Browsing by Author "Panin E."

Now showing 1 - 14 of 14
  • No Thumbnail Available
    Item
    COMPUTER MODELING AND INVESTIGATION OF THE DEFORMATION PROCESS IN CONVEX-CONCAVE AND TRAPEZOIDAL STRIKERS
    (2023-01-01) Volokitin A.; Naizabekov A.; Panin E.; Tolkushkin A.; Nurakhmetov D.; Yordanova R.; Volokitina I.; Arbuz A.
    The article presents the results of a comparative analysis of the deformation process in convex-concave and trapezoidal strikers using computer modeling by the finite element method in the Deform program. In both designs, two variants are considered - with an equal and unequal ratio of the protrusion to the depression. For comparative analysis, equivalent stresses and strains, energy - power parameters are considered. Also, on the basis of computer modeling, the analysis of the microstructure evolution during the deformation in convex - concave and trapezoidal strikers was carried out. In the course of computer modeling, some advantage of the design of convex - concave strikers in comparison with trapezoidal strikers was proved.
  • No Thumbnail Available
    Item
    DESIGN IMPROVEMENT OF THE STEP-WEDGE DIES AND EXPERIMENTAL STUDY OF THE FORGING PROCESS OF 45 STEEL BILLETS
    (2024-01-01) Tolkushkin A.; Naizabekov A.; Panin E.; Yordanova R.; Shvarts D.; Tsyba P.; Volokitina I.; Rovin S.; Esbolat A.
    In this paper, a forging tool of a new design is proposed, which allows to implement shear and alternating strain in the entire volume of the deformed billet with a smaller change in its initial dimensions. To confirm the effectiveness of the proposed new forging tool in obtaining billets and forgings of the plates and slabs type of the required quality, a laboratory experiment was conducted. During the laboratory experiment, the forging of billets made of the steel 45 was carried out in such forging tools as step-wedge dies of two different variants (proposed and previously known) and in step dies. Analysis of the shape change of billets and the evolution of the microstructure of steel after two deformation cycles showed that the use of the step-wedge dies with a wedge protrusion on the upper die and a wedge cavity on the lower die is more promising for forging billets and forgings of the plates and slabs type with a given level of mechanical properties, since it allows to obtain a fine-grained structure with a smaller change in the initial dimensions of the billet.
  • No Thumbnail Available
    Item
    Development and Computer Simulation of the New Combined Process for Producing a Rebar Profile
    (2023-01-01) Lezhnev S.; Naizabekov A.; Panin E.; Tolkushkin A.; Kuis D.; Kasperovich A.; Yordanova R.
    The study presents results of computer simulation by finite elements method of a new metal forming process combining the deformation of a billet with round cross-section on a radial-shear rolling mill and subsequent billet twisting in a forming die with a specific design. To analyze the efficiency of metal processing, the main parameters of the stress-strain state are considered: effective strain, effective stress, average hydrostatic pressure, and Lode-Nadai coefficient. The maximum value of effective strain up to 13.5 is achieved when a screw profile on the billet in the die is forming, which indicates an intensive refinement of the initial structure of the billet. During combined process, the nature of the deformation changes in the transverse direction from the axis of rotation to the surface. The central area of the billet is under the action of tensile stresses. In the peripheral part, compressive stresses grow. In the surface area, Lode-Nadai coefficient is 0.1 approximately, which indicates the high level of shear strain.
  • No Thumbnail Available
    Item
    Development and theoretical study of new scheme of realization of combined process ``rolling - pressing`` using equal channel step matrix
    (2017-01-01) Naizabekov A.; Lezhnev S.; Panin E.; Koinov T.; Mazur I.
    Using a computer simulation it was conducted a study of new modification of the combined process ``rolling-pressing``, the distinctive feature of which is the use at the exit of equal-channel step matrix vertical rolls instead of horizontal rolls. It was performed the investigation on the stress-strain state, the deformation of the workpiece and the microstructure evolution. The values obtained were compared with those of the model with two pairs of horizontal rolls. As a result, it was found that the use of vertical rolls at the exit of the equal-channel step matrix has the following advantages: the treatment of the workpiece is more uniformly throughout the section; in general, by changing the direction of compression during rolling in the vertical rolls the deformation occurs at much lower values of the extrusion, which entails a slight change in the original dimensions of the workpiece; the initial grain size is reduced more intensively both on the surface and in the central zone.
