A detailed examination of two types of inoculants used in ductile irons

摘要

An experimental study was carried out in order to investigate some aspects of inoculation and nucleation in ductile iron. Two different types of inoculants were used at two different levels of addition. The fading effect of the potential nucleiwere studied by holding the melt for 15 minutes and then repeating the same experiments. Plates (4 to 50 mm) were cast and the cooling curves were studied by thermal analysis to evaluate some key parameters as well as the rate of the solidificationprocess.It was shown that the nodule count is proportional to the supercooling below the eutectic temperature in agreement with literature, but that a critical supercooling is needed for massive nucleation to occur.From the thermal analysis it was found that there may be at least two classes of nuclei being activated at different super-coolings.