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Park et al. J Mater Inf 2023;3:5 Journal of
DOI: 10.20517/jmi.2022.37
Materials Informatics

Research Article Open Access

Thermodynamic modeling of the Fe-Sn system
including an experimental re-assessment of the

liquid miscibility gap

2
1,2
1
Won-Bum Park , Michael Bernhard , Peter Presoly , Youn-Bae Kang 1,3,*
1
Graduate Institute of Ferrous and Energy Materials Technology, Pohang University of Science and Technology, Pohang 37673,
Korea.
2
Chair of Ferrous Metallurgy, Montanuniversität Leoben, Leoben 8700, Austria.
3
Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea.
* Correspondence to: Prof. Youn-Bae Kang, Graduate Institute of Ferrous and Energy Materials Technology, Pohang University of
Science and Technology, 77 Cheongamro, Namgu, Pohang 37673, Korea. E-mail: ybkang@postech.ac.kr
How to cite this article: Park WB, Bernhard M, Presoly P, Kang YB. Thermodynamic modeling of the Fe-Sn system including an
experimental re-assessment of the liquid miscibility gap. J Mater Inf 2023;3:5. https://dx.doi.org/10.20517/jmi.2022.37

Received: 24 Nov 2022 First Decision: 10 Feb 2023 Revised: 2 Mar 2023 Accepted: 13 Mar 2023 Published: 23 Mar 2023
Academic Editors: Xingjun Liu, Yu Zhong Copy Editor: Ke-Cui Yang Production Editor: Ke-Cui Yang

Abstract
The usage of low-grade ferrous scrap has increased over decades to decrease CO emissions and to produce steel
2
products at a low cost. A serious problem in melting post-consumer scrap material is the accumulation of tramp
elements, e.g., Cu and Sn, in the liquid steel. These tramp elements are difficult to remove during conventional
steelmaking processes. Sn is considered as one of the most harmful tramp elements because, together with Cu, it
sometimes induces the liquid metal embrittlement in high-temperature ferrous processing, e.g., continuous casting
and hot rolling. Furthermore, the chemical interaction between Fe and Sn plays an important role in the Sn smelting
process. The raw material used in the Sn smelting process is SnO (cassiterite), in which Fe O is a gangue in the Sn
2 3 4
ore. In the process, the reduction of Fe O is unavoidable, which results in forming a Fe-Sn alloy (hardhead). The
3 4
recirculation of the hardhead decreases the furnace capacity and increases the energy consumption in the
smelting. The need to efficiently recover Sn from secondary resources is therefore inevitable. The CALculation of
PHAse Diagrams (CALPHAD) approach helps to predict the equilibrium state of the multicomponent system.
Previously reported studies of the Fe-Sn system show inconsistencies in the calculations and the experimental
results. Mainly the miscibility gap in the liquid phase was under debate, as experimental data of the phase
boundary are scattered. Experimental study and re-optimization of model parameters were carried out with
emphasis on the correct shape of the miscibility gap. Three different experimental techniques were employed:

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0
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