Showing papers on "Butt welding published in 1980"

Method for induction butt-welding metal parts, in particular parts of irregular cross-section

Abstract: Method of butt-welding metal parts by induction, in particular parts of irregular cross-section such as rails, consisting in pressing the parts against one another with an initial pressure for the entire period of heating, in heating them by induction by means of an inductor which encloses the parts parallel to their contours about the plane of their interface, firstly for a first period at a lower frequency and then, for a second period following the first, at a frequency two to four times higher than the first frequency, and, at the end of the second period, in applying the parts against one another at a forging pressure which is from two to more than six times higher than the initial pressure. The quality of the welded joint is greatly improved and the dimensions of the bulge or upset are limited by restricting the depth of the penetration of the induced current to both sides of the interface by means of two short-circuited turns disposed symmetrically relatively to the inductor to either side thereof.

Panel welding system

Abstract: An integrated welding torch and work positioning roller head assembly is mounted for controlled movement on a cross travelling gantry carriage overlying a vacuum hold-down bed that supports a workpiece panel. The torch and roller head assembly has two related configurations, one for forming a butt weld along a seam joining edgewise abutting sections of flat stock to form a relatively larger unitary panel, and another head configuration for subsequently positioning and fillet welding stiffener webs to one face of the panel. Each of the head assembly configurations is provided with a cofunctioning arrangement of a welding torch (or torches) and seam tracker (or seam trackers) for positioning the torch (or torches) relative to the head assembly as the assembly is automatically guided by the gantry carriage along the intended seam, and a plurality of workpiece positioning and holding rollers which cofunction with the vacuum hold-down bed to form distortion-free panels, having consistently uniform welds along the seams, without the need of preliminary tack welding and without requiring special purpose jigs and tooling for each different panel and stiffener shape.

Application of Microcomputers to Automatic Weld Quality Control

Abstract: The demand for increased productivity of welding operations has led to the expanded use of computer control to allow higher production rates while maintaining weld quality. The charateristics of the gas metal arc welding process and the relationship between welding parameters, the desired output of the welding process, and the automation of the process are discussed. A strategy for two-axis welding torch positioning and velocity control is developed based on preview control techniques. To evaluate the applicability of the proposed control method the motion of heat source along different welding paths is simulated on an analog computer with on-line control of process time constants by an LSI-11 microcomputer. The simulation results show that high quality seam tracking can be accomplished by controlling the torch motion using the proposed method. The method appears to be suitable for on-line control of welding processes.

Method of welding the internal layers of multi-layer paper sacks

Abstract: For a method of welding multi-layer paper sacks with weldable inner surfaces, the outer layers are folded back from the weldable inner layer during welding. The welding energy reaches the inner layer directly. The welding process is substantially shortened in comparison with known methods, and both the production time and processing time with such paper sacks is reduced.

Pipe resistance butt welding apparatus

Abstract: A pipe resistance butt welding apparatus disposable within the pipes to be welded comprises a fixed expanding clamp and a movable expanding clamp, provided with clamping elements and actuating cylinders and intended to fix the pipes to be welded with respect to the apparatus. A cylinder to effect an axial movement of the movable expanding clamp is installed at the end at which this expanding clamp is located; the axial movement provides for drawing together the ends of the pipes to be welded in the course of fusion and upsetting. The cylinder for the axial movement of the movable expanding clamp is coupled with the actuating cylinder of the same clamp and with the clamping elements. The devices making up the apparatus and the cylinders are coaxially installed within a body wherefrom the clamp elements extend outwardly to engage the inner surface of the pipes being welded. Modifications of the apparatus for weld-joining of medium and large diameter pipes respectively are also described.

