JPH1029004A - Hot rolling method and rolling equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the manufacturing yield of a thin strip in finished thickness. SOLUTION: This equipment is provided with a slab soaking device 18 for soaking a slab 2 delivered from a continuous casting machine 1, the groops 19, 20 of rolling mills for rolling/forming the slab 2 after soaking into the strip 4, a cooling device 6 for cooling the strip 4 after rolling/forming and coilers 21, 22 for coiling the strip 4 after cooling. A strip cutting device 30 is provided between the cooling device 6 and the coiler 21 and, by taking the entire length of the slab soaking device 18 as the length of the slab 2 necessary to roll the strip 4 equivalent to plural coils to be coiled with the coilers 21, 22, the number of threading of the strip 4 to the groops 19, 20 of the rolling mills is reduced and by suppressing rolling of a part where desired material characteristics are not held due to the finished thickness, threading speed and rolling conditions into the strip 4, the manufacturing yield of the thin strip 4 in the finished thickness is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a hot rolling method and a hot rolling facility.

[0002]

2. Description of the Related Art In recent years, it has been proposed to directly connect a continuous casting facility and a rolling facility.

FIG. 2 shows an example of a hot rolling facility directly connected to a continuous casting facility. The hot rolling facility is a slab for equalizing the temperature of a slab 2 delivered from a mold type continuous casting machine 1. A heating device 3, a rolling mill group 5 for rolling and forming the slab 2 sent from the slab heating device 3 into a strip 4, a strip cooling device 6 for cooling the strip 4 sent from the rolling mill group 5, Strip cooling device 6
And a winding machine 7 for winding the strip 4 delivered from the coil into a coil shape.

[0004] The continuous casting machine 1 comprises a pair of molds 8 arranged opposite to each other, a tundish 9 for flowing molten metal between the molds 8, and a ladle 10 for supplying molten metal to the tundish 9. Have, mold 8
Is set to a predetermined value, and the tundish 9 to the mold 8
Mold 8 formed by allowing molten metal to flow between the molds and gradually cooling the molten metal by the mold 8.
Is a device for continuously pulling down the slab 2 having a thickness corresponding to the distance between the slabs 2. When the thickness of the slab 2 is about 90 mm, the slab 2 is sent out at a speed of about 5 m / min.

[0005] Below the mold 8, a roll segment constituted by a number of guide rolls 11 is arranged.
When the thickness of the slab 2 is about 90 mm, the solidified shell forming the outer skin portion of the slab 2 is pressed by the guide rolls 11 to reduce the thickness of the slab 2 to about 70 mm and guide the slab 2 in the lateral direction. And the slab heating device 3
The slab 2 to be fed into the slab 2 is provided for each length specified by a pair of upper and lower cutting tools 25 constituting a slab cutting device 24 disposed between the above-mentioned roll segment and the slab heating device 3. Is cut off.

[0006] The slab heating device 3 is provided with a transfer table and a heating burner (not shown) inside an apparatus body 12 in which the slab 2 can be housed, and the slab 2 is roll-formed by the heating burner. It is soaked to a suitable temperature.

The total length of the slab heating device 3 is
1 strip of coil to be wound by
Of slab 2 length (25m-30m) required for the production of
It has a total length of about 5 times and is designed to balance the production of the continuous casting machine 1 and the rolling mill group 5, while the roll forming in the rolling mill group 5 is interrupted due to roll change. In addition, the slab heating device 3 receives the slab 2 sent from the continuous casting machine 1 to prevent the continuous casting machine 1 from stopping.

The rolling mill group 5 includes a pair of work rolls 13 and a pair of upper and lower stay rolls 14 that support the work rolls 13.
, Each of which is formed by rolling six slabs 2 as strips 4 at a speed corresponding to the peripheral speed of the work roll 13 (500 m). A strip 4 having a thickness of about 1.5 mm to 12.7 mm at a speed of about 850 m / min) is delivered from a horizontal four-high rolling mill 15 located at the most downstream side in the strip moving direction.

A scale removing device 16 for injecting high-pressure water into the slab 2 sent from the slab heating device 3 is provided upstream of the rolling mill group 5 in the slab moving direction. (Oxide) formed on the surface of slab 2 by high-pressure water injected from
Is removed.

The strip cooling device 6 injects strip cooling water to the strip 4 sent from the rolling mill group 5, and the strip cooling water causes the strip 4 having a temperature suitable for rolling and forming to a predetermined value. The material is cooled so as to exhibit the material characteristics described above.

Further, the strip 4 delivered from the strip cooling device 6 is wound by a winder 7 into a coil suitable for transportation and storage.

In the drawing, reference numeral 17 denotes a pair of pinch rolls. The pinch rolls 17 are provided upstream of the winding machine 7 in the strip moving direction so as to hold the strip 4 in the thickness direction. I have.

In FIG. 2, the slab cutting device 2
4, a slab heating device 3, a rolling mill group 5 is illustrated, and a strip cooling device 6 and a winding machine 7 are illustrated in a lower stage. These slab heating device 3, rolling mill group 5, strip cooling device 6, The machine 7 is often arranged linearly in an actual machine.

