Abstract: A three-dimensional (3D) printer is configured to introduce a liquid metal onto a first part and a second part while the first part and the second part are in contact with one another. The liquid metal subsequently solidifies to join the first part and the second part together to produce an assembly.

Abstract: A welded connection kit for joining first and second lined pipes together includes a coupling sleeve to connect the first and second pipes together. The coupling sleeve has a thermal break in it. The coupling sleeve includes a first coupling member that attaches to the first pipe and a second coupling member that attaches to the second pipe. The first and second coupling members attach to each other to connect the first and second pipes. A first liner lines the first pipe and includes a first flange. A second liner lines the second pipe and includes a second flange. The first and second coupling members compress the first and second flanges together to form a fluid seal.

Abstract: A bowl holder including a base for supporting the device on a surface and a holder for receiving a bowl on top of the device. The base may include a plurality of support legs and a threaded aperture in the center of the base. The holder may include a threaded shaft which engages the threaded aperture in the base. The threaded shaft may be placed vertically so that rotating the holder causes it to raise or lower on the threads. The bowl holder is useful for supporting a bowl and adjustably raising the bowl's height above a table or countertop.

Abstract: A pressure vessel includes: (a) a cylindrical sidewall having a wall thickness, an inside surface, an outside surface, and the cylindrical sidewall extending between a first end and a second end, wherein one of the first end or the second end includes a sidewall edge that forms part of an outwardly opening weld groove; (b) an end cap constructed to engage the cylindrical sidewall edge, the end cap comprising an end cap edge corresponding to the sidewall edge and that, when combined with the sidewall edge, forms the outwardly opening weld groove; (c) a cylindrically extending backer bar located in support of the outwardly opening weld groove formed by the sidewall edge and the end cap edge; and (d) a weld joint formed in the outwardly opening weld groove and holding the cylindrical sidewall to the end cap. A method for welding a pressure vessel sidewall and end cap together is provided.

Abstract: A roll-on applicator ball and a method of forming the roll-on applicator ball, the roll-on applicator ball comprising a first half ball part and a second half ball part. A generally annular connecting ring connects the ball halves together.

Abstract: A welded shaped steel manufacturing device for weld-connecting a butt portion of a web member having an end butting perpendicularly against a flange member and thereafter correcting in shape the flange member subjected to thermal deformation caused by heat input during welding, the device includes: a corrective device including flange-member correcting rollers arranged for respective ends of the flange member, each configured to press each end on a web-member side of the flange member so as to correct the thermal deformation over a range of the flange member from each end thereof to the butt portion thereof against the web member, and web-member supporting rollers configured to support a web surface of the web member, wherein the flange-member correcting rollers arranged for the respective ends of the flange member apply independent pressures to the respective ends so as to correct the thermal deformation.

Abstract: Tubulars are joined for subterranean borehole use in the production of hydrocarbons by a technique of magnetically impelled arc butt (MIAB) welding. Large casing can be accommodated and the weld quality is maintained with control over the pattern of arc movement on the end walls by virtue of relative movements of the tubulars as the arc is generated and the magnetic field is applied. One or both tubulars can be manipulated relatively in a variety of direction to control the movements of the arc as the magnetic field induces circular arc movement along the end walls of the tubulars to heat up the ends to the temperature needed to effectively fuse the wall ends together. Movement can be rotational or axial about a fixed axis or lateral with respect to the axes both with and without skewing of the axes. The movements can be combined to obtain the desired track.

Abstract: Methods for welding a particle-matrix composite body to another body and repairing particle-matrix composite bodies are disclosed. Additionally, earth-boring tools having a joint that includes an overlapping root portion and a weld groove having a face portion with a first bevel portion and a second bevel portion are disclosed. In some embodiments, a particle-matrix bit body of an earth-boring tool may be repaired by removing a damaged portion, heating the particle-matrix composite bit body, and forming a built-up metallic structure thereon. In other embodiments, a particle-matrix composite body may be welded to a metallic body by forming a joint, heating the particle-matrix composite body, melting a metallic filler material forming a weld bead and cooling the welded particle-matrix composite body, metallic filler material and metallic body at a controlled rate.

