Abstract: The present invention relates to a method of manufacturing formed aluminum components. The method comprises the steps: i. Providing a hollow profile of aluminum or aluminum allow, the profile having a predetermined length and comprising an outer wall having a pre-determined thickness; ii. Placing a hollow aluminum profile in a cavity of a bending tool and press bending the profile using the bending tool; and iii. Transferring the profile to a cavity of a forming tool and subjecting the interior of the profile to elevated gas pressure, whereby the section of the profile is distended until the outer wall of the profile abuts the forming tool, thereby providing a formed aluminum component; wherein the steps ii. and iii. are performed at a tool temperature of 350-470° C. The present invention further relates to formed aluminum components manufactured by such a method.

Abstract: A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.

Abstract: A stabilizer formed by using a metal bar having a solid structure and configured to reduce a displacement between right and left wheels, including a torsion part extending in a vehicle width direction, being capable of a torsional deformation, and having a diameter of 10 to 32 mm, is provided. The stabilizer has a chemical composition containing at least C: 0.15% by mass or more to 0.39% by mass or less, Mn, B, and Fe, and also has a metal structure 90% or more of which is a martensite structure.

Abstract: A first method is disclosed for forming a tubular reinforcement that comprises the steps of: providing a 7xxx aluminum tube, heating tube to at least 450° C. and water quenching the tube in less than or equal to 20 seconds after heating. All of the forming processes on the tube are then completed from within 1 to 8 hours of quenching. A second method for forming a tubular reinforcement is disclosed that comprises the steps of providing a 7xxx-O temper aluminum tube and forming the tube into a predetermined shape. The tube in then heated the tube to at least 450° C. and quenched the tube with water or air in a hydroforming die just prior to or while hydroforming the tube.

Abstract: The example methods and apparatus reduce and/or eliminate adverse effects of welding work pieces having dissimilar compositions. An example method includes depositing a first weld layer on a first end of a first work piece. The first work piece has a first content of a metallic element and the first weld layer has a second content of the metallic element higher than the first content. The example method includes depositing a second weld layer between the first weld layer and a second end of a second work piece to couple the first work piece to the second work piece. The second weld layer has a third content of the metallic element higher than the second content, and the second work piece has a fourth content of the metallic element higher than the first content.

Abstract: A disclosed forming system is a forming system which expands and forms a metal pipe in a die. The forming system includes a preliminary forming apparatus which preliminarily forms a metal pipe material, a forming apparatus which includes a gas supply unit which supplies gas into the preliminary-formed and heated metal pipe material to expand the metal pipe material and a main body portion to which the die is attached, and a cutting device which cuts at least a portion of the formed metal pipe. The gas supply unit is provided so as not to be disposed on a first straight line which connects the preliminary forming apparatus and the main body portion in a plan view and a second straight line which connects the cutting device and the main body portion in a plan view.

Abstract: The present disclosure is directed to a method and system for monitoring hydrogen-induced cracking in at least one test specimen. The method includes the steps of: saturating a test solution with a gas comprising H2S and delivering the saturated test solution into a test cell, wherein the test cell comprises at least one specimen port and at least one test specimen. The specimen port is configured to receive the test specimen. The method also includes the step of exposing the at least one test specimen to the saturated test solution, wherein only one surface of each specimen is exposed to the saturated test solution and the step of scanning the test specimen with a ultrasonic transducer at two or more time points, wherein the ultrasonic transducer is operatively connected to the specimen port and configured to rotate completely around the symmetry axis of the test specimen to complete each scan.

Abstract: The present disclosure is directed to a method and system for monitoring hydrogen-induced cracking in at least one test specimen. The method includes the steps of: saturating a test solution with a gas comprising H2S and delivering the saturated test solution into a test cell, wherein the test cell comprises at least one specimen port and at least one test specimen. The specimen port is configured to receive the test specimen. The method also includes the step of exposing the at least one test specimen to the saturated test solution, wherein only one surface of each specimen is exposed to the saturated test solution and the step of scanning the test specimen with a ultrasonic transducer at two or more time points, wherein the ultrasonic transducer is operatively connected to the specimen port and configured to rotate completely around the symmetry axis of the test specimen to complete each scan.

