Effect of Molten Iron Treatment on Nucleation of Primary Austenite
The hypoeutectic Fe-C alloy was melted at 1 723 K,holding for 1 h,followed by molten glass purification,then grey cast iron,white cast iron and electrolytic iron were added into the purified melt,the effect of molten iron purification and the adding modes of carbon on the degree of undercooling for nucleation,the number of nucleation,and the growth morphologyof the primary austenite(γ) was investigated.The results show that it is difficult for primary γ and entectic to nucleate after glass purification.When the grey cast iron is added into the purified molten iron,primary γ and eutectic can nucleate easily.Different treatments can eliminate or form "an enriched region in Fe",thus has a significant effect on the heterogeneous nucleation of primary γ.