Application of Thermo-Calc TCFE7 to High-Alloyed Mottled Cast Iron

Abstract:

The thermodynamic modeling of alloy systems consisting of stable and metastable phases e.g. high-alloyed mottled cast iron can be problematic. Thermodynamic databases are rather well-developed for low, medium and high alloyed steels (e.g. HSS) but the application of those databases is not yet very common for high-alloyed (mottled) cast irons. The Thermo-Calc software together with the TCFE7 database is used to calculate isopleth and property diagrams, using the CALPHAD method. Additionally Scheil-Gulliver calculations are performed to simulate the effects of microsegregation during solidification. The results from the thermodynamic calculations are compared with measurements on own samples and with literature values. Those measurements include quantitative light-optical analysis, SEM with BSE detector, EDX measurements for the distribution of the alloying elements as well as XRD and DSC measurements. The investigations show the possibilities which are offered by thermodynamic calculations for high-alloyed mottled cast iron as well as the limitations and the compromises which have to be taken into account when calculating stable and metastable phases existing next to each other.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 1431-1436
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.1431
• Online since: November 2016
• Authors: Armin Paar*, Leonel Elizondo, Michael Brandner, Thomas Trickl, Bernhard Sonderegger, Coline Beal, Christof Sommitsch
• Keywords: Mottled Cast Iron, TCFE7, Thermo-Calc, Thermodynamic Modeling

References

[1] K. Yamamoto and K. Ogi, The Analysis of the Solidification Process of Abrasion Resistant Cr-V Cast Iron by the Use of Thermo-Calc, Proceedings of the 65th World Foundry Congress, (2002).

[2] M. Pellizzari, Thermodynamic modeling for the alloy design of high speed steels and high chromium cast irons, Materials and technology 44 (2010) 3 121-127.

[3] H. Qu, B. Liao, L. Liu, D. Li, J. Guo, X. Ren and Q. Yang, Precipitation rule of carbides in a new high speed steel for rollers, CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry 36 (2012) 144-150.

DOI: 10.1016/j.calphad.2011.06.006

[4] A. Sommerfeld, Untersuchungen zur Graphitkeimbildung in GJL-Schmelzen, Dissertation Technische Universität Clausthal, (2010).

[5] S.V. Bravo, K. Yamamoto, H. Miyahara and K. Ogi, Control of Carbides and Graphite in Cast Irons Type Alloy's Microstructures for Hot Strip Mills, Journal of Metallurgy (2012).

DOI: 10.1155/2012/438659

[6] G. Pöckl, Karbidfeinung und nichtmetallische Einschlüsse in ledeburitischen Werkzeugstählen insbesondere Schnellarbeitsstählen, Dissertation Montanuniversität Leoben, (2000).

[7] K. H. Ziehenberger, Legierungstechnische Verbesserung gegossener Schnellarbeitsstahlwalzen für Warmbreitbandstraßen, Dissertation Technische Universität Wien, (2002).

[8] K. Inoue, N. Ishikawa, I. Ohnuma, H. Ohtani und K. Ihsida, Calculation of Phase Equilibria between Austenite and (Nb, Ti, V)(C, N) in Microalloyed Steels, ISIJ International 41 (2001) 2 175-182.

DOI: 10.2355/isijinternational.41.175

[9] K. Frisk, Thermodynamic modelling of multicomponent cubic Nb, Ti and V carbides/carbonitrides, Computer Coupling of Phase Diagrams and Thermochemistry 32 (2008) 326-337.

DOI: 10.1016/j.calphad.2007.11.007

[10] A. Markström, D. Andersson und K. Frisk, Combined ab-initio and experimental assessment of A1-xBxC mixed carbides, Computer Coupling of Phase Diagrams and Thermochemistry 32 (2008) 615-623.

DOI: 10.1016/j.calphad.2008.07.014