Abstract
Fe-Si-O alloy melt kept at 1 600°C or 1 645°C in silica crucible for 20 min was cooled to 1 555°C, and then heated again to the initial temperatures and kept for 20 min. Such cooling and heating cycle was repeated several times. Specimens were taken from the melt at 1 600°C and 1 555°C during each cooling period. Silica inclusions in the specimens generally consisted of three groups of different sizes; the smaller particles of 0.5 μ diam. delineated the cellular structure of the specimen, the medium ones of roughly 4 μ appeared inside of the cell, and the larger ones of 620 μ were randomly distributed. The number, size and form of particles of each size changed significantly with the silicon content of the melt, the sampler used and the repeated number of the cycle. It was concluded that the larger particles were formed during cooling of the melt and the medium and smaller ones precipitated during solidification of the specimen. The numbers of the larger sized particles in the specimens taken at 1 600°C and 1 555°C during each cooling period from 1 645°C agreed well with each other.
