Use of Special Reduction of Thick-Walled Metal Pipes in the Production of Space Structures

Methods to produce a metal pipe with different diameters at the ends including joining pipes with different diameters and reducing the pipe using different methods and tools are described. Reduction by a press, including a hydraulic one, allows for the required reduction in the diameter at the ends of a thick-walled pipe on an industrial scale, within the permissible ovality parameters of the internal diameters, and for preserving the metal structure at the reduction site by means of dosing the press power. The important parameters include not only the press power and the ratio of the diameter to the wall thickness of the pipe but also the following: whether the pipe is pre-heat-treated, the material of punches used to set the required diameter, and others. An important issue is to achieve stability in obtaining the required diameters and the required level of ovality since in practice a thick-walled pipe behaves less stably than a thin-walled pipe under any plastic deformations.