Plant and method for producing flat rolled products

Patent metadata

Field	Value
Publication number	US-12337365-B2
Application number	US-202318100701-A
Country	US
Kind code	B2
Filing date	Jan 24, 2023
Priority date	Nov 11, 2022
Publication date	Jun 24, 2025
Grant date	Jun 24, 2025

Abstract

A plant and a method for producing a final strip starting from a slab having a determinate starting thickness, including: at least one heating furnace configured to heat at least the slab to a determinate starting temperature; at least one reversible roughing stand configured to subject the slab to one or more rolling passes in order to obtain an intermediate rolled product; and a continuous rolling train disposed operatively in line with the roughing stand and configured to reduce the thickness of the intermediate rolled product, until the final strip having a determinate final thickness is obtained.

First claim

The invention claimed is:

1. A rolling plant, for producing a final strip starting from a slab having a determinate starting thickness, comprising:
at least one heating furnace configured to heat at least said slab to a determinate starting temperature between about 1100° C. and 1200° C.;
at least one reversible roughing stand configured to subject said slab to one or more rolling passes in order to obtain an intermediate rolled product;
a continuous rolling train disposed operatively in line with said at least one roughing stand and configured to reduce the thickness of said intermediate rolled product, until said final strip having a determinate final thickness is obtained;

wherein said rolling train comprises at least one pre-finishing stand disposed at a minimum distance D from said roughing stand so that the intermediate rolled product is never operatively engaged with one roughing stand of the at least one roughing stand and simultaneously engaged with one pre-finishing stand of the at least one pre-finishing stand, and wherein the at least one pre-finishing stand is able to reduce the thickness of said intermediate rolled product in order to obtain a pre-finished rolled product, and a plurality of finishing stands able to reduce the thickness of said pre-finished rolled product in order to obtain said final strip, and wherein a rapid heating device consisting of selectively activatable elements, the selectively activatable elements together having a total rated output between 38 MW and 45 MW, is interposed between said at least one pre-finishing stand and said plurality of finishing stands, and is configured to heat said pre-finished rolled product so that a target temperature of said final strip, in correspondence with the outlet of the last finishing stand of said rolling train, is higher than at least 830° C., even for a final thickness <1.2 mm, and
wherein a rolling speed in said plurality of finishing stands is lower than 12 m/s in order to reduce or eliminate a need for a speed-up as a tool for reaching said target temperature.

2. The plant as in claim 1 , wherein it comprises at least one warehouse configured for the storage of said slabs, said warehouse being disposed substantially upstream of said heating furnace and able to selectively feed at least one of said slabs to said heating furnace.

3. The plant as in claim 1 , wherein said rolling train comprises from one to three pre-finishing stands and from five to six finishing stands.

4. The plant as in claim 1 , wherein said at least one roughing stand is configured to define said intermediate rolled product having a thickness comprised between 45 mm and 80 mm, wherein said at least one pre-finishing stand is configured to define said pre-finished rolled product having a thickness comprised between 10 mm and 50 mm, and wherein said plurality of finishing stands are configured to define said final strip having a determinate final thickness comprised between about 0.9 mm and about 26 mm.

5. The plant as in claim 1 , wherein it comprises at least first descaling means interposed between said heating furnace and said at least one roughing stand, second descaling means interposed between said roughing stand and a first of said pre-finishing stands, and third descaling means interposed between said rapid heating device and a first of said plurality of finishing stands.

6. The plant as in claim 1 , wherein it comprises a cutting machine interposed between said pre-finishing stand and said rapid heating device.

7. A rolling method, for producing a final strip starting from a slab having a determinate starting thickness, in a rolling plant which comprises:
at least one heating furnace configured to heat at least said slab to a determinate starting temperature T 1 between about 1100° C. and 1200° C.;
at least one reversible roughing stand configured to subject said slab to one or more rolling passes in order to obtain an intermediate rolled product;
a continuous rolling train disposed operatively in line with said at least one roughing stand and configured to reduce the thickness of said intermediate rolled product, until said final strip having a determinate final thickness is obtained;

wherein said method comprises at least one pre-finishing rolling of said intermediate rolled product, by means of at least one pre-finishing stand of said rolling train disposed at a minimum distance D from said roughing stand so that the intermediate rolled product is never operatively engaged with one roughing stand of the at least one roughing stand and simultaneously engaged with one pre-finishing stand of the at least one pre-finishing stand, and
wherein the at least one pre-finishing stand reduces the thickness of said intermediate rolled product in order to obtain a pre-finished rolled product, at least one finishing rolling of said pre-finished rolled product, by means of a plurality of finishing stands of said rolling train which are able to reduce the thickness of said pre-finished rolled product, in order to obtain said final strip, and at least one step of heating said pre-finished rolled product, by means of a rapid heating device consisting of selectively activatable elements, the selectively activatable elements together having a total rated output between 38 MW and 45 MW, and interposed between said at least one pre-finishing stand and said plurality of finishing stands, so that a target temperature of said final strip, in correspondence with the outlet of the last finishing stand of said rolling train, is higher than at least 830° C., even for a final thickness <1.2 mm, and
wherein a rolling speed in said plurality of finishing stands is lower than 12 m/s in order to reduce or eliminate a need for a speed-up as a tool for reaching said target temperature.

8. The method as in claim 7 , wherein it comprises at least one storage and feeding step in which, by means of a warehouse disposed substantially upstream of said heating furnace, said slabs are stored and fed selectively toward said heating furnace.

9. The method as in claim 7 , wherein the thickness of said intermediate rolled product in correspondence with the inlet of said rolling train is comprised in a range from 45 mm to 80 mm.

Assignees

• Danieli Off Mecc

Inventors

• Benedetti Gianpietro
• Bobig Paolo
• Bulfone Matteo Remy

Classifications

• B21B2001/225

  by hot-rolling · CPC title

• B21B1/34

  by hot-rolling · CPC title

• B21B37/74

  Temperature control, e.g. by cooling or heating the rolls or the product (B21B37/32, B21B37/44 take precedence) · CPC title

• B21B37/16

  Control of thickness, width, diameter or other transverse dimensions (B21B37/58 takes precedence) · CPC title

• B21B45/004 Primary

  Heating the product · CPC title