Production of electric welded tube

Abstract: PURPOSE: To prevent the oxidation of oxidative or high toughness metals and prevent the welding defects of an electric welded tube by heating oppposing edge parts by high frequency current at a junction point, heating the same by low frequency current at the weld point and performing butt welding. CONSTITUTION: A work coil W connected to a high frequency power source is disposed on the upper stream side on the junction point O 1 of both side edge parts E, E of an open pipe OP. Induced high frequency current is flowed via the point O 1 to the edge parts E, E, so that said parts are heated to raise temp. up to their melting temp. or the temp. around the same. On the other hand, a pole ring EW is connected to a low frequency power source, and is flowed with low frequency current at the weld point O 2 via the junction part O 1 of the edge parts E, E, thereby heating said parts up to the molten state sufficient for butt welding to be executed. Thence, an upset is given by squeeze rolls SR, and in the state that most of the molten metal thereof is discharged from between both side edge parts, butt welding is carried out, whereby a pipe P is formed. COPYRIGHT: (C)1981,JPO&Japio

Contact nozzle assembly for MIG welding burners - esp. hand welding guns, where gas nozzle is flattened so it can enter narrow gaps between workpieces

Abstract: Current contact tube through which a welding wire travels towards the zone being welded, is concentrically surrounded by gas delivery pipe. On the bottom end of the pipe is a gas nozzle, which tapers conically to form a flattened pipe extending downwards nearly to the tip of the tube. Flattened pipe pref. has a middle zone forming a friction clamp on the outside of the tube and two gas channels, one on each side of the tube. Used esp. in the welding of thick workpieces, e.g. the butt welding of two thick plates, where flattened pipe can enter a narrow welding gap.

Process for joining pre-insulated pipe sections that carry a medium, and pipe sections joinded by this process

Abstract: Pipes (1) used for transporting hot water or other heated fluids are supplied with a thermal insulation jacket protected by an outer covering (3). A joint between pieces of such pipe is made in the following way. The insulation (2) and outer cover (3) are removed over a short distance from the end of each piece of pipe. The two pieces of pipe are then joined together by butt welding. The gap between the two sections of thermal insulation is then filled with two half shells of insulating material. Finally these half shells of insulation are covered with half shells of a protective layer which is butt welded along circumferential seams (4) to the ends of the existing protective cover (3) and these outer half shells are also welded to each other along the longitudinal seam (5). The edges of the welded material are chamfered to produce a flush weld.

Welding method of pipings

Abstract: PURPOSE: To enable to perform centering of pipings accurately and improve workability of pipe welding considerably, by welding the connected part after fitting a depressed part, a projected part provided at the end of a pipe to be welded or a connecting part of a shape. CONSTITUTION: Pipe 11 and pipe 12 are fitted to connect each other through annular notches 46 and 47 and annular projections 48 and 49. Then a torch of TIG welding is moved along the circumference boundary on the outer surface of projections 17 and 18 fitted to each other. Projections 17 and 18 are arc welded in the primary layer as the torch moves along the boundary. Since no fixing jigs which has been used in a conventional method are required, the torch can be moved continuously along the circumference direction and welding work can be made easily. When the welding of primary layer is completed, welding surfaces 13 and 14 are welded completely using a welding rod. COPYRIGHT: (C)1981,JPO&Japio

Welded joint method for stainless steel tube

Abstract: PURPOSE:To manufacture a stainless steel tube joint which can prevent a stress corrosion cracking without requiring a post treatment, by previously performing build-up welding with a anticorrosion metal on the internal circumferential surface of the edge of the coupling part of a stainless steel tube, and then by performing butt welding at the tube end. CONSTITUTION:Over the entire internal circumferential surface of stainless steel tube 1 extending from the tube end by length (l), built-up part 2 made of anticorrosion metal of thickness (q) is provided by welding. After the build-up welding, shot peening or roll work is carried out at build-up part 2 and its circumference. As a result, layer 3 given the residual stress of compression is formed on the surface. The edges of this tube 1 and tube 1A of the same structure are formed and butted for coupling at weld zone 4 of low-carbon stainless steel, thereby obtaining a tube joint. Of this tube joint, the metallurgically sensitized part generated in the formation of weld zone 4 is covered with build-up parts 2 and 2A, so that stress corrosion cracking is prevented.

