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Investigation of the Effect of Solidification Time and Addition Amount of Inoculation on Microstructure and Hardness in Lamellar Graphite Cast Iron

Çolak Murat, Uslu Emin, Teke Çağatay, Şafak F., Erol Ő., Erol Y., Çoban Y., Yavuz M.

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 4

24--33

EN

Material suppliers typically recommend different additive amounts and applications for foundry practices. Therefore, even in the production of the same standard materials, different results may be obtained from various production processes on different foundry floors. In this study, the liquid metal prepared with the addition of different proportions of a FeSi-based inoculation, which is most commonly used in foundries in the production of a cast iron material with EN-GJL-250 lamellar graphite cast iron, was cast into sand molds prepared with a model designed to provide different solidification times. In this way, the optimization of the inoculation amounts on the casting structure for different solidification times was investigated. In addition, hardness values were determined depending on solidification time in varying amounts of inoculation additions. SolidCast casting simulation software was used to determine the casting model geometry and solidification time. In the scope of the study, sand casting, modeling, microstructure analysis, image analysis, microstructure analysis, and hardness tests techniques were used. When the results are examined, the required amount of inoculation for the optimal structure is optimized for the application procedure depending on the casting module and the solidification time.

2

The Reliability of the Results of the Modified Low-cycle Fatigue Test for Cast Iron Evaluated by Metallographic Studies

Maj M., Pietrzak K.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 1

41--46

EN

This study discloses the characteristic features of the modified low-cycle fatigue test used for the determination of the mechanical properties of two types of cast iron, i.e. EN-GJL-250 and EN-GJS-600-3. For selected materials, metallographic studies were also conducted in the range of light microscopy and scanning microscopy.

3

Modeling the kinetics of solidification of cast iron with lamellar graphite

Kapturkiewicz W., Fraś E., Burbelko A. A.

Archives of Metallurgy and Materials

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2009

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Vol. 54, iss. 2

369-380

EN

The most important results of own studies on modeling the solidification kinetics in lamellar (flake) graphite cast iron were reviewed. A set of basic equations used for modeling the solidification process in macro- and micro-scales was given. A numerical solution of these model equations enables the determination of thermodynamic equilibrium temperature and actual temperature of cast iron solidification, the cooling rate, the heat flux generated during solidification, the fractions of the solidified structural constituents, the size of graphite eutectic grains and austenite dendrites, thickness of graphite lamellar, as well as the segregation of cast iron alloying constituents in liquid phase and in the forming grains. It has also been proved and confirmed by experiments that the grains of graphite eutectic are formed in a two-step process, that is, at the beginning and end of the solidification process. Some important differences in the size of graphite precipitates were observed to exist between the cast plate and cylinder.

PL

Zaprezentowano najistotniejsze rezultaty własnych prac, dotyczących modelowania komputerowego krystalizacji żeliwa z grafitem płatkowym. Przedstawiono zestaw podstawowych równań procesu, odnoszących się do mikro i makro skali. Rozwiązanie numeryczne zestawu równań w postaci programu symulacyjnego pozwoliło na wyznaczenie przebiegu temperatury w czasie stygnięcia odlewu wraz z rozkładem temperatury równowagowej, ciepła generowanego podczas krystalizacji, ilości frakcji zakrzepłej poszczególnych składników strukturalnych żeliwa, wymiaru ziaren austenitu i eutektyki grafitowej, wymiary płatków grafitu jak również mikrosegregacji składników stopu w ziarnach. Potwierdzono eksperymentalnie, że ziarna eutektyki grafitowej mogą zarodkować w dwóch etapach: na początku i pod koniec procesu krystalizacji. Istotne różnice zauważono w wymiarach grafitu w zależnosci od kształtu odlewu.