Development and Experimental Testing of a New Technology for Producing Screw Fittings from Bar Scrap of Ferrous Metals

Abstract

One of the simplest and most frequently used methods of recycling ferrous scrap is its remelting and further reuse. But at the same time, in some countries of the world, another method of processing ferrous scrap has entered into practice, namely, recycling of some metal products that have served their service life by various methods of hot pressure treatment to obtain a finished commercial product. In our opinion, this method of processing ferrous scrap and alloys can be attributed to "green" technologies, as it allows you to make a small contribution to improving the environmental situation in the world. This work, carried out within the framework of grant № AP14869135, funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan, is devoted to the development and research of a new technology for processing scrap in the form of pieces of reinforcement made of 25G2S steel to obtain high-quality finished metal products in the form of screw fittings. The developed technology included two stages. At the first stage, the reinforcement pieces are performed on a radial-shear rolling mill to obtain conventional rods of the desired diameter and create initial conditions for the formation of a gradient ultrafine-grained structure in the resulting screw profile. The second stage is the direct production of screw fittings with a gradient ultra-fine-grained structure on a combined installation. Metallographic studies have shown that after the implementation of the second stage of obtaining screw fittings, a gradient structure is observed in 25G2S steel in the longitudinal direction, with equiaxed grains (ranging in size from 11-14 μm) in the peripheral region and with elongated, directional-oriented grains in the central region of the resulting reinforcement.

Keywords

• Radial-shear rolling
• Combined installation
• Bar scrap
• Recycling
• Screw reinforcement profile

References

1. Lezhnev, S., Goldabin, D., Shiriaeva, E., & Kuis, D. (2025). Development and experimental testing of a new technology for producing screw fittings from bar scrap of ferrous metals. The Eurasia Proceedings of Science, Technology, Engineering and Mathematics (EPSTEM), 34, 87-92.