Preparation of welded pipe

Abstract: PURPOSE:To produce a welded pipe of high tension without performing quenching treatment, by heating the edge parts of both the sides of a skelp, carrying out butt welding, and after that, cooling them forcibly under the specified condition. CONSTITUTION:The skelp 1 connected with coils endlessly is led to the heating furnace 2 through the loop floor and the preheating furnace, and the edge parts of both the sides are heated up to the welding temperature. subsequently, the skelp is welded and reduced by making it pass through the forming rolls 3, and the welded pipe 1' which has been obtained is cut to the fixed length by feeding it to the forming machine 4 and the flying cutter 5. Before the welded pipe becomes the temperature less than the transformation point AC3 when deposition of alpha phase is started, it is fed into the cooling device, is suddenly cooled to the temperature below the transformation point AC1 by a suitable method among water cooling, oil cooling, airblast, etc., is carried to the reformation roller 7, and the tempering treatment is performed as occasion demands. By the afore-mentioned method, it is possible to economize the heat consumption amount and to shorten the time required for the production, therefore a hlgh class welded pipe is supplied at low cost.

Polarized mechanical filter

Abstract: PURPOSE:To reduce the harmful spurious response and the characteristic dispersion as well as to realize miniaturization of the filter by using the 2nd-style flexion lateral vibration tuning bar for the pole-use resonator which couples the additional couplers. CONSTITUTION:The 2nd-style flexion lateral vibration is applied for pole-use resonators 3' and 9' which connect folding resonator 6 to additional couplers 20' and 21'. And the 1st-style flexion lateral vibration is adapted for other main resonators 4, 5, 7 and 8 each. Main couplers 12-19 are given the butt welding at the center of each vibrating belly point of main resonators 4, 5, 7 and 8, pole-use resonators 3' and 9' plus folding resonator 6 respectively. While the butt welding is given to additional resonators 20' and 21' at the center of the belly lines of resonators 3' and 9' and also at the outer edge area of resonator 6 respectively. As a result, no coupled vibrating force affect resonators 3' and 9', thus reducing occurrence of the spurious response. Furthermore, the effective length can be stabilized due to the butting, thus ensuring the stabilized characteristics.

Butt welding method of pipe body

Abstract: PURPOSE:To enable the obtaining of sufficient penetration at the welding of both tubular bodies and enable the defect-free joining by cutting away the support fitting of the backing ring tentatively supported to the end part of one tubular body then fitting the end part of the other tubular body to the backing ring. CONSTITUTION:The lower half part in the axial center direction of a backing ring 5 with its welding 9 being faced upward is fitted to the inside circumference of the top end part 1a of a lower pile 1 and is pushed until its support fitting 8 abuts against the top end face 1a of the lower pile. Next, root-spacing holding beads 11a- 11d are formed between the respective fittings 8 integrally with the ring 5 onto the face 1b, after which the fittings 8 are cut away by a gas torch or the like. Next, the slag of the beads 11a-11d is removed and its height is so controlled by a grinder as to come within the specified value. After this, the bottom end part 2a of the upper pile 2 is fitted to the upper half of the ring 5, after which the top end part 1a of the lower pile 1 and the bottom end part 2a of the upper pile 2 are semi-automatically welded, whereby the lower pile 1 and upper pile 2 are joined in the state free from any welding defect.

Reducing method of residual stress at circumferential weld zone of steel pipe

Abstract: PURPOSE:To reduce the residual stress at the circumferential weld zone of steel pipes as far as possible by making use of the advantages of a local stress relief annealing method which is used for residual stress relieving of the circumferential weld zone after butt welding and preventing the production of new residual stress after stress relief annealing being a disadvantage. CONSTITUTION:The butt circumferential weld zone of steel pipes and its neighborhood are so heated as to become maximum temperatures 580-700 deg.C after finishing of welding so that the maximum heating temperature area thereof is held in a range of more than 5 times the wall thickness of the pipes to the right and left with the weld line as a center. Or heat treatment is so accomplished that the distances between the positions reaching 450 deg.C on the outer side of said maximum heating temperature area and the weld line are held at more than 10 times the wall thickness of the pipe respectively to the right and left of the weld one and even temperature distributions are given in the thickness direction of the pipes. In this way, the residual stress of the weld zone of the butt-welded steel pipe may be reduced.

