Evaluation of Casting Modulus on the Microstructure and Mechanical Properties of Spheroidal Graphite Cast Iron

Nodular graphite (Ductile) cast iron is produced by a double treatment; Nodularization / Spheroidization (Mg and/or Rare Earth) treatment + Inoculation (FeSiX-alloy treatment, with X = Ca, Ba, Sr, Ce, La, Zr etc.). Each step has specific objectives. The spheroidization of the graphite depends on the thickness of the mould and thus cooling rate is an important factor. In this work, GGG70L alloy was cast into plates that had different cross-sections. The change in the modulus has been investigated by means of microstructure and mechanical properties. It turned out that as nodule size was decreased, tensile stress and elongation at fracture were decreased however hardness was increased. It was concluded that the section thickness was an important parameter that determines the microstructure and mechanical properties of spheroidal cast irons.