Influence of Al on Evolution of the Inclusions in Ti-Bearing Steel with Ca Treatment

• Main Authors: Yandong Li, Tongsheng Zhang, Huamei Duan
• Format: Article
• Language: English
• Published: MDPI AG 2019-01-01
• Series: Metals
• Subjects: deoxidation; inclusions; thermodynamics; Ti-bearing steel; Ca treatment
• Online Access: https://www.mdpi.com/2075-4701/9/1/104

Experimental simulations of steelmaking with different amounts of aluminum were achieved in the tube furnace at 1873 K and field scanning electron microscopy and energy dispersive X-ray spectroscopy (FE-SEM and EDX) were employed to explore the characteristics of the inclusions in Ti-bearing steel during the calcium treatment process. It was found that morphologies, chemical compositions, and the size distribution of the inclusions were obviously different before and after calcium treatment. The calcium addition need be carefully considered regarding the mass fraction of aluminum with the purpose of modifying the solid inclusions to liquid phases. The thermodynamic analysis of inclusion formation in the Al⁻Ti⁻Ca⁻O system at 1873 K was conducted, as well as transformation behaviors of inclusions including all types of solid inclusions and liquid phases during solidification. The thermodynamic equilibrium calculations are in good agreement with experimental data, which can be used to estimate inclusion formation in Ti-bearing steel.