Method of preventing stress corrosion crack at austenite stainless steel welding

Abstract: PURPOSE:To provide a welded joing having superior stress corrosion crack resistance by limiting the carbon content of a steel at the welding portion treated with solid solution. CONSTITUTION:Welding groove edge 2 is formed at a steel pipe 1 or the like of austenite stainless steel having less than 0.03% of carbon content (SUS304L, SUS304LN, SUS316L) for butt welding. Depositing metal 3 contains less than 0.03% of carbon content (D308L or D309MoL). The entire welded portion is treated with solid solution to thereby decompose and solidsolve chromium carbide occurred at the crystal boundary of welding heat affected portion 4 of the pipe 1. Since the welded joint thus treated contains low carbon content different from SUS304, it hardly lower its quality due to precipitation of chromium carbide even if it is used at a boiling water reactor operated at 300 deg.C of operating temperature for long time to provide superior stress corrosion resistance.

Electromagnetic coupler of magnetic particle type

Abstract: PURPOSE:To prevent leakage from exciting coil and improve the clutch performance by simultaneously welding a pair of members constituting the main body of the coupler and a plate over the entire periphery and thus ensuring spacial cut-off between the annular space and outside. CONSTITUTION:An annular stator 3 is disposed to face a cylindrical rotor 2 mounted on a shaft 1 via a cylindrical space g, and the rotor 2 is rotatably supported by a bearing 4 on the shaft 1. The stator 3 consists of symmetrical opposite side members 3a and 3b welded together by butt welding at a position A, and an exciting coil 6 is disposed in an annular space 5 within the stator 3. A plate 4 is welded to the outer periphery of the left side startor member 3a, and magnetic particles 8 are sealed in the annular space g. The symmetrical opposite side members 3a and 3b permit use of common parts. Also, since the plate is provided as a separate member, the machining of stationary parts can be simplified. Further, since the welding is made over the entire periphery by butt welding, it is possible to reliably prevent intrusion of water and the like.

Automatic welding and cladding in heavy fabrication

Abstract: A description is given of the automatic welding processes used by an Italian fabricator of pressure vessels for petrochemical and nuclear plant. The automatic submerged arc welding, submerged arc strip cladding, pulsed TIG, hot wire TIG and MIG welding processes have proved satisfactory in terms of process reliability, metal deposition rate and cost effectiveness for low alloy and carbon steels. An example shows sequences required during automatic butt welding, including heat treatments. Factors which govern satisfactory automatic welding include automatic anti-drift rotator device, electrode guidance and bead programming system, the capability of single and dual head operation, flux recovery and slag removal systems, operator environment and controls, maintaining continuity of welding and automatic reverse side grinding. Automatic welding is used for: joining vessel sections; joining tubes to tubeplate; cladding of vessel rings and tubes, dished ends and extruded nozzles; nozzle to shell and butt welds, including narrow gap welding.

Penetration control method in arc welding

Abstract: PURPOSE:To prevent burn-through and enable correct penetration to be obtained by comparing the signal of the photo detector synchronously moving to the opposite side of torch firing point and a set value and controlling welding conditions at the welding such as butt-welding in which back beads are not formed. CONSTITUTION:A photoelectric detector 3 (3, 3' at the fillet welding is moved in synchronization with a torch 2 at a fixed spacing from the material 1 to be welded on the opposite side of the firing point of the torch 2 in the butt welding or fillet welding of the materials 1, 1' to be welded. The signal corresponding to the quantity of light received from the photo detector 3 is compared with the preset correct photo detection signal in a comparator via amplifier and the welding conditions are so controlled that the signal difference thereof becomes 0. In this way, in the butt welding or fillet arc welding in which no back beads are formed, the lack of penetration and burn-through occuring in the inadequate welding conditions of conventional methods are prevented with the simple device.

Butt welding method of thinnwall tubular bodiy

Abstract: PURPOSE:To form a beautiful bead appearance by preventing recess or protrusion in the inner and outer surfaces of tubular body, by moving the arc start piece together with the welding torch, with respect to the thin-wall tubular body to be welded CONSTITUTION:A thin-wall tubular body to be welded 1 is rotated at a specified speed, and a welding arc 3 is struck in the upper surface of an arc start piece 6 by means of a welding torch 2 Next, the arc start piece 6 is brought close to the thin-wall tubular body 1, and the arc part 6a thereof is caused to contact with the outer circumference of the thin-wall tubular body 1 Then, the welding torch 2 is moved, together with the welding arc 3, to just above the thin-wall tubular body 1, and the thin-wall tubular body 1 is subjected to full-circled butt welding After complete welding, the welding arc 3 is, without shielding, returned to above the arc start piece 6 together with the welding torch 2, and the arc start piece 6 is drawn back In this method, wastefull comsumption of tungsten electrode 2a of the torch 2 may be prevented, and always stable welding may be performed

