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

In this paper, a comprehensive analysis of the process of natural gas reform in MIDREX technology was carried out, which was aimed at optimizing this process in order to increase hydrogen yield, reduce the specific consumption of natural gas and minimize the risks of soot formation. The paper also calculates the thermal balance, combined steam-carbon dioxide reforming (SMR + DRM). Based on the conducted studies, optimal reforming modes were determined: gas outlet temperature ~915-920°C; H2O/C ~1.8; increased CO2 fraction. Switching to an optimized reforming mode reduces natural gas consumption by 5.5%, increases H2 output by 6.4%, and reduces CO2 emissions due to better energy efficiency and H2 addition potential. The results obtained in this work are useful for upgrading existing Midrex installations in the direction of decarbonization, including the transition to MIDREX Flex/H2 technologies.

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.

In this article, is to develop a physical and mathematical model of the process under complex asymmetric loading in conditions of single-area and two-area deformation zone during plastic processing of medium-thickness strips. The stress state in case of loss of stability during rolling of strips of medium thickness was investigated. The patterns of changes in the stress state of the strip under conditions of reach of the limiting deformation zone, as well as the effects of plastic shaping determined by a decrease in contact stresses under conditions of increasing deformation loading, are revealed. The described method is a visual approach to assessing the stress state of a plastic medium under conditions of complex interaction and asymmetric loading.