The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
A P Karamyshev - One of the best experts on this subject based on the ideXlab platform.
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Determination of Residual Ductility in the Forging of Bars on a Lever-Type Radial Forging Machine
Metallurgist, 2016Co-Authors: A P Karamyshev, I I Nekrasov, V S Parshin, A. A. Fedulov, A I PuginAbstract:A method is proposed for determining the residual ductility of the material of a Semifinished Product. The method makes it possible to forge bars on a radial forging machine with the use of technically sound regimes for the reduction of Semifinished Products. The investigation that was performed involved both theoretical and experimental research. The theoretical part included determination of the stress state in the deformation zone in accordance with a new mathematical model, determination of the shear strain and ductility of the metal, and evaluation of its residual ductility in the forging of bars on a radial forging machine. In addition, an experiment was performed which involved the multi-pass forging of bars of different alloys with different reductions in each pass. The adequacy of the model was checked by comparing the calculated data with the experimental results obtained by forging bars made of different alloys.
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finding an efficient shape for the cross section of the front end of a tubular Semifinished Product to perform drawing
Metallurgist, 2011Co-Authors: A P Karamyshev, I I Nekrasov, V S Parshin, A I PuginAbstract:Pipe plants use radial forging to reduce the diameter of shafts, tubes, and axles. A three-dimensional finite-element method employing the software DEFORM-3D is used to optimize the radial forging operation. Three different tool configurations are examined for obtaining smooth and folded reduced Semifinished Products, and suggestions are made for an efficient shape for the tubular Semifinished Product prior to drawing, the design of the dies, and the configuration of the tool.
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Determination of the active forces in the reduction of Semifinished Products on an AVS radial forging machine
Metallurgist, 2009Co-Authors: A P Karamyshev, I I Nekrasov, V S Parshin, V. A. SysterovAbstract:This article examines the problem of constructing a mathematical model to describe the process of deformation carried out on an AVS radial forging machine to prepare the ends of tubes for further processing. The model makes it possible to determine the energy-force parameters of the reduction process - the most important factors for drawing up Production schedules and choosing the composition and design of the equipment. A computational program is created to determine the reducing forces in tubes and bars. The program accounts for strain-hardening and makes it possible to determine the extent to which the ductility of the tube material is used. It also allows variation of the parameters of the forging operation, including the angle of the die, the friction index, the front and rear thrust of the Semifinished Product, and the feed. Experiments involving the shaping of different types of Semifinished Products on an AVS radial forging machine fully substantiate the accuracy of the mathematical model.
E. I. Panov - One of the best experts on this subject based on the ideXlab platform.
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Effect of the kinematics of rotary rolling on the fineness of the structure of hypereutectoid silumins
Metallurgist, 2006Co-Authors: E. I. PanovAbstract:It has been established experimentally that the internal layers of cylindrical Semifinished Products that are made of hypereutectoid silumins and contain embedded lengthwise pins do not intermix during rotary rolling. The experiment also determined that the angles through which different concentric internal layers of the Semifinished Product (ω1 > ω2 > ω3) are twisted are different and depend on the radii of those layers (R′1 > R′2 > R′3). This finding contradicts the hypothesis of rigid sections in the classical theory of the strength of materials. An analytic relation (empirical formula) is found to describe the pitch of the internal layers of metal flow in relation to the main parameters of the rotary-rolling operation (the feed angle α and deformation e) and the radius of the given internal layer (R′x). Another empirical formula is proposed to determine the angle of inclination of the helical lines along which the metal inside the rolled specimen is displaced. A mathematical model is constructed to describe the dependence of the ductility properties of hypereutectoid silumin alloys on changes in the dimensions of the silicon crystals in the alloys when Semifinished Products made of these alloys are deformed by rotary rolling.
