JP3146786B2 - Hot rolling equipment and hot rolling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling equipment and a hot rolling method for metal sheets.

[0002]

2. Description of the Related Art Conventional hot rolling equipment is a method in which a slab having a thickness of 200 mm or more is rolled to a final target sheet thickness through a row of rough rolling mills and a row of finish rolling mills. In this case, after rolling several times with a rough rolling mill, the rolling mill passes through a finishing mill row once, so the total equipment length from the heating furnace upstream of the rough rolling mill to the final winding is 300 m, depending on the production amount. As mentioned above, it is a very large facility.

On the other hand, DE 4041206 discloses a facility in which a rough rolling mill is eliminated in order to make hot rolling equipment compact, and a tandem reverse rolling of an odd-numbered pass or an even-numbered pass is performed in a finishing mill train.

[0004]

However, the tandem reverse rolling has the advantage that the rolling can be performed a number of times in the reverse direction. However, in the case of an even-numbered pass, the hot rolling slab is crushed and the final rolling is performed in the rolling mill that rolls first. , Both functions of low-temperature thin rolling are required. In such a method, there was a problem that a fine crack on the roll surface generated when a high-temperature slab was rolled was transferred to a plate at the final stage as a mark.

In the case of an odd-numbered pass, the exit side of the first pass becomes a cooling zone in the final pass, so that it is not desired to cool down in the first pass. Therefore, place the cooling zone farther than this length or turn the cooling zone on off
However, there is a drawback that the apparatus becomes complicated, for example, the first pass that has come to the cooling zone is not cooled down.

An object of the present invention is to provide a reverse rough rolling mill and a finishing machine.
The continuous rolling of the upper rolling mill makes the equipment compact and
Do not allow heat to escape to the
Hot rolling equipment for small to medium scale production of strip
And a hot rolling method.

[0007]

Means for Solving the Problems The hot rolling equipment of the present invention
Has a rough rolling mill and a finishing rolling mill
After the reverse rolling in the final pass, the rough rolling mill and finish rolling mill
The hot rolling equipment is designed to reduce the pressure continuously.
Between the rough rolling mill and the finish rolling mill.
Heat insulation with an adiabatic effect so that the temperature does not escape to the outside
Equipment, and a coiler on the side of the roughing mill opposite to the finishing mill.
Is arranged and wound up before the final pass
And

[0008] Alternatively, the hot rolling method according to the present invention comprises a slab.
Reverse rolling by a reverse rough rolling mill
When producing a strip, the roughly rolled strip is
Continuous finishing in the final pass of reverse rolling by a rough rolling mill
A hot rolling method for rolling by a rolling mill,
Before the final pass of reverse rolling by a roughing mill,
Located downstream of the furnace and upstream of the reverse roughing mill.
Winding the strip with a coiler
And reverse the strip by the reverse rough rolling mill.
After the last pass of rolling, the strip temperature is released to the outside
Insulate with a heat insulator to prevent the
Rolling by a rolling mill is performed.

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

Normally, when reverse rolling is performed in a rough rolling mill, the strip is cooled on a table between the rough rolling mill and the finishing rolling mill and on a table in front of the rough rolling mill. The heat is prevented from escaping to the outside by disposing a coiler in front of the rough rolling mill or by providing a heat insulating device having an adiabatic effect between the rough rolling mill and the finishing rolling mill. In addition, by making it possible to heat the inside of the heat insulating device having an adiabatic effect, it is possible to more reliably prevent heat from escaping to the outside.

