Application on statistical value of phase structure formation factor to Fe-C phase diagram

Based on the empirical electron theory in solids and molecules (EET), the statistical value of phase structure formation factor (S') was calculated by using the calculation methods of statistical value of alloying valence electron structure parameters. The effects of alloying elements upon austenitic zone of Fe-C phase diagram were discussed. The results show that: 1) Mn and Ni can increase the S' value of gamma-Fe and austenitic phase, which increase their stability, leading to expand the gamma-zone; 2) Cr, Mo and Si can increase the S' value of ferrite and cementite, which make them easier to precipitate, leading to reduce gamma-zone. The research results agree well with real situations.