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Mathematical model of the movement of layers of metal during the rotary rolling of Semifinished Products made of hypereutectic silumins
Metallurgist, 2006Co-Authors: E. I. PanovAbstract:A mathematical model has been constructed to describe the kinematics of the movement of metal on the surface of Semifinished Products made of hypereutectic silumin alloys as they undergo rotary rolling. The model is based on the dependence of the pitch of the helical lines of metal flow on the deformation e of the Product and the feed angle α. The pitch is minimal when e = 50–55%, regardless of the feed angle α. The degree of deformation e = 50–55% is optimum for ensuring that the unit number of cycles in which the Semifinished Product is loaded by the work rolls is such as to produce a fine-grained structure and maximize the ductility characteristics of hypereutectic silumins.
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Shear Stresses and their Dependence on Different Process Parameters in the Helical Rolling of Solid Semifinished Products
Metallurgist, 2005Co-Authors: E. I. PanovAbstract:An analysis of the results obtained from modeling the two- and three-roll helical rolling of solid Semifinished Products with tension permits the following conclusions: • despite the change in the scheme of deformation of the Semifinished Product (from two- to three-roll), the pattern of distribution of the shear stresses and the overall distribution of the positive and negative stresses remain similar to the cases of two- and three-roll helical rolling with thrust; • despite this, comparison of two-roll rolling with thrust T_b = 60 kN and with tension T_f = 40 kN shows that that the positively directed components of the shear stresses which develop in the part of the cross section of the Semifinished Product outside the zone of contact with the work rolls are greater with thrust than with tension. Conversely, the application of the maximum possible amount of tension (T_f = 80 kN) to the front end of the Semifinished Product results in greater positive shear stresses on the same part of the cross section than does the application of the maximum possible amount of thrust (T_b = 120 kN); • in the three-roll scheme, an increase in tension increases the intensity of the negative shear stresses in the zones not in contact with the rolls, while an increase in thrust increases the positive shear stresses in the same zones; • the absolute values of the shear stresses in the two-roll scheme with tension fluctuate within the range 104–113 MPa, i.e., they are nearly independent of the amount of tension applied; in the three-roll scheme, the shear stresses created with different amounts of tension are within the range 90–97 MPa, i.e., the shear stresses in the three-roll scheme are also nearly independent of the amount of tension or thrust that is applied. Curves are constructed to describe the dependence of the shear stresses on the combined action of thrust and tension. The results collectively show that shear stresses may not be the main reason for the formation of internal cavities in Semifinished Products during the rolling operation.
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EFFECT OF THE PARAMETERS OF HELICAL ROLLING ON THE MAGNITUDE OF THE CIRCUMFERENTIAL STRESSES THAT DEVELOP IN SOLID Semifinished ProductS
Metallurgist, 2005Co-Authors: E. I. PanovAbstract:It is shown that increasing the degree of deformation increases the tensile circumferential stresses in the Semifinished Product. Although these stresses are considerably greater than the ultimate and yield strengths of the metal, no lamination or internal cavities were seen in tests that were conducted.
A I Pugin - One of the best experts on this subject based on the ideXlab platform.
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Determination of Residual Ductility in the Forging of Bars on a Lever-Type Radial Forging Machine
Metallurgist, 2016Co-Authors: A P Karamyshev, I I Nekrasov, V S Parshin, A. A. Fedulov, A I PuginAbstract:A method is proposed for determining the residual ductility of the material of a Semifinished Product. The method makes it possible to forge bars on a radial forging machine with the use of technically sound regimes for the reduction of Semifinished Products. The investigation that was performed involved both theoretical and experimental research. The theoretical part included determination of the stress state in the deformation zone in accordance with a new mathematical model, determination of the shear strain and ductility of the metal, and evaluation of its residual ductility in the forging of bars on a radial forging machine. In addition, an experiment was performed which involved the multi-pass forging of bars of different alloys with different reductions in each pass. The adequacy of the model was checked by comparing the calculated data with the experimental results obtained by forging bars made of different alloys.
