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Compacted Graphite Iron with the Addition of Tin

Gumienny G., Kurowska B., Fabian P.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

15--20

EN

The paper presents the effect of tin on the crystallization process, microstructure and hardness of cast iron with compacted (vermicular) graphite. The compacted graphite was obtained with the use of magnesium treatment process (Inmold technology). The lack of significant effect of tin on the temperature of the eutectic transformation has been demonstrated. On the other hand, a significant decrease in the eutectoid transformation temperature with increasing tin concentration has been shown. It was demonstrated that tin narrows the temperature range of the austenite transformation. The effect of tin on the microstructure of cast iron with compacted graphite considering casting wall thickness has been investigated and described. The carbide-forming effect of tin in thin-walled (3 mm) castings has been demonstrated. The nomograms describing the microstructure of compacted graphite iron versus tin concentration have been developed. The effect of tin on the hardness of cast iron was given.

2

Approximation of Ausferrite Content in the Compacted Graphite Iron with the Use of Combined Techniques of Data Mining

Regulski K., Wilk-Kołodziejczyk D., Kacprzyk B., Gumienny G., Rojek G., Mrzygłód B.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 3

117--122

EN

This article presents the methodology for exploratory analysis of data from microstructural studies of compacted graphite iron to gain knowledge about the factors favouring the formation of ausferrite. The studies led to the development of rules to evaluate the content of ausferrite based on the chemical composition. Data mining methods have been used to generate regression models such as boosted trees, random forest, and piecewise regression models. The development of a stepwise regression modelling process on the iteratively limited sets enabled, on the one hand, the improvement of forecasting precision and, on the other, acquisition of deeper knowledge about the ausferrite formation. Repeated examination of the significance of the effect of various factors in different regression models has allowed identification of the most important variables influencing the ausferrite content in different ranges of the parameters variability.

3

Charakterystyka warstwy wierzchniej odlewów z żeliwa z grafitem wermikularnym

Maniarski G., Janik S.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2006

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z. 66 [227]

159-165

PL

Wpływ właściwości technologicznych warstwy wierzchniej odlewów żeliwnych na kształtowanie wyrobów gotowych należy do zagadnień nie do końca zbadanych. Wiele ośrodków badawczych na świecie rozpatruje warstwę wierzchnią jako warstwę wierzchnią kształtowaną poprzez obróbkę mechaniczną. Podjęte prace badawcze prowadzone na naszej uczelni skupiły się na wykorzystaniu WWO do procesu kształtowania w zakresie strefy przejściowej warstwy wierzchniej odlewów z żeliwa. Wyniki badań dotyczące żeliwa z grafitem płatkowym i grafitem sferoidalnym wykazaly, iż ze wzrostem twardości w strefie przejściowej odlewu WWO z żeliwa szarego z grafitem płatkowym oraz stabilizacja twardości WWO odlewu z żeliwa sferoidalnego istnieje możliwość kształtowania powierzchni roboczej w zakresie strefy przejściowej WWO o żądanej twardości. Artykuł ma wskazać, że podobne zależności można uzyskać przy żeliwie z grafitem wermikularnym - tworzywem przyszłościowym.

EN

Influence of specificity of high layer of technological cast belongs to questions on forming of finished product researched not up to the end examined. Many research centers treats high layer as high layer formed through mechanical processing in the world. Taken research led have concentrated on our college on utilization for process of forming in range of transitional zone from WWO of high layer of cast irons. Results of research with petal graphite concerning irons and they have exerted graphite SGI, that with incrementation of hardness number in transitional zone WWO of cast from petal graphite gray irons and stabilization of hardness number exists with in range of transitional zone WWO about demand hardness number capability of forming of working surface cast SGI. Artiele has to indicate, that it is possible to get similar dependences at with compacted graphite irons material of the future.

4

Comparison of evaluation methods of the chemical inhomogeneity of ductile irons alloyed with graded nickel contents

Vojtkuláková Z., Pacal B.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2004

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z. 78

195-200

EN

Graphite irons are multicomponental systems of Fe-C-Si-Mn-i, where i presents another possible additional element. Chemical inhomogeneity of their matrix strongly affects their mechanical and physical properties, and therefore their technical usage. Elemental redistribution during eutectic crystallization is determined, among others, by the distribution coefficients of an element M between the austenite and the melt saturated with carbon. To describe the elemental redistribution, effective distribution coefficient kef(M) is used. The kef(M) is defined as the ratio of concentration of the element M near the graphite to that measured at the periphery of the eutectic cell. Many distribution coefficient measurements in graphite irons show that elements increasing thermodynamic activity of carbon concentrate near graphite, hence their kef(M) after solidification is greater than 1. These are Si, Ni, Cu, Mg, P, S, Al and Co. On the contrary, elements like Mn, Cr, V and Mo, having kef(M) usually smaller than 1, concentrates at the eutectic cell boundary. The contribution deals with comparison of kef(M) for Si and Ni in the as cast state and after heat treatment. Two different methods were used for the effective distribution coefficient determination. Previous experiences show that reliably reproducible determination of kef(M) is possible only for the alloying element content in the order of units of weight percent. For the lower alloying elements content (in the order of 0.1 wt. %), the standard deviation grows due to the cast iron matrix inhomogeneity.