  • No Thumbnail Available
    Item
    EFFECT OF THE LIMITING DEFORMATION ZONE UNDER CONDITIONS OF ASYMMETRIC LOADING DURING ROLLING OF MEDIUM THICKNESS STRIPS
    (2024-01-01) Chigirinsky V.; Naizabekov A.; Lezhnev S.; Kuzmin S.; Panin E.; Tolkushkin A.; Volokitina I.; Yordanova R.; Knapinski M.
    The aim of the work 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.
  • No Thumbnail Available
    Item
    Evaluation of the effectiveness of the use of horizontal and vertical rolls in the ``rolling-pressing`` process on the basis of the stress-strain state studying
    (2017-03-01) Lezhnev S.; Naizabekov A.; Panin E.; Koinov T.; Mazur I.; Arbuz A.
    In this work was performed a comparative analysis of the efficiency of horizontal and vertical rolls in the ``rolling-pressing`` process. The comparison was performed based on the study of stress-strain state of both variants with the aid of computer simulation in the program DEFORM-3D based on the finite element method. For analysis of the stress state was used the Lode-Nadai coefficient, allowing you to determine which type of deformation is realized at a specific point - tension, compression or shear. For analysis of the strain state was used equivalent strain, which allows to estimate the common level of accumulated strain. In the comparative analysis of parameters of SSS was revealed that the use of vertical rolls at the exit from the matrix during ``rolling-pressing`` process, allows you to achieve a more favorable distribution of deformation along the entire length of the deformable workpiece.
  • No Thumbnail Available
    Item
    Finite Element Modeling of ECAP-Linex Combined Process of Severe Plastic Deformation
    (2023-01-01) Panin E.; Volokitina I.; Volokitin A.; Naizabekov A.; Akhmetova G.; Lezhnev S.; Tolkushkin A.; Esbolat A.; Yordanova R.
    The paper presents theoretical studies of a new deformation process combining the stages of equal-channel angular pressing (ECAP) and the ``Linex``scheme. For correct finite element modeling of the process, a technique with sequential input for the calculation of conveyor links is presented. To analyze the efficiency of metal processing, the main parameters of the stress-strain state are considered: equivalent strain, equivalent stress, and average hydrostatic pressure, as well as the deformation force on the main elements of the combined process: pulley, matrix, and conveyor link. To analyze the resulting deformation forces, the stages of pressing in a matrix and compression by a chain conveyor were separately considered. Equations for determining the forces acting on the drive pulley, ECA matrix, and the chain element link were obtained. Comparison of values showed that the force values in the calculation and simulation have a high level of convergence. In all three considered details, the difference value did not exceed 10%. The variational modeling allowed to determine the optimal values of the main technological and geometric parameters of the process.
  • No Thumbnail Available
    Item
    Improvement and theoretical study of new technology of forging of blanks such as ``shaft``
    (2017-01-01) Kulzhabayeva A.; Panin E.; Koinov T.; Toleuova A.
    In this work a new technology for forging and the tool for its implementation - strikers with sloping faces and circular segments, are developed. The use of this technology allows to implement in the course of intense deformation the processing of metal over the entire cross section. The distribution of the stress has shown that when the deformation of the almost all section of the billet is dominated by compressive stresses, contributed to the closure of internal defects. The study of the strain state has shown that the development of the strain is on forging cross, after contact of the side edges with circular segments the deformation zones are expanding, covering the entire cross section of the workpiece. When modeling the process of closing the internal defect it is found that the decrease in the angle of the faces leads to a decrease in shear strain during drawing, resulting in the closure of the defect occurs only in a zone located at a distance of 50% of the feed value. The optimal value of the angle of the faces of the dies is equal to 30° with the angle of the through hole in the axial portion of the workpiece is completely closed. The use of the angle of inclination more than 30° is not recommended, since in this case high-rise deformation is insufficient for complete closure of the defects.
  • No Thumbnail Available
    Item
    Recycling of metal scrap of ferrous metals using mini-mill of radial-shear rolling and drawing mill
    (2020-01-01) Lezhnev S.; Naizabekov A.; Panin E.; Volokitina I.; Turabaeva M.; Yordanova R.; Sal'ko O.
    Re-processing of scrap metal is one of the most important directions in the production of metals and alloys, as well as in the manufacture of various metal products. This activity is called the recycling. Recycling of scrap metal can be carried out, both by melting it, or by technology, currently gaining distribution in some metallurgical and engineering plants and which includes the processing of end-of-life metal products by hot forming. In this paper, the technology of recycling of ferrous metal scrap in the conditions of Akmola branch of JSC ``Kazvtorchermet``, in order to obtain high-quality commercial product in the form of bars of circular cross-section or wire, is proposed.
