2014 Volume 86 Issue 2 Pages 109-115
The shrinkage of cast iron was studied using 80mmΦ spherical test pieces with two kinds of molds, carbon dioxide process mold and organic self-hardening mold, and with flake and spheroidal graphite cast iron. Shrinkage volume and melt level changes during cooling were also measured using the same molds. The melt level changes were measured in a small tube in the electric furnace located above the shrinkage test pieces.
The shrinkage volume of spheroidal graphite cast iron was found to be greater than that of the flake one, and the volume of the carbon dioxide mold larger than that of the organic self-hardening mold. The carbon dioxide mold showed slower on-set of melt level height increase due to the eutectic graphite formation in the spheroidal graphite cast iron, and lower melt level height than the organic self-hardening mold.
