Patent ID: 7108047
Filing Date: 2006-09-19
Classification: B22D

Abstract:
1. Process for producing a metal strip with a strip-casting machine, comprising the steps of pouring molten metal ( 18 ) between two rotating casting rolls ( 11 , 12 ) each having a jacket ring, forming a gaseous film (G) between the surface ( 11 ′, 12 ′) of each casting roll and the strip skin (D 1 , D 2 , D 3 ) forming on the molten metal at the surface of the casting roll by introducing the gas into the inerting chamber ( 24 ) located above the metal bath, wherein each jacket ring has a base layer material (A), a material layer (B) applied on the base material layer (A), and an additional layer of material (C) applied on the layer (B) that contains at least two different ceramic materials (C 1 , C 2 ), oxide and/or nonoxide ceramics and/or cement, whereby one of the ceramic materials (C 1 ) extends over the entire jacket surface of the jacket ring and the other ceramic material (C 2 ) being embedded in the ceramic material (C 1 ) as particles that are spaced a substantially uniform distance apart, the two different ceramic materials (C 1 , C 2 ) of the material layer (C) having different thermal conductivities, and feeding a defined mixture of argon and nitrogen into the inerting chamber ( 24 ) during casting, so that the heat transfer from the strip skin to the casting roll ( 11 , 12 ) is influenced by the thickness of the gaseous film (G) which forms so that the surface ( 11 ′, 12 ′) of the casting roll is not provided with depressions ( 51 ), and a smooth surface of the strip to be cast is produced.