  • No Thumbnail Available
    Item
    Research and development of technology for rolling of high-quality plates of non-ferrous metals and alloys in relief rolls
    (2016-01-01) Naizabekov A.; Lezhnev S.; Koinov T.; Mazur I.; Panin E.
    Studies on deformation of a plate workpiece in rolls with a surface relief in the form of annular grooves forming a trapezoidal ledges and cavities alternating each other along the entire length of the barrel (the first pair with unequal ratio of the ledge to the cavity and the second pair with equal ratio of the ledge to the cavity) have been carried out. Computer simulation of the rolling process in the rolls with unequal and equal treatment of the ledge to the depression showed the advantage of the first scheme, because in this case is implemented pure shear without compression, which is beneficial to the uniformity of distribution of accumulated plastic deformation, which, in turn, affects the forming of the workpiece. Laboratory studies have confirmed the simulation results. The analysis of the intensity of shear strain proved the superiority of the first scheme and the analysis of rolling load showed the advantage of using the relief rolls instead of smooth.
  • No Thumbnail Available
    Item
    Simulation of radial-shear rolling of austenitic stainless steel AISI-321
    (2019-01-01) Naizabekov A.; Lezhnev S.; Arbuz A.; Panin E.; Koinov T.
    This paper presents the results of modelling of a radial-shear rolling process of austenitic stainless steel AISI- 321. The simulation is performed by Simufact Forming Program Complex. The conditions of simulation refer to those of 14-40 radial-shear mill of Rudny Industrial Institute. The various parameters of the stress-strain state (the effective plastic strain, the effective stress, the mean normal stress and the Lode-Nadai coefficient) as well as the microstructure evolution with the rolling force are considered. It is revealed that the radial-shear rolling is an effective process for obtaining high quality round billets from stainless steels of the austenitic class.
  • No Thumbnail Available
    Item
    Study of broadening in a combined process ``rolling-pressing`` using an equal-channel step die
    (2015-01-01) Naizabekov A.; Lezhnev S.; Panin E.; Koinov T.
    This article is devoted to studying of broadening in a combined process ``rolling - pressing``, using an equal-channel step die. In laboratory conditions an experiment for implementation of this process, using smooth rolls and three dies with different values of angle of the channels junction was done. A formula, which allows finding the value of broadening in the combined process ``rolling-pressing``, using an equal-channel step die was obtained. This formula is applicable for any value of the angle of the channel's junction.
  • No Thumbnail Available
    Item
    The effect of preliminary and final heat treatment in course of the combined ``rolling-pressing`` process realization on microstructure evolution of copper
    (2016-01-01) Lezhnev S.; Naizabekov A.; Panin E.; Volokitina I.; Koinov T.
    A number of new methods of pressure processing of metals aimed at obtaining sub-ultrafine-grained structure have been recently developed. Their basic principle refers to realization of a simple shear scheme deformation. One of the approaches is to press blanks in matrices of different designs, in equal-channel step die in particular. However, this method has a significant disadvantage - it cannot be used to deform lengthy billets. Furthermore, this method does not provide the continuity of the pressing process. To remove these shortcomings a combined ``rolling-pressing`` process using an equal channel step matrix with calibrated and smooth rolls is developed at the Department of ``Metal Forming`` at the Karaganda State Industrial University. This work investigates the impact of the process advanced. It focuses on the preliminary and final heat treatment during its implementation on the microstructure evolution and the mechanical properties of the copper alloy produced. The results indicate that the technology proposed can be recommended for implementation in production of blanks of ferrous and non-ferrous metals and alloys with ultrafine-grained structure and good mechanical properties.
  • No Thumbnail Available
    Item
    Theoretical grounds of the combined ``rolling - equal - channel step pressing`` process
    (2016-01-01) Panin E.; Lezhnev S.; Naizabekov A.; Koinov T.
    The present paper describes the common theoretical grounds referring to the realization of the combined ``rolling - equal-channel step pressing`` process. The investigation carried out lead to the formulation of empirical equations providing the calculation of the values of the forces of rolling, pressing and back pressure from the matrix as well as those of the diameters of the rolls determining the best capture angle of the work piece. The computer simulations required focused on the stress-strain state, the temperature distribution, the effect of the work piece tilting on the process parameters. A program for the estimation of the optimal value of the channels intersection angle in the matrix and hence of a quick determination of the optimal conditions for this combined process implementation was advanced. All results obtained indicate that the combined ``rolling-pressing`` process can be implemented to produce parts of a sub-ultrafine-grained structure.