On Equilibrium Phase Diagram of the Iron - Carbon System

In the present work theoretical and experimental investigations have been carried out, which made it possible to show that at temperatures below 727 degrees C ferrite and cementite at carbon content up to 6.67% (mass) and cementite and graphite at carbon content over 6.67% are equilibrium phases. Thus, it turns out that in the iron-carbon equilibrium phase diagram at the temperature 727 degrees C there is one more non-alternative three-phase equilibrium and the mono-alternative two-phase equilibrium in the temperature range from 738 degrees C to 727 degrees V at any iron and carbon ratio. A new version of the complete equilibrium phase diagram of the iron-carbon system has been proposed, which enables to reject the conventional superposed version of the equilibrium and non-equilibrium phase diagram of this system.