Abstract: A purge dam assembly confines a volume within an assembly of pipes, including a distal pipe and a proximal pipe together arranged for butt welding at a seam. A distal disk is covered at its periphery with a distal bootie including gasketing material. A proximal disk is covered at its periphery with a proximal bootie including the gasketing material. The each disk is sized such that the bootie contacts but does not completely seal against an inner surface of one of the tubes or pipes permitting a purging flow of gas from the volume and past each disk. A cross-member having a proximal and a distal end, the proximal end is affixed to the proximal disk and the distal end is affixed to the distal disk to preserve the spatial separation between the proximal disk and distal disks and to maintain the proximal and distal disks in coaxial alignment.

Abstract: A trailer frame including an axle section having two spaced longitudinal frame members connected by at least one cross member, the longitudinal frame members each having a first end and a second end; a rear section attachable to the axle section; and a dimple assemble joining the axle section to the rear section, the dimple assembly including a dimple pattern formed on each frame member of the axle assembly, the dimple pattern on the axle assembly defining a first dimple axis, and a dimple pattern formed on one end of the rear section and nestable within the dimple pattern formed on the axle section, the dimple pattern on the rear section defining a second dimple axis offset relative to the first dimple axis to create a camber between the axle section and the rear section when the first dimple is nested within the second dimple pattern.

Abstract: A magnetically impelled arc butt (MIAB) welding device positioned on the rig floor heats facing ends of a pair of wellbore tubulars. After the facing ends are heated and/or melted, a force application device compressively engages the facing ends to form a welded joint.

Abstract: A connection element for an electrical conductor contains a first section to be connected to another component, and a second section having a front surface to be welded to an electrical conductor. The front surface has a three-dimensional form raised in a central region in relation to an edge region surrounding the central region. The connection element is hollow in the region of the front surface.

Abstract: A wire butt welding apparatus includes at least two clamps, individual ones of the at least two clamps configured to hold a respective wire. The individual ones of the at least two clamps are positioned within the wire welder such that the ends of individual ones of the respective wires, when held by the respective clamps, will contact each other. One or more individual ones of the at least two clamps are associated with an adjustment axis about which the individual ones of the at least two clamps are configured to rotate. An adjustment mechanism is operatively coupled to fix one or more of the at least two clamps corresponding to the associated adjustment axis at an angular orientation with respect to a second clamp.

Abstract: A method for optimizing a schedule for impulse welding including generating a weld lobe using a preexisting welding schedule, the schedule prescribing a current, a weld time, and a pressure; identifying an operating window on the weld lobe; analyzing the operating window, the analysis including determining a maximum time range of the operating window, and determining a maximum current range of the operating window; until (i) the determined maximum time range of the operating window is greater than a predetermined percentage of the prescribed weld time of the schedule and (ii) the determined maximum current range is greater than the prescribed current of the schedule, creating additional weld lobes by varying the pressure and repeating the identifying an operating window and the analyzing the operating window steps; and selecting, within the operating window satisfying conditions (i) and (ii), a second schedule including a second weld time, a second current, and a second pressure.

Abstract: An intravascular guide wire having two core materials joined together without the use of a connector tube or sleeve, the core materials being stainless steel and psuedoelastic metal alloy, nitinol. The core materials are joined to each other through an intermediate transition piece made essentially of nickel, which is welded on either side to the two core materials. In a multi-segment intravascular guide wire, discrete, high modulus and medium modulus core portions of different materials are welded to a shapeable, low modulus distal core portion made of a third material having a flattened, shapeable section at a most distal end that is not welded to but made from the distal core portion, so the flattened, shapeable section can be deformed to create a steerable tip. Processes such as simultaneous resistance and friction welding can be used to join the core portions.

Abstract: The invention relates to a flanged bearing ring produced from a high carbon steel profile bar comprising at least one flash butt welded joint, where the bearing ring is provided with an inner peripheral surface and an outer peripheral surface and where one peripheral surface comprises a raceway for rolling elements, where the bearing ring further comprises a flange adapted for fixing the bearing ring to a mechanical member, where the flange protrudes from the bearing ring in a substantially radial direction. The invention further relates to a method for producing such a homogenous flanged bearing ring from a straight profile bar. The advantage of the invention is that a homogenous flanged bearing ring is obtained in a simple and cost-effective way.

