Analysis of ladle processing technologies for IF steel

Three different IF steel production technologies at metallurgical plants were analyzed and compared. Using process logs of completed smelts, changes in the carbon, nitrogen, and oxygen contents of the metal during ladle processing were compared, as well as the contents of various types of oxide nonmetallic inclusions in the analyzed metal samples collected at different sections of the steel ladle processing. The comparison revealed that the technologies at the plants differed in ladle weights, different types of vacuum degassers, different alloying and deoxidation schemes, types of introduced additives, and different ladle movement logistics between ladle metal processing units during IF steel production. The initial concentrations of dissolved carbon, nitrogen, and oxygen in the steel melt before vacuum processing also differ significantly. Metal samples collected at various stages of IF steel production were analyzed. As a result of the study of metal samples taken during the ladle treatment and casting stages of IF steel, using scanning electron microscopy (SEM) and fractional gas analysis (FGA), the main types of nonmetallic inclusions in the steel were quantitatively determined, as well as the total content of oxygen and nitrogen in the metal, respectively. The paper describes the dynamics of changes in various types of nonmetallic inclusions in metal samples during ladle processing after vacuum decarburization and IF steel casting.