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

Despite the rapid development of metallurgical processes for the production of semi-finished products aimed at improving the modes of smelting, casting and crystallization, a significant improvement in the properties of any cast metal, ensuring its wide application in modern mechanical engineering, is achieved by combined thermomechanical processing of workpieces, combining hot metal forming and heat treatment. The technologies and equipment currently used in Kazakhstan by machine-building manufacturers have long been obsolete and ineffective. A common problem for everyone is the high energy intensity of production, its low productivity and the quality of forgings and blanks produced, which leaves much to be desired. Namely forgings and blanks are the starting materials for the manufacture of highquality tools and technological equipment at mining and metallurgical engineering enterprises. Therefore, the purpose of this work is to develop rational modes of thermal and thermochemical processing of 5KHV2S steel, previously forged in a tool that implements alternating strain in metal, as well as to study the influence of combined thermomechanical processing modes on the mechanical properties of this steel. The studies carried out in this work on the hardness of 5KHV2S steel samples subjected to combined thermomechanical processing showed that the developed technologies contributed to an increase in both total and surface hardness compared with samples not subjected to preforging in a new forging tool that implements alternating strain in the metal.

Despite the rapid development of metallurgical processes for the production of semi-finished products aimed at improving the modes of smelting, casting and crystallization, a significant improvement in the properties of any cast metal, ensuring its wide application in modern mechanical engineering, is achieved by combined thermomechanical processing of workpieces, combining hot metal forming and heat treatment. The technologies and equipment currently used in Kazakhstan by machine-building manufacturers have long been obsolete and ineffective. A common problem for everyone is the high energy intensity of production, its low productivity and the quality of forgings and blanks produced, which leaves much to be desired. Namely forgings and blanks are the starting materials for the manufacture of highquality tools and technological equipment at mining and metallurgical engineering enterprises. Therefore, the purpose of this work is to develop rational modes of thermal and thermochemical processing of 5KHV2S steel, previously forged in a tool that implements alternating strain in metal, as well as to study the influence of combined thermomechanical processing modes on the mechanical properties of this steel. The studies carried out in this work on the hardness of 5KHV2S steel samples subjected to combined thermomechanical processing showed that the developed technologies contributed to an increase in both total and surface hardness compared with samples not subjected to preforging in a new forging tool that implements alternating strain in the metal.

One of the effective ways to control the properties of copper is to refine its structure to a nano- or ultrafine-grained level, and primarily with the help of severe plastic deformation. At the same time, radial-shear rolling is one of the promising methods for obtaining long-length rods with a gradient ultra-fine-grained structure. It is known from a number of scientific works that one of the main factors influencing the possibility of obtaining an ultrafine-grained structure in various ferrous and non-ferrous metals and alloys is the deformation temperature of these metals and alloys. The aim of the work is to study the influence of the deformation temperature at the radial-shear rolling mill on the microstructure evolution of copper. The following deformation temperatures of copper rods were selected for the planned studies: 20°C, 100°C and 200°C. The conducted studies have shown that the implementation of radial-shear rolling at ambient temperature compared with rolling at temperatures of 100°C and 200°C made it possible to achieve more intensive refinement of the initial structure. And first of all, this is due to the fact that with radial-shear rolling of copper, realized at ambient temperature, there are no dynamic return processes.

The paper presents the results of microstructural studies of 16MnCrS5 steel hypereutectoid structure subjected to reforging under pulsating contact stress loading. It is revealed that the local evolution of the structure in the focus of contact loading has signs of selfimprovement with the transformation of the isotropic morphology of the carbide phase into an anisotropic one with signs of textural riveting. Instead of the initial structure with a uniform carbide phase distribution, signs of textural anisotropy with reinforcement elements of the modified layer high-carbon hypereutectoid zone with carbide inclusions are formed.

One of the effective ways to control the properties of copper is to refine its structure to a nano- or ultrafine-grained level, and primarily with the help of severe plastic deformation. At the same time, radial-shear rolling is one of the promising methods for obtaining long-length rods with a gradient ultra-fine-grained structure. It is known from a number of scientific works that one of the main factors influencing the possibility of obtaining an ultrafine-grained structure in various ferrous and non-ferrous metals and alloys is the deformation temperature of these metals and alloys. The aim of the work is to study the influence of the deformation temperature at the radial-shear rolling mill on the microstructure evolution of copper. The following deformation temperatures of copper rods were selected for the planned studies: 20°C, 100°C and 200°C. The conducted studies have shown that the implementation of radial-shear rolling at ambient temperature compared with rolling at temperatures of 100°C and 200°C made it possible to achieve more intensive refinement of the initial structure. And first of all, this is due to the fact that with radial-shear rolling of copper, realized at ambient temperature, there are no dynamic return processes.

The article describes the concept of a new forging method of circular cross-section blanks in a forging tool, the design of which makes it possible to develop significant alternating deformations in the deformable metal. The results of comparative studies of the microstructure and mechanical properties of AISI-5140H low-alloy structural steel, formed in a new forging tool that implements alternating deformation and in flat strikers are presented.

The main consumers of grinding balls are mining, metallurgical, cement and energy industries. In these industries one of the main and very common operations is the grinding of various materials. Rolled steel balls are mainly produced by plastic deformation on crossscrew rolling mills. Technological limitations of increasing the hardness groups and the wear resistance of the balls currently available at the Metal Rolling plant of JSC “Sokolov-Sarbay mining and processing production association” (MRP JSC “SSGPO”), and they do not allow currently to quickly improve their quality. But at the same time, if the quality of finished products is improved, the MRP JSC “SSGPO” may have the opportunity to sell balls not only between its enterprises, but also to the domestic market, as well as the opportunity to develop export sales of balls to the countries of near and far abroad. Therefore, this paper presents the results of the study of the main causes of defects at the ball rolling mill 30-60 of metal rolling plant JSC “SSGPO” and the search for their exclusion

This article describes the technology of the combined process “equal-channel angular pressing-drawing”. The analysis of the influence of this process on the structure and mechanical properties of aluminum, copper and steel wires is given. The results of the study showed that the proposed combined deformation method “equal-channel angular pressing-drawing” has a significant advantage over the existing technology for the production of high-strength wire. This deformation method due to the combination of two deformations: severe plastic deformation in a matrix with parallel channels and the process of deformation through a drawing die, allows to get a wire with an ultra-fine structure and a high level of mechanical properties, the required size and shape of the cross section in a small number of deformation cycles.

In this paper, a computer simulation of a new technology of thick-sheet rolling, including rolling in rolls with a relief surface followed by rolling on rolls with a smooth barrel to the desired size. The analysis of effective plastic deformation, hydrostatic pressure and temperature field was carried out according to the results of modeling. According to the results of the analysis of effective strain, maximum of processing in the first pass receives the ridge area, but after the second pass observed alignment distribution of this parameter over the cross section. The study of the temperature field showed that the greatest temperature difference in the cross section occurs when rolling in relief rolls, in the future when rolling in smooth rolls due to the increase in the contact surface area, this difference decreases. Analysis of hydrostatic pressure showed the presence of both compressive and tensile stresses in the deformation zone. Such distribution is caused by the presence of a relief surface after 1 pass in the further alignment of the strip profile, which occurs both in the longitudinal and transverse directions.