Аннотация
"In this work, the influence of technological factors and the macrostructure of hollow cast billets made of 25CrV steel on the mechanical properties at various temperatures was studied. It has been established that the branched transcrystalline macrostructure of pipe billets is the most favorable. The temperature parameters of continuous casting are determined, which ensure the production of a branched transcrystalline macrostructure of pipe hollow billets. A comparative analysis of the mechanical properties of pipe billets obtained at different temperatures of casting the melt, which have a transcrystalline (columnar) macrostructure, is carried out, and with an increase in the degree of its dispersion, the strength and plastic properties increase. It is shown that the presence of a large temperature gradient promotes the formation of columnar crystals, the orientation of which is determined by the direction of the heat flow. To ensure high mechanical properties, it is necessary to obtain a finely branched transcrystalline macrostructure of the billets. Keywords: 25CrV, hollow billet, macrostructure, mechanical properties, casting temperature."