Fe4C

Fe₄C is an iron carbide compound representing a stoichiometric phase in the iron-carbon system, situated between pure iron and cementite (Fe₃C) in the equilibrium phase diagram. This material is primarily studied in metallurgical research and materials science rather than as a commercial standalone product, serving as a reference phase for understanding steel microstructure, carburization behavior, and the thermodynamics of iron-carbon interactions. Engineers encounter Fe₄C conceptually when analyzing hardened steel surfaces, case-carburized components, and high-carbon iron alloys, where it may form transiently or as a metastable phase during heat treatment or wear processes.