is temporarily assembled, thereafter, a bevel root along a welding line is irradiated with a laser and is melted to cut so that the root intervals reach 0.1 to 3.0 mm, and subsequently, the composite welding of laser welding and gas-shielded arc welding is performed. The heat input in the laser welding is set to ≥0.1 kW, and also, the heat input in the gas-shielded arc welding is set to 0.1 to 2.5 kJ/mm. COPYRIGHT: (C)2005,JPO&NCIPI

Method and device for welding plastic parts, in particular for connecting plastic parts along a weld line

Abstract: of EP1415789Parts(34,36) to be connected are heated along their intended welding lines using radiation. Simultaneously, hot gas is supplied from a row(18) of nozzle bores which follow the welding line. When heating is complete both plastic parts are pressed together. Both parts(34,36) are heated on the welding line to above the required welding temperature. An Independent claim is included for the process equipment which includes a radiation plate(16) with a row(18) of nozzle bores along the welding line connected to a hot gas supply system.

Method for laser welding resin component and laser welding device

Abstract: PROBLEM TO BE SOLVED: To prevent a finished product which meets no required welding strength due to a gap generated in the welded part from being manufactured. SOLUTION: The joint flange part 4a of a half component 4 which absorbs a laser light 6 and a joint flange part 5a of a half component 5 which allows transmission of the laser light 6, are butted to each other and weld-joined at a joint area 9 by emitting the laser light 6. The laser welding is divided into two processes, i.e. tack welding and regular welding and in the meantime, an airtightness test is conducted. In the tack welding, when a gap G exceeds the tolerance limits G 0 , a compatible layer 14 is not formed and therefore, the judgement of the airtightness test results is "leakage present". Consequently, the half component 5 is rejected as a non-conforming article before applying the regular welding. On the other hand, the gap G falls within the tolerance limits G 0 in the tack welding, it is judged that the compatible layer 14 is formed and "no leakage is present" and therefore, the regular welding is applied for the first time. COPYRIGHT: (C)2005,JPO&NCIPI

Method for red copper transition welding without preheating metal alloy

Abstract: An alloy transition method for welding thick red copper materials without preheating is an argon arc welding method with W electrodes protected by He gas or He-A gas mixture, and includes such steps as build-up welding of flux at the position to be welded, and butt welding. Its advantages are high welding quality and high strength of welded seam. The thickness of workpiece to be welded may be 8-20 mm.

Laminate with butt-welded metal layers

Abstract: A laminate consisting of at least two metal layers and a fibre-reinforced plastic bonding layer located between the metal layers comprises metal sheets joined to one another. The metal sheets of a metal layer are joined to one another by means of a butt weld. The weld seam determined by the butt weld has a thickness that is at most the same as the thickness of the metal sheets. The metal sheets can consist of Al, Cu, Li, Mg, Si or Ti or an alloy thereof.

Automatic welding machine

Abstract: An automatic welding machine for planar plastic materials, such as sealing sheets, tarpaulins or films, the chassis, in the welding position, in addition to being carried by the driving unit and the pressure device, also being carried by a rigid guide wheel, preferably in the front region of the chassis. With respect to a pressure roller running essentially on the welded overlap region, the guide wheel is arranged in such a way that, during the welding, it runs along the bottom plastic material parallel to the edge of the top plastic material. In addition, the guide wheel has a narrow running surface. During the welding, the guide wheel runs along the edge of the overlapping plastic material and the pressure roller runs essentially on the weld region. Due to this configuration, the automatic welding machine can follow the edge in such a way as to keep to the track, so that guidance by the operator or frequent corrections of the welding direction are not necessary. This leads to an increased weld quality and also to a higher welding speed. There is less interference from the background or due to the welding device swinging in laterally.

Production process of rolled straight steel rod for cold drawing multiple thread steel bar

Abstract: The present invention an extra-long straight strip production process of cold-drawn multi-head twisted steel bar The production process includes mother material preparation, butt welding connection and naturally unwinding, descaling, guide centering ring, rotary rolling formation, drawing from a drawing machine reel, straightening, cutting to defined length, bundling and inspection The one-run forming and straightening process has low production cost and high production efficiency and is suitable for producing various cold-processed deformed steel bar

Weld zone image processing method, welding management system, feedback system for welding machine, and butt line detection system

Abstract: PROBLEM TO BE SOLVED: To provide a measurement method and an inspection method for reducing the cost and improving the operation to enhance the reliability of a welded product when steel plates are butt-welded by laser beams. SOLUTION: In a lap weld zone of thin steel plates to be welded, two-dimensional coordinates of the weld line and parts in a vicinity of the weld line and information on brightness of each pixel are totaled by using an image sensor, weld defects and deviation between the butt line and the weld line are immediately detected, the welding condition of a welding machine is optimized on the real time basis, and the optimized condition is immediately fed back to the welding machine. The efficiency of the entire welding system is enhanced thereby, and the welding quality is uniformized to positively prevent weld defects. COPYRIGHT: (C)2005,JPO&NCIPI

