Process for manufacturing hot rolled steel strips

Abstract

The invention is directed to a process for the production of hot-rolled steel strip from continuously cast precursor strip in at least two deformation stages, each deformation stage having one or more roll stands, wherein initial rolling is carried out in the first deformation stage at the output speed at which the precursor strip exits from the continuous casting plant and the intermediate strip thus produced is coiled prior to the second deformation stage at the output speed at which it exits from the first deformation stage, wherein the coil is uncoiled after reaching the coil weight and is supplied to the second deformation stage for finish rolling at the initial roll pass speed and is then coiled in the desired finished coil sizes. In the first deformation stage, at least 40 tons of a casting sequence of the continuous casting plant is rolled out in endless manner to form intermediate strip and is coiled to form an intermediate coil without severing, and after more or less endless finish rolling the intermediate strip of this intermediate coil is severed according to the desired coil weights and coiled as finished strip only following the second deformation stage.

1 . Process for the production of hot-rolled steel strip from continuously cast precursor material in at least two deformation stages, each deformation stage having one or more roll stands, wherein the precursor material is rolled out in endless manner to form an intermediate strip in the first deformation stage at the output speed at which the precursor material exits from the continuous casting plant, and prior to the second deformation stage at the output speed at which it exits from the first deformation stage the intermediate strip is coiled without severing to form an intermediate coil and is subsequently uncoiled in order to supply the intermediate strip to more or less endless finish rolling, after which this intermediate strip is severed in accordance with the desired coil weights and is coiled as finished strip, characterized in that at least 40 tons of a casting sequence of the continuous casting plant is cast to form precursor strip and is rolled out in the first deformation stage to form intermediate strip whose metallurgical characteristics are changed by changing the temperature control prior to coiling the intermediate coil and/or prior to the second deformation stage and by flexible speed control within an intermediate coil length.  
     
     
         2 . Process for the production of hot-rolled steel strip from continuously cast precursor strip according to    claim 1   , characterized in that the geometrical characteristics of the finished coils produced from an intermediate coil are changed by suitable adjustment of the rolling parameters during the deformation of the intermediate strip within the second deformation stage.  
     
     
         3 . Process for the production of hot-rolled steel strip from continuously cast precursor strip according to claims  1  and  2 , characterized in that the coiling of the intermediate strip to form an intermediate coil is carried out on a mandrel.  
     
     
         4 . Process for the production of hot-rolled steel strip from continuously cast precursor strip according to claims  1  and  2 , characterized in that the coiling of the intermediate strip to form an intermediate coil is carried out without a mandrel.  
     
     
         5 . Process for the production of hot-rolled steel strip from continuously cast precursor strip according to    claims 1    to    4   , characterized in that at least the edges of the intermediate strip are protected from cooling during the coiling of the precursor strip to form the intermediate coil.