L'air Liquide

Liquid Air Corporation

Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges

Noel F Lutgen

Jean Foulard

Sara H Anderson

Sara Hornby-Anderson

The present invention relates to a process for producing steel in a ladle furnace in which the molten steel is stirred by injection of an inert gas in the lower part of the furnace. According to the invention, the stirring of the bath of steel is effected by the injection of gaseous argon so as to distribute in a homogeneous manner the additives added and the metal temperature in the course of the treatment, while there is simultaneously injected liquid argon above the surface of the bath in the region of intumescence. In this way, substantially any increase in the concentration of nitrogen of the bath of steel in the course of the treatment is avoided. In some cases, and in particular when wires of the type filled with silico-calcium are employed, a reduction in the concentration of nitrogen in the bath of steel is found.

Process for producing steel having a low content of nitrogen in a ladle

Liquid argon or nitrogen is poured with a lance into a furnace during the production of molten metal. According to the invention, the lance comprises a double wall in which a hole is respectively located in order to vent the argon or nitrogen gas to reduce the rate of diphasic. The tip of the lance is equipped with a diffuser to improve the liquid discharge.

Growing community of inventors

Igny, France

Noel F Lutgen