|
The
difference between the various grades of ductile iron is in the
microstructure of the metal around the graphite. This
microstructure varies with the composition (relative amounts of carbon,
silicon, nickel, manganese, etc) and the cooling rates in the
casting.
-
High
ductility grades have a ferrite microstructure.
-
Intermediate
grades have a mixed ferrite and pearlite microstructure.
-
High
strength grades have a primary pearlite microstructure.
|