That is, according to the present invention, in the continuous rolling in the rough rolling mill and the finishing rolling mill, the strip can be rolled after the rough rolling without being wound once, and a coiler required for winding the strip is not required.
The length of the coiler can be reduced, and the hot rolling equipment can be made compact. In addition, since the equipment cost for the coiler is not required, the total equipment cost can be reduced. Further, it is possible to eliminate a winding mistake in the winding operation. That is, a rough rolling mill and a finishing rolling mill
After continuous rolling and reverse rolling with a rough rolling mill, the final pass
So that the rolling can be continuously reduced by the rough rolling mill and the finish rolling mill.
In the hot rolling equipment of the type described above, the rough rolling mill and the finishing
Do not let the strip temperature escape to the outside between the upper rolling mill
Provide a heat insulating device having an insulating effect as described above,
Place a coiler on the anti-finishing mill side and wind it before the final pass
Or slab reverse rough rolling
When producing strip by reverse rolling with a machine,
The roughly rolled strip is re-rolled by the reverse rough rolling mill.
In the final pass of the berth rolling, the pressure is continuously
In the hot rolling method, the reverse rough rolling mill is used.
Before the last pass of the reverse rolling
A coiler arranged upstream of the reverse rough rolling mill
The strip is wound and reverse-rolled, and the reverse rough pressure is applied.
Final pass rolling of reverse strip of the strip by rolling mill
Later, heat insulation so that the strip temperature does not escape to the outside
Insulation by the equipment and continuous rolling by the finishing mill
In this way, the reverse rough rolling mill and finish rolling mill
By rolling, keep the equipment compact while keeping heat
In a compact facility with hot strip
Hot rolling equipment and hot rolling method that can realize small and medium scale production
Law can be provided.

Further, by arranging a plurality of rolling roll groups close to each other in the same housing, the amount of reduction in one pass is large, so that the final exit side plate thickness can be reduced without increasing the number of rolling mills.

On the other hand, if the diameter of the work roll is small in the finishing mill, the rolling load and the driving torque become small, and it is possible to perform strong rolling. When strong rolling is possible, the number of rolling mills can be reduced, so that a compact finishing mill can be provided. In the case of a work roll whose drive unit is reduced in diameter to a diameter that cannot withstand the driving torque required for rolling, a thinned sheet material can be strongly reduced by driving a reinforcing roll or an intermediate roll that supports the work roll. . High pressure reduction simultaneously realizes low speed rolling. This is because the ability of the rolled sheet to retain heat is better than under low pressure.

As a result, the rolling energy can be reduced.

By disposing the descaling device on the entrance side of the finishing mill, the scale on the strip surface can be removed and the surface shape can be stabilized.

Further, by providing a tension detecting device between the rough rolling mill and the finishing rolling mill, the tension can be kept constant and the waving of the plate can be suppressed.

The rough rolling mill allows the crown to be adjusted, and the finish rolling mill allows the crown and the shape of the strip to be adjusted.

In addition, by using a high-speed roll as a work roll of the rough rolling mill and the finish rolling mill, and by installing a roll polishing device in the rolling mill, the rolls can be rearranged in rolling under severe conditions of high pressure and low speed. The frequency can be reduced.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows a schematic configuration of a hot rolling facility, in which a heating furnace 14 for adjusting the temperature of the slab 15 to a temperature suitable for rolling before rolling is performed, and the scale of the surface of the slab 15 is roughened. Coarse descaling device 1, which is removed before rolling
Coarse rolling mill 2, Heat retaining device having an adiabatic effect for preventing the temperature of strip 11 from being lowered during reverse rolling 3, Tension detecting device 4 for preventing strip 11 from waving 4, Before finishing mill And a finishing No. 1 stand 6, a finishing No. 2 stand 7, a finishing No. 3 stand 8, a strip cooling zone 9, a coiler 10, and the like.

Normally, when reverse rolling is performed in a rough rolling mill, the strip is cooled on a table between the rough rolling mill and the finish rolling mill and on a table in front of the rough rolling mill. In the present embodiment, heat is prevented from escaping to the outside by providing a heat retaining device 3 having an insulating effect between the rough rolling mill and the finishing rolling mill.

