Effect of pouring temperature, composition, mould strength and metal flow resistance on shrinkage cavities in spheroidal graphite cast iron

• Published in: International journal of cast metals research (Online) Vol. 21; no. 1-4; pp. 2 - 6
• Main Author: Kanno, T.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.08.2008
• Subjects: COMPOSITION; METAL SUPPLY RESISTANCE; MOULD STRENGTH; POURING TEMPERATURE; SHRINKAGE CAVITY
• ISSN: 1364-0461; 1743-1336
• DOI: 10.1179/136404608X361567

Under the subject of this study, it was found that the growth of graphite in eutectic solidification is the most important factor. Also, shrinkage cavity increases in hypereutectic composition because the crystallisation volume of graphite in eutectic solidification becomes smaller. In addition, the Al amount contained in spheroidal agent or molten metal works negatively for shrinkage cavity, which could be said the same for P, Mo and Cr. As for the shrinkage cavity in non-alloyed ductile iron, the metal supply resistance P MSR is the most significant element in regard to the occurrence of shrinkage cavity. For tight mould, there is no relationship between modulus and shrinkage cavity while the P MSR of a product is the dominant factor. This theory of P MSR can be applied to final solidification loops of products based on simulation. Based on this, it became possible to make shrinkage cavity free products without a riser.