Modeling of stable and metastable eutectic transformation of spheroidal graphite iron casting

In this work, a mathematical model for stable and metastable transformation of SG cast iron, coupling with microsegregation of some elements and laten t heat resulted from different phase formation, was presented. The quantita tive experimental results of specimens obtained from a step-shape sample ca sting were compared with the simulation, and two results of nodular counts and sizes agreed quite well, For white eutectic growth in mottled SG iron, the frequent impingement of white eutectic with austenite-graphite bulks mi ght suppress its growth remarkably and result in quite lower growth rate th an that from the melt exclusively. Meanwhile, the relationship of morpholog y of carbides and solidification was discussed, and it was indicated that t he growth of white eutectic and carbide morphology could also be predicted by solidification simulation. It was found that neglecting silicon microseg regation, if metastable transformation was advantageous to stable, the simu lated carbide fraction was higher, and vice versa.