Abstract: Method of assembly of a first element (I) and a second element (II) each having an assembly surface, at least one of the assembly surfaces comprising recessed metal portions (6, 106) surrounded by dielectric materials (4, 104) comprising: A) a step to bring the two assembly surfaces into contact without application of pressure such that direct bonding is obtained between the assembly surfaces, said first and second assemblies (I, II) forming a stack with a given thickness (e), B) a heat treatment step of said stack during which the back faces (10, 110) of the first (I) and the second (II) elements are held in position so that they are held at a fixed distance (E) between the given stack thickness+/?2 nm.

Abstract: A method of bonding superalloys is provided. The method includes: aligning a first superalloy subcomponent having a gamma-prime solvus g?1 and a second superalloy subcomponent having a gamma-prime solvus g?2, with a filler material that includes at least 1.5 wt % boron disposed between the first and second superalloy subcomponents; performing a first heat treatment at a temperature T1, where T1 is above the solidus of the filler material and below the liquidus of the filler material; and performing a second heat treatment at a temperature T2, where T2 is greater than T1, and where T2 is greater than or equal to the lower of g?1 and g?2.

Abstract: An apparatus and method for heating a pipe prior to performing a welding operation, an interpass welding operation, a hydrogen bake-out operation of a weld joint or for post heat-treating of a weld joint is provided. The heating apparatus can include at least one heating collar placed around a pipe or weld joint, and a controller unit for controlling the thermal heat energy transferred from the heating collar to the pipe or weld joint.

Abstract: A splicing apparatus for joining a trailing end of a downstream metal strip to the leading end of an upstream metal strip includes a base having a working surface, a cover assembly operatively connected to the base and movable between an open position and a closed position, a fixed platen fixedly secured to the working surface, a moving platen slidably connected to the working surface, and a laser device for both cutting said downstream and upstream metal strips and for welding said metal strips together, the laser device including a laser source and a laser head in communication with the laser source, the laser head being connected to said cover assembly.

Abstract: A process is provided for producing a rotor which is made by welding together disk-shaped and/or drum-shaped elements, in particular disks, wherein a device is used to join the disks together axially in sequence along a longitudinal axis and the disks are welded in a two-stage welding process. As they are joined together, the disks are stacked axially in the vertical direction. A first welding process takes place in a vertical orientation of the stacked disks, followed by a second welding process in a horizontal orientation of the stacked disks.

Abstract: The present invention provides a heat treatment method comprising: welding a small diameter pipe (12) to a bonded joint (31) joined to a large diameter pipe (10), the small diameter pipe (12) having a diameter of 200 mm or less and a thickness of 15 mm or less, the large diameter pipe (10) having a diameter greater than that of the small diameter pipe (12); then heating the vicinity of the welded portion; and then cooling an inner surface of the pipes by use of coolant; wherein a distance between a heating area and the large diameter pipe (10) is equal to or greater than 70 mm. The heat treatment method can reduce the intention residual stress caused by welding or processing the pipes.

Abstract: A structural member comprising at least two aluminum alloy parts displaying different property balances, said at least two parts being welded and wherein one of said parts either is (i) selected from an aluminum alloy different from the other of said at least two parts and/or (ii) is selected from an initial temper different from the other of said at least two parts, and wherein at least one of said at least two parts has been pre-aged prior to being welded, and, wherein said structural member has undergone a post-welding thermal treatment conferring a final temper to each of said at least two parts. The parts are advantageously welded by friction stir welding. Another subject of the invention is a method for manufacturing a structural member.

Abstract: Providing a metal mold repair method and a metal mold repair paste agent which are capable of repairing cracks with simple work. A repair paste agent containing components that become an alloy is directly applied to a surface of a metal mold having a crack so as to cover the crack part, subsequently a surface of the repair paste agent is coated with an oxidation inhibitor and the repair paste agent is made to penetrate the inside of the crack by heating and becomes an alloy, thereby filling up the crack.

Abstract: A method in which no voids occur during the soldering processes is provided. A component with a soldering material is heated using a first temperature plateau for a first time duration such that the solder material is completely melted. Each subsequent heating is at a temperature plateau with a temperature that is lower than a temperature of the previous plateau.

Abstract: A method for soldering or welding components in a series production wherein: a fixing seam which connects the components (1, 2) is produced by melting a connecting material (3), which is supplied as an additional material or is formed by a base material of the components (1, 2), along a joint formed by the components (1, 2); and a volume-forming layer of connecting material is deposited onto the fixing seam by melting, or the fixing seam produced by means of the connecting material supplied as an additional material is re-melted.

