OBRABOTKAMETALLOV Vol. 23 No. 3 2021 MATERIAL SCIENCE EQUIPMENT. INSTRUMENTS 6 2 4 Study of the kinetics of forming of spherical sliding bearing parts made of corrosion-resistant steels by die forging of porous blanks Badrudin Gasanov a, *, Nikolai Konko b, Sergey Baev c Platov South-Russian State Polytechnic University (NPI), 132 Prosveshcheniya st., Novocherkassk, 346428, Russian Federation a https://orcid.org/0000-0001-7610-4541, gasanov.bg@gmail.com; b https://orcid.org/0009-0003-8098-2226, konko2013@mail.ru; c https://orcid.org/0009-0006-5527-6620, baiev93@mail.ru Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2024 vol. 26 no. 2 pp. 127–142 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2024-26.2-127-142 ART I CLE I NFO Article history: Received: 13 March 2024 Revised: 08 April 2024 Accepted: 13 April 2024 Available online: 15 June 2024 Keywords: Die forging Powder blank Relative density Coefficient of contact friction Simulation Strain state Acknowledgements Access to QForm cloud license is provided by the Department of Pressure Processing Technologies of Bauman Moscow State Technical University and QuantorForm LLC. ABSTRACT Introduction. Spherical powder sliding bearings are widely used in various branches of mechanical engineering. Therefore, the development of a promising method of production of spherical sliding bearing parts from powders of corrosion-resistant steels with specified properties is an urgent task. Purpose of work: is to study the kinetics of forming during cold die forging of spherical sliding bearing parts from stainless steel powder blanks, and to assess the effect of the chemical composition of lubricants and the design of the pressing tool on the structure and properties of the bearing outer ring. Materials from sprayed powders of stainless chromium-nickel steels obtained by cold die forging of sintered blanks coated with lubricants are studied in the work. The following research methods were used: mechanical tensile testing, metallographic studies and cold die forging process simulation. Results and its discussion. It is revealed that the resistance and work of deformation, as well as the kinetics of forming of the outer ring of the spherical sliding bearing are influenced by chemical composition of powders and lubricants, microstructure and mechanical properties of the blank material, configurations of the end surfaces of punches. The top and bottom edges of the outer bearing are most intensively sealed when the punch faces are made with a chamfer angle of 30–40 degrees. With an increase in the relative strain degree by height up to 0.30–0.35 its residual porosity amounted to 0.5–2.0 %. The features of definition of strain state and calculation of strain energy in the implementation of the offered method and the choice of technological parameters of the cold die forging process of sliding bearings parts are shown. A simple method for calculating and experimentally determining the coefficient of contact friction in the process of cold die forging of porous stainless steel blanks is developed, which allows to establish the effect of lubricant composition on the strain resistance at different values of the degree of radial deformation and to develop optimal methods of cold die forging of porous blanks in the production of parts of different complexity. For citation: Gasanov B.G., Konko N.A., Baev S.S. Study of the kinetics of forming of spherical sliding bearing parts made of corrosionresistant steels by die forging of porous blanks. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2024, vol. 26, no. 2, pp. 127–142. DOI: 10.17212/1994-6309-2024-26.2-127-142. (In Russian). ______ * Corresponding author Gasanov Badrudin G. D.Sc. (Engineering), Professor Platov South-Russian State Polytechnic University (NPI), 132 Prosveshcheniya st., 346428, Novocherkassk, Russian Federation Tel.: +7 928 227-07-16, e-mail: gasanov.bg@gmail.com Introduction Depending on the configuration, dimensions, mechanical and technological properties of materials, various methods of hot and cold die forging of powder products are used [1–3, etc.]. When die forging parts with curvilinear elements, characteristic, for example, of spherical sliding bearings, levers, fine-modular gears and others, it is advisable to design powder blanks taking into account the plasticity of the material, forming schemes, as well as the requirements for the die forged products [4–8]. Particular attention is paid to the design and optimization of technological parameters of powder blanks production, since powder metallurgy methods guarantee greater metal savings, productivity growth, energy costs reduction, etc.
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