Comparison of Measured Phase Volumes with Calculated ones Created by TTT-CCT Diagram Transformation

Abstract:

Knowledge of the TTT (Time-Temperature-Transformation) or CCT (Continuous- Cooling-Transformation) diagrams of steels is an important factor in the thermo-mechanical processing of steels. Much experimental work has been undertaken to determine such diagrams. Significant works have been written which can calculate TTT and CCT diagrams for steels. The aim of the present work is to show the developed model that can provide accurate enough TTT and CCT diagrams for steel 42 CrMo4 (where the austenitisation temperature was 1050°C). The calculated results are compared by the experimental results. The developed TTT phase transformation diagrams based on FEM-based phase elements and the star-like cooling simulation make it possible to create virtual CCT diagram data.

• Periodical: Materials Science Forum (Volumes 537-538)
• Pages: 497-504
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.537-538.497
• Online since: February 2007
• Authors: Zoltán Dudás
• Keywords: 42 CrMo 4 Steel, CCT-Diagram, Finite Element Method (FEM), Phase Element, Phase Transformation, Star Like Cooling, TTT Diagram

References

[1] Z. Dudás, J. Ginsztler: Phase Elements for coupled Simulation of TTT and CCT diagrams, Proc. of. 3th Conference on Mechanical Engineering, Budapest, 30-31 May 2002, Hungary, Vol. I., pp.149-153.

[2] Z. Dudás, J. Ginsztler: Some Examples of the Use of Phase Elements for coupled Simulation of TTT and CCT diagrams, Proc. of. 3 th Conference on Mechanical Engineering, Budapest, 30-31 May 2002, Hungary, Vol. I., pp.154-158.

[3] Z. Dudás, J. Ginsztler: Creation and interactive Control of the data of the isothermal TTT diagrams constructed by Phase Elements, Proc. of. 4th Conference on Mechanical Engineering, Budapest, 27-28 May 2004, Hungary, Vol. I., pp.47-51.

[4] Z. Dudás, J. Ginsztler: Analysis and Comparison of the isothermal transformation Processes of the CrMo4 type Materials applying TTT diagrams containing FEM based Phase Elements, Proc. of. 4th Conference on Mechanical Engineering, Budapest, 27-28 May 2004, Hungary, Vol. I., pp.77-81.

DOI: 10.4028/www.scientific.net/msf.473-474.321

[5] Z. Dudás: Comparing of the Processes of the isothermal Phase Transformations of the Material 50 CrV4 using different TTT diagrams and applying FEM based Phase Elements, Materials Science Forum, Vols 473-474, Switzerland, 2005, p: 321-328.

DOI: 10.4028/www.scientific.net/msf.473-474.321

[6] I. Tzitzelkov: Eine mathematische Methode zur Beschreibung des Umwandlungsverhaltens eutektoidischer Stähle, PhD Dissertation, TH Aachen 1973, pp.1-66.

[7] Rose: Atlas für Wärmebehandlung der Stähle, Düsseldorf, 1952 Fig. 13 The picture of the volume of the phases at the temperature 650°C Fig. 14 The picture of the change of the volume of the second phases depending on the stare like time steps from T=780° to T=650°C.