Abstract
A literature review of the effect of scanning heating or cooling rate and alloying elements on the eutectoid reaction in spheroidal graphite cast irons is made. These data are used to verify the potentialities of a previous description of the conditions for the start of the transformation during direct and reverse eutectoid reaction. At finite cooling rate as used in practical heat treatments, the direct eutectoid transformation starts at the lowest temperature limit of the relevant three phase field, either stable or metastable. Upon heating, decomposition of a ferritic matrix starts at the highest temperature of the stable three-phase field, while the reference temperature for the start of the transformation for alloys with a pearlitic matrix is the same upon cooling and heating.
