Mathematical Model of Bainitic Transformation in Austempered Ductile Iron

Open access


A mathematical model of austenite - bainite transformation in austempered ductile cast iron has been presented. The model is based on a model developed by Bhadeshia [1, 2] for modelling the bainitic transformation in high-silicon steels with inhibited carbide precipitation. A computer program has been developed that calculates the incubation time, the transformation time at a preset temperature, the TTT diagram and carbon content in unreacted austenite as a function of temperature. Additionally, the program has been provided with a module calculating the free energy of austenite and ferrite as well as the maximum driving force of transformation. Model validation was based on the experimental research and literature data. Experimental studies included the determination of austenite grain size, plotting the TTT diagram and analysis of the effect of heat treatment parameters on the microstructure of ductile iron. The obtained results show a relatively good compatibility between the theoretical calculations and experimental studies. Using the developed program it was possible to examine the effect of austenite grain size on the rate of transformation.

[1] Chester, N.A. & Bhadeshia, H. (1997). Mathematical modelling of bainite transformation kinetics. Journal de Physique IV. C5(7), 41-46.

[2] Bhadeshia, H. (1982). Thermodynamic analysis of isothermal transformation diagrams. Metal Science. 16, 159-165.

[3] Bhadeshia, H. (2001). Bainite in steels. Transformations, microstructure and properties. 2 red., Cambridge: Institute of Materials.

[4] Ławrynowicz, Z. & Dymski, S. (2006). Mechanism of bainitic transformation in ADI. Archives of Foundry. 6(19), 171-176. (in Polish).

[5] Bhadeshia, H. & Edmonds, D.V. (1980). The mechanism of bainite formation in steels. Acta Metallurgica. 28(9), 1265-1273.

[6] Bhadeshia, H. (1981). A rationalisation of shear transformations in steels. Acta Metallurgica. 29(6), 1117-1130.

[7] Ławrynowicz Z. & Dymski, S. (2006). Application of bainitic transformation mechanism for ADI cast iron window molding. Archiwum Odlewnictwa. 6(19), 177-182. (in Polish).

[8] Ławrynowicz, Z. (2016). Kinetics of the bainite transformation in austempered ductile iron ADI. Advances in Materials Science. 16(2), 47-56.

[9] Rees, G.I. & Bhadeshia, H.K. (1992). Bainite transformation kinetics. Part1 Modified model. Materials Science and Technology. 8, 985-993.

[10] Chang, L.C. (2003). An analysis of retained austenite in austempered ductile iron. Metallurgical and Materials Transactions A. 34A, 211-217.

[11] Ławrynowicz, Z. (2009). Attempt to use the bainitic transformation mechanism to model kinetics and microstructure of low alloy steel. Bydgoszcz: Wydawnictwa Uczelniane Uniwerystetu Technologiczo-Przyrodniczego. (in Polish).

[12] Adrian, H. (2011). Numerical modeling of heat treatment processes. Kraków: Wydawnictwa AGH. (in Polish).

[13] Wróbel, M. & Burbelko, A. (2014). CALPHAD method - modern technique for obtaining thermodynamic data. Archives of Foundry Engineering. 14(spec.3), 79-84. (in Polish).

[14] Huang, W. (1991). Termodynamic properties of the Fe-Mn- V-C system. Metallurgical Transactions A. 22A, 1911-1920.

[15] Mrzygłód, B., Kowalski, A., Giętka, T. & Głowacki, M. Characteristics of ADI ductile cast iron with single addition of 1.56% Ni. Archives of Metallurgy and Materials, at editor

[16] Olejarczyk-Wożeńska, I., Mrzygłód, B., Giętka, T., Kowalski, A. & Adrian, H. (2017). Effect of austempering parameters on microstructure of ADI with 1.5% Ni. METAL 2017: 26th International Conference on Metallurgy and Materials. Ostrava: TANGER.

[17] Kluska-Nawarecka. S., Gorny, Z. & Wilk-Kolodziejczyk, D. et al., (2007). The logic of plausible reasoning in the diagnosis of castings defects. Archives of Metallurgy and Materials. 52(3), 375-380.

[18] Nawarecki, E., Kluska-Nawarecka, S. & Regulski, K. (2012). Multi-aspect character of the man-computer relationship in a diagnostic-advisory system, Human - computer systems interaction: backgrounds and applications 2, eds. Zdzisław S. Hippe, Juliusz L. Kulikowski, Teresa Mroczek. - Berlin; Heidelberg: Springer-Verlag.

[19] Kluska-Nawarecka, S. Regulski, R., Krzyżak, M., Leśniak, G. & Gurda, M. (2013). System of semantic integration of non-structuralized documents in natural language in the domain of metallurgy. Archives of Metallurgy and Materials. 58(3), 927-930.

Archives of Foundry Engineering

The Journal of Polish Academy of Sciences

Journal Information

CiteScore 2016: 0.42

SCImago Journal Rank (SJR) 2016: 0.192
Source Normalized Impact per Paper (SNIP) 2016: 0.316


All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 189 189 11
PDF Downloads 79 79 12