Rolling line and relative method

Patent metadata

Field	Value
Publication number	US-9186711-B2
Application number	US-201113704155-A
Country	US
Kind code	B2
Filing date	Jun 14, 2011
Priority date	Jun 14, 2010
Publication date	Nov 17, 2015
Grant date	Nov 17, 2015

Abstract

A rolling line for the production of flat product includes a casting machine to continuously case a thin slab, a temperature maintenance and homogenization unit, a rolling unit a forming stand or roughing stand connected to the exit of the casting machine to reduce the thickness of the slab. The forming stand or roughing stand is configured to perform an adaptive reduction of the thickness of the cast slab smaller than or equal to about 65% at least as a function of the thickness, width and type of material of the finished flat product. The rolling unit is configured to perform a reduction of the reduction of the thin slab coming from the temperature maintenance and homogenization unit to a thickness comprised between about 1.2 mm and about 20 mm by three or fewer double rolling passes through the double rolling stand.

First claim

The invention claimed is:

1. A rolling line for production of flat products, comprising:
a casting machine suitable to continuously cast a thin slab;
a temperature maintenance and homogenization unit;
a rolling unit including a Steckel rolling train with two reversing stands downstream of the temperature maintenance and homogenization unit;
at least one forming or roughing stand connected to the exit of the casting machine and upstream of the temperature maintenance and homogenization unit for reducing the thickness of the thin slab just solidified, the at least one forming or roughing stand being configured to perform an adaptive reduction of the thickness of the thin slab smaller than or equal to about 65% at least as a function of the thickness, width and type of material of the finished flat product,
wherein the rolling unit is configured for performing at most three double rolling passes through the two reversing stands, wherein each of the double rolling passes includes a pass of the rolled product in a forward direction through the two reversing stands, and then a pass of the rolled product in an inverse to the forward direction through the two reversing stands, which reduces the thickness of the rolled product to produce a flat product having a final thickness between about 1.2 mm and about 20 mm; and
a shearing unit disposed upstream of the at least one forming or roughing stand.

2. The rolling line as in claim 1 ,
wherein the casting machine is suitable to cast, at an average casting speed comprised between about 5 m/min and 7 m/min, a thin slab with a constant thickness smaller than or equal to about 130 mm, and
wherein the at least one forming or roughing stand is suitable to perform an adaptive reduction of the thickness of the cast slab to a thickness comprised between about 30 mm and about 80 mm.

3. The rolling line as in claim 1 , wherein the diameter of each of the rolling rolls of the at least one forming or roughing stand is comprised between about 650 mm and about 750 mm.

4. The rolling line as in claim 1 , wherein the temperature maintenance and homogenization unit comprises a tunnel furnace of a length sized to allow, during stoppages of the rolling unit, to accumulate inside it some thin slabs for at least 8 minutes at a casting speed being in the range of from about 3 m/min to 12 m/min.

5. The rolling line as in claim 1 , wherein the rolling stands which constitute the at least one forming or roughing stand are of the four-high stand type.

6. The rolling line as in claim 1 , comprising at least a rapid heating unit of the cast material disposed between the casting machine and the rolling unit.

7. The rolling line as in claim 1 , further comprising:
a cooling unit; and
one or more winding units of the final product,
wherein the cooling unit and the one or more winding units of the final product are downstream of the rolling unit.

8. The rolling line as in claim 1 , wherein the temperature maintenance and homogenization unit includes a tunnel furnace.

9. The rolling line as in claim 1 , further comprising winding/unwinding reels, and the at least two reversing stands of the Steckel reversing train are in cooperation with the winding/unwinding reels.

10. The rolling line as in claim 1 , further comprising winding/unwinding reels, wherein the winding/unwinding reels include a heated reel.

11. The rolling line as in claim 1 , further comprising a drawing unit; and a winding/unwinding reel, wherein the winding/unwinding reel is configured to cooperate with the drawing unit.

12. A method for production of flat products, the method comprising:
a continuous casting step of a thin slab;
a temperature maintenance and homogenization step;
a rolling step subsequent to the temperature maintenance and homogenization step;
a shearing step, for shearing the thin slab; and
a forming or roughing step for reducing the thickness of the thin slab solidified, performed after the casting step and the shearing step, and before the temperature maintenance and homogenization step,
the forming or roughing step includes performing an adaptive reduction of the thickness of the thin slab smaller than or equal to about 65% at least as a function of the thickness, width and type of material of the finished flat product, and
the rolling step includes performing a reduction of the thickness of the rolled product emerging from the forming or roughing step to a final thickness of between about 1.2 mm and about 20 mm by carrying out at most three double rolling passes through a double rolling stand, wherein each of the double rolling passes includes passing of a rolled product in a forward direction through the double rolling stand, and then passing of the rolled product in an inverse to the forward direction through the double rolling stand.

13. The method as in claim 12 , wherein the casting step is performed at a speed comprised between about 5 m/min and 7 m/min of a thin slab with a constant thickness smaller than or equal to about 130 mm, and in that the forming or roughing step performs an adaptive reduction of the thickness of the thin slab to a thickness of between 30 mm and about 80 mm.

14. The method as in claim 12 , wherein in the first double rolling pass a first reduction of thickness performed is between about 30% and 40%.

15. The method as in claim 12 , wherein in the first double rolling pass a second reduction of thickness performed is between about 30% and 52%.

16. The method as in claim 12 , wherein in the second double rolling pass a first reduction of thickness performed is between about 28% and 50%.

17. The method as in claim 12 wherein in the second double rolling pass a second reduction of thickness performed is between about 28% and 50%.

18. The method as in claim 12 , wherein in the third double rolling pass a first reduction of thickness performed is between about 24% and 39%.

19. The method as in claim 12 , wherein in the third double rolling pass a second reduction of thickness performed is between about 20% and 25%.

Assignees

• Benedetti Gianpietro
• Bobig Paolo
• Danieli Off Mecc

Inventors

• Benedetti Gianpietro
• Bobig Paolo

Classifications

• Y10T29/49991

  Combined with rolling · CPC title

• B21B1/26

  by hot-rolling {, e.g. Steckel hot mill} · CPC title

• B21B15/005

  Lubricating, cooling or heating means · CPC title

• B21B45/004

  Heating the product · CPC title

• B21B1/466 Primary

  in a non-continuous process, i.e. the cast being cut before rolling · CPC title