A heat retaining device 3 is provided between the rough rolling mill and the finish rolling mill.
Is provided so that the strip can be rolled after the rough rolling without having to wind the strip, and the coiler required for winding the strip is not required. Therefore, the length of the coiler can be reduced, and the hot rolling equipment can be made compact. In addition, since the equipment cost for the coiler is not required, the total equipment cost can be reduced. In addition, it is possible to eliminate winding mistakes in the winding operation.

Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a view showing the arrangement of the rough descaling device 1 of the hot rolling equipment shown in FIG. 1 for the purpose of shortening the equipment length of FIG. 1 and not lowering the temperature of the strip 11. 1 shows a hot rolling facility in which a coiler 12 is installed.

That is, when the slab 15 is reverse-rolled by the rough rolling mill 2, the distance between the heating furnace and the rough rolling mill can be reduced by winding the strip 11 after two passes on the coiler 12. Further, by winding the strip 11 around the coiler 12, the heat retention effect can be increased and the temperature of the strip 11 can be prevented from lowering.

The shear 13 disposed downstream of the coiler 12 cuts off the rear end of the strip 11 wound by the coiler 12 after rough rolling, and prepares the rear end of the strip 11.

In the hot rolling equipment described with reference to FIGS. 1 and 2, the finishing No. 1 stand 6 and the finishing No. 2
Stand 7, Finish No. 3 The stand 8 has been described as a six-high rolling mill having a small-diameter work roll. In this rolling mill, the drive system for the small-diameter work roll is a small-diameter work roll that cannot withstand the driving torque, and therefore drives the intermediate roll or the reinforcing roll. In some cases, a four-stage rolling mill can be used.

FIG. 3 illustrates the heat retaining device 3 having the adiabatic effect described with reference to FIGS. The heat retaining device 3 is provided with a heating mechanism for heating the strip 11.

The heat retaining device 3 includes a cover 16 for preventing heat from being released to the outside, a gas nozzle 17 attached to a side surface of the cover 16, a roll 18 for flowing the strip 11, and the like.

Further, it has a function of preventing the temperature of the surface of the strip 11 from dropping due to a flame coming out of the gas nozzle 17 from the outlet of the gas nozzle 17 attached to the side of the cover 16.

The heat retaining device 3 may be a cover or a furnace depending on the equipment.

Although not shown, a heat retaining device 3 for heating by electricity instead of gas can be used.

FIG. 4 is a sectional view taken along line AA in FIG.

The heat retaining device 3 holds and transports the strip 11 on a roll 18.

FIG. 5 is a schematic view of a rolling mill applicable to the rough rolling mill 2 of the hot rolling equipment described with reference to FIGS.

In this rolling mill, two-high rolling mills of large-diameter work rolls 20 to 23 are arranged side by side in two rows in one housing 19, and can be rolled twice by one pass of a rolled material. It has become. There is an advantage that the equipment can be shortened as compared with a rolling mill having individual housings, and the generation of scale between two rollings can be reduced.

FIG. 6 is a schematic view of a rolling mill applicable to the finish rolling mill of the hot rolling equipment described in FIGS. 1 and 2 and shows a small-diameter work roll driven rolling mill and upper and lower intermediate rolls 26 and 2.
Reference numeral 7 denotes a roll that can move in the axial direction (the direction of the arrow). The upper and lower work rolls 24 and 25 are subjected to a vertical roll bending force (in the direction of the arrow). In this case, the driving rolls are upper and lower intermediate rolls 26,
27 or upper and lower reinforcing rolls 28 and 29. Although not shown, the upper and lower intermediate rolls 26 and 27 may be provided with a roll bending force similarly to the upper and lower work rolls 24 and 25. The plate crown and plate shape can be adjusted by the above-described axial movement of the roll and the roll bending force. Further, the upper and lower work rolls 24,
25 can be moved in the axial direction similarly to the upper and lower intermediate rolls 26 and 27. By periodically moving the work roll in the axial direction, the wear of the work roll can be dispersed, and Can be used for a long time, and excellent rolling of the sheet crown and sheet shape can be achieved.

