Tula State University (Tula, Russia):
O. V. Pantyukhin, Cand. Eng., Associate Prof., e-mail: olegpantyukhin@mail.ru
S. A. Vasin, Dr. Eng., Prof., e-mail: vasin_sa53@mail.ru

On the basis of the conducted experiments with the use of pressing and thermal equipment, a mathematical model of the value of the wall hardness of the semi-hot extrusion machine as a key process in the manufacturing technology of steel cylindrical hollow parts manufactured for the mechanical engineering and mining industries was obtained using experimental planning methods. It is noted that the technological process of manufacturing steel cylindrical hollow parts with a key operation of double-sided semi-hot extrusion with distribution is a promising process that allows to ensure high plasticity and strength of the semi-finished product material and obtain the required mechanical properties of the metal. The developed mathematical model made it possible to solve the actual problem of choosing the optimal modes and parameters of the semi-hot extrusion process (processing temperature, degree of deformation, temperature of the cooling medium, geometry of the working tool) and to provide the ability to control the formed properties of the product together with the finishing operations of drawing. Graphical dependences of the wall hardness of the semifinished product on the processing temperature at different values of the radius of the working part of the punch, the degree of deformation and the temperature of the cooling medium are constructed and analyzed. Analysis of the obtained graphs allowed us to identify the parameters that have the greatest impact on the wall hardness of the semi-finished product.

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