Abstract: A method of producing a metal pipe which can suppress quenching defects is provided. In the method, a bend of the metal pipe is straightened by a straightening machine 10. Next, both pipe end portions of the metal pipe whose bend has been straightened are cut off by a pipe cutting apparatus 20. Next, a plurality of the metal pipes whose both pipe end portions have been cut off are aligned in the axial direction thereof to be conveyed to a quenching apparatus 30, and the metal pipes are quenched by being cooled after being heated by induction heating.

Abstract: A cross member system for a coupling device of a motor vehicle includes a tubular cross member, which extends between two lateral fastening consoles and a coupling mounting, which is connected with the cross member in a central section of the cross member. The cross member has a varying cross sectional course in longitudinal direction and is formed from a cut-to size-plate by a U/O-forming and is longitudinal seam welded. A central section of the cross member has a polygonal cross section. The cross member further has lateral end sections with a cross section which deviates from the polygonal cross section.

Abstract: A method for improving a residual stress in a pipe includes improving the residual stress in the inner surface to the compressive direction by rapid cooling of the inner surface after heating of the pipe. The heating is to heat a vicinity of a welded part of the pipe from the outer surface to raise the temperature to a construction temperature. The rapid cooling is to rapidly cool the inner surface in the vicinity of the welded part by supplying cooling water into the pipe. The heating and the rapid cooling are repeated twice or more. A method for construction management includes determining whether construction has been executed properly based on a maximum value of a lowering rate of an outer surface temperature of the pipe when the cooling water is supplied for the rapid cooling of the inner surface and a thickness of the pipe in a measuring position of the outer surface temperature.

Abstract: A method for making a tube is described in which a multi-layer billet is extruded to provide a tube having a wall comprising an inner layer metallurgically bonded to an outer layer.

Abstract: Apparatus and method are provided for making the longitudinal temperature distribution of the bulbous end of a longitudinally oriented workpiece, such as a rail's head, generally uniform when the head has a non-uniform longitudinal temperature distribution. A combination of crown and skirt electric inductors is used to achieve the generally uniform temperature distribution by modulating the magnetic field intensity produced by current flow through one or more of the combination of crown and skirt inductors as required for the non-uniformly heated regions of the rail's head.

Abstract: A high-strength welded steel pipe is obtained by welding a seam weld portion of a steel plate that are formed in a pipe shape. In the high-strength welded steel pipe, a base metal of the steel plate includes, by mass %, C: 0.010% to 0.080%, Si: 0.01% to 0.50%, Mn: 0.50% to 2.00%, S: 0.0001% to 0.0050%, Ti: 0.003% to 0.030%, Mo: 0.05% to 1.00%, B: 0.0003% to 0.0100%, O: 0.0001% to 0.0080%, N: 0.006% to 0.0118%, P: limited to 0.050% or less, Al: limited to 0.008% or less, and the balance of Fe and inevitable impurities, Ceq is 0.30 to 0.53, Pcm is 0.10 to 0.20, [N]?[Ti]/3.4 is less than 0.003, the average grain size of the prior ? grains in heat affected zones in the steel plate is 250 ?m or less, and the prior ? grains include bainite and intragranular bainite.

Abstract: The present invention provides a thick welded steel pipe excellent in low temperature toughness in which contents of Mn and Mo satisfy (Expression 1) below, Pcm obtained by (Expression 2) below is 0.16 to 0.19, and a metal structure of a base material steel plate consists of ferrite being 30 to 95% in an area ratio and a low temperature transformation structure, and in a metal structure of a coarse-grained HAZ, an area ratio of grain boundary ferrite is 1.5% or more, the total area ratio of the grain boundary ferrite and intragranular ferrite is not less than 11% nor more than 90%, an area ratio of MA is 10% or less, and its balance is composed of bainite. 1.2325?(0.85×[Mn]?[Mo])?1.5215??(Expression 1) and Pcm=[C]+[Si]/30+([Mn]+[Cu]+[Cr])/20+[Ni]/60+[Mo]/15+[V]/10??(Expression 2).

