9th ECCC European Continuous Casting Conference – ECCC 2017

Steel cleanliness is a complex topic, which is influenced at almost every step in the production line. It starts on the liquid side in the converter and ends in the solidified slab, and is further topic to modification by heat-treatments or rolling. To produce and provide high quality steel, the steelmaker has to be able to control the inclusions in the as cast slab, where inclusions can range from the nano- to micro scale. In this work, the authors studied the influence of alumina, magnesia and MA-spinel refractories as a stopper rod material in a Ca-treated low carbon, high manganese steel. The stopper rods were recovered after a full casting sequence and are compared to virgin stopper rods. The experimental work consists of optical light microscopy, scanning electron microscopy, and computer aided surface analysis. While the alumina stopper rod shows a chemical reaction to the Ca-treatment, with the formation of various calcium-aluminates, the MA-spinel and magnesia stopper rods show only a minor chemical reaction zone.