Influence of different inoculants on the nucleation potential and the contraction ability of the ductile iron

The use of advanced control systems based on cooling curves allows to analyse the characteristics of the melt in real time along the manufacturing process. In this work, the system mentioned above has been utilised so as to study the efficiency of the inoculation step, to determine which substrates have the optimum ability for nucleating spheroidal graphite, to minimise the tendency to form cementite phase and to reduce the capacity of the melt to form microshrinkage defects. Thus, 10 different commercial inoculants have been selected in order to investigate the efficacy of several chemical elements included in their composition for nucleating nodules in ductile iron. In addition, trials performed on real castings are included in this work so as to verify the results obtained from the selected inoculants.