inclusions present, and the evolution of inclusions during the ladle process. Heats of aluminium killed steels were Heats of medium carbon aluminium killed, low sampled with short time intervals during ladle treatments. carbon silicon-aluminium killed, and low carbonThe non-metallic inclusions were extracted from the steel aluminium killed steels were sampled with short matrix and investigated in detail using scanning electron time intervals during ladle metallurgy. Non-metallic microscopy and energy dispersive spectrometry. inclusions were extracted from the steel matrix and investigated using scanning electron microscopy INDUSTRIAL PROCESS DESCRIPTION and energy dispersive spectrometry. Six inclusion morphologies were recognised, i.e. spherical, After the converter process, steel contains 500-700 ppm of faceted, platelike, and dendritic shapes, as well as dissolved oxygen. It has to be deoxidised to prevent CO clusters and aggregates. For each sample also the formation during casting. Deoxidation and adjustment of total oxygen content was measured. Spherical the nal steel composition is carried out during ladle inclusions were most abundant, but clusters, treatment. The ladle treatment at Sidmar starts with aggregates, and large faceted inclusions made up tapping of the converter, a basic oxygen furnace (BOF), most of the oxide volume fraction. The present holding 300 t of steel at ~1650°C. During tapping, alloying research shows that clusters, which are formed elements and deoxidation elements can be added, e.g. during the deoxidation operation, are removed carbon, manganese, silicon, and aluminium. Next the slag, within ~15 min after aluminium addition.consisting of entrapped converter slag and deoxidation Aggregates and large polyhedra appear after products, is skimmed and replaced by a synthetic slag that 5-10 min and their sizes increase with holding time.consists mainly of calcium oxide and, dependent on the Small, mainly spherical and polyhedral, and to steel composition, bauxite. The synthetic ladle slag has some extent also platelike, inclusions do not show three functions, i.e. inclusion removal, thermal insulation, evolution in size or in composition.I&S/1648 and prevention of atmospheric reoxidation. The nal slag composition, after complete deoxidation of the steel, Dr Dekkers

A study was carried out to compare the inclusions present in low carbon aluminium killed (LCAK) steel with oxide particles in a clogging deposit formed during casting of LCAK steel. Steel pin samples were taken in the ladle and in the tundish. It was observed that oxide particles in the clogging deposit are mainly coral-shaped clusters, dendritic clusters and irregular plates. From the comparison with inclusions in LCAK steel, it is concluded that the particles in the clogging deposits are formed during reoxidation of the steel, at least after the ladle metallurgy process and most probably in the submerged entry nozzle. They are not the result of sintering of small pre-existing inclusions. Ein morphologischer Vergleich der nichtmetallischenEinschlusse im flussigen, aluminiumdesoxidierten Stahl und in Tauchrohr-Ablagerungen. Nichtmetallische Einschlusse in einem niedriggekohlten, aluminiumdesoxidierten Stahl (LCAK) wurden untersucht und mil denen in Tauchrohr-Ablagerungen verglichen. Dazu wurden Stiftproben aus Pfanne und Kokille entnommen. Es wurde beobachtet, dass abgelagerte Oxidpartikel, die sog. Ansatze, in Tauchrohren hauptsachlich Aluminiumoxidkorallen, -dendriten und -platten bilden. Diese Ausbildungsformen sind nicht Agglomerate schon in der Pfanne existierender kleiner nichtmetallischer Teilchen, sondern echte Reoxidationprodukte, entstanden beim Vergiessen in Kokille und Tauchrohr.

The goal of this work is to assess the applicability of the concept of a “slag foaming index” on industrial data. For this purpose, process data from the steel plant of ArcelorMittal Ghent are used. An acoustic measurement is used to identify the heats with high levels of slag foaming. A model based on process data is developed to estimate the slag's composition during the converter process. The results of this model, together with industrial data on the slag's end composition, are used as input to calculate the slag's viscosity, density, and surface tension. Subsequently, the calculated foaming indices are compared with the acoustic measurements from industry. No distinct link between the calculated foaming index and the slopping behavior of the industrial slag is observed. Furthermore, it is observed that the slag's viscosity is the dominant parameter in the foaming index for the industrial slags. In conclusion, it seems that the calculated foaming index cannot be used as a tool to identify foamy slags within the considered industrial context.

to express a FeO as a function of wt-%FeO. No general Institute of Materials, Minerals and Mining formula for c FeO is available. Empirical expressions such as log(wt-%FeO)= 0•0042E +0•582 . . . . . . . (4) have to be used to estimate the iron oxide content of the 1 Sensor with indication of parts of electrochemical cell 5

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