The microstructure and, thus, the mechanical properties of cast iron alloys are essentially dependent on
- the chemical composition
- the number of nuclei
- the local cooling rates.
To make reliable predictions, simulation models need to take these three influencing parameters into account.
The fraction of eutectic phase that occurs in equilibrium for a composition during solidification can be described via the corrected degree of saturation SR according to E. Piwowarsky (fraction of eutectic solidification/total solidification) → (C-CE)/(CC-CE).
In the following example of an alloy with a carbon equivalent (CE) of 3.9 %, the eutectic fraction is 83 %, see Figure 1.