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E. Povoden-Karadeniz, S. Zamberger, E. Kozeschnik:
"Impacts of thermodynamic and kinetic model parameterisation on precipitation simulations - Case study of NbC precipitation in microalloyed steel";
Talk: 46. Calphad International Conference, St. Malo; 2017-06-11 - 2017-06-16.

Computational simulation of precipitation in microalloyed steel is a powerful tool for
improved steel processing. Since the kinetic formulations for nucleation, growth and
coarsening contain thermodynamic state variables, predictive precipitation simulation
requires a proper thermodynamic modelling base, or more general, thermodynamic model
parameterisation affects the kinetic simulation results [1]. For face-centered cubic NbC
precipitates in microalloyed Fe-Nb-C steel, these interrelations were pointed out by Radis
& Kozeschnik [2]. Meanwhile, the Fe-Nb system has been re-assessed three times [3-5],
associated with particular changes of alloy phase descriptions. However, none of these
assessments considered available enthalpies of mixing from first-principles analysis [6].
We present and discuss the consequences of differences of suggested mixing
thermodynamics in Fe-Nb alloy phases on the kinetics of NbC precipitation and propose a
revised thermodynamic parameter set for the reproduction of experimental phase equilibria,
first-principles enthalpies of mixing and kinetics of NbC precipitation during aging of
microalloyed steels.