Abstract: A unique heat treat method for relieving stresses caused by a repairing weld joint in a full hoop part heat treats locally, at the location of the weld joint, and at a diametrically opposed location. By providing the diametrically opposed heat treat location, the present invention relieves stresses caused by the weld joint, without creating any additional residual stress in the weld joint.

Abstract: A welded component includes at least one high temperature segment of a high alloy Cr steel with high creep strength and a low temperature segment of a low alloy steel with high toughness and/or a high yield strength which are connected materially to one another via a weld joint. In one such component a gradual transition of chemical, physical and mechanical properties in the joining area is achieved in that between the weld joint and the high temperature segment there are at least two successive clad layers of at least two lower alloy weld metals with a total content of elements which increase the creep strength, such as for example Cr, Mo, W and V, which total content decreases toward the weld joint, and/or an increasing total content of elements which increase the toughness and/or yield strength, such as for example Ni and Mn, which total content increases toward the weld joint.

Abstract: A method of welding connection is directed towards the construction and subsequent heat treatment of industrial grade manual tools and, specifically, their tool heads to handles or handle attachment connections. The method employs the use of matching, non-heat treated, compatible material such as steel alloys, for the tool heads and steel handles or attachment sockets. These components are welded together prior to their heat treatment, resulting in a superior weld joint without the normal annealing which occurs during welding. Such tools are, as a result, extremely resistant to bending or breaking under normal usage. With regard to spades and shovels, a stronger blade-to-handle junction is created, as no annealing takes place, compared to blades and handles which are first heat treated separately then welded together.

Abstract: The present invention provides a method for welding and heat-treating seam-welded constructions of hardenable steel and ferrous alloys with reduced weld-zone hardness and improved weld-zone ductility and toughness. This method consists of controlling the cooling rate of the seam weld with a secondary heat source, applied after the weld cools below the materials upper critical temperature (AC3), but prior to the weld cooling to ambient temperature. This invention is particularly suited to the production of high strength hardenable alloy seam-welded pipe and tubing.

Abstract: The present invention provides seam-welded, air hardenable steel tubes, methods of manufacturing seam-welded air hardenable steel tubes, tube mills for practicing such methods and applications for using seam-welded, air hardenable steel tubing of the present invention.

Abstract: A process is provided for crack-free welding a nickel based single crystal superalloy article containing at least 5 weight % total of Al and Ti. The process comprises: melting an article surface to be welded and a filler alloy with an energy source, preferably a laser, wherein the filler alloy is a composition of a nickel based single crystal superalloy except that the total of Al and Ti is reduced below 5 wt %; allowing the melted article surface and filler alloy to solidify to form a bead of deposit; providing a plurality of beads of adjacent deposits covering the article surface to be welded; and remelting the adjacent beads of deposits with the energy source to provide vertically oriented crystal growth in the deposits.

Abstract: Method for forming a weldment in a nickel based alloy substrate comprising subjecting the substrate prior to welding to a pre-heating step at an elevated temperature which is above ambient temperature and less than an aging temperature of the substrate.

Abstract: A novel process for manufacturing Solid-Solder-Deposit Printed Circuit Boards (SSD-PCBs) by directly melting dry solder powder over a bare-PCB 230 consequently forming relatively thick individual layers of solid solder over each soldering pad of said bare-PCB 230. Solid Solder Deposit (SSD) refers to a relatively thick layer of solid solder metallurgically bonded over the soldering pads of a bare-PCB 230 such as that said SSD-PCB by itself is the source for solder alloy during a subsequent soldering operation. The manufacture of SSD-PCBs provides the electronic assembly industry with ready-to-solder PCBs consequently eliminates the need to use solder paste at the assembly floor. This invention, unlike the prior art for producing SSD-PCBs, utilizes a dry solder powder pile 232 that is melted by localized heating.

Abstract: Described is a method for producing a diffusion bonded sputtering target assembly which is thermally treated to precipitation harden the backing plate without compromising the diffusion bond integrity. The method includes heat treating and quenching to alloy solution and artificially age the backing plate material after diffusion bonding to a target. Thermal treatment of the diffusion bonded sputtering target assembly includes quenching by partial-immersion in a quenchant and is performed after diffusion bonding and allows for various tempers in the backing plate.

