Özet:

Obtaining conical shells by forging is an important and relevant task in energy and heavy engineering. Existing processes of their manufacture come down to simplifying the configuration of such billets. The result is the increased material’s consumption while the internal fiber is cut during machining, which also leads to a decrease in mechanical properties. A new forging technique necessitated a study into the shape change of the billet and the distribution of deformations in the process of rolling. A finite-element method was used to investigate the process of rolling out the step hollow billets. Based on the study results, the forging’s taper was established, obtained during the forging process. A research procedure involving the finite-element method was devised to study the operation of conical shells’ rolling, which made it possible to determine a change in the shape and size of a hollow forging when rolled out by a step tool. A parameter has been proposed to quantify the formation of taper in the process of rolling a billet with a flange. Based on the study results, a step-wise distribution of the intensity of logarithmic deformities in the body of a forging was established when conical shells were rolled out. It was found that the step deformation leads to an increase in the uneven distribution of deformations on the part of the protrusion and ledge. Maximum deformations of 1.0...1.2 occur at the inner and outer surfaces of the step billet’s protrusion. Dependences of the shape change in a step billet for the investigated ratios of sizes and rolling modes have been established. It was found that the maximum taper is obtained at a deformation degree of 15 %. It was determined that the degree of compression in the ledge and protrusion is leveled after 3 deformation runs of the step billet Author Biographies Oleg Markov, Donbass State Engineering Academy Akademichna str., 72, Kramatorsk, Ukraine, 84313 Doctor of Technical Sciences, Professor, Head of Department Department of Computerized Design and Modeling Processes and Machines

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