International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This work is devoted to the development and research of a new technology for processing bar scrap from 40X steel to obtain high-quality finished metal products in the form of a screw reinforcement profile. The developed technology included two stages. At the first stage, the round-section bar scrap is formed on a radial-shear rolling mill to obtain conventional bars of the desired diameter and create initial conditions for the formation of an ultrafine grained gradient structure in the resulting screw profile. The second stage is the direct production of a screw profile with a gradient ultrafine-grained structure on a combined installation. Metallographic studies have shown that after the implementation of the second stage of obtaining a screw reinforcement profile, a gradient structure is observed in 40X steel, with equiaxed grains, the size of which lies within 1.2-1.4 μm in the peripheral region and to a greater extent with elongated, directional-oriented grains in the central region of the resulting reinforcement.

This work is devoted to the study of a new technology for processing bar scrap – a precision shaft made of Cf53 structural steel (DIN 17212) that has proven its service life and produces high-quality finished metal products in the form of a screw reinforcement profile. The precision shaft used for recycling of its proven service life included two stages: preliminary deformation of the shaft on a radial shear rolling mill to obtain rods of the required diameter and create initial conditions for the formation of a gradient ultrafine-grained structure in the resulting screw profile; direct production of a screw profile with a gradient ultrafine-grained structure on a combined installation. The conducted research has shown that the new combined technological process of rolling bar scrap is feasible in practice and makes it possible to obtain a high-quality finished product from this scrap in the form of a screw reinforcement profile with a gradient ultrafine-grained structure.