Abstract: Disclosed is an Al alloy for a welded construction having excellent welding characteristics, which Al alloy comprises 1.5 to 5 wt % of Si (hereinafter, wt % is referred to as %), 0.2 to 1.5% of Mg, 0.2 to 1.5% of Zn, 0.2 to 2% of Cu, 0.1 to 1.5% of Fe, and at least one member selected from the group consisting of 0.01 to 1.0% of Mn, 0.01 to 0.2% of Cr, 0.01 to 0.2% of Ti, 0.01 to 0.2% of Zr, and 0.01 to 0.2% of V, with the balance being Al and inevitable impurities. Also disclosed is a welded joint having this Al alloy base metal welded with an Al—Mg- or Al—Si-series filler metal.

Abstract: A multi-element composite object composed from first, second, and third metal components is provided, wherein the first metal and the third metal are weld incompatible. The multi-element composite object includes a first component fabricated from a first metal. A second component, fabricated from a second metal, is brazed to the first component. A third component, fabricated from a third metal, is inertia welded to the second component. The first metal may be provided as a titanium alloy, e.g. a TiNi alloy. The second metal may be provided as low-carbon mild or alloy steel. The third metal may be provided as alloy steel, e.g., 9310 nickel alloy steel. In an embodiment, the multi-element composite object is a gear assembly, with the first element of the gear assembly object being a shaft and the third element of the gear assembly being a gear member with hardened teeth surfaces. The first and second components can be mechanically keyed together via an anti-rotational element.

Abstract: A semiconductor device manufacturing method comprises the steps of forming solder bumps on an underlying metal film of a semiconductor device, and placing the semiconductor device and the solder layer in a reduced pressure atmosphere containing formic acid to form the solder bumps. Accordingly, the solder bumps can be formed without flux generating voids in the solder layer. Furthermore, the cleaning required after the solder bumps are formed can be omitted.

Abstract: A process is provided for welding a nickel or cobalt based superalloy article to minimize cracking by preheating the entire weld area to a maximum ductility temperature range, maintaining such temperature during welding and solidification of the weld, raising the temperature for stress relief of the superalloy, then cooling at a rate effective to minimize gamma prime precipitation.

Abstract: The description relates to a procedure for fastening a carbide tooth (1) at a saw blade (2), with a carbide tooth (1) fabricated according to the saw tooth geometry being held butt-jointed to the prepared front-side abutting surface (3) of the saw blade (2) and then being attached to the saw blade under addition of heat along the joint (10) between the saw blade (2) and the carbide tooth (1). To create favorable process conditions it is suggested that the carbide tooth (1) is welded to the saw blade (2) by means a focal spot (9) of a laser beam (7) extending over the whole joint length.

Abstract: Described is a method for producing a diffusion bonded sputtering assembly which is thermally treated to precipitation harden the backing plate without compromising the diffusion bond integrity. The method includes heat treating and quenching to alloy solution and artificially age the backing plate material after diffusion bonding to a target. Thermal treatment of the diffusion bonded sputtering target assembly includes quenching by partial-immersion in a quenchant and is performed after diffusion bonding and allows for various tempers in the backing plate.

Abstract: A method of manufacturing a stainless steel ventilated brake disc is provided that results in a relatively inexpensive stainless steel ventilated brake disc. In manufacturing the ventilated brake disc a pair of annular plate members are provided that are constructed of stainless steel. Then a spacing member constructed of stainless steel is inserted between the inner axially facing surfaces of the first and second annular plate members. A nickel bonding paste is applied at the points of contact between the spacing member and the inner axially facing surfaces of the first and second annular plate members. Heat is now applied to the spacing member and the annular plate members as a combined unit with the nickel bonding paste applied thereto. This heating of the assembled unit austenitizes the spacing member and the annular plate members and simultaneously bonds the spacing member to the inner axially facing surfaces of the annular plate members.

Abstract: The method provides a diffusion-bonding of dual-phase stainless steel material having excellent strength and corrosion. The method includes: cold-working a material to be bonded so as to enhance the proof stress; inserting into the bonding portion an insert material; applying pressure thereto while performing shielding by mixed nitrogen/argon gas; heating the restricted bonding portion; cooling at a restricted rate; so as to form a bonded portion having the ferritic phase percentage of 30-70% by volume.