Method of manufacturing electromagnetic shield of superconductive rotor

Abstract: PURPOSE:To obtain a highy conductive electromagnetic shield of a superconductive rotor by forming first cylinder of conductive material and second cylinder of reinforcing material by machining and butt welding and shrinkage fitting or explosion conneting the cylinders. CONSTITUTION:Conductive material such as oxygen free copper of the like is bent to form a semi-circular member. The members are connected by an electron beam welding as a butt welding to thereby form a first cylinder 22. In order to reinforce the first cylinder, reinforcing material is similarly formed from metal having higher strength than the first cylinder such as, for example, nonmagnetic steel to form a second cylinder 21' by welding at 25. Then, the second cylinder 21' of smaller diameter is inserted into the first cylinder 22, and shrinkage fitted or explosion connected. In some cases, large-diameter second 21 is formed by reinforcing material' the composite cylinder thus formed is inserted into the second cylinder 21 to explosion connect them from outside of the cylinder 21 to thereby obtain electromagnetic shield of tripple construction.

Backing strip for butt welding of thin plate

Abstract: PURPOSE:To prevent the decrease in strength at the end part of weld by using the backing strip engraved with the grooves of the specific shape at the time of butting thin plates and welding the same while forming back beads on the back side. CONSTITUTION:A backing strip 7 engraved with a parallel groove 8 of a depth h and tapered grooves 9, 9' of a length S is applied on the back side of the butt part of thin plates and arc welding is performed. It is desirable that h be made 0.5- 3mm and S 5mm or over. As a result, back beads are not formed on the back side owing to cooling effect in the portions where the thin plates make close contact with the backing strip and the convex form back beads are formed in correspondence to the depths of the grooves along with the progression of welding. Hence, the abrupt concave beads are not produced in the beginning end and terminal end parts of welding, hence nicking phenomenon is prevented and the weld zone free from any welding defect is formed.

Ceramic Weld Backing Evaluation

Abstract: : Representative ceramic weld backing systems were evaluated with representative FCAW and SAW processes to determine their efficacy to produce second side weld contours not requiring subsequent back welding or preparation for inspection Weldments were prepared and evaluated for soundness, toughness, bead shape, ceramic attaching methods and ceramic neutrality Significant weldment soundness problems were identified for certain FCPW processes in certain positions Changes in welding technique appear promising for control of these problems (though at some expense in bead shape) but further development in certain instances is required Relatively minor bead shape problems were identified and corrected for FCAW More significant bead shape problems were identified for submerged arc particularly in tandem applications No other problems of potential significance were identified Promising joint designs, parameters and techniques were identified for welding over ceramic backing Recommendations for future development are made

Production of aluminum plated or aluminum alloy plated steel pipe

Abstract: PURPOSE:To obtain the captioned plated steel pipe free from any welding defect occuring in the remaining of aluminum oxides at the welding by removing the plating layers near the butt portions of an Al or Al alloy plated steel hoop between the slitting process of said steel hoop and its roll forming process. CONSTITUTION:Blank steel 1 comprising slitting an Al or Al alloy plated steel hoop to the specified width has the abovementioned plating layers 2 on both surfaces. At the time of producing the steel pipe by roll forming this blank steel 1, a process for removing the plating layers near the butt portions 6, 7 of the blank steel 1 is provided and the shear droops 4, 5 of the plating layers are removed by shaping them off with, e.g., a grinder or the like. As a result, the inclusion of oxide aluminum into the deposited portion at the butt welding does not occur and the Al plated or Al alloy plated steel pipe free from any welding defect such as crack, etc. occuring in the remaining of aluminum oxides is obtainable.

