Carbon is one of the most important alloying elements in steel and many properties of these systems strongly depend from the redistribution of carbon atoms during aging and tempering processes. Then, accurate prediction and control the mechanical properties of steel depends on a detailed understanding of the kinetics and microstructure of Fe-C system. According to metastable phase diagram, at room temperature the ferrite bcc phase (α-Fe) coexists with carbides. At this temperature, one of the more stable carbide is cementite (θ-Fe₃C) which appears during slow cooling. However, beside cementite phase many other metastable iron carbides has been observed experimentally or predicted by theoretical consideration.In this work, we studied structural transformations during low-temperature aging in Fe-C alloy using computer modeling  based on the atomic density field method. It is shown that homogeneous bcc solid solution with 2at% of C undergoes disorder-order phase transformation passing  by the formation of different metastable phases. The link between  all these metastable carbides is discussed based on the Fe2n+1Cn (n=1,2,3,…) Magnéli phases.  Simulated microstructures are compared with experimental data.