Modelling of precipitation in an Fe-C-Cr alloy

Abstract: Precipitation modelling is interesting from both an academic and an industrial point of view. Such modelling tools may be used in the field of integrated computational materials engineering (ICME) for design and optimization of material properties. The aim of this thesis was to provide validation and further development of the model developed by Bonvalet et al (Acta Materialia 100, 2015, p. 169–177). The model was implemented in a Python code, which utilizes the TC-Python SDK from Thermo-Calc Software. Comparisons between the present work implementation and the commercial software module TC-PRISMA were carried out for precipitation simulations in a Fe–0.16 wt% C–4.0 wt% Cr alloy. Moreover, a systematic study of the influence of the interfacial energy and the number of nucleation sites on precipitation kinetics was performed. The results indicate that the present work model and TC-PRISMA calculate growth and coarsening of precipitates in a similar manner, but the models differ in how nucleation-related parameters are treated. Most significantly, the two models calculate the driving force in different ways. This causes the precipitation kinetics to be shifted in time between the two models.