Abstract: The seam welding apparatus welds a workpiece held by a robot while delivering the workpiece between a pair of electrode rolls. The seam welding apparatus includes a load cell mounted on the robot, for detecting a load imposed along a Y direction which is perpendicular to a pressing direction Z along which the electrode rolls press the workpiece at a weld point and a delivering direction X along which the robot delivers the workpiece at the weld point, a robot controller and an arithmetic unit, a turning mechanism for turning the electrode rolls about the pressing direction Z, and a control device for controlling the turning mechanism to operate depending on the magnitude of the load in the Y direction detected by the load cell.

Abstract: A method of resistance butt welding in which a current-conducting insert is placed into a gap between the parts being welded, axial pressure force is applied and electrical current is passed. The current-conducting insert is a shaped metal insert having cavities filled with a welding flux and is placed in the gap between the parts being welded.

Abstract: The invention relates to a method of providing a duplex stainless steel strip for an armouring layer of a flexible pipe, said method comprising providing at least two duplex stainless steel pieces each having an end-face, welding said end-faces of said two pieces of duplex stainless steel together to form a welded interface section using resistance welding, such as dual upset welding or flash welding, and providing a controlled cooling of said welded interface section. The duplex stainless steel strip should preferably be heated to a temperature of at least about 1100° C., preferably at least about 1200° C., such as at least about 1500° C. in said interface section, and the controlled cooling of said welded interface section preferably comprises prolonging the cooling of the interface section preferably at least for the cooling from about 800° C. to about 600° C., more preferably at least for the cooling from about 1100° C. to about 600° C.

Abstract: In resistance welding, an end portion and a flange portion are welded together at contact surfaces thereof by applying a voltage between two electrodes a while an inner casing and a main metal piece are pressed in directions toward each other. When a shearing stress due to the pressure is applied to a ceramic guide pin, the guide pin is more resistant to wear as compared to a phenolic resin guide pin, for example. In addition, a clearance is provided between a large-diameter portion of the guide pin and an inner surface of a guide-pin insertion hole. Accordingly, the guide pin is capable of tilting in the radial direction, to partially absorb the shearing stress. Therefore, the guide pin is more resistant to breakage compared to a non-tilting ceramic guide pin. Thus, the life of the guide pin used in the resistance welding process can be prolonged.

Abstract: Manufacturing method, welding arrangement and door frame structure for a door frame (21) of a windmill tower (10), wherein a hole (15) is made in the tower shell (10) for the door and a door frame is placed in the hole and welded on the shell. In the method, the shape of the door frame for the shell and the shape of the surface of the shell at the opening (15) to be made are measured with a measuring sensor (40). Based on the measurements, a cutting torch (41) is controlled so that an opening corresponding to the shape of the door frame is cut in the shell and bevels (16, 17) are cut in the edge of the opening on both sides. The door frame is welded on the shell with a weld (24), such as a double bevel, double J or square butt weld, from the inside and the outside of the shell.

Abstract: Method and apparatus for forming an optical-fiber-array assembly, which include providing a plurality of optical fibers including a first optical fiber and a second optical fiber, providing a fiber-array plate that includes a first surface and a second surface, connecting the plurality of optical fibers to the first surface of the fiber-array plate, transmitting a plurality of optical signals through the optical fibers into the fiber-array plate at the first surface of the fiber-array plate, and emitting from the second surface of the fiber-array plate a composite output beam having light from the plurality of optical signals. Optionally, the first surface of the fiber-array plate includes indicia configured to assist in the alignment of the plurality of optical fibers on the first surface of the fiber-array plate. In some embodiments, the second surface of the fiber-array plate includes a plurality of beam-shaping optics configured to shape the composite output beam.

Abstract: A guide wire includes a first wire disposed on the distal side of the guide wire and a second wire disposed on the proximal side. The second wire has an elastic modulus larger than the first wire. The first wire is joined to the second wire at a welded portion by welding. A coil is disposed on the distal side of the first wire. A cover layer is formed on the outer peripheral surface of the wire member in such a manner as to cover at least the welded portion. The cover layer is made from a material capable of reducing the friction of the cover layer, for example, a fluorocarbon resin or a hydrophilic material, to thereby improve the sliding performance of the guide wire. Such a guide wire is excellent in operationality and kink resistance.

Abstract: A housing assembly for a gas generating system includes a housing and a shim welded to the housing to provide a substantially gas-tight seal between the shim and the housing. A method for attaching a shim to a housing is also described.

