Abstract: A process and apparatus for achieving narrow workpiece tolerances in isothermal drop-forging, the relative movement of the two die halves (1, 2) in an xy plane perpendicular to the pressing direction z being measured and monitored by means of an optical measuring device (10, 11, 12, 14) or mechanical measuring device (14, 15, 16) and being corrected by means of a mechanical adjusting device (6, 17, 21, 23, 24, 25, 26) for one die half (2). A first workpiece is forged, and the divergence from the nominal value is measured, with the die halves (1, 2) closed, the die halves (1, 2) are opened, the first workpiece is removed, the position of one die half (2) is corrected, and a new workpiece is introduced and forged completely, without the workpiece having to be cooled and remeasured and without the die having to be cooled and reheated.

Abstract: An apparatus and a process for the zone-annealing of a workpiece (1) consisting of a high-temperature material, in which the workpiece (1) is hung on a suspension device (2) actuated via a roller (3) driven by a drive motor (4) and is provided with a plate-shaped covering screen (10) having an orifice. For the dipping of the workpiece (1), there is underneath the latter a salt bath (5) which is enclosed in an insulating vessel (6) and is provided with a heating system (7) with centrally symmetrical guide plates (8) and which is closed off at the top by means of a floating insulating cover (9). The cooling of the part of the workpiece (1) which is not immersed is guaranteed by a cooling body (11) through which cooling air (14) flows and which has a central passage (12) and, at the lower end of the passage (12), a projecting edge (13) serving as a stop for the covering screen (10).

Abstract: A tool for isothermal forging is disclosed. The tool consists of two die halves, at least one of which consists of an assembly of individual components whose side facing the workpiece is provided with a thin electrically insulating layer. The assembly of the die half from individual components occurs following forming of the components by casting and/or forging, and machining of the formed components. The forming of the die halves from separate components makes it possible to adapt the components of the die half to the particular working conditions in an optimum manner. The provision of an insulating layer on the individual components reduces the risk of local welding and nonuniform temperature distribution during inductive heating.

Abstract: A method and apparatus for the expansion of a hollow article out of a memory alloy, in which the hollow article, cooled below the transformation temperature, is mounted between two mandrels each having an opposing taper, and in a first phase is expanded on one face to the final dimension by one mandrel and is supported against a stop, whereupon the final shape is produced by pulling the other mandrel through the hollow article from the opposite face.