Abstract: An Fe—Ni alloy pipe stock containing, by mass %, C?0.04%, Si?0.50%, Mn: 0.01 to 6.0%, P?0.03%, S?0.01%, Cr: 20 to 30%, Ni: 30 to 45%, Mo: 0 to 10%, W: 0 to 20%, with Mo(%)+0.5W(%): more than 1.5% to not more than 10%, Cu: 0.01 to 1.5%, Al?0.01% and N: 0.0005 to 0.20%, and the balance being Fe, with 1440?6000P?100S?2000C?1300, Ni+10(Mo+0.5W)+100N?120, (Ni?35)+10(N?0.1)?2(Cr?25)?5(Mo+0.5W?3)+8?0, can be manufactured into a seamless pipe by use of a Mannesmann piercing and rolling mill because of its excellent inner surface properties. The resulting seamless pipe has excellent mechanical properties and moreover has excellent corrosion resistance in a sour gas environment.

Abstract: This high-strength steel pipe includes, by mass %, C: 0.02% to 0.09%, Mn: 0.4% to 2.5%, Cr: 0.1% to 1.0%, Ti: 0.005% to 0.03%, Nb: 0.005% to 0.3%, and a balance consisting of Fe and inevitable impurities, in which Si, Al, P, S, and N are limited to 0.6% or less, 0.1% or less, 0.02% or less, 0.005% or less, 0.008% or less, respectively, the bainite transformation index BT is 650° C. or less, and the microstructure thereof is a single bainite microstructure including first bainite and second bainite, the first bainite being a gathered microstructure of bainitic ferrite including no carbide, and the second bainite being a mixed microstructure of bainitic ferrite including no carbide and cementite between the bainitic ferrites.

Abstract: A steel pipe blank having a composition containing 0.5% or less C and 85% or more Fe in terms of mass percent is heated, and stretch-reducing is then performed so that the diameter decrease ratio is 15% or more and the rolling finishing temperature is (the Ar3 transformation point?10)° C. or lower. Consequently, a structure in which the ratio of X-ray diffraction intensity obtained from the plane in which the <100> direction of crystal grains is preferentially oriented parallel to the circumference direction and the <011> direction of crystal grains is preferentially oriented parallel to the rolling direction of the steel pipe to that obtained for a three-dimensionally randomly oriented sample is 3.0 or more is formed, and the r-value is increased, thereby improving the magnetic properties of the steel pipe.

Abstract: Disclosed is a concrete slurry transporting pipe for concrete pump-cars, which has improved wear resistance to friction with sands or gravels and impact resistance during transportation of concrete slurry. The pipe is a steel pipe made of carbon steel, and includes a heat-treated section having a hardness of Hv 450 or more and formed by induction-heating a portion of an inner or outer surface of the pipe, followed by cooling the heated portion of the inner or outer surface to harden the heated portion, and a non-heat treated section adjoining the heat-treated section. The heat-treated section and the non-heat treated section are alternately formed in a spiral band arrangement along a length of the pipe, and the heat-treated section has a greater width than the non-heat treated section.

Abstract: The invention relates to a method and a device which are used to heat materials in order to produce objects industrially, especially by mass production, and which allow a large variety of transformation methods.

Abstract: A bulging apparatus has a heating station, a tube expanding station, a preforming station, and a main forming station. A straight tube as a workpiece is gripped by first holding mechanisms or second holding mechanisms, and delivered between the stations as the first holding mechanisms or second holding mechanisms are displaced. During a preforming process and a main holding process, both the first holding mechanisms and second holding mechanisms can be lifted and lowered vertically and can be moved horizontally.

Abstract: A method of forming a dual chamber seamless tube (64) includes providing a slug of steel (56) and cold working a first end (70) of the slug (56) to form a first chamber (114) and cold working a second end (72) of the slug (56) to form a second chamber (116). The first and second chambers (114 and 116) are axially aligned and separated by a wall portion (126) of the tube (64).

Abstract: A method of fabricating a bare aluminum electrical conductor including a step of heat treating the conductor while wound on a winding form. The method comprises the step of coating the outer surface of the aluminum conductor with an inorganic powder material prior to winding the wire or cable on the winding form. The invention also relates to a method of protecting an aluminum conductor from damage during heat treatment and shipment when wound on a winding form. This method comprises providing a layer of aluminum or aluminum alloy between said conductor and parts of said winding form that would contact said wound conductor if not for said layer.

