Quantification of the solidification morphology of lamellar and spheroidal graphite cast iron

Abstract

The solidification morphology of lamellar and spheroidal graphite cast iron is examined in a quantitative way. The results are based on quenching experiments of cylindrical castings. Subsequent metallographic examination allows to plot several types of figures. A marked difference may be noticed between lamellar and spheroidal graphite cast iron. The experimental results show that lamellar graphite cast iron solidifies with the formation of tight solid skin. This is not the case in ductile iron, which solidifies in a very mushy way so that a continuous liquid phase remains in contact with the mold wall relatively long during solidification. The quenching experiments also enable to measure the graphite volume, which precipitates during solidification. A considerable difference has been noticed between lamellar and spheroidal graphite cast iron. In view of these results, the shortcomings of the present simulation models for both types of cast iron are discussed.