Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia
V. M. Kolokoltsev, Dr. Eng., Prof., Advisor to the Rector’s Office, e-mail: kwm@magtu.ru
N. A. Feoktistov, Cand. Eng., Associate Prof., Head of the Dept. of Foundry Processes and Materials Science, e-mail: fna87@mail.ru
A. S. Savinov, Dr. Eng., Associate Prof., Director of the Institute of Metallurgy, Mechanical Engineering and Materials Processing, e-mail: savinov_nis@mail.ru
E. V. Skripkin, Postgraduate Student, Dept. of Foundry Processes and Materials Science, e-mail: skripkin.ev@mzpv.mmk.ru

The article presents the research results of experimental steel for sHSS mill roll working layer. The issue of structure and properties controlling for the developed alloy by heat treatment is considered. In crystallization process of a cast billet, a martensitic structure is formed, in which a carbide phase of a certain composition is separated. Moreover, there is a certain amount of residual austenite, which can lead to the product damage while it is in operation in the stands of hot rolling mills. Heat treatment in the form of homogenization and subsequent tempering leads to a change of qualitative and quantitative characteristics of the microstructure, thereby changing the properties of a mill roll working layer, affecting wear resistance. The research results showed that the heat treatment of experimental steel has an effect on the grain size, the amount of carbide phase, and residual austenite. The issue of complex microstructure transformation in the process of heating steel during heat treatment is considered and the temperature ranges of martensite decomposition, the austenitic phase formation and dissolution of carbides in solid solution are determined. Metallographically, the volume fraction of the carbide phase that remains undissolved in austenite has been determined, as well as the effect of the homogenization temperature on this process has been established. In addition, the data on the effect of the homogenization temperature on the process of the grain solid solution transformation during heat treatment are presented. The article also examines a correlation between the quantitative characteristics of the carbide phase and the properties of experimental steel. The established results allow controlling the process of structure formation through heat treatment, as well as influence on the product performance.
The work was carried out within the framework of the project "Advanced production technologies and materials", project No. 2022-26.

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