Abstract: A method of forming an elongated metal blank into a structural component having a predetermined outer configuration. The method includes providing a shape imparting cavity or shell section formed from a rigid material which includes an inner surface defining the predetermined shape, placing the metal blank into the cavity or shell section, and forming the metal blank into the component by heating axial portions of the metal blank and forcing a fluid at a high pressure into the metal blank until the metal blank at least partially conforms to at least a portion of the inner surface of the cavity or shell section to form the structural component.

Abstract: A method of forming an elongated tubular blank into a tubular structural component having a predetermined outer configuration, the method comprising: providing a shape imparting shell formed from a low permeability, rigid material which includes an inner surface defining the predetermined shape, plugging the open ends of the tubular blank, placing the plugged blank into the shell, and forming the tubular blank into the tubular component by inductively heating axial portions of the blank by axially spaced conductors adjacent the shell while or before forcing gas at a high pressure into the plugged blank until the blank conforms to at least a portion of the inner surface of the shell to form the structural component.

Abstract: A heat treatment apparatus includes a plurality of induction heating devices which heat a steel product, a correctional device which corrects the steel product, a computing device which computes supply predetermined electric power which is supplied to the induction heating device, on the basis of a size of the steel product, a conveying speed of the steel product, a heating target temperature of the steel product, and a predetermined temperature of the steel product at the previous stage of the induction heating devices, and a power supply unit which supplies the supply predetermined electric power computed by the computing device to the induction heating devices, and the computing device which computes electric power for uniform heating processing on the steel product or electric power for surface layer heating processing on the steel product.

Abstract: A method of forming an elongated tubular blank into a tubular structural component having a predetermined outer configuration, the method comprising: providing a shape imparting shell formed from a low permeability, rigid material which includes an inner surface defining the predetermined shape, plugging the open ends of the tubular blank, placing the plugged blank into the shell, and forming the tubular blank into the tubular component by inductively heating axial portions of the blank by axially spaced conductors adjacent the shell while or before forcing gas at a high pressure into the plugged blank until the blank conforms to at least a portion of the inner surface of the shell to form the structural component.

Abstract: A method of forming an elongated tubular blank into a tubular structural component having a predetermined outer configuration, the method comprising: providing a shape imparting shell formed from a low permeability, rigid material which includes an inner surface defining the predetermined shape, plugging the open ends of the tubular blank, placing the plugged blank into the shell, and forming the tubular blank into the tubular component by inductively heating axial portions of the blank by axially spaced conductors adjacent the shell while or before forcing gas at a high pressure into the plugged blank until the blank conforms to at least a portion of the inner surface of the shell to form the structural component.

Abstract: A vehicle structural beam, such as a door intrusion beam, which possesses an elongate tubular beam part which at opposite ends is provided with mounting flanges for securement to a vehicle frame. The elongate tubular beam part and the flanges provided at opposite ends are defined by an integral, one-piece, monolithic steel structure which has been initially roll-formed from an elongate flat metal sheet to define the closed tubular structure of the tubular beam part, and which has been subjected to heating and quenching so that the elongate tubular beam part is of relatively high strength steel throughout its entire length, whereas the integrally and monolithically joined end flanges remain as lower strength steel which has been significantly unaffected by the heat treatment and quenching so as to permit appropriate shaping thereof and ease of welding to the vehicle frame.

Abstract: Disclosed is a hardfacing alloy capable of withstanding abrasion of the order of silicious earth particles and weldable in crack free state on industrial products, such as tool joints and stabilizers used in oil and gas well drilling, and other industrial products. The hardfacing alloy has a low coefficient of friction, high abrasion resistance as welded without working, and in tool joints and stabilizers achieves an optimum balance between tool joint and stabilizer wear resistance and induced casing wear. Other embodiments of the invention include tool joints having the hardbanding alloy welded to the outer cylindrical surface to its box and pin members and to stabilizer ribs on the stabilizer used in earth boring, such as boring for oil and gas, other industrial products, methods of producing the hardfacing alloy, and methods of applying the hardfacing alloy to surfaces including preheat and post-welding conditions to withstand abrasive use.

Abstract: A method of forming an elongated tubular blank into a tubular structural component having a predetermined outer configuration, the method comprising: providing a shape imparting shell formed from a low permeability, rigid material which includes an inner surface defining the predetermined shape, plugging the open ends of the tubular blank, placing the plugged blank into the shell, and forming the tubular blank into the tubular component by inductively heating axial portions of the blank by axially spaced conductors adjacent the shell while or before forcing gas at a high pressure into the plugged blank until the blank conforms to at least a portion of the inner surface of the shell to form the structural component.