Abstract: A vane member comprises a first member and a second member, the first member and the second member are joined by that an insert member whose melting temperature is lower than melting temperatures of the first and second members contacts the first and second members, the insert member is heated to a welding temperature which is lower than the melting temperatures of the first and second members and is higher than the melting temperature of the insert member so that a mutual diffusion between at least an original base component of the insert member and at least an original base component of the first member different from the original base component of the insert member and a mutual diffusion between at least the original base component of the insert member and at least an original base component of the second member different from the original base component of the insert member are caused by the heating, and the mutual diffusions by the heating are continued at least until the original base component of the i

Abstract: A surface metal plate 2 made of aluminium or aluminium alloy is overlayed upon a backing metal plate 1 and integrally bonded by cold rolling bonding of a rolling machine 30. After that, the thus obtained composite metal plate 3 is annealed, so that the bonding strength between a surface metal layer 1a having a thickness of 2 to 8 mm and a backing metal layer 2a is enhanced.

Abstract: A method for increasing the strength of a solder joint between a nickel-iron lead frame of an electronic circuit module and a copper pad of a printed circuit board on which the module is mounted includes baking the joint for at least one hour at a temperature in the range 373K to 456K. The baking step is found to significantly increase the strength of the joint.

Abstract: The method of forming a seamed metal tube having a metal coating of this invention includes applying a metal coating to the upper face of a metal strip prior to welding. The strip is then formed into an open seam tube and welded, preferably in a non-oxidizing atmosphere with the seam preferably located in the lower portion of the tube. Finally, at least a lower portion of said tube is reheated with the seam located in the lower portion of the tube, thereby causing the metal coating to flow downwardly over the seam, coating the seam. In one embodiment, the strip is preformed into an arcuate shape and coated, wherein the metal coating increases in thickness toward the lateral strip edges, such that the coating will flow over the seam following welding. The inside coated seamed tube may also be immersed in a galvanizing or metal coating bath to coat the outside of the tube.

Abstract: A process for providing a significant improvement in the detrimental tensile residual stress condition on the root side of welds, especially on the inside wall of piping welds. The method uses a high welding torch travel speed (>10 inches/min), especially on the last one or two cap passes. The process relies on the limited thermal heat sink capability of the pipe wall and nearly completed weld joint itself to generate a significant through-wall temperature gradient, and therefore a sufficient through-wall stress gradient during the welding. This stress gradient results in metal plasticity and permanent strains, and therefore a reduction in the magnitude of the final residual stress or, preferably as conditions allow, a reversal in the direction of the stresses from tensile to compressive. The method can be used as a welding process or as a heat treatment. In the case of heat treatment, the far surface of the weld joint is heated without fusion of the material making up the far surface.

Abstract: A welding material for hard-facing which is to be hardened by a supercooling treatment after overlaying onto a cast iron base metal has a basic component composition which meets, in an overlaid condition, both a first condition and a second condition. The first condition is that a nickel (Ni) equivalent and a chromium (Cr) equivalent fall within that region to be defined in Schaeffler's structure diagram in which a difference in hardness before and after the supercooling treatment is a predetermined value or above. The second condition is that a starting temperature of martensitic transformation is a predetermined temperature or below.

Abstract: A gas knife cooling system for reflow soldering cools soldered articles by impinging a gas flow directly on the articles and as a result uses less cooling gas. A heater is associated with the cooling system to remove flux deposits. The cooling system is installed in the cooling section of a reflow soldering apparatus and comprises at least one gas knife to direct a gas stream at soldered products passing through the cooling section on a conveyor. A heater is associated with the gas knife which is activated for predetermined cleaning cycles to heat the gas knife to a temperature above flux vaporization temperature of flux deposits from the soldered products.

Abstract: A mold (1) has two molding members (4, 6) each comprising two plates (11, 13; 15, 17) secured to one another. In the contact surface of one of the plates (13, 15) a groove (19) has been provided to form a cooling duct. In order to reduce the dimensions of such a molding member (4, 6) the two plates (11, 13; 15, 17) are secured to one another by means of a soldering process. In comparison with the known method of securing the plates of a molding member to one another by means of bolts this method has the advantage that no screwthread has to be provided in the plates and no additional sealing, for example by means of an O-ring, has to be provided between the plates in order to seal the cooling duct. As a result of this, the plates can be thinner so that the molding members (4, 6) and the mold (1) can be smaller.

Abstract: A process of preparing clad contact material comprises forming a contact belt-like member by bonding an Au or Au alloy tape to the surface of an Ag or Ag alloy tape, thermally treating that contact member for forming an Au diffusion layer, and cladding that contact member having the Au diffusion layer to a base belt-like member made of Cu or a Cu alloy. Since, according to the process, the thermal diffusion treatment is carried out before the contact belt-like member is set in the base belt-like member, the thermal diffusion treatment of the contact belt-like member can be performed in the most suitable conditions for obtaining an Au diffusion layer with excellent characteristics, and no dissolution may occur at the interface between the two belt-like members.

