Effect of Modulus on Shrinkage Cavity of Spheroidal Graphite Cast Iron Castings Predicted by Considering Expansion and Contraction during Solidification

Abstract

  The purpose of this study is to investigate the influence of the modulus size on the solidification cooling curve, expansion and contraction etc. by casting a spherical graphite cast iron having a cube shape with a modulus of 1 to 5cm.

  It was found that the reaction temperature in the solidification curve of the primary crystal reaction and the eutectic test block rises as Mc increases up to Mc ＝ 3cm. In addition, the solidification completion angle decreases as Mc increases up to Mc ＝ 3cm. The eutectic reaction interval in the expansion / contraction behavior during the solidification process was constant regardless of Mc. As Mc increased, the solidification rate decreased, suggesting the solidified form of the casting changed from mushy to semi-mushy solidification. This nominal expansion and contraction behavior was applied to the shrinkage prediction method.

  Applying this analysis to actual products improves contraction prediction accuracy over conventional analysis methods.