Bauman Moscow State Technical University, Moscow, Russia
A. V. Ivanov, Associate Prof., Dept. of Equipment and Rolling Technology, e-mail: avivanov@bmstu.ru
V. V. Stulov, Dr. Eng., Prof., Dept. of Equipment and Rolling Technology, e-mail: stu@bmstu.ru
O. M. Shafiev, Postgraduate Student, Dept. of Equipment and Rolling Technology, e-mail: oleg.shafiev2016@gmail.com

Approaches to the numerical study of the thermomechanical state of the shell of a continuously cast billet at the early stage of solidification in a mold are presented. Methods are proposed for constructing finite element models that make it possible to adequately describe the state of a continuously cast billet at the stage of solidification in the mold and in the secondary cooling zone, taking into account the real boundary conditions and properties of the materials of the billets and the mold. An approach has been developed for determining, on the basis of experimental data, the values of material constants of material models under high-temperature creep. For unalloyed carbon steels with a carbon content of 0.005–1.540 %, the form of the most suitable equations has been obtained to describe the state of the billet`s shell in the mold and secondary cooling zone at high homologous temperatures in the strain rate range 2.3∙10-2 – 5.5∙10-6 s-1 and degree ofd eformation up to 2 %. Based on the developed finite element model in a flat formulation, thermomechanical processes occurring in the shell of a continuously cast rectangular billet of 3sp steel during solidification in the mold and secondary cooling zone were studied, taking into account real thermal and mechanical boundary conditions, material properties, as well as the temperature and the stress-strain conditions of the mold were determined. Based on the solution of the iterative problem, a mold profile was found at which heat transfer reaches the greatest value. A numerical study of the operation of a continuous casting machine based on the developed approaches makes it possible to determine the thermomechanical state of the billet and operating modes of the mold, as well as to evaluate the influence of various casting factors on the risk of the initiation and development of cracks of various natures.

The work was supported by the Russian Science Foundation grant No. 24-29-00055, https://rscf.ru/progect/24-29-00055/.

1. Ulyanov V. A., Gushchin V. N. Continuous casting of billets. Molds and secondary cooling zone: tutorial. Moscow; Vologda : Infra-Inzheneriya, 2023. 184 p.
2. Gabelaya D. I., Kabakov Z. K., Gribkova Yu. V. Mathematical models and improvement of technology for continuous casting of steel: monograph. Cherepovets : ChSU, 2016. 182 p.
3. Siddiqui M. I. H., Maurya A., Asiri F. Mathematical modeling of continuous casting tundish: A Review. VW Appl. Sci. 2021. Vol. 3, Iss. 1. pp. 92–103.
4. Kamenev S. V. Fundamentals of the finite element method in engineering applications: textbook. Orenburg : OSU, 2019. 110 p.
5. Petrus B., Chen Z., Bentsman J., Thomas B. G. Investigating dynamic thermal behavior of continuous casting of steel with CONOFFLINE. Metallurgical and Materials Transactions B. 2020. Vol. 51, Iss. 6. pp. 2917–2934. DOI: 10.1007/s11663-020-01941-6
6. Wu Zh. et al. Determination of high-temperature creep and post-creep response of structural steels. Journal of Constructional Steel Research. 2022. Vol. 193. DOI: 10.1016/j.jcsr.2022.107287
7. Volkov I. A., Igumnov L. A., Kazakov D. A., Shishulin D. N. Equations of state of unsteady creep under complex loading. Prikladnaya mekhanika i tekhnicheskaya fizika. 2018. Vol. 59. No. 3. pp. 191–202.
8. Novak J. et al. Accelerated cyclic plasticity models for FEM analysis of steelmaking components under thermal loads. Procedia Structural Integrity. 2018. Vol. 8. pp. 174-183.
9. Stulov V. V., Shafiev O. M. On the issue of deformation of the steel billet shell in a CCM mold. Stal. 2021. No. 6. pp. 13–16.
10. Muhammad K. et al. Effect of temperature, cooling rate and casting speed on quality of continuous cast steel billets. Advanced Materials Research. 2022. Vol. 1171. pp. 61-72.
11. Thomas B. G. Simulation of longitudinal surface defect in steel continuous casting. MCWASP XV, Jönköping, Sweden, June 22–23, 2020, 2020 IOP Conf. Ser.: Mater. Sci. Eng. Vol. 861. 012016. DOI: 10.1088/1757-899X/861/1/012016
12. Kong Y. W. et al. A prediction model for internal cracks during slab continuous casting. Metals. 2019. Vol. 9, Iss. 5. pp. 587-604.