The purpose of inoculation is to assist in providing sufficient nucleation sites for dissolved carbon to precipitate
as graphite rather than iron carbide (cementite, Fe3C). This is done by pre venting undercooling below the meta stable eutectic temperature where carbidic (white) structures are formed. The iron solidification mechanism is prone to form chilled iron structures when the inoculation is inadequate. There are several reasons why chilled structures are normally unStable