Abstract: A weld fairing apparatus and a welding method using the apparatus effectively prevent a weld metal zone from forming a humping bead. The welding method includes: butting first and second object pieces together; heating the butted first and second object pieces using a heating device, thus forming a weld metal zone; and placing a fairing device such that the fairing device comes into contact with the weld metal zone and fairs the weld metal zone.

Abstract: A guide wire includes a wire body having a first wire disposed at a distal end and a second wire joined to a proximal end of the first wire at a joint by welding. The joint is curved. In the joint, at least one component (e.g., Ti) of the material of the first wire decreases toward the proximal end and at least one component (e.g., Fe) of the material of the second wire decreases toward the distal end. When a tensile test is conducted on a region of the wire body including the joint, the region of the wire body has, in a tensile load and elongation diagram, an elastic section extending substantially straight upwardly to the right, a yield section extending substantially horizontally or upwardly to the right from the elastic section, and a substantially straight section extending upwardly to the right from the yield section.

Abstract: A device for the linear butt welding of thin metal sheets without weld filler materials comprising movable welding heads, a clamping device having at least two pressing elements which operate independently of one another at least one of the pressing elements being suitable for applying two or more distinct pressure levels and additional horizontal pressing elements are further provided in order to press the metal sheets to be welded against one other while being deformed, until full-area contact of the metal-sheet edges butting against one another is achieved as well as a welding method making use of the device.

Abstract: The seam welding apparatus welds a workpiece held by a robot while delivering the workpiece between a pair of electrode rolls. The seam welding apparatus includes a load cell mounted on the robot, for detecting a load imposed along a Y direction which is perpendicular to a pressing direction Z along which the electrode rolls press the workpiece at a weld point and a delivering direction X along which the robot delivers the workpiece at the weld point, a robot controller and an arithmetic unit, a turning mechanism for turning the electrode rolls about the pressing direction Z, and a control device for controlling the turning mechanism to operate depending on the magnitude of the load in the Y direction detected by the load cell.

Abstract: The present invention relates to a method for butt joint of rolling pieces comprising: cutting a head part of a first rolling piece which is in a feeding direction to form a first inclined butt joint edge in a preset sharp angle ? against a working roll generatrix of a working roll, wherein a value of the angle makes the width of the first inclined butt joint edge along a vertical direction of the working roll generatrix greater than the width of a distortion area where the working roll touches the rolling pieces; cutting a tail part of a second rolling piece which is in the feeding direction to form a second butt joint edge parallel to the first inclined butt joint edge; setting the first inclined butt joint edge and the second inclined butt joint edge relatively clingy; and welding relatively clingy parts to connect the first rolling piece with the second rolling piece.

Abstract: A plurality of attachments having springs hold the outer plate of a fuel tank, and an inner jig positions the inner plate. The attachments are attached to clamp arms which are opened/closed by cylinders. When the overlap portion between the outer and inner plates is welded, the thermal deformation caused by welding is accommodated by the springs. The attachments are spaced from the fuel tank in the order in which the welding point is approached.

Abstract: A butt welding apparatus and a butt welding method where end faces of at least one plate member to be welded are butted to each other to form a butt portion, and butt welding can be performed on respective plate members which have various thickness sizes on both side portions of the butt portion with electric resistance heat by a pair of electrode members which are common to the respective plate members. At least one electrode member (1) is provided on an outer face thereof with a convex portion (1A) which gradually retreats from one plate member (31) of two plate members (31, 32) as it extends from an intermediate portion, in a thickness direction, of the one electrode member (1) along the one plate member (31).

Abstract: A method of resistance butt welding in which a current-conducting insert is placed into a gap between the parts being welded, axial pressure force is applied and electrical current is passed. The current-conducting insert is a shaped metal insert having cavities filled with a welding flux and is placed in the gap between the parts being welded.

Abstract: A forced-insertion welded structure is provided which is formed by welding members making up a metal component and which is easy to manufacture and has low cost, a good finish precision and a high bonding strength. The forced-insertion welded structure comprises: a first member 2 with a hole 13 which has the same geometry as a cross section of a forcibly inserted portion of a second member; and the second member 4 having a constant cross section over its length which is similar in shape to the hole 13; wherein a press-fit interference of the second member 4 relative to the hole 13 of the first member 2 is set to 0.

