REFINING PRACTICE AND APPLICATION OF THE LADLE FURNACE (LF) PROCESS IN JAPAN.

Abstract

The main features of this ladle technology are refining under non-oxidizing atmosphere and acceleration of slag-metal reaction through stirring by Ar gas injection. It is possible to obtain clean materials having low oxygen and sulfur levels ground 10 ppm. In recent years, the application has extended to the entire steel industry for quality improvement, cost reduction, production increase and ladle-CC matching in sequence casting. There are 24 LF installations including 3 integrated steelmakers and the total LF steel will exceed 7 million t. Many plants in Japan are now equipped with FAF(BOF)-LF-RH-CC combined lines for high quality steels, in which reduction refining is exclusively LF. The portion of special steels produced by this process is expected to increase.