Fundamental Properties of Cementite and Their Present Understanding

The fundamental properties of cementite (Fe3C) in the literatures have been reviewed. The nonisotropic crystal structure of cementite and its effect on the mechanical and physical properties were presented. The effect of annealing temperature and alloying content on the lattice parameters has been summarized. The thermodynamics of cementite such as specific heat, formation free energy were discussed to show the metastability of cementite. The engineering importance and thermodynamical stability of alloyed cementite was discussed. Finally the mechanical properties (elastic constants, hardness and strength), thermal properties (thermal expansion) and electrical and magnetic properties (electrical resistivity and saturation magnetization) of cementite have been presented.