Vliv jakosti feroslitin na znečištění oceli nekovovými vměstky

Abstract

This Bachelor thesis is focused on the study of influence of ferroalloys quality on steel contamination with non-metallic inclusions. Ferroalloys which are added to the melted steel play an important role in the secondary refining processes of the steel. The residual elements and impurities found in ferroalloys are significant from the point of view of purity of the steel grade that is being produced. In order to increase the knowledge of ferroalloys quality and their influence on steel contamination with non-metallic inclusions, the ferroalloys were characterized by collecting and analyzing samples with respect to the number, morfology, size and composition of inclusions. The main conclusion to be achieved is, that for a better controlled steelmaking process the characteristics of inclusions in ferroalloys should be known before their addition to the liquid steel, especially in the case of late additions in a ladle just before casting, because there will not be enough time for the flotation of inclusions.