Relation between Solidification Conditions and Microstructure of Unidirectionally Solidified White Cast Iron

摘要

To investigate the relation between solidification conditions and microstructure of white cast iron, eutectic and hypereutectic pure white cast iron were solidified unidirectionally in the quartz tube mold which was put on a cooled copper block and heated circumferentially. Solidifying length is in proportion to the square root of elapsed time after pouring. Good ledeburitic eutectic microstructure appeared in the eutectic composition specimens, while in the hypereutectic ones, primary cementite was formed near the chill end and at the upper part, then the cementite was substituted by spheroidal graphite and primary flaky graphite. Ledeburite eutectic cell width grew in plate-like form in parallel with solidifying direction and was inversely proportional to the square root of solidification rate.