Material evaluation to prevent nozzle clogging during continuous casting of Al killed steels

Abstract

Al2O3-carbon composite submerged entry nozzles (SEN) are used for continuous casting of steels. Although this material has excellent mechanical and thermal properties, it frequently leads to clogging. The purpose of our research is to find a suitable refractory material that can be used to coat SENs. This paper reports on the chemical compatibility of a number of potential refractory materials: Al2O3, ZrO2, Al2O3-carbon, SiO2 and MgO with liquid steel, an amount of simulated inclusions and synthetic slag. For this purpose, an experimental laboratory procedure was optimised to simulate the nozzle behaviour during continuous casting. Al2O3 was found to give satisfactory results, and therefore a Al2O3 plasma coated Al2O3-carbon material was also tested in the laboratory with good results.