Abstract: The method of forming a coated seamed metal tube of this invention is particularly, but not exclusively adapted to existing continuous tube forming mills, wherein the tube is formed from a metal strip and welded with the seam located in an upper portion of the tube. In the process of this invention, at least one surface of the strip is coated with a metal coating prior to forming and welding. The tube is then turned to relocate the welded seam in a lower portion of the tube and the lower portion of the tube is then reheated to melt the metal coating and the metal coating then flows downwardly over and coating the welded seam. In the most preferred continuous or in line process of this invention, the tube is continuously spirally twisted following welding to locate the seam in a lower portion of the tube adjacent a heater and the tube is then heated by the heater to the melting temperature of the metal coating, causing the coating to coat the seam.

Abstract: A method of producing an aluminum alloy heat-exchanger is disclosed, wherein, upon producing an aluminum alloy heat-exchanger by soldering technique, it is retained for 10 minutes to 30 hours at 400.degree. to 500.degree. C. after finishing a heating for soldering. It is better to retain the heat-exchanger during cooling. Alternatively, the heat-exchanger may be cooled to 150.degree. C. or lower and reheated to 400.degree. to 500.degree. C. for at least 10 minutes to up to 30 hours. Furthermore it is preferable to cool at a cooling velocity of not slower than 30.degree. C./min across a temperature range from about 200.degree. C. to about 400.degree. C. after the retainment. Excellent thermal efficiency, high strength and excellent corrosion resistance can be achieved this way.

Abstract: The present invention provides a new and improved titanium metal drum cathode for use in the production of metal foils and a novel method of making the same. The method includes the steps of welding together the ends of a strip of titanium that has been roll formed into a cylinder. During the welding operation some of the weld beads that form the weld are hot peened immediately upon solidification. Upon complete formation of the weld, the formed and welded trip of titanium is subjected to a heat treating cycle that includes a double anneal. Preferably, the strip of titanium metal and the weld metal that is used to form the weld both comprise an addition agent such as yttria.

Abstract: A metallic press die having an edge portion or high pressure portion for processing a workpiece therewith is made by overlaying a welding material to that portion of a base material for the metallic press die which forms the edge portion or high pressure portion, and then machining an overlaid portion into a predetermined shape of the edge portion or high pressure portion. The welding material has a hardness after welding of HRC 45 or below. After the machining step, the overlaid portion is subjected to a subzero treatment to increase the hardness of the overlaid portion. The welding material contains, as a basic composition thereof, 0.5-1.5% by weight of carbon (C), 0.2 -2.0% by weight of silicon (Si), 0.3-6.0% by weight of manganese (Mn), 0.3-10.0% by weight of chromium (Cr), 0.3-10.0% by weight of cobalt (Co), and the remaining parts of iron (Fe) inclusive of unavoidable impurities, and wherein a starting temperature of martensitic transformation is 150 .degree. C. or below.

Abstract: A secondary coil for a linear motor, which is a composite metal plate comprising a backing metal layer 1, an intermediate bond metal layer 2 and a surface metal layer 3 which are integrally connected, the intermediate bond metal layer being formed of aluminum or aluminum alloy, the surface metal layer being formed of copper or copper alloy having a thickness of 2 to 8 mm. A copper plate or a copper alloy plate for the surface layer and an aluminum plate or an aluminum alloy plate for the intermediate layer are placed on each other and connected by rolling. The surface-layer metal plate with the bond layer is placed on a metal plate for the backing metal layer, with the bond layer being contacted with the metal plate for the backing metal layer, and two plates are connected by rolling.

Abstract: The method of forming a seamed metal tube having a metal coating of this invention includes galvanizing the strip prior to welding. The strip is then formed into an open seam tube and welded in an inert atmosphere with the seam located in the lower portion of the tube. Finally, the metal coating is caused to flow downwardly over the seam, coating the seam by several means. In one embodiment, the strip is preformed into an arcuate shape and galvanized, wherein the zinc coating increases in thickness toward the lateral strip edges, such that the coating will flow over the seam following welding. The tube may also be reheated following welding, preferably in an enclosure containing an inert atmosphere which includes the weld apparatus. In another embodiment, an inert gas is directed over the inner and outer surfaces of the tube, adjacent the seam, driving the molten metal downwardly over the seam to coat the seam.

