Behaviors of Manganese-Sulfide in Aluminum-killed Steel Solidified Uni-directionally in Steady State. Dendrite Structure and Inclusions.

Abstract

Morphology, size and distribution of ll-type manganese-sulfide are investigated taking steel-dendrite structures into account. auantitative relationships between solidification conditions and steel-dendrite morphologyare discussed first, based on steady state uni-directional solidification experiments. Anew idea is proposed as Solidification-Unit-Cell, which is applied to a numerical treatment of relationship between dendritic structure of manganese-sulfide inclusions and solidification conditions. Diameter of dendritic II-type manganese-sulfide rods is correlated to a solidification parameter: R-mG-nwhich originally is related to steel-dendrite arm spacings, whereas streches of the inclusions are related to the size and shape of residual melt pool, and amounts of constituent e]ements supplied thereinto.