Volgograd State Technical University, Volgograd, Russia
S. B. Gamanyuk, Cand. Eng., Associate Prof., Dept. of Technology of Materials, e-mail: gamanuk@mail.ru
D. V. Rutskii, Cand. Eng., Associate Prof., Head of the Dept. of Technology of Materials, e-mail: drutskii@vstu.ru
N. A. Zyuban, Dr. Eng., Prof., Dept. of Technology of Materials, e-mail: tecmat49@vstu.ru
M. V. Kirilichev, Head of the Laboratory of the Dept. of Technology of Materials, e-mail: tecmat@vstu.ru

The paper presents the results of a laboratory study of refilling the profitable part of the ingot with melt, after a certain time interval after pouring the ingot body on the quantitative and qualitative characteristics of convective motion, the process of solidification and structure formation of the model ingot. The research was carried out by the method of physical (cold) modeling, for which a laboratory installation (mold-mold) was developed and manufactured, which allows visually studying the processes occurring during solidification and structure formation on a model of an ingot weighing 19.6 tons. Sodium sulfuric acid (crystalline hyposulfite) was used as a modeling solution. The correspondence of the processes occurring on the model and in real conditions of casting of industrial ingots was evaluated using similarity criteria obtained on the basis of dimension theory based on the analysis of physico-chemical processes occurring during casting and crystallization of the ingot. The casting of the melt into the mold-mold was carried out from above. The results of the research have established that model ingots, which are cast with refilling of the profitable part by melt after a specified time interval after pouring the ingot body, harden 1.4 times faster than the ingot cast according to classical technology. It was found that refilling the profitable part with melt contributed to a 1.3-fold increase in the volume fraction of the zone of columnar crystals, a 1.3-fold decrease in the volume fraction of the axial zone and a 2.2-fold decrease in the volume fraction of the zone of differently oriented crystals in model ingots. It is shown that for an ingot cast with refilling of profit by melt after 20 minutes, the length of the axial zone of the ingot is reduced by 1.8 times. The obtained results make it possible to develop a technology for differentiated casting of ingots when filling their profits with melt, which will allow regulating the processes of forming the metal structure and reducing the length of the axial zone.
The research was supported by the Russian Science Foundation grant No. 23-29-00973, https://rscf.ru/project/23-29-00973/.

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