FIG. 7 is a schematic diagram of a rolling mill applicable to the rough rolling mill and the finishing rolling mill of the hot rolling equipment described in FIGS. The upper work roll 30 and the reinforcing roll 32 and the lower work roll 31 and the reinforcing roll 33 cross each other in the upper and lower directions (pair cross). By crossing the rolls in this manner, the gap profile between the upper and lower work rolls can be changed, and the plate crown and the plate shape can be adjusted.

In the case where the rough rolling mill is a two-high rolling mill, there is a method in which the upper and lower work rolls are crossed in opposite directions, thereby making it possible to adjust the sheet crown in the same manner as described above. In the case where the rough rolling mill and the finishing rolling mill are four or more rolling mills, the same effect can be obtained by a method in which only the work rolls are crossed.

FIG. 8 is a schematic view of a rolling mill applicable to the rough rolling mill and the finishing rolling mill of the hot rolling equipment described in FIGS. Upper and lower work rolls 34 and 35 and upper and lower intermediate rolls 3
6 and 37 and upper and lower reinforcing rolls 38 and 39. Initial crowns having substantially the same shape are provided for at least one pair of upper and lower working rolls 34 and 35 or upper and lower intermediate rolls 36 and 37 or upper and lower reinforcing rolls 38 and 39, respectively. The upper and lower intermediate rolls 36 and 37 and / or the upper and lower work rolls 34 and 35
In the same manner as in FIG. 6, the plate crown and the plate shape can be adjusted by moving the plate in the axial direction or applying a roll bending force.

FIG. 9 is a schematic view of a rolling mill applicable to the rough rolling mill and the finish rolling mill of the hot rolling equipment described in FIGS. At least one pair of upper and lower work rolls 40, 41 and / or upper and lower reinforcing rolls 42, 43 are provided with initial crowns having substantially the same shape so as to be symmetrical with respect to each other.
The plate crown and plate shape can be adjusted by moving 41 in the axial direction or applying a roll bending force.

FIG. 10 is a schematic diagram of a rolling mill applicable to the finish rolling mill of the hot rolling equipment described with reference to FIGS. This is a case of a small-diameter work roll driven rolling mill, wherein the axis of the upper and lower work rolls is offset by δ to the rolling direction exit side with respect to the axis of the other rolls that come into contact with the work roll. Thus the horizontal force component F ₂ driving tangential force F ₁ acting on the work roll by offset acting on the work rolls of the rolling load acting on the rolling direction entry side with respect to the work rolls in the rolling direction exit side Since it acts, the horizontal force acting on the work roll can be reduced. In addition, a tension acts on the entrance and exit sides of the strip 11, and in consideration of this force, the offset amount δ is changed according to the rolling state so that the horizontal force acting on the work roll can be adjusted so as to be reduced. is there.

In the hot rolling equipment described above,
By performing the rolling in the finishing mill under low pressure and high pressure, the strip is produced with compact equipment, and the rolls of the finishing mill are used under severe conditions.

On the other hand, by installing a roll polishing apparatus, it is possible to operate without shortening the roll changing cycle even if the roll wear increases.

Also, by using a high-speed roll excellent in abrasion resistance and surface roughening resistance, which has recently been widely applied as a roll for hot rolling, the amount of wear can be reduced to 1/4 to 1 / compared to a conventional nickel grain roll. Since the number of rolls can be reduced to 5, there is an advantage that the roll can be used for a long time and the roll changing cycle can be greatly extended.

[0053]

According to the present invention, a reverse rough rolling mill and
With continuous rolling of the finishing mill, while making the equipment compact,
Do not allow heat to escape to the outside,
Hot rolling equipment for small and medium-scale production of hot strip
And hot rolling method can be provided.
To play.

[Brief description of the drawings]

FIG. 1 is a view showing a hot rolling facility according to a first embodiment of the present invention.

FIG. 2 is a view showing a hot rolling facility according to a second embodiment of the present invention.

