Numerical Investigation of Temperature and Phase Development of (Deformation-) Dilatometer Specimens

Abstract:

The Gleeble 3500 thermo-mechanical testing machine with ISO-Q dilatometer set-up allows the creation of time temperature transformation diagrams at high cooling rates, after deformation and under constant load with a simple experimental set-up. An isothermal plane with temperature gradients perpendicular to this plane arises in the sample which is used for dilatometrical evaluation. The homogeneity and size of this isothermal region has a decisive influence on the measurement results, but cannot be measured with sufficient accuracy. To gain an accurate understanding of the processes in the sample, a coupled thermo-electrical, thermo-metallurgical, thermo-mechanical finite element model of the experiments is set up. To map the temperature control circuit of the machine, a PID controller is implemented, which controls the voltage of the conductive sample heating between the simulation steps. By comparing the temperature and hardness distribution with the experiments, it is shown that in this way the temperature distribution and phase transformation can be mapped. By the findings, the experimental setup was adjusted. This led to an improvement of the measurement results.

• Periodical: Key Engineering Materials (Volumes 611-612)
• Pages: 1539-1544
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.611-612.1539
• Online since: May 2014
• Authors: Stefan Lutz*, Johannes Weninger, Bastian Helldörfer, Marion Merklein
• Keywords: Closed Loop Control, Heat Treatment, Numerical Simulation, Quenching Dilatometry

References

[1] C. Acht, et al, Ermittlung der Marterialdaten zur Simulation des Durchhärtens von Komponenten aus 100Cr6, HTM J. Heat Treatm. Mat., Vol. 63, Nr. 5 (2008) 234-244.

DOI: 10.3139/105.100470

[2] S. G. R. Brown, et al, A 3D numerical model of the temperature-time characteristics of specimens tested on a Gleeble thermomechanical simulator, Modelling Simul. Mater. Sci. Eng, Vol. 5 (1997) 539-548.

DOI: 10.1088/0965-0393/5/6/001

[3] N. N., Applications of ISO-Q Quenching and Deformation Dilatometer, Dynamic Systems Inc., Poestenkill, (2001).

[4] S. D. Norris, I. Wilson, Application of 3D numerical modeling for thermal profile optimization on the Gleeble thermomechanical simulator, Modelling Simul. Mater. Sci. Eng, Vol. 7 (1997) 297-309.

DOI: 10.1088/0965-0393/7/3/301

[5] C. Zhang, et al, A Coupled Electrical-Thermal-Mechanical Modeling of Gleeble Tensile Tests for Ultra-High-Strength Steel at a High Temperature, Metall. Mater. Trans., Vol. 41 (2010) 2304-2317.

DOI: 10.1007/s11661-010-0310-7

[6] F. Wever, A. Rose, Atlas zur Wärmebehandlung der Stähle, Verlag Stahleisen M. B. H., Düsseldorf, (1961).