| 摘要 |
PROBLEM TO BE SOLVED: To display an inculant effect equal to Ca or higher regardless of whether or not Ca or a rare earth metal element exists and to reduce occurrence of chilling by containing a specified composition containing Si, Mg and C a large part of which exists as silicon carbide phase. SOLUTION: This alloy is composed by wt. of 38-70% Si, 2-15% Mg, 0.4-5% C and the balance Fe with inevitable impurities. When using this alloy for a graphite spheroidizing treatment, the silicon carbide existing in the alloy delays the melting of the alloy and the reaction time is prolonged by restraining the reaction of Mg and, at the same time, when the alloy is melted little by little, a fine zone rich in Si and C is formed in surrounding molten iron, and when the molten cast iron solidifies, the foundation for cystallizing graphite is formed and this alloy plays a role to reduce chilling phenomenon. IN this alloy, if necessary, a rare earth metal element or Ca can be contained and it is desirable that their contents are 0.5-9 wt.% and 0.5-5 wt.%, respectively.
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