Successive steps of growth of compacted graphite in cast irons
Jon Sertucha, Jacques Lacaze, Anna Regordosa, Urko de la Torre
Abstract
Holding during 8 hours a melt prepared for casting SGI leads to fading of the spheroidizing treatment and thus to growth of compacted graphite instead of spheroidal graphite. Such a melt was cast in thermal analysis cups at 25-30 minutes interval without inoculation. It solidified first in the stable system and more and more in the metastable system. Accordingly, recalescence first increased as more of compacted graphite solidified, but then decreased when more and more of the solidification occurred in the metastable system. Comparison of the results of the present study with those of a previous similar series showed a higher peak recalescence while the number of compacted graphite cells and the graphite fraction were the same within experimental scattering. Furthermore, as the amount of spheroidizers was similar in both series, there is no clear reason for this difference in recalescence, which should be investigated further.
Keywords
References
1 Guesser WL, Martins LPR. Stiffness and vibration damping capacity of high strength cast irons. SAE Technical Papers. 2016;25:36-0126.
2 Menk W, Brandenberger U. Process for manufacturing cast iron containing vermicular graphite. United States patent US 4,900,509, 1990.
3 Bazdar M, Abbasi HR, Yaghtin AH, Rassizadehghani J. Effect of sulfur on graphite aspect ratio and tensile properties in compacted graphite irons. Journal of Materials Processing Technology. 2009;209:1701-1705.
4 Regordosa A, de la Torre U, Sertucha J, Lacaze J. Quantitative analysis of the effect of inoculation and magnesium content on compacted graphite irons: experimental approach. Journal of Materials Processing Technology. 2020;9:11332-11343.
5 Liu J, Yi L, Li G, Liu C, Li Y, Yang Z. Influence of fading on characteristics of thermal analysis curve of compacted graphite iron. China Foundry. 2011;8:295-299.
6 Hernando JC, Domeij B, Gonzalez D, Amieva JM, Dioszegi A. New experimental technique for nodularity and Mg fading control in compacted graphite iron production on laboratory scale. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science. 2017;48:5432-5441.
7 Domeij B, Hernando JC, Dioszegi A. Size distribution of graphite nodules in hypereutectic cast irons of varying nodularity. Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science. 2018;49:2487-2504.
8 Regordosa A, de la Torre U, Loizaga A, Sertucha J, Lacaze J. Microstructure changes during solidification of cast irons - Effect of chemical composition and inoculation on competitive spheroidal and compacted graphite growth. International Journal of Metalcasting. 2020;14:681-688.
9 Lacaze J, Regordosa A, Sertucha J. Quantitative analysis of the effect of inoculation and magnesium content on compacted graphite irons: a modelling approach. ISIJ International. 2021;61:1539-1549.
10 Pan EN, Ogi K, Loper CR. Analysis of the solidification process of compacted/vermicular graphite cast iron. AFS Transactions. 1982;90:509-527.
11 Sun GX, Loper CR. Influence of hypereutectic graphite on the solidification of gray cast iron. AFS Transactions. 1983;91:217-224.
12 Shi GQ, Yang Z, Li JP, Tao D, Ma ZJ. Investigation on the graphite nucleation and growth mechanism of the compacted graphite iron. Journal of Materials Processing Technology. 2020;9:8186-8196.
13 Xu C, Wigger T, Azeem MA, Andriollo T, Fæster S, Clark SJ, et al. Unraveling compacted graphite evolution during solidification of cast iron using in-situ synchrotron X-ray tomography. Carbon. 2021;184:799-810.
14 Stefanescu DM, Loper CR, Voigt RC, Chen IG. Cooling curve structure analysis of compacted/vermicular graphite cast irons produced by different melt treatments. AFS Transactions. 1982;90:333-348.
Submitted date:
07/20/2021
Accepted date:
10/22/2021
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