Iron chromium potential to model high-chromium ferritic alloys

Giovanni Bonny (1) , Roberto C Pasianot (2) , Dmitry Terentyev (3) , Lorenzo Malerba (3)

1 Nuclear Materials Science Institute
2 CAC - Centro Atómico Constituyentes
3 SCK-CEN - Centre d'Etude de l'Energie Nucléaire

In this paper we present a Fe-Cr interatomic potential to model high-Cr ferritic steels. The potential is fitted to thermodynamic and point-defect properties obtained from density functional theory (DFT) calculations and experiments. The here developed potential is also benchmarked against other potentials available in literature. It shows particularly good agreement with the DFT obtained mixing enthalpy of the random alloy, the formation energy of intermetallics and experimental excess vibrational entropy and phase diagram. Also DFT calculated point-defect properties, both interstitial and substitutional, are well reproduced as is the screw dislocation core structure. As a first validation of the potential we study the precipitation hardening of Fe-Cr alloys by means of static simulations of the interaction between Cr precipitates and screw dislocations. It is concluded that the description of the dislocation core modification near a precipitate might have a significant influence on the interaction mechanisms observed in dynamic simulations.

Mots clés: Physical Sciences

Domaines: Matière Condensée [cond-mat]

Giovanni Bonny, Roberto C Pasianot, Dmitry Terentyev, Lorenzo Malerba. Iron chromium potential to model high-chromium ferritic alloys. Philosophical Magazine, 2011, pp.1. ⟨10.1080/14786435.2010.545780⟩. ⟨hal-00667589⟩