Development of a novel degassing process consisting with single large immersion snorkel and a bottom bubbling ladle

Abstract

A novel vacuum degassing process consisting of a large immersion snorkel and a bottom bubbling ladle has been invented for the efficient production of ultra-low carbon stool. This process has been confirmed by industrial scale test using 175 and 350 t ladle and named REDA (Revolutionary degassing activator). The carbon content reaches 10 ppm in 15 to 20 min treatment, and decreases to 4 ppm without any stagnation. As REDA has a wide bubble activated surface area and a deep injection position, relatively low gas flow rate is necessary to produce ultra-low carbon steel efficiently.