FIG. 3 is a schematic view of a heat insulating device having an adiabatic effect according to the first and second embodiments of the present invention.

FIG. 4 is a schematic view of a heat retaining device having an adiabatic effect, and is a cross-sectional view taken along line AA in FIG.

FIG. 5 is a schematic diagram of a two-stage two-row rolling mill applicable to the rough rolling mills of the first and second embodiments of the present invention.

FIG. 6 is a schematic view of a rolling mill applicable to the finishing mills of the first and second embodiments of the present invention.

FIG. 7 is a schematic view of a rolling mill applicable to the rough rolling mill and the finish rolling mill of the first and second embodiments of the present invention.

FIG. 8 is a schematic view of a rolling mill applicable to the rough rolling mill and the finish rolling mill of the first and second embodiments of the present invention.

FIG. 9 is a schematic diagram of a rolling mill applicable to the rough rolling mill and the finish rolling mill of the first and second embodiments of the present invention.

FIG. 10 is a schematic view of a rolling mill applicable to a finish rolling mill.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coarse descaling device, 2 ... Coarse rolling machine, 3 ... Heat keeping device, 4 ... Tension detection device, 5 ... Finish descaling device,
6 ... Finish No. 1 stand, 7 ... Finish No. 2 stand, 8 ... Finish No. 3 stand, 9 ... Strip cooling zone, 10, 12 ... Coiler, 11 ... Strip, 13
… Shear, 14… heating furnace, 15 slab, 16… cover, 17… nozzle, 18… roll, 19… housing
20, 22, 24, 30, 34, 40 ... upper work roll,
21, 23, 25, 31, 35, 41 ... lower work roll,
26, 36: Upper intermediate roll, 27, 37: Lower intermediate roll, 28, 32, 38, 42: Upper reinforcing roll, 29, 3
3, 39, 43: Lower reinforcing roll.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor ▲ Kiichi Kenichi 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Hitachi, Ltd. Inside the Hitachi Plant (72) Inventor Koichi Seki, Sachi-machi, Hitachi-shi, Ibaraki Hitachi 1-1, Hitachi, Ltd., Hitachi Works (72) Inventor Kenji Horii 3-1-1, Sakaimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Factory (56) References JP-A-61-206506 JP, A) JP-A-61-71121 (JP, A) JP-A-2-42706 (JP, A) JP-A-1-249214 (JP, A) JP-A-6-320202 (JP, A) JP JP-A-6-122003 (JP, A) JP-A-6-15306 (JP, A) JP-A-57-124505 (JP, A) JP-A-4-262804 (JP, A) JP-A-4-123802 (JP) , A) JP-A-4-33715 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B21B 45/00 B21B 1/26

Claims (2)

(57) [Claims] 1. A rough rolling mill and a finishing rolling mill are continuously arranged,
After reverse rolled by a rough rolling mill, in a continuous heat-rolling equipment scheme so that reduction in the rough rolling mill and finish rolling mill in the final pass, the strip between the rough rolling mill and the finish rolling mill Provide a heat insulating device having an adiabatic effect so that the temperature does not escape to the outside, on the non -finish rolling mill side of the rough rolling mill
A hot-rolling facility characterized by placing a coiler and winding it before the final pass . 2. When a slab is reverse-rolled by a reverse rough rolling mill to produce a strip, the hot rolled strip is continuously rolled by a finish rolling mill in the final pass of the reverse rolling by the reverse rough rolling mill. In the cold rolling method, before the final pass of the reverse rolling by the reverse rough rolling mill, the strip is wound and reverse-rolled by a coiler disposed downstream of the heating furnace and upstream of the reverse rough rolling mill, and the reverse rolling is performed. After the final pass rolling of the reverse rolling of the strip by a rough rolling mill, insulated by a heat retaining device so as not to escape the strip temperature to the outside,
A hot rolling method, wherein rolling is continuously performed by the finishing mill.