A method and apparatus for producing gun barrels having a grooved or ribbed inner surface with straight or helical grooves or ribs, by providing a metallic hollow cylindrical pre-form, placing the pre-form on a core mandrel being part of a flow forming machine having a main machine axis, the core mandrel having a structured outer surface comprising ribs and/or grooves extending straightly parallel to and/or helically around the main axis; and applying forming rollers, in a roller arrangement, to the outside surface of the pre-form so as to apply radial pressure on the pre-form such that its material begins to flow. As the rollers apply force upon the pre-form, a relative motion between the pre-form and the rollers is performed by moving the pre-form in axially parallel to the main axis through the roller arrangement or by moving the roller arrangement alongside the pre-form.

A method for producing a tube segment and a tube for an evacuated tube transport system and a method for producing the tube segment.

A method for producing a tube segment and a tube for an evacuated tube transport system and a method for producing the tube segment.

An apparatus that manufactures a closed-structure part includes a bottom portion and left and right side wall portions, including a press-forming die that form a plurality of first out-of-plane deformed portions and bent portions, the first out-of-plane deformed portions being formed in a region of a workpiece corresponding to the bottom portion and arranged along a longitudinal direction, each of the first out-of-plane deformed portions having a recessed shape or a protruding shape; a pad and a punch that squash the first out-of-plane deformed portions by clamping the region of the workpiece corresponding to the bottom portion therebetween, a cross-sectional shape of a pressing portion of the punch being curved along the longitudinal direction; and bending dies that bend the bent portions by pressing the punch into a space therebetween while the region of the workpiece corresponding to the bottom portion is clamped between the pad and the punch.

An apparatus that manufactures a closed-structure part includes a bottom portion and left and right side wall portions, including a press-forming die that form a plurality of first out-of-plane deformed portions and bent portions, the first out-of-plane deformed portions being formed in a region of a workpiece corresponding to the bottom portion and arranged along a longitudinal direction, each of the first out-of-plane deformed portions having a recessed shape or a protruding shape; a pad and a punch that squash the first out-of-plane deformed portions by clamping the region of the workpiece corresponding to the bottom portion therebetween, a cross-sectional shape of a pressing portion of the punch being curved along the longitudinal direction; and bending dies that bend the bent portions by pressing the punch into a space therebetween while the region of the workpiece corresponding to the bottom portion is clamped between the pad and the punch.

Tube forming methods can be used for efficient transition in the production of tubes having varying thickness. Material used to form consecutive tubes may have the same thickness along a separation plane separating a first discrete section from a second discrete section of the material, and the first discrete section and the second discrete section may each have varying thickness in a feed direction of the material. With such a thickness profile, the first discrete section of the material may be formed into a first cylinder having varying thickness and separated from the second discrete portion as the second discrete section is formed into a second cylinder having varying thickness. In particular, the transition between the first cylinder and the second cylinder may be achieved without scrap and/or interruption, resulting in cost-savings and improvements in production throughput associated with forming tubes having varying thickness.

A tube for use in a heat exchanger including a base portion, an upper portion spaced from and opposing the base portion, and a partitioning wall extending between the base portion and the upper portion to divide a hollow interior of the tube into a first flow channel and a second flow channel. The partitioning wall includes a plurality of windows spaced from each other in a longitudinal direction of the tube to provide fluid communication between the first flow channel and the second flow channel. At least one of the windows includes a tabbed portion of the partitioning wall bent to extend into one of the first flow channel or the second flow channel.

The application relates to a method for producing a double-walled pipe (1) and a pipe (1) of this type, having an outer pipe (3) which is press-fitted with an inner pipe (2) consisting of a corrosion-resistant alloy, wherein an adhesive (4) is inserted at least in regions between the outer pipe (3) and the inner pipe (2), wherein, after adhering the inner pipe (2) with the outer pipe (3), the inner pipe (2) and the adhesive layer (4) are removed at the pipe ends, and the inner side of the outer pipe (3) is plated via an integral connection with the inner pipe (2).

A method of manufacturing a tubular member for an automotive application that includes providing a flat workpiece of a material; forming at least one lance in the flat workpiece; roll-forming the flat workpiece into a tubular configuration; induction welding a seam of the tubular workpiece after the roll-forming; and trimming the tubular workpiece through the lance after welding the seam.

A method of producing a clad billet includes heating a corrosion resistant alloy (CRA) cylinder having a hollow interior to expand its inner diameter; inserting a solid carbon or low-alloy steel (CS) material into the hollow interior of the heated (CRA) cylinder so that an outer surface of the (CS) material faces the inner diameter of the (CRA) cylinder; cooling the (CRA) cylinder to contract and shrink the inner diameter of the (CRA) cylinder onto the outer surface of the (CS) material creating an interference fit at an interface with the outer surface, resulting in a composite billet assembly; and hot extruding the composite billet assembly to reduce its size and form the clad billet having a metallurgical bond between the (CS) material and the (CRA) cylinder. The clad billet can be hot-rolled to form metallurgically-bonded clad bar, or can be cold pilgered/cold drawn to form a metallurgically-bonded clad pipe.