Phase Diagrams

· The iron-iron carbide diagram is not a true equilibrium diagram as Graphite, and not Fe₃C is the thermodynamically stable phase. The true equilibrium diagram between iron and graphite is shown.

· The choice of phase diagram to use depends on the chemistry and kinetics of the alloy formation.
· High carbon content and slow cooling rates favor graphitization.
· Added alloying elements such as Silicon also increase the graphite content of the alloy.

From: Callister, "Materials Science and Engineering,"
Wiley (1994)