The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 01, 1988
Filed:
Nov. 25, 1987
Jean Foulard, Ablon, FR;
Raymond Borasci, Chatenay-Malabry, FR;
L'Air Liquide, Paris, FR;
Abstract
Process of casting steel from a ladle into a tundish, in which the metal which is in the tundish is protected against oxidation and nitridation. The process comprises two consecutive steps: a first step which includes flushing the tundish before the start of the casting of the liquid metal during which a high flow of dry ice or liquid argon is introduced until the oxygen concentration in the vicinity of the zone corresponding to the base of the jet of liquid metal at the start of the casting is lower than about 0.5%; and a second step for the upkeep of the atmosphere in the vicinity of the base of the jet which begins when the liquid metal starts to flow in the tundish, during which dry ice or liquid argon is injected as an upkeep flow which is less than the flushing flow, so as to maintain an oxygen concentration lower than about 0.5% in the vicinity of the base of the jet.