Butt welding method of centrifugal force cast pipe for heat resistance

Abstract: PURPOSE:To obviate the production of creep cracking in weld metal by performing welding of the second and subsequent pass after root pass welding by making the temperature of the already built-up weld metal higher than the temperature of the base metal. CONSTITUTION:Welding II of the second and subsequent passes after the root pass welding I is performed is accomplished by making the temperature of the already built-up weld metal higher than the temperature of the base metals 3, 3. As a method for this, the welding II is accomplished is succession to the excecution of the welding I without cooling the weld zone thereof. Or when the temperature of the already built-up weld metal has dropped after the root pass or second pass welding, there is a method of heating said weld metal with a TIG welding torch or the like and built up the next pass by rewelding a part thereof. According to this method, the flow of heat at the cooling of the weld metal 2 becomes less in the weld metal 1 and more in the base metals and the columnar crystals having a centrain angle to both of the axial direction (Y direction) and circumferential direction (X directin) grow. Hence, the weld metal having good creep repture and ductility for the X, Y diections may by obtained.

Flash butt welding machine - with sensors for all parameters affecting weld quality (OE 15.6.80)

Abstract: A butt welding machine is equipped with a minicomputer for the automatic control of the start of the upsetting operation and the upsetting distance. A sensor at the output of the current transformer for the input to the primary winding of a welding transformer indicates the short-circuit duration. Another pair of sensors detect any slip of the workpieces in the clamps. Third sensor responds to the displacement of the servo valve rod (which controls the hydraulic clamp moving mechanism) relative to its housing. A command shaper is controlled by the minicomputer output. The presence of sensors for all possible defects ensures a consistent high quality of the butt welded joints produced by this machine.

Gas shielded arc welding method

Abstract: PURPOSE:To prevent the production of defects such as undercuts by performing pulse arc welding in down welding position and using the shielding gas mixed with oxidative gas for inert gas in consumable electrode type gas shielded arc welding CONSTITUTION:In butt welding or the like of steel sheets, the one comprising mixing some oxidative gas such as carbonic acid gas and oxygen gas into inert gas such as Ar is used as shielding gas and pulse-arc welding is done in downhill welding posture With this method, the forward melt flow of welding pool becomes considerable and the production of undercuts becomes less In addition, the arc length becomes slightly longer than that by a short arc welding method and both arcs of dislocation between both plates may be melted and fused together Further, there is no burn-through and since the molten metal flows on the surface of the edge joint so as to go after the arc, the good welding may be accomplished

Resistance Flash Butt Welding of Pipelines

Abstract: The E. O. Paton Welding Institute has developed a new technology of resistance flash butt welding of pipes of various diamaters and has designed welding machines providing pipe welding within the range of 114 − 325 mm and 720 − 1420 mm diameter. For welding of 720 −1420 mm diameter pipes the internal pipe welding machines are used which move inside the pipe by means of the drive built-in into the welding machine. This type of the machines is equipped with a flash remover which cuts the internal flash in a hot state. The E.O. Paton Welding Institute conducted a wide scope of investigations and tests of welded joints of the pipes welded by resistance flash butt welding machines. The tests covered the X52 through X70 grades of pipe steels and 12.5 mm to 25.4 mm wall thicknesses. The tests were performed to reveal a correspondence of the welded joint quality obtained to the requirements of the codes used (API 1104 and oth.). The results of the mechanical tests, X-ray and ultrasonic inspections, the data of metallographic examinations accomplished in accordance with the requirements of code API 1104 and also the results of the additional Charpy and COD strength tests confirmed a high quality of welded joints.

Lift arm plate

Abstract: PURPOSE:To promote a weight lightness and eliminate a distortion due to the heat of a welding work for the lift arm plate, by constructing an almost triangular plate installed to the lift arm with a combined body of the sheet metal work. CONSTITUTION:The lift arm A is constructed as follows. Peripheral edge portions 2, 2' of the material of plate main units 1, 1' fabricated into the same shape are curved inward to form inner protruding parts 3, 3' in the central position by the work of press molding. A pair of said press molded plate main units 1, 1' are arranged at a face-to-face position to each other to contact each of the inner protruding parts 3, 3' and construct the peripheral edge portions 2, 2' by the method of butt welding. In this way, said plate A can be applied a thinner steel material as compared with that as conventionally used, formed into a three-dimensional structure of excellent strength in addition to the weight lightness further eliminated a deformation deriving from a distortion due to the heat of a welding work at the peripheral edge portions 2, 2' and finished in a good make by equalizing the shape of products simultaneously facilitated an easy process of automatic welding by equalizing the shape of the plate main units 1, 1' thus more increased its work efficiency.