Abstract: An improved method for joining together the edge portions of first and second panels includes applying a heat curable adhesive along the edge portion of the first panel and then abutting the edge portion of the second panel with the edge portion of the first panel so that the adhesive is interposed between the edge portions of the first and second panels and the adhesive spaces the panels apart and provides a gap between the panels. A brazing material is melted and fills the gap and the heating of the panels by the brazing causes at least partial curing of the adhesive so that the panels are joined together by both brazing and adhesive bonding.

Abstract: A butt welding apparatus, a butt welding method, and a product manufactured by the butt welding method involves two electrode rollers disposed on both the front and back sides of a thick sheet member and a thin sheet member whose end surfaces are butted. The electrode rollers bridge across the sheet members and are composed of small diameter portions on the side of the thick sheet member and large diameter portions on the side of the thin sheet member. The small diameter portions come into contact with and press the thick sheet member before the large diameter portions come into contact with the thin sheet member. Thus, the end surface of the thick sheet member swells and deforms toward the thin sheet member and reliably comes into contact with the end surface of the thin sheet member, and power is applied between the end surfaces, even if not polished.

Abstract: The invention concerns a method for controlling the butt welding, by flash welding, of two metallic parts (A, A?) in a welding machine of the type comprising two pairs of clamping dies (2, 2?) mounted respectively on a fixed frame (1) and on a mobile frame (1?) for contacting rear (3) and front (3?) ends of both parts (A, A?) and the flow of an electric welding current. According to the invention, on the one hand a set of electric parameters including at least the voltage (Us) and the intensity (Is) of the welding current and on the other hand the relative position of the mobile frame (1?) with respect to the fixed frame (1) are measured at any moment and the travel of the mobile frame (1?) is regulated in position from at least one of the measured value of said electric parameters, in order to control the closing-in speed v(t) of the ends (3, 3?) of both parts (A, A?) taking in account the progress of the welding process, during at least a portion thereof.

Abstract: An improved apparatus and method for the prevention of deformation and buckling of metal plates during welding processes is disclosed. The improved apparatus and method are used to apply pressure to a welded seam created between two metal plates during the welding process. Pressure is applied to the area of the plates surrounding the welded seam until the welded seam has sufficiently cooled to prevent deformation and buckling of the metal plates.

Abstract: A method of securing a cap on a piston body includes forming a first annular V-shaped surface at an open end of a cylindrical piston body; forming a second annular V-shaped surface on an annular surface of an oil conduit in the interior center of the piston body; forming a cap to close the open end of the piston body and forming a pair of annular surfaces therein which are flat in shape and in contact with first and second annular V-shaped surfaces on the piston body; placing the cap over the open end of the piston body and thereby placing the annular surface on the cap and the body in close intimate contacting relation; and welding the respective annular surface of the cap and the piston body together by subjecting the cap and body to an extreme high current density to fuse respective contacting annular surfaces together.

Abstract: A welding device for butt welding of bars as well as blooms, slabs, or billets produced by continuous casting, includes a roller conveyor for simultaneous conveying of at least two bars along a rolling line, jaws for gripping the bars, and electric power supplies which are set in contact with the surfaces of the two bars for carrying out a welding operation. The electric power supplies are provided with respective positioning and actuating devices controlled to actuate them independently from one another during setting in contact and detachment of the bars.

Abstract: A welding device for butt welding of bars, blooms, slabs, or billets produced by continuous casting comprises a roller conveyor for simultaneous conveying of at least two bars along a rolling line, jaws for gripping bars, electric power supplies which are set in contact with the surfaces of the two bars, for carrying out a welding operation. The electric power supplies are provided with respective positioning and actuating means, controlled by an actuation device which actuates them independently from one another during setting in contact and detachment of the bars.

Abstract: A method for producing rotational-symmetrical sheet metal articles with double-curved shape and varying thickness, particularly rocket nozzles, in which a number of sheet metal part-blanks in flat condition are cut to partially circular ring-like shape, whereupon said part-blanks are bent to the desired curvature and welded together to form a blank of the article for final machining.

Abstract: An apparatus for welding fluoropolymeric pipe liners together comprising: a plate having first and second opposing surfaces, the first and second opposing surfaces facing away from each other; a temperature-resistant coating overlaying at least one of the opposing surfaces; and means for heating the first and second opposing surfaces. A method for joining fluoropolymeric liners using the apparatus of the present invention is also disclosed.

