Process and apparatus for the continuous casting of a slab

Abstract

The invention relates to a process for the continuous casting of a slab ( 1 ), in particular of steel, wherein the cast slab ( 1 ) is conveyed through a furnace ( 2 ) and the slab ( 1 ) is subjected to a descaling operation. To increase the quality of the slab by reducing scale, the invention provides for the slab surface to undergo reduction in at least one section ( 3 ) of the furnace ( 2 ) as a result of an atmosphere consisting of an inert gas and hydrogen (H 2 ) or of pure hydrogen being maintained in said section ( 3 ) of the furnace ( 2 ). The invention further relates to an apparatus for the continuous casting of a slab.

1 - 17 . (canceled) 
     
     
         18 . A method for continuous casting of a slab, comprising the steps of: conveying a cast slab through a furnace in a conveying direction; subjecting the slab to a descaling operation; subjecting a surface of the slab to a reduction in at least in one section of the furnace by maintaining in the section of the furnace an atmosphere which consists of an inert gas and hydrogen (H 2 ) or of pure hydrogen (H 2 ); and, subjecting the slab surface to oxidation in a section of the furnace in front of and/or behind, in the conveying direction, the at least one section of the furnace with reducing atmosphere. 
     
     
         19 . The method according to  claim 18 , wherein the reducing atmosphere has a proportion of hydrogen (H 2 ) between 3% and 99.5%. 
     
     
         20 . The method according to  claim 19 , wherein the proportion of hydrogen (H s ) is between 5% and 50%. 
     
     
         21 . The method according to  claim 18 , wherein the inert gas is nitrogen (N 2 ). 
     
     
         22 . The method according to  claim 18 , wherein the inert gas is argon (Ar). 
     
     
         23 . The method according to  claim 18 , wherein the section of the furnace with oxidizing atmosphere contains oxygen (O 2 ) at least partially. 
     
     
         24 . The method according to  claim 18 , including heating the slab in the furnace takes place by induction. 
     
     
         25 . The method according to  claim 18 , wherein the continuous casting takes place as a casting/rolling process. 
     
     
         26 . The method according to  claim 18 , including heating the slab following a casting process and in front of a rolling process in the conveying direction. 
     
     
         27 . The method according to  claim 18 , including conveying the slab continuously. 
     
     
         28 . An apparatus for continuously casting a slab, comprising: a furnace through which the slab can be conveyed; descaling means for descaling the slab surface, wherein the furnace has at least two sections; means provided in at least one of the sections of the furnace for maintaining a reducing atmosphere; and means provided in at least another of the sections of the furnace for maintaining an oxidizing atmosphere. 
     
     
         29 . The apparatus according to  claim 28 , wherein the means for maintaining a reducing atmosphere includes at least one supply line for hydrogen (H 2 ). 
     
     
         30 . The apparatus according to  claim 29 , wherein the means for maintaining a reducing atmosphere additionally includes at least one supply line for an inert gas. 
     
     
         31 . The apparatus according to  claim 28 , wherein the means for maintaining an oxidizing atmosphere includes at least one supply line for oxygen (O 2 ). 
     
     
         32 . The apparatus according to  claim 28 , wherein the furnace is a muffle furnace. 
     
     
         33 . The apparatus according to  claim 28 , wherein the sections of the furnace are formed by steel pipes. 
     
     
         34 . The apparatus according to  claim 28 , wherein the furnace includes inductive heating means.