Year: 2026
Type: article
Abstract: In ultra-high cleanliness steel, it is necessary to control not only primary inclusions but also fine secondary inclusions generated during solidification process. Therefore, thermodynamic information on molten steel and inclusions at solidification temperatures is required to establish precise inclusion control. However, past thermodynamic studies of molten steel and oxides have been conducted mainly around the steelmaking temperature of approximately 1873 K, and there have been no studies below 1773 K. In this study, equilibrium experiments between Fe-Ni alloy and Al2O3-MnO-SiO2 slag were conducted. Fe-Ni alloys are used in precision machinery and microfabrication due to their low thermal expansion. Al2O3-MnO-SiO2 system is one of the major composition of inclusions of Fe-Ni alloys. By using an Al2O3 crucible in equilibrium experiments, Al2O3 saturation condition (activity of Al2O3 is unity) was achieved, and the Al deoxidation equilibrium of Fe-36mass%Ni and Fe-50mass%Ni was measured. The experimental temperature was set at 1733K, which is near the solidification temperature of Fe-Ni alloys. This is the lowest temperature studied on Al deoxidation equilibrium of Fe-Ni alloys. The experimental results were analyzed based on Wagner's interaction formalism. Then interaction coefficients for the Al deoxidation equilibrium of Fe-Ni alloys valid from 1733 K to 1973 K were determined. Liquid Al2O3-MnO-SiO2 slag compositions saturated with Al2O3 were also obtained in this study, and the reported phase diagrams of Al2O3-MnO-SiO2 system were also evaluated.
Source: ISIJ International
Institutions: Tohoku University, Japan Steel Works (Japan), Curtin University
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $700
Award: 究極的な介在物分布制御による次世代金属組織制御技術の開発
OpenAlex ID: W7204971983