A process of pre-heating treatment is performed such that steel sheets or plates as working materials are heated by a heating unit provided ahead of a rotational tool moving in a welding direction to precisely control the surface temperature, area, position and the like of a heating region in the process of pre-heating treatment when performing friction stir welding on structural steel.

A method for producing a connection between a sandwich element and a metal element is disclosed herein. In this method, the sandwich element has an interlayer arranged between two cover elements. The method includes providing the sandwich element and the metal element; placing the sandwich element and the metal element in face-to-face contact at least partially overlapping; adding a fastener from the sandwich-element side while a base of the fastener extends within the sandwich element; and friction welding, from the metal-element side, to form a hybrid connection having a mechanical connection between the fastener and the sandwich element and a welding connection between the fastener and the metal element.

A method for producing a connection between a sandwich element and a metal element is disclosed herein. In this method, the sandwich element has an interlayer arranged between two cover elements. The method includes providing the sandwich element and the metal element; placing the sandwich element and the metal element in face-to-face contact at least partially overlapping; adding a fastener from the sandwich-element side while a base of the fastener extends within the sandwich element; and friction welding, from the metal-element side, to form a hybrid connection having a mechanical connection between the fastener and the sandwich element and a welding connection between the fastener and the metal element.

Provided is an apparatus of manufacturing a seamless pipe. The apparatus includes a container receiving a work therein, a stem pressing one end of the work within the container, a die installed in a direction opposite to the stem, and having an extrusion hole comprised of a plurality of ports, a rotation member installed on a front end of the die, having a stirring tip inserted into a joint surface formed by abutting a plurality of metal pieces to each other on one surface, and rotating to perform a friction stir bonding in a state in which the one surface contacts the joint surface, and a correction mold including a metal pipe discharging path receiving a metal pipe manufactured by the friction stir bonding and discharging the metal pipe to an outside.

In a bobbin tool including a first shoulder surface which comes into contact with a front surface of a subject work piece, a second shoulder surface which is disposed so as to face the first shoulder surface and comes into contact with a rear surface of the work piece, and a shaft portion which connects the first shoulder surface and the second shoulder surface to each other with a gap therebetween fixed, the first shoulder surface and the second shoulder surface are provided with a first vortex groove and a second vortex groove which extend toward the front side of a tool rotation direction so as to be opened to the outer peripheral edge as it moves to the outer peripheral side.

A pressure welding method and a pressure welding device (1) are provided. The pressure welding device (1) includes a plastification device (7), an upsetting device (8) and component mountings (34,35,36,37) for the components (2,3,3′,4) to be welded together and a machine frame (12). The pressure welding device (1) further includes a plurality of machine heads (13,14), each having a component mount (34,35), which machine heads are movably arranged on the machine frame and are connected to respective upsetting drives (22). The machine heads (13,14) and respective upsetting drives (22) can be independently driven. An upsetting head or support head (27), which is preferably secured on the frame, is arranged between the machine heads (13,14).

A pressure welding method and a pressure welding device (1) are provided. The pressure welding device (1) includes a plastification device (7), an upsetting device (8) and component mountings (34,35,36,37) for the components (2,3,3′,4) to be welded together and a machine frame (12). The pressure welding device (1) further includes a plurality of machine heads (13,14), each having a component mount (34,35), which machine heads are movably arranged on the machine frame and are connected to respective upsetting drives (22). The machine heads (13,14) and respective upsetting drives (22) can be independently driven. An upsetting head or support head (27), which is preferably secured on the frame, is arranged between the machine heads (13,14).

A method for producing a cavity valve is provided. The method includes providing a valve body which has a cavity in the interior. The valve body has a circular opening having an opening edge surface on a bottom side. A circular valve cover with a cover edge surface is provided. Inductive heating of at least one of the opening edge surface or the cover edge surface takes place and then welding the valve body to the valve cover by friction welding of the opening edge surface to the cover edge surface.

A method for producing a cavity valve is provided. The method includes providing a valve body which has a cavity in the interior. The valve body has a circular opening having an opening edge surface on a bottom side. A circular valve cover with a cover edge surface is provided. Inductive heating of at least one of the opening edge surface or the cover edge surface takes place and then welding the valve body to the valve cover by friction welding of the opening edge surface to the cover edge surface.

A friction stir welding device (1) includes a workpiece disposition unit (2) at which workpieces (W) is disposed, a main body section (3) disposed at a surface (W4) of the workpieces (W) disposed at the workpiece disposition unit (2), a tool holding unit (4) formed in the main body section (3) to enable advance and retreat in a direction facing the workpieces (Z), which is a direction approaching and separating from the workpieces (W) disposed at the workpiece disposition unit (2), and configured to hold a tool (100), and a support medium (5) formed to satisfy a predetermined relative positional relationship in the direction facing the workpieces (Z) with respect to a first shoulder surface of the tool (100) attached to the tool holding unit (4) and configured to support the tool holding unit (4) on the surface (W4) of the workpieces (W) disposed at the workpieces disposition unit (2).