Laser welding system

Abstract: PROBLEM TO BE SOLVED: To provide a laser welding system where, prior to butt welding of a pair of members to be welded in a welding process, the edge faces of the members are subjected to grinding so that the precision of the edge faces is improved and the welding precision is also improved. SOLUTION: The laser welding head 200 is provided with a grinding means 300 of grinding both butt edge faces 10A and 11A of the pair of members to be welded. In the grinding means, the tip of a rotary shaft is mounted with a rotary grindstone 305 or a rotary cutting edge, and further the grinding means is arranged at a suitable place in the laser welding head movably forwards and backwards, and moves forwards from a waiting position (b) to a grinding position (a) on grinding both butt edge faces of the pair of members to be welded. COPYRIGHT: (C)2004,JPO&NCIPI

Flux shielded arc butt welding of concrete reinforcing steel

Abstract: The present paper reports on a new variant of flux shielded arc butt welding without the addition of a filler material, applied to steel bars for concrete reinforcement. The welding process is described, including the arc ignition and forcing together of the workpieces, via the application of a mechanical force, to form an upset. A new portable machine is described, using which it is possible to apply flux shielded arc welding on site. Experiments were carried out, from which optimum welding parameters such as welding current, weld time, and upsetting force were found. The strength properties of the welded joints obtained were determined via mechanical testing, i.e. a bend test, a tensile strength test, and an impact toughness test. Macroscopic sections of the welded joints were also produced. A quality analysis of the butt welded joints showed that the mechanical properties of the joints were equivalent or even superior to the properties of the parent metal.

Laser beam micro welding of dissimilar metals

Abstract: The combination of dissimilar materials like brass and stainless steel is often needed in watch movements due to tribologic aspects. For mass production in automotive applications, a joining technique for alloyed copper with alloyed steel is needed. Laser beam micro welding offers an alternative to conventional joining techniques like press fit or soldering. Depending on the joining geometry, two different welding techniques are investigated: seam and spot welding. High strength and reproducibility are the main objective of joining dissimilar metals. Cracks and spillings are affected by the metallic continuity and should be avoided. Lap- and T-joints can be produced by the SHADOW-Welding technique. The length of the continuous welding seams are up to 15.7 mm at a feed rate of up to 60 m/min with a pulsed laser source. The weld width attained ranges from 50 to 250 μm and a weld depth from 20 to 150 μm. This low energy joining process with minimized heat input results in low distortion of the parts joined. Applying spot welding, the pulse forming capability is needed especially for highly reflective metals like copper. The welded joints have a higher strength than the basic material.

Process for manufacturing steel sheet made butt-welded single seam pulling bend

Abstract: The present invention belongs to the field of metal pipe manufacturing technology, and relates to the manufacture process of steel plate butt welding single-seam elbow. The manufacture process includes the technological steps of cutting steel plate, winding, welding, pushing to form, finishing, surface treatment and others. During the mass manufacture, no mechanical allowance is needed and the MF current and voltage are controlled properly to raise product quality, reduce loss, lower pollution and raise production efficiency.

Large heat input butt welded joint superior in brittle fracture characteristic resistance

Abstract: PROBLEM TO BE SOLVED: To form a welded joint having sufficiently high fracture toughness Kc by butt-welding a high strength ship steel plate whose yield strength is 460 Mpa class and whose thickness is >50 mm. SOLUTION: In the large heat input butt welding joint being a structure obtained by butt-welding high strength steel plates having a thickness of ≤50 mm, it is defined that: (a) the hardness of weld metal is ≥70% and ≤110% of the hardness of the base material; (b) the width of the weld metal is ≤70% of the plate thickness of the base material; (c) the width of a weld heat-affected zone is ≥5 mm which is softened to the hardness of ≤95% of that of the base material unaffected by heat if necessary; and/or (d) the original austenitic grain size is ≤200 μm in the weld heat-affected zone in contact with a fusion weld line. COPYRIGHT: (C)2005,JPO&NCIPI

Investigation of temperature transients during flux-cored CO2 butt welding of CMn steel plates

Abstract: Multiply-stiffened, thin plate, welded fabrications are used in a wide variety of transport fields, however the resulting out-of-plane distortion associated with welding exacts a severe design penalty. Depending on the information required, the size of the structure under investigation and the computer power at hand, three computational strategies may be considered to predict welding distortion. If prediction of the localized residual stresses from welding is of major importance, then a full transient, uncoupled thermo-elastoplastic analysis is preferred.

Welded structure excellent in brittle fracture propagation resistance

Abstract: PROBLEM TO BE SOLVED: To provide a welded structure such as a ship construction, even if brittle fracture is generated on a butt welded joint, and is propagated, whose fatal fracture can be prevented even in the case of a steel plate with a plate thickness of ≥50 mm. SOLUTION: In the welded structure excellent in brittle fracture resistance, to an aggregate arranged so as to be crossed with a butt weld zone, over the region of a ≥3 mm thickness in the surface layer part and the back layer part, a steel plate having an average diameter of the equivalent circle of 0.5 to 5 μm and where an X-ray face intensity ratio of the (100) crystal face in the face parallel to the plate thickness face is ≥1.5 is welded at a width at least equal to or above the bead width of the butt weld zone and also in the range having a length of ≥70% of the plate thickness from the surface or the back face of the aggregate in the region where the butt weld zone and the aggregate are crossed. COPYRIGHT: (C)2005,JPO&NCIPI