of the chemical composition
and mechanical properties
will create a great many sites of nucleation as well
as supercooling which will precipitate the austenite
first. Then the graphite will appear at the parting
of the dendrites, thus forbidding the precipitation
of the primary graphite. This graphite formed during
solidification will generate a graphite expansion, more
so as we have a hyper-eutectic iron.
The structure of the iron will be 100%
ferritic, with an extremely fine size of graphite flakes,
which strongly increases the machinability over standard
And as the graphite expansion cannot take place outwards,
like in a sand mold, this will give the iron an increased
compactness, which will in turn give perfectly leak
tight castings obtained by this process. This characteristic
is very useful for parts which are subject to pressure.
The heat treatment brings an added
advantage, as it will get rid of all residual internal
stresses, which could have resulted from the solidification.
This will give the casting a very good dimensional stability