Patent ID: 6616778
Filing Date: 2003-09-09
Classification: B21B

Abstract:
A process for producing a ferritically rolled steel strip, comprising:casting liquid steel in a continuous-casting machine to form a slab having a thickness of less than 150 mm; conveying the slab, utilizing the casting heat, through a furnace device; preliminary rolling of the slab in a preliminary rolling device; and finishing rolling of the slab, after preliminary rolling, in a final rolling device to form the ferritic steel strip with a desired final thickness; wherein, in an endless or a semi-endless process, the slab is rolled in the austenitic range in the preliminary rolling device and, after rolling in the austenitic range, is cooled to a temperature at which the steel has a substantially ferritic structure, and the strip is rolled, in the final rolling device, at speeds which substantially correspond to the speed at which the strip enters the final rolling device and the following thickness reduction stages of the final rolling device, and in at least one stand of the final rolling device, the strip is ferritically rolled at a temperature of between 850Â° C. and 600Â° C., and cooling the steel strip, after leaving the final rolling device, rapidly to a temperature below 500Â° C. in order substantially to avoid recrystallization.