Abstract: A method of forming an elongated tubular blank into a tubular structural component having a predetermined outer configuration, the method comprising: providing a shape imparting shell formed from a low permeability, rigid material which includes an inner surface defining the predetermined shape, plugging the open ends of the tubular blank, placing the plugged blank into the shell, and forming the tubular blank into the tubular component by inductively heating axial portions of the blank by axially spaced conductors adjacent the shell while or before forcing gas at a high pressure into the plugged blank until the blank conforms to at least a portion of the inner surface of the shell to form the structural component.

Abstract: The method for coating the seam of a welded tube of this invention includes applying a mixture of the desired protective metal coating in powdered form and a liquid flux over the internal surface of the welded seam with the welded seam located in a lower portion of the tube, then heating the welded seam to the melting temperature of the protective metal coating, melting the metal coating which flows over the seam forming an adherent metallurgical bond. The preferred apparatus includes a wand which extends between the opposed edges of the open seam tube in the welding apparatus and extends axially through the tube to overlie the welded seam spaced from the welding apparatus. The wand includes three conduits transmitting the powdered protective metal coating, liquid flux and nonoxidizing gas to the applicator which includes a nozzle which atomizes and sprays the liquid flux over the internal surface of the seam and which combines with the powdered protective metal coating to form a paste.

Abstract: An improved method of coating the welded seam of a metal tube comprising heating the weld area only of the metal tube to a first temperature which is less than the melting temperature of the protective metal coating, applying the protective metal coating over the seam and heating the entire tube preferably with a full body induction coil to a second temperature which is at least equal to the difference between the first temperature and the melting temperature of the metal coating, such that the temperature of the seam area is heated to a temperature equal to or greater than the melting temperature of the metal coating, whereby the metal coating firmly adheres to the welded seam.

Abstract: A method of producing a welded steel pipe which comprises: (a) forming a steel strip having two edges in a cylindrical form so that the two edges face each other; (b) preheating the two edges of the steel strip to a temperature of a melting point or less by applying a high frequency electric current to the two edges; (c) pressing the two edges of the steel strip towards each other by contact with squeeze rolls to form a joint portion including a joint line; (d) radiating a high density energy beam sufficient to fuse a full thickness of the steel strip to a portion adjacent to a squeeze point to weld the joint portion; and (e) controlling an upset by applying the squeeze rolls sufficiently to reduce weld defects.

Abstract: A method for treating heat exchanger tubing to be expanded by fluidic or electromagnetic expansion. The tubing treatment reduces the increased material hardness of the tubing in areas where cold work has been imparted thereon. By reducing these areas which have increased material hardness, the tubing will have a substantially similar tube yield along its entire length and can therefore be expanded to substantially the same cross-sectional area throughout by either fluidic or electromagnetic expansion. After forming the cold work regions, the regions are annealed with a heat source, such as through flame or induction heating, and are gradually cooled to avoid the effects of quenching.

Abstract: A method of manufacturing nuclear fuel elements which include fuel rods whose cladding tubes are provided with an internal liner layer to obtain PCT resistance in the nuclear fuel element involves carefully choosing parameters for heat treatment of the inner component even from the machining of an ingot of the inner component. The internal layer of zirconium or a zirconium alloy, suitable as inner layer in a PCI-resistant cladding, from the fabrication of an ingot of the inner component up to the completion of a cladding tube, including forging, rolling, extrusion, heat treatment and final heat treatment, is manufactured in such a way that the temperature in the inner component never exceeds the temperature when an incipient phase transformation to beta phase takes place.

Abstract: A method and a system for heat treating an impact beam of an automotive vehicle door. Hot rolled steel sheets are prepared having a composition consisting essentially of 0.18% to 0.22% carbon; 1.0 to 1.5% manganese; 0.15 to 0.4% silicon; not more than 0.025% phosphorous; not more than 0.008% nitrogen; not more than 0.0010% sulfur; 0.01 to 0.04 aluminum; 0.001 to 0.003% boron; 0.1 to 0.3% chromium; 0.01 to 0.035% titanium; and the balance essentially iron, roll-forming and welding the steel sheets to make a tube-shaped impact beam. The heat treatment is carried out by high frequency induction heating and air cooling the impact beam, and water cooling the heat treated and air cooled impact beam.

