Fe-Si-O溶融合金の冷却過程におけるSiO₂介在物の生成機構

抄録

Dissolved oxygen contents of Fe-Si-O alloy (0.1% Si addition) were determined at 1555°C during repeated cooling from 1600°C to 1555°C. The difference between the dissolved oxygen contents at 1600°C and 1555°C was significantly greater than the oxygen content corresponding to the larger sized silica particles formed during such cooling processes. This means that, besides the larger sized particles, a large number of very fine silica particles are present in the melt. It was thus proposed that very fine silica, presumably of several tens angstrom in size, precipitated easily in the melt with decreasing temperature and silica particles were formed by their successive adhesion to the possible nuclei suspended in the melt.
From a striking resemblance of morphology between the double-leaf type inclusion and the precursor of spherulite, the morphology of silica particles was explained on the basis of the regular branching mechanism known well as the formation mechanism of spherulite.