Ni is an alloying element added to ferrous alloys designed for rugged use or to obtain alloys with special properties. In the Phase Transformations Laboratory at the Metallurgical and Materials Engineering Department of the University of São Paulo (USP), Fe-Ni-C alloys are used as model systems in order to study decomposition of austenite during cooling, taking advantage of the strong effect of Ni on the driving force of the transformation. Moreover, there is little interaction between Ni and C found in solid solution. In this framework, the aim of the project detailed in the following pages is to support the experimental work that has been carried out in the Department of Melalurgical and Materials Engineering of the University of São Paulo by employing atomistic simulations. Three different approaches are envisaged. First principles calculations should be performed in order to assess an eventual chemical contribution of the alloying elements (Ni and C) in the transformations that Fe-Ni-C alloys may undergo. These calculations are restricted to small volues (a few hundreds of atoms) and take into account only the ground state, i.e., a system state corresponding to a potential energy minimum at T = 0 K. In a larger scale, the classical molecular dynamics allows the treatment of thousands of atoms. This approach makes possible to simulate the evolution in time of the Fe-Ni-C alloys at T >0 K. The underlying chemistry is implicitly taken into account by means of empirical potentials based on the embedded atom method (EAM). In order to reach a time scale larger than what can be done with molecular dynamics, a simple method that has been successfully used is kinetic Monte Carlo.
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