大型鋼塊におけるV偏析について(I)

Abstract

In succession of the investigation about the Λ-segregates of large steel ingots, the author is in the way of investigation about the V-segregates of ingots. He reported here some results of investigation about the V-segregates as an intermediate report.At the bottom solidification of ingots the author finds the fact, that dendritic erystals grow after the completion of zone of columnar crystal to some but so much restricted extent. This fact lets him suppose, that the occurrence of free crystals in front of solidified dendritic shell becomes already considerably vigorous even just after the start of the so-called dendritic crystallization, and that dendrites at the bottom are arrested to grow by the shower of free crystals formed in front of themselves, while the growth of dendrites at the side is not so arrested.And in the course of formation of zones of sedimentary and free crystal, free crystals being created in front of the solidified side shell are presumed to sink downwards and to be piled up on the solidified bottom Shell, forming inverted conical piled surfaces with some stationary inclination in succession. The author describes the V-segregates as those formed under the influenbe of these conical surfaces. Then, it is observed from the actual results, that the V-inclination of V-segregates has close correlations with the ratio of height to diameter of ingots and the dia-ratio of zone of free crystals; and some explanations are given. In conclusion the author refers to the relations between the flaws in V-segregates and varlous manufacturing conditions.