HYPO-EUTECTIC SPHEROIDAL GRAPHITE CAST IRON

摘要

PROBLEM TO BE SOLVED: To produce hypo-eutectic spheroidal graphite cast iron showing high strength, high rigidity and high toughness as-cast without requiring heat treatment and moreover produced by using general molds and melting equipment with the increase of the casting temp. suppressed to a minimum.;SOLUTION: This cast iron contains, by weight, 1.5 to 3.0% C, 1.0 to 5.5% Si, 0.008 to 0.25% rare earth metal and 0.005 to 0.015% (B equivalent) BN, and the balance substantially Fe. By allowing it to contain BN with a hexagonal ferrite type crystal structure same as that of graphite, graphite is produced with BN as neclei at the time of eutectic reaction, and a structure in which fine spheroidal graphite is dispersed is obtained.;COPYRIGHT: (C)2001,JPO