Abstract: A method for making a spacer assembly comprises: forming a plurality of projections along an edge of a portion of sheet metal; roll forming the portion of sheet metal into a tubular configuration; positioning the roll formed portion of sheet metal and a metal base member to which the roll formed portion of sheet metal is to be welded in a discharge welding apparatus having a pair of electrodes so that the projections of the roll formed portion of sheet metal contact a surface of the metal base member; providing a force so that the projections are disposed in forcible engagement with the surface of the metal base member; and supplying an electrical current between the pair of electrodes and through the roll formed portion of sheet metal and the metal base member so that the projections reach a molten metal stage and are subsequently solidified to enable the roll formed portion of sheet metal to be welded to the metal base member.

Abstract: An improved method for welding and passivation forms a chromium oxide passivated film over the welded portion during the welding process. In a shielding step, a backshield gas, preferably argon, is flowed around the welding site. In a welding step, an arc gas, preferably argon with approximately 10% hydrogen and less than 1 ppm moisture content, is flowed through the welding head and a welded joint is formed, for example by high speed tungsten-inert gas (TIG) orbital welding. In the passivation step, a process gas, preferably argon with approximately 30-100 ppm of oxygen and less than 1 ppm moisture content, and preferably less than 1 ppb moisture content, is flowed over the welded portion to form a chromium oxide passivated film on the welded portion. The process gas is passed through a gas purifier prior to being flowed over the welded portion to maintain its moisture level at less than 1 ppb.

Abstract: The system of the present invention includes a homopolar generator, a hydraulic uniaxial press to hold the metal alloys to be welded, and electrical connections set at selected distances from the weld interface to provide a desired cooling rate for metal alloys being welded. A method is disclosed for determining a cooling rate for a metal alloy pipe in an electrical resistance welding process in a homopolar welding system following the resistive heating of a weld interface by discharging energy from a homopolar generator through electrodes attached to each of first and second pipes to form a welded pipe segment. The temperature of the welded pipe segment is measured at periodic time intervals to determine a cooling rate for the welded pipe segment. A desired range for the cooling rate may be determined by adjusting the electrode gap for repeated samples and analyzing the resulting metallurgical properties for each sample.

Abstract: An improved welding process in which two metallic pieces are each composed of weld compatible parent metal, one metallic piece has one surface and the other metallic piece has another surface each having prominences positioned thereon and an oxide of parent metal disposed on the overlying surfaces and prominences including the steps of applying a force along longitudinal axis of metallic pieces to position the prominences to abut; applying a force transverse to the longitudinal axis of one metallic piece providing relative movement in first and second directions transverse to the longitudinal axes, causing displacement to the cross sections of the metallic pieces, moving one surface transverse relative to other surface and the longitudinal axis; and causing an electrical current to pass through metallic pieces elevating temperatures with electric resistance heating for thermal-fusion welding by the relative movement.

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

Abstract: This method of electric welding metal band ends together comprises a fusion cycle with the introduction of inert gas, a cooling cycle with the introduction of cooling air, and an annealing cycle. The method is carried out in a fusion head having grippers to manipulate the band ends, and a control system for the grippers, inert gas, cooling air, welding and annealing currents and timing functions.

Abstract: A method is provided for manufacturing a clad tube comprising a metallic tube coated on the interior surface with a thermally deformable coating material, comprising:(a) coaxially positioning the metallic tube within a cylindrically formed induction coil;(b) coaxially positioning a tube of the coating material within the metallic tube;(c) applying a current to the induction coil such that the induction coil serves as a heater and heats the metallic tube which in turn radiantly heats the tube of coating material to a temperature sufficient to make the coating material deformable; and(d) applying pressure on the interior of the tube of coating material such that the softened tube of coating material deforms to contact and fuse with the interior surface of the metallic tube to form a clad tube. The coating material can be, for example, glass or a thermally deformable resin. Optionally, a magnetic tube can be inserted into the interior of the tube of coating material.

Abstract: A flash-butt resistance welding process including a flashing of parts being welded and their upsetting. The direction of speed of motion of the parts during flashing is changed by converging and diverging them. The parts being welded are converged up to the moment when the total resistance of elementary contacts arising between the flashed surfaces of the parts becomes equal to 0.4-0.5 of the short-circuit impedance of the welding machine. Then the parts are diverged up to the moment when the summary resistance of elementary contacts reaches 1.4-1.6 of the short-circuit impedance of the welding machine.