Effect of MgO on crystallization behavior of MnO-SiO2-Al2O3 based inclusions in tire cord steel

Qiang Zeng; Jianli Li; Qi Xu; Yue Yu

doi:10.1016/j.heliyon.2022.e11800

Effect of MgO on crystallization behavior of MnO-SiO₂-Al₂O₃ based inclusions in tire cord steel

Heliyon. 2022 Nov 23;8(11):e11800. doi: 10.1016/j.heliyon.2022.e11800. eCollection 2022 Nov.

Authors

Qiang Zeng¹, Jianli Li^{1

2

3}, Qi Xu¹, Yue Yu¹

Affiliations

¹ The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China.
² Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan, 430081, China.
³ Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan, 430081, China.

Abstract

Increasingly MgO content in refining slag and molten steel is the major cause of corrosion of refractory materials at slag line during the refining process of Si-Mn deoxidized tire cord steel, the effects on the crystallization behavior of typical MnO-SiO₂-Al₂O₃ based inclusions in tire cord steel were studied. The relation between the formation of high melting point and high hardness inclusions (Al₂O₃, 3Al₂O₃·2SiO₂, MgO·Al₂O₃ and 2MgO·SiO₂) with MnO-SiO₂-Al₂O₃-(0wt.%, 4wt.%, 8wt.%, 12wt.%, 16wt.%) MgO system was verified by ICP, XRD, SEM-EDS and FactSage 8.0. The results indicated that the crystallization temperature of MnO-SiO₂-Al₂O₃ system increases with the increase of MgO content. Mg _x Mn_(2-x)SiO₄(1 ≤ x < 2) solid solution is the main crystalline phase due to isomorphism. Only a small amount of 2MgO·SiO₂ which is not enough to cause wire breakage was formed in the trial with the highest MgO content (16wt.%) after the low melting point MnO-SiO₂-Al₂O₃ composition added different MgO content and the other three kinds of inclusions were not produced in the five trials.

Keywords: Crystallization; Isomorphism; Olivine; Si–Mn deoxidation; Tire cord steel.