Abstract: Disclosed is a welded tube with an excellent corrosion-resistant inner surface, in which the inner surface including the bead part has a first plate layer of one metal material selected from Sn, Sn--Zn, Sn--Ni, Ni--P and Ni--B and the first plate layer is overcoated with a second plate layer of one metal material selected from Ni, Co and alloys based on the metals. The welded tube is free from exposure of the steel base out of the plate layer and is also free from cracks, pin holes, overplated spots and peeling of the plate layer. It has excellent corrosion resistance and good workability for working the terminals. The welded tube is produced by forming a first plate layer of Sn, Sn--Zn, Sn--Ni, Ni--P or Ni--B on at least one surface of a steel strip, then forming a second plate layer of Ni, Co or an alloy based on the metals over the first plate layer, shaping the thus plated steel strip into a tube by welding with the plated surface being inside and then heat-treating the tube.

Abstract: An improved welding method is provided for repairing rotating shafts, particularly cracked high pressure steam turbine rotors. The welding method preferably employs a 2.25Cr--1.0Mo--0.3V-type welding filler metal, preferably deposited using a narrow groove automatic gas tungsten arc welding technique. A narrow groove is formed in the rotor to remove the crack. The groove is preheated, filled with the welding filler metal, and postheated, resulting in a strong, high temperature resistant, long lasting weld.

Abstract: A method of joining metal materials by spraying molten metal into a cavity between the articles to be joined. Prior to deposition of the metal, the surface of the cavity is cleaned and the articles to be joined are preheated. Subsequent to deposition of the metal within the cavity, the joined articles are cooled at a rate that precludes damage due to thermal effects and the deposited metal is consolidated in the cavity by hot pressing.

Abstract: The present invention relates to a process for the manufacture of zirconium based tubes formed from layers of varying composition. The process consists in preparing the tubular blank which is intended to form the outer layer of the tube by rolling-soldering a sheet, and then in fitting it onto another tubular blank, or core block, of smaller diameter, which is obtained by piercing a small bar, and which may be coated on the inside with a plating, in soldering the ends of said blanks in order to subject the assembly to a treatment of placing it in solution in a beta phase, followed by soaking it in water and drawing it. The invention is used for the production of Duplex or Triplex type tubes with an improvement in the gross weight of zirconium needed to make 1000 kg of useful metal, with good adherence being obtained between the layers of said tube.

Abstract: A wire mesh face mask for hockey or other sports is manufactured from a steel having carbon content in the range of AISI grades C-1018 to C-1038, and preferably C-1022. The mask is made by forming a grid of generally horizontal wires overlaid by generally vertical wires, shaping the grid into a mask shape, welding the wires to each other where they intersect, heat treating and quenching the grid to increase hardness, dipping the grid to coat it with an epoxy coating. This combination of materials and processes permits the use of a thinner wire than has previously been possible in face masks.

Abstract: In a manufacturing method for a semiconductor device, first, a diffused layer of a soldering material is provided previously either on the reverse surface of a die or on the obverse surface of a die pad. Then, a diffusing layer is formed on either surface of the diffused layer. The diffusing layer between the die and the die pad is brought into contact with the die and die pad, and then these components are heated. The die is thereby and fully bonded to the die pad, even when the diffusing layer, which is an initial bonding layer, is made thinner. Because the time for the diffusing layer to diffuse can be shortened, the time for installing the die can also be shortened.

Abstract: A method and an apparatus for friction welding two elements together are disclosed in which the areas of the two elements to be welded are heated by an induction heater. The induction heater may be used to heat the areas to be welded prior to contact between the elements, during such contact, and after the friction welding has been achieved in order to provide a heat treatment of the welded zone. The induction heater is generally annular in shape and may be dimensioned so as to be located around the elements at the welding zone, or to be placed between the surfaces of the elements to be welded together.

Abstract: The method of forming a seamed metal tube having a metal coating of this invention includes galvanizing the strip prior to welding. The strip is then formed into an open seam tube and welded in an inert atmosphere with the seam located in the lower portion of the tube. Finally, the metal coating is caused to flow downwardly over the seam, coating the seam by several means. In one embodiment, the strip is preformed into an arcuate shape and galvanized, wherein the zinc coating in creases in thickness toward the lateral strip edges, such that the coating will flow over the seam following welding. The tube may also be reheated following welding, preferably in an enclosure containing an inert atmosphere which includes the weld apparatus. In an other embodiment, an inert gas is directed over the inner and outer surfaces of the tube, adjacent the seam, driving the molten metal downwardly over the seam to coat the seam.