Thermodynamic Analysis and Impact of Quenching on Microstructure & Mechanical Properties of High Silicon Ductile Iron
DOI:
https://doi.org/10.24425/afe.2025.153773Abstract
Solid-solution-strengthened ferritic ductile iron (SSFDI) exhibits superior tensile strength to elongation ratios up to a critical silicon content of 4.3 wt.%. Beyond this threshold, this material experiences a sudden drop in ultimate tensile strength and elongation at breakage. Previous studies indicate that this is may be because of the formation of superstructures like B2 and D03 especially at regions with high silicon content. This study aims to comprehend thermodynamics behind phase transition during solid-state transformation in high silicon ductile iron. Using thermodynamic simulations, this current investigation tries to pinpoint the transition temperature from the ferritic phase to superstructure formation especially B2 superstructure. Additionally, analysis is made to see consequences of quenching above this transition temperature on microstructure, and mechanical properties. The results contribute insights into phase transitions in high silicon ductile iron, offering practical guidance for optimizing heat treatment processes. By isolating the transition temperature and evaluating the impact of quenching, we provide actionable strategies for controlling microstructural evolution and enhancing mechanical performance in SSFDI. In conclusion, this research represents a crucial advancement in realizing the full potential of high silicon ductile iron for engineering applications. The findings deepen our understanding of the material's behavior and furnish practical approaches for improving its mechanical properties through controlled heat treatments and quenching processes.References
[1] Björkegren, L.E. (1994). Ferritic ductile iron with higher silicon content. Secondary Ferritic ductile iron with higher silicon content. Swedish Foundry Association (941028).
[2] Alhussein, A., Risbet, M. & Favergeon, J. (2014). Evolution of ferritic iron resistance through silicon content in secondary evolution of ferritic iron resistance through silicon content.
[3] White, W.H., Rice, L.P. & Elsea, A.R. (1951). Influence of silicon content on mechnical and high-temprature properties of nodular cast iron. Secondary Influence of Silicon Content on Mechnical and High-Temprature Properties of Nodular Cast Iron. AFS Transactions. 337-345.
[4] Riebisch, M., Pustal, B. & Bührig-Polaczek, A. (2020). Impact of carbide-promoting elements on the mechanical properties of solid-solutions strengthened ductile iron. International Journal of Metalcasting. 14(2), 365-374. https://doi.org/10.1007/s40962-019-00358-5.
[5] Deutsches Institut für Normung e.V. (2012). DIN EN 1563: Gießereiwesen - Gusseisen mit Kugelgraphit. Deutsche Fassung EN 1563:2011.
[6] de la Torre, U., Loizaga, A., Lacaze, J. & Sertucha, J. (2014). As cast high silicon ductile irons with optimised mechanical properties and remarkable fatigue properties. Materials Science and Technology. 30(12), 1425-1431. https://doi.org/10.1179/1743284713Y.00000004.
[7] Stets, W., Löblich, H., Gassner, G. & Schumacher, P. (2014). Solution strengthened ferritic ductile cast iron properties, production and application. International Journal of Metalcasting. 8, 35-40. https://doi.org/10.1007/BF03355580.
[8] David Joseph, B., Alkhozaae, H., Pustal, B. & Bührig-Polaczek, A. (2023). Impact of quenching and aluminium on si-segregation and B2 superstructure formation in solid
solution strengthened ferritic ductile cast iron. International Journal of Metalcasting. 1-11. https://doi.org/10.1007/s40962-023-01238-9.
[9] Weiß, P., Tekavčič, A. & Bührig-Polaczek, A. (2018). Mechanistic approach to new design concepts for high silicon ductile iron. Materials Science and Engineering A. 713, 67-74. https://doi.org/10.1016/j.msea.2017.12.012.
[10] Hasse, S. (1996). Duktiles Gußeisen: Handbuch für Gusserzeuger und Gussverwender in Secondary Duktiles Gußeisen: Handbuch für Gusserzeuger und Gussverwender. Fachverlag Schiele & Schoen.
[11] Retrieved June 10, 2024, from https://micress.rwth-aachen.de/
[12] Retrieved June 10, 2024, from https://thermocalc.com/
[13] Andersson, J. O., Helander, T., Höglund, L., Shi, P., & Sundman, B. (2002). Thermo-Calc and DICTRA, computational tools for material science. Calphad. 26(2), 273-312. https://doi.org/10.1016/S0364-5916(02)00037-8.
[14] Deutsches Institut für Normung e.V.(2022). DIN 50125: Prüfung metallischer Werkstoffe – Zugproben.
[15] Beckert, M. & Klemm, H. (1962). Handbuch der metallographischen Ätzverfahren.
[16] Deutsches Institut für Normung e.V. (2010). DIN EN ISO 945-1: Mikrostruktur von Gusseisen – Teil 1: Graphitklassifizierung durch visuelle Auswertung.