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finding an efficient shape for the cross section of the front end of a tubular Semifinished Product to perform drawing
Metallurgist, 2011Co-Authors: A P Karamyshev, I I Nekrasov, V S Parshin, A I PuginAbstract:Pipe plants use radial forging to reduce the diameter of shafts, tubes, and axles. A three-dimensional finite-element method employing the software DEFORM-3D is used to optimize the radial forging operation. Three different tool configurations are examined for obtaining smooth and folded reduced Semifinished Products, and suggestions are made for an efficient shape for the tubular Semifinished Product prior to drawing, the design of the dies, and the configuration of the tool.
V. P. Romanenko - One of the best experts on this subject based on the ideXlab platform.
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effect of preliminary deformation of the cast Semifinished Product on the service properties of wheel steel
Metallurgist, 2013Co-Authors: V. P. Romanenko, A V Fomin, A N NikulinAbstract:An experimental study is made to determine how the mechanical properties of grade-T wheel steel are affected when hollow shells of this steel obtained by piercing solid Semifinished Products are deformed by rotary rolling. It is shown that piercing the Semifinished Products on the mill significantly improves the steel’s impact toughness and resistance to fatigue fracture.
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Study of the temperature regimes in the heating and piercing of steel ingots to obtain thick-walled shells
Metallurgist, 2011Co-Authors: V. P. Romanenko, P. L. Alekseev, E. A. Kharitonov, A. A. Yandimirov, A. A. SevastyanovAbstract:This article examines aspects of the use of thermal imaging and mathematical modeling to determine temperature inside a Semifinished Product as it is heated and pierced on a rotary rolling mill. A scheme is devised to thoroughly examine the thermal state of metal during shaping operations, and thermograms are obtained of the surface of metal at different moments in the piercing operation.
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measurement of Semifinished Product temperature during shaping operations using a thermal imaging method
Metallurgist, 2005Co-Authors: E. A. Kharitonov, P. L. Alekseev, V. P. RomanenkoAbstract:An experimental method which has been developed makes use of thermal vision to study the temperature of metal during hot shaping. The method also uses a computer to analyze video images and does not require costly equipment. It is suited for noncontact measurement of the surface of heated Semifinished Products within the range 400– 1600°C. The article reports the results of commercial trials in which the thermal state of Semifinished Products was examined during radial-shear rolling, forging, the piercing of shells, and the rolling of tubes on a unit equipped with a Pilger mill.
A K Shmakov - One of the best experts on this subject based on the ideXlab platform.
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analysis of the thermal state of a Semifinished Product during hot die forging
Metallurgist, 2016Co-Authors: I V Kolmogortsev, E V Ledovskikh, S A Osipov, A K ShmakovAbstract:Results are presented from the use of numerical modeling to perform an empirical assessment of the effect of the initial process parameters in hot die forging (the temperatures to which the deforming tools and Semifinished Product are heated) on the temperature field in the Semifinished Product during deformation. A series of numerical experiments is performed on the basis of the finite-elements method, the resulting data are analyzed, and relationships between the parameters are established and explained.
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Effect of the Average Velocity of the Free Part of the Semifinished Product on the Process of Pneumothermal Forming in the Superplastic Regime
Metallurgist, 2013Co-Authors: A K Shmakov, V. Mironenko, K. K. Kirishina, A. S. Stanislavchik, V. V. KotovAbstract:Results are presented from two experiments involving the pneumothermal forming of a cellular Product of alloy OT4-1 in the superplastic regime. It was determined that the average velocity of the free part of the Semifinished Product must be taken into account when using a model in which the stresses depend directly on the deformation rate. © 2013 Springer Science+Business Media New York
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Effect of the Average Velocity of the Free Part of the Semifinished Product on the Process of Pneumothermal Forming in the Superplastic Regime
Metallurgist, 2013Co-Authors: A K Shmakov, V. Mironenko, K. K. Kirishina, A. S. Stanislavchik, V. V. KotovAbstract:Results are presented from two experiments involving the pneumothermal forming of a cellular Product of alloy OT4-1 in the superplastic regime. It was determined that the average velocity of the free part of the Semifinished Product must be taken into account when using a model in which the stresses depend directly on the deformation rate.
