抄録
1) The author investigated the effect of melting temperature on the graphitization of pig iron, and found the fact that graphite content in the melt varied with its oxygen content which depended on the partial pressure of oxygen of the atmosphere and the velocity of reaction between oxide and carbon in the melt. The author is of the opinion that the well-known theory demonstrated by Piwowarsky is improper. 2) The coke pig iron was melted in vacuum furnace at high temperature The structure and properties of the melt changed to the same as those of Swedish charcoal pig iron. 3) The structure which consisted of the fine eutectic graphite colonies surrounded by continuous net work, was obtained by melting the pig iron in vacuum. From the structure, it was sujested that, on cooling, the fine eutectic graphite colonies at first separated out and then the final liquid, comparatively more impure, solidified around them, forming the continuous net work structure. 4) Cementite scarcely crystallized out even by rapid cooling, when the molten pig iron, low in silicon, was cooled in vacuum state.
