Method and device for controlled straightening and cooling of a wide metal strip, especially a steel strip or sheet metal, running out of a hot rolled strip rolling mill

Abstract

A method and device for controlled straightening and cooling of a wide metal strip, especially a steel strip ( 1 ) or sheet metal, running out of a hot rolled strip rolling mill, using pinching rollers ( 5 ) arranged in the moving direction of the strip ( 2 ) behind vertical double rollers ( 3,4 ), said pinching rollers producing a tensile stress ( 6 ) acting in a longitudinal direction. According to the invention, the range of use of conventional sheet metal cooling systems can be extended to obtain a more even surface of said steel strip ( 1 ) with an increased cooling effect. This is achieved by displacing the metal strip ( 1 ) or sheet metal between a pre-straightening machine ( 7 ) and splash cooling facility ( 8 ) in defined conditions of tensile stress ( 6 ) by adjusting the tensile stress ( 6 ) and by cooling said strip or sheet metal inside said splash cooling facility ( 8 ) between successive pairs ( 5 a ) of pinching rollers and by additionally controlling the tensile stress ( 6 ).

1 . Method for controlled straightening and cooling of wide metal strip, especially steel strip or sheet, running out of a hot-rolled strip mill, with the use of pinch rolls, which are installed after (in the direction of strip flow) vertical double rolls and produce a tensile stress that acts in the longitudinal direction, wherein the metal strip or sheet is moved between a pre-straightening machine and a splash cooling installation under defined conditions of tensile stress by adjustment of the tensile stress, and that the metal strip or sheet is cooled inside the splash cooling installation between successive pairs of pinch rolls, and the tensile stress is additionally controlled.  
     
     
         2 . Method in accordance with  claim 1 , wherein the tensile stress is adjusted by switching the speed to the respective next or last supporting pinch roll with progressive passage of the metal strip or sheet.  
     
     
         3 . Method in accordance with  claim 1 , wherein the pinch rolls are set with a spacing, such that a cooling unit is formed between two rolls, depending on the spacing.  
     
     
         4 . Method in accordance with  claim 3 , wherein this spacing can be adjusted to a half-length of the resulting characteristic form for a strip or sheet with the least thickness, at maximum width and high cooling intensity.  
     
     
         5 . Device for controlled straightening and cooling of a wide metal strip, especially steel strip or sheet, running out of a hot-rolled strip mill, with vertical pairs of double rolls followed (in the direction of strip flow) by pairs of pinch rolls, between each of which a cooling unit is installed, wherein a pre-straightening machine ( 7 ) is installed before the pairs of pinch rolls ( 5   a ) with the cooling units ( 9 ), between which a controllable tensile stress can be produced.  
     
     
         6 . Device in accordance with  claim 5 , wherein the cooling units ( 9 ) are each designed for a high and an intermediate cooling intensity.  
     
     
         7 . Device in accordance with  claim 5 , wherein the cooling unit ( 9 ) is provided with finely adjustable cooling elements ( 19 ) at the outlet ( 18 ) of the metal strip ( 1 ).  
     
     
         8 . Device in accordance with  claim 5 , wherein the cooling unit ( 9 ) is designed for a high and/or an intermediate cooling intensity in accordance with a predetermined product spectrum.  
     
     
         9 . Device in accordance with  claim 5 , wherein tensile stresses ( 6 ) can also be produced between the last, supporting pinch rolls ( 5 ) or the straightening rolls ( 23 ) at the trailing end ( 1   a ) of the metal strip ( 1 ) or sheet and the pinch rolls ( 5 ) or the straightening rolls ( 24 ) at the leading end of the metal strip ( 1 ) or sheet.