Abstract: In a zirconium-alloy fuel element cladding, a method for generating regions of coarse and fine intermetallic precipitates across the cladding wall is provided. The method includes steps of specific heat treatments and anneals that coarsen precipitates in the bulk of the cladding. The method also includes at least one step in which an outer region (exterior) of the cladding is heated to the beta or alpha plus beta phase, while an inner region (interior) is maintained at a temperature at which little or no metallurgical change occurs. This method produces a composite cladding in which the outer region comprises fine precipitates and the inner region comprises coarse precipitates.

Abstract: A method for fabricating a composite cladding comprised of a moderate-purity metal barrier of zirconium metallurgically bonded on the inside surface of a zirconium alloy tube which improves corrosion resistance. The improved corrosion resistance of the liner is accomplished by suitable heat treatment of the Zircaloy-zirconium composite cladding to allow diffusion of alloying elements, notably Fe and Ni, from the Zircaloy into the zirconium, in particular, to the inner surface of the zirconium liner. This diffusion anneal reduces the undesirable tendency of zirconium liner to oxidize rapidly.

Abstract: A method of manufacturing corrosion resistant tubing from seam welded stock of a titanium or titanium alloy metallic material having a hexagonal close-packed crystal structure. The method includes cold pilgering a seam welded tube hollow having a weld area along the seam in a single pass to a final sized tube. The cold pilgering effects a reduction in cross sectional area of the tube hollow of at least 50% and a reduction of wall thickness of at least 50% thereby orienting the crystals in a radial direction. The method also includes annealing the final sized tubing at a temperature and for a time sufficient to effect complete recrystallization and reform grains in the weld area into smaller, homogeneous radially oriented grains. After the recrystallization annealing step, the tubing exhibits enhanced corrosion resistance which is similar to seamless tubing.

Abstract: A method of manufacturing corrosion resistant tubing from seam welded stock of a titanium or titanium alloy metallic material having a hexagonal close-packed crystal structure. The method includes cold pilgering a seam welded tube hollow having a weld area along the seam in a single pass to a final sized tube. The cold pilgering effects a reduction in cross sectional area of the tube hollow of at least 50% and a reduction of wall thickness of at least 50% thereby orienting the crystals in a radial direction. The method also includes annealing the final sized tubing at a temperature and for a time sufficient to effect complete recrystallization and reform grains in the weld area into smaller, homogeneous radially oriented grains. After the recrystallization annealing step, the tubing exhibits enhanced corrosion resistance which is similar to seamless tubing.

Abstract: An automobile body reinforcing steel pipe having a wall thickness-to-outer diameter ratio, t/D, defined by:0.09-4.8.times.10.sup.-5 .times.L.ltoreq.t/D.ltoreq.0.16-6.0.times.10.sup.-5 .times.Lwhere L(mm) is a span of a bending load applied to the pipe. The pipe has a tensile strength of 120 kgf/mm.sup.2 or more and an elongation of 10% or more, and is preferably made of a steel consisting of 0.15-0.25 wt % C, 1.8 wt % or less Mn, 0.5 wt % or less Si, 0.04 wt % or less Ti, 0.0003-0.0035 wt % B, and the balance of Fe and unavoidable impurities including 0.0080 wt % or less N. A process for producing the steel pipe comprises: coiling a hot rolled steel sheet at a temperature of 600.degree. C. or higher; electric welding the adjoining edges of the sheet to form a steel pipe; and quench hardening the pipe.

Abstract: A metal tube induction annealing apparatus employs an induction heating enclosure having an elongated glass tube encircled by an electromagnetic coil of an induction heating system which provides an induction annealing chamber for receiving a hollow metal tube for undergoing annealing and an inert purge gas for bathing the tube during annealing. Cooling stages are located end-to-end downstream of the induction enclosure for progressively cooling the annealed tube. The inert purge gas is made to flow upstream in a direction opposite to the downstream direction of tube movement through the annealing chamber and cooling stages for accomplishing constant bathing or shielding of the exterior and interior wall surfaces of the tube and removal of heat by inert purge gas flowing through and out of the trailing end of the tube.