Characterization and thermodynamics of Al2O3-MnO-SiO2(-MnS) inclusion formation in carbon steel billet

Autor: Chong-min Zhang, Sheng-li Li, Chao-bin Lai, Xin-gang Ai, Guo-cheng Wang
Rok vydání: 2015
Předmět:
Zdroj: Journal of Iron and Steel Research International. 22:566-572
ISSN: 2210-3988
1006-706X
DOI: 10.1016/s1006-706x(15)30041-8
Popis: A method to extract inclusion particles from solid steel by electrolysis with organic electrolyte solution was introduced; meanwhile, thermodynamics of inclusion formation was calculated using FactSage software. The results showed that there were two kinds of inclusions in the billet, i.e. Al2O3-MnO-SiO2-MnS (AMS-MnS) and Al2O3-MnO-SiO2 (AMS). Most of AMS-MnS inclusion particles, with diameter of 10 – 30 μm, showed three-layer structures: SiO2-rich core with a small quantity of Mn, intermediate AMS layer, and MnS outer layer containing small quantities of Al and O. Most AMS inclusion particles were 50 − 90 μm and exhibited homogeneous composition. Thermodynamic results indicated that SiO2-rich core could form firstly by Si reacting with O in molten steel at temperatures above 1 923 K during Si-Fe alloy addition, and then, the SiO2-rich core could react with Mn and Al to form liquid AMS enveloping the SiO2-rich core at 1823 – 1873 K. MnS began to precipitate from AMS when temperature reached 1 728 K. Liquid AMS could form by coupled reaction among Si, Mn, Al and O in molten steel.
Databáze: OpenAIRE
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