Fe-Mn-Al-C steels are promising materials to design lighter automotive safety parts. It has been shown experimentally that upon cooling, high temperature austenite decomposes into low temperature austenite and kappa carbides via spinodal decomposition and ordering process. In this paper, a meanfield model at the atomic scale designed to simulate the formation of kappa-carbides is proposed. The first results obtained prove the ability of the model to reproduce several experimental observations such as the L1(2) ordering of the disordered FCC, the E2(1) ordering of C atoms leading to the formation of the kphase or the partition of C atoms between disordered FCC and the L1(2) phase during the spinodal decomposition. (C) 2016 Elsevier B. V. All rights reserved.