System and method for producing rod-shaped steels

Abstract

A system ( 1 ) and a method for thermomechanically rolling long steel semi-finished products ( 2 ) includes: a first rolling unit ( 5 ); a first thermomechanical sizing block ( 8 ) arranged downwards in the transport direction of the first rolling unit ( 5 ); a first cooling device ( 6 ) arranged between the first rolling unit ( 5 ) and the first thermomechanical sizing block ( 8 ); a separating device ( 14 ) arranged downstream of the first thermomechanical sizing block ( 8 ) in the transport direction; a second cooling device ( 11 ) arranged between the first thermomechanical sizing block ( 8 ) and the separating device ( 14 ); and a coil winding device ( 13 ) arranged downstream of the separating device ( 14 ) in the transport direction.

1 - 15 . (canceled) 
     
     
         16 . A system ( 1 ) for thermomechanically rolling long steel semi-finished products ( 2 ), comprising:
 a first rolling unit ( 5 );   a first thermomechanical sizing block ( 8 ) arranged downstream of the first rolling unit ( 5 );   a first cooling device ( 6 ) arranged between the first rolling unit ( 5 ) and the first thermomechanical sizing block ( 8 );   a separating device ( 14 ) arranged downstream of the first thermomechanical sizing block ( 8 );   a second cooling device ( 11 ) arranged between the first thermomechanical sizing block ( 8 ) and the separating device ( 14 ); and   a coil winding device ( 13 ) arranged downstream of the separating device ( 14 ).   
     
     
         17 . The system ( 1 ) according to  claim 16 , further comprising:
 a second thermomechanical sizing block ( 8 . 2 ) arranged between the first thermomechanical sizing block ( 8 ) and the second cooling device ( 11 ).   
     
     
         18 . The system ( 1 ) according to  claim 17 , further comprising:
 an intermediate cooling device ( 10 ) arranged between the first thermomechanical sizing block ( 8 . 1 ) and the second thermomechanical sizing block ( 8 . 2 ).   
     
     
         19 . The system ( 1 ) according to  claim 16 ,
 wherein the first cooling device ( 6 ) comprises at least one water tank.   
     
     
         20 . The system ( 1 ) according to  claim 16 ,
 wherein the first cooling device ( 6 ) comprises two water tanks.   
     
     
         21 . The system ( 1 ) according to  claim 16 ,
 wherein the second cooling device ( 11 ) comprises at least two water tanks which are each arranged spaced apart from one another.   
     
     
         22 . The system ( 1 ) according to  claim 16 ,
 wherein the second cooling device ( 11 ) comprises at least four water tanks which are each arranged spaced apart from one another.   
     
     
         23 . The system ( 1 ) according to  claim 17 ,
 wherein the first thermomechanical sizing block ( 8 . 1 ) is of one-, two-, four-, six—and/or eight-stand design, and   wherein the second thermomechanical sizing block ( 8 . 2 ) is of one-, two-, four-, six- and/or eight-stand design.   
     
     
         24 . The system ( 1 ) according to  claim 16 ,
 wherein the coil winding device ( 13 ) is a vertical coil winding device.   
     
     
         25 . The system ( 1 ) according to  claim 16 , further comprising:
 a structure-sensor device ( 15 ), which is arranged
 directly upstream of the coil winding device ( 13 ), 
 directly upstream of the separating device ( 14 ), or 
 downstream of the second cooling device ( 11 ). 
   
     
     
         26 . The system ( 1 ) according to  claim 25 ,
 wherein the structure-sensor device ( 15 ) comprises an ultrasonic measuring device, an X-ray measuring device, a radar measuring device, and/or an electro-magnetic measuring device.   
     
     
         27 . The system ( 1 ) according to  claim 25 ,
 wherein the structure-sensor device ( 15 ) is coupled to an open-loop or closed-loop controller for setting
 a temperature in the cooling devices ( 6 ,  10 ,  11 ), or 
 a rolling temperature and/or a rolling speed in the respective rolling units ( 5 ,  8 ,  8 . 1 ,  8 . 2 ) of the system ( 1 ). 
   
     
     
         28 . A method for producing rod-shaped steel ( 3 ) from a long steel semi-finished product ( 2 ), comprising:
 heating the semi-finished long steel product ( 2 ) to a temperature of at least 900° C.;   initially pre-rolling the semi-finished long steel product ( 2 ) in a first rolling unit ( 5 );   cooling the semi-finished long steel product ( 2 ) to a temperature of at least 850° C. in a subsequent first cooling device ( 6 );   subsequently finish-rolling the semi-finished long steel product ( 2 ) into the rod-shaped steel ( 3 ) in a first thermomechanical sizing block ( 8 ) arranged downstream of the first cooling device ( 6 );   cooling the rod-shaped steel ( 3 ) to a temperature in a range of 400° C. to 600° ° C. in a second cooling device ( 11 ) downstream of the first thermomechanical sizing block ( 8 );   subsequently cutting the rod-shaped steel ( 3 ) in a separating device ( 14 ) arranged downstream of the second cooling device ( 11 ); and then   feeding the rod-shaped steel ( 3 ) to a coil winding device ( 13 ) arranged downstream of the separating device ( 14 ) and winding the rod-shaped steel ( 3 ) into a coil.   
     
     
         29 . The method according to  claim 28 , wherein the long semi-finished steel product ( 2 ) is finish-rolled at a temperature in the range of 700 to 850° C. 
     
     
         30 . The method according to  claim 28 , wherein the rod-shaped steel ( 3 ) is wound onto a mandrel of the coil winding device ( 13 ) at a temperature in the range of 450 to 550° C. 
     
     
         31 . A rod-shaped steel ( 3 ), having a yield strength of at least 300 MPa and a proportion of martensite of at most 15.0% by area. 
     
     
         32 . The rod-shaped steel ( 3 ) according to  claim 31 , comprising the following composition in % by weight:
 Carbon: 0.04 to 0.35
 Silicon: 0.10 to 0.80 
 Manganese: 0.40 to 1.60 
 Phosphorus: maximum 0.06 
 Sulfur: maximum 0.06 
 Nitrogen: maximum 0.012, 
   a balance being iron, possibly other accompanying elements, and unavoidable impurities.   
     
     
         33 . The rod-shaped steel ( 3 ) according to  claim 31 , having a carbon equivalent (Ceq) of ≤0.60.