Simulation of Non-Metallic Inclusions Formation during Liquid Steel Reoxidizing

Alexander Alexeenko and Elena Baybekova
Laboratory of Special Metallurgy Co.

International Symposium on Liquid Metal Processing and Casting - Presentation at Steel Processing Session

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Аннотация

Proceedings of the International Symposium on Liquid Metal Processing and Casting. TMS. Santa Fe (New Mexico, USA), September 23-26 2009, pp. 151 - 158.

Processes of inclusion formation during steel reoxidation have been explored by both computer simulation and SEM analysis of oxide inclusions in steel samples. The thermodynamic-based model of interaction between oxide inclusions and liquid metal in approaching the equilibrium state and a program for computation of inclusions transformation are developed. For Al- and Si-killed steels the trajectories for change chemical composition of inclusions from an initial FeO phase formed during reoxidation to the final inclusion oxide phase were computed. The computation results correlate well with SEM analysis of real reoxidation inclusions. The heterogeneous inclusions (grains of solid spinels solution |MnO.Al2O3,FeO.Al2O3| + interlayers from a phase based on the Al2O3–SiO2–MnO system and the Al2O3 cover) are formed in LCAK-steel with Si content 0.01 wt. pct. The solid inclusions based on Al2O3–SiO2–MnO system are generated in LCAK-steel with Si content 0.2 wt. pct. The manganese silicates are formed in low carbon Si-killed steel. The results of the computer simulation and SEM analyses provide both a better understanding of genesis of inclusions detected in steel, including coarse oxide inclusions found near defects, and an optimal way for technology improvements.

References

1. D. Ya. Povolotskii, Deoxidation of steel (Мoscow, Metallurgiya, 1972), 208.

2. H.- U. Lindenberg and H. Vorwerk , Effect of atmospheric oxidation on the steel purity, in Pure steel, Ed. by A. G. Shalimov (Moscow, Metallurgiya, 1987), 176–188.

3. D.A. Frank-Kamenetskii, Mass and heat transfer at chemical kinetics (Moscow, Nauka, 1967), 492.

4. V.A. Grigoryan, L.N. Belyanchikov, A.Ya. Stomachin, Theoretic fundamentals of electric steel-making processes (Мoscow, Metallurgiya, 1987), 272.