On Non-metallic Inclusions and Their Distributions in Low Carbon Rimmed Steel Ingots by Slime Method: Study of non-metallic inclusions in low carbon rimmed steel-II

From the metallurgical point of view, it is important to make clear the relation between the distribution of inclusions in rimmed steel ingots and the rimming action of the liquid steel in the mold. With the object of investigating on inclusions in rimmed steel ingot, the liquid steel in a ladle was teemed into two 15t ingot molds, with varied addition of aluminum in the mold. Inclusions in these ingots were extracted by the electrolytic procedure-the slime method, and their quantities, distribution, compositions and microstructures were investigated. From the core of the ingots, many small duplex inclusions of MnS (FeS) and MnO (FeO) were extracted. Inclusions extracted from the bottom are of rather larger size and contain higher Al2O3 and SiO2. Comparing the quantities and distributions of inclusions in the two ingots, the duplex inclusions in the core are distributed more uniformly in the ingot added with more aluminum in the mold, but the larger inclusions in the bottom increase.