[0014]

However, the hot-rolling equipment shown in FIG.
mm, so that the thickness of the strip 4 to be sent out from the rolling mill group 5 becomes a finished thickness of about 0.8 mm to 1.0 mm from the beginning of rolling. When the interval between the upper and lower work rolls 13 of the horizontal four-high rolling mill 15 is set in advance and rolling is started, the strip that is thinly rolled to a state close to the finished thickness is obtained in a portion of the rolling mill group 5 downstream of the strip moving direction. The tip of 4 is folded or narrowed down,
In particular, when the moving speed of the strip 4 is increased, the strip is not passed between the upper and lower work rolls 13 and the
In some cases, a heavy-biting state may cause a threading accident that damages the horizontal four-high rolling mill 15.

Further, the finished thickness is 0.8 mm to 1.0 m
When the strip 4 of about m passes through the cooling device 6,
The moving strip 4 rises under the influence of the strip cooling water, collides with the table roll of the cooling device 6 and jumps up, or a passing-through accident such as being unable to move at high speed on the table occurs. is there.

In order to prevent such a threading accident caused by thin high-speed threading such as folding or narrowing of the strip 4, the finished thickness of the strip 4 sent from the rolling mill group 5 at the beginning of rolling is reduced. The distance between the upper and lower work rolls 13 of the horizontal four-high rolling mill 15 is set so that the strip 4 can move in a stable state.
After being sent out from the rolling mill group 5 without folding the leading end portion of the horizontal roll mill 15, the upper and lower work rolls 13 of the horizontal four-high rolling mill 15 are so adjusted that the thickness of the subsequent portion of the strip 4 becomes the specified finished thickness. The spacing needs to be adjusted.

Accordingly, in the rolling equipment shown in FIG. 2, if it is intended to reliably produce a strip 4 having a finished thickness of 0.8 mm to 1.0 mm at a specified temperature without causing a passing-through accident, According to the setting of the thickness at the start of rolling as described in the above, the moving speed in the cooling device 6 and the limitation of the strip cooling water, the strip which is pressure-formed from one slab 2 at a specified temperature to a specified finished thickness. 4, that is, the production yield of the strip 4 tends to be low.

The present invention has been made in view of the above circumstances, and has as its object to improve the manufacturing yield of a strip having a small finished thickness.

[0019]

According to a first aspect of the present invention, there is provided a hot rolling method comprising the steps of: equalizing a long slab corresponding to a plurality of strips of a coil; Set the interval between the work rolls of the rolling mill group so that the thickness of the strip roll-formed from the slab by the mill group will be the specified finished thickness, and then transfer the soaked long slab to the rolling mill group. Feeding, after the leading end of the strip is sent out by a predetermined length from the rolling mill group, the interval between the work rolls of the rolling mill group is adjusted so that the thickness of the strip sent from the rolling mill group is reduced, and Then, the strips sent from the rolling mill group are cooled, and the strips are cut into finished lengths and wound into coils.

In the hot rolling equipment according to a second aspect of the present invention, a slab cutting device for cutting a slab sent from a continuous casting machine, and a slab cut by the slab cutting device are soaked. A slab soaking device, a rolling mill group for rolling and forming the slab sent from the slab soaking device into a strip, a strip cooling device for cooling the strip sent from the rolling mill group, and the strip cooling device A plurality of winding machines for winding the strip delivered from the coil into a coil shape, a strip cutting device for cutting the strip is provided between the strip cooling device and the winding device, and a total length of the slab soaking device is provided. Corresponds to the length of the slab required for rolling the strip of a plurality of coils to be wound by the winder.

In the hot rolling method according to the first aspect of the present invention, the distance between the work rolls of the rolling mill group is set to be equal to the thickness of the strip roll-formed from the slab by the rolling mill group. It is set so as to be secured, and a long slab with uniform temperature is fed to a group of rolling mills to prevent a passing-through accident, and after the leading end of the strip is sent out from the group of rolling mills, a work roll of the group of rolling mills is set. Is adjusted so that the thickness of the strip sent out from the rolling mill group is reduced, and then the strip is cut at each finished length and wound into a coil, thereby reducing the production yield of the strip having a smaller finished thickness. Improve.

In the hot rolling apparatus according to a second aspect of the present invention, the interval between the work rolls of the rolling mill group is set so that the thickness of the strip roll-formed from the slab by the rolling mill group is a specified finished thickness. The long slab soaked by the slab soaking device is sent to a group of rolling mills to prevent a passing-through accident, and after the end of the strip is sent out from the group of rolling mills, rolling is performed. The interval between the work rolls of the mill group is adjusted so that the thickness of the strip sent from the rolling mill group is reduced, and the strip is cut by a strip cutting device for each finishing length and wound into a coil by a winder. In other words, it is possible to suppress the formation of a portion where the desired material characteristics are not maintained in the strip, and to improve the production yield of the strip having a small finished thickness.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an embodiment of the hot rolling equipment according to the present invention. In the drawing, the parts denoted by the same reference numerals as those in FIG. 2 represent the same parts.

The hot rolling equipment shown in FIG.
Cutting device 24 for cutting slab 2 sent from
A slab soaking device 18 for soaking the slab 2 cut by the slab cutting device 24, and a first rolling and forming of the slab 2 sent from the slab soaking device 18 into a strip 4. Rolling mill group 19 and the first rolling mill group 19
A second group of rolling mills 20 for rolling and forming the strips 4 sent from the mill, a strip cooling device 6 for cooling the strips 4 sent from the second rolling mill group 20, and a strip cooling device 6 A first winder 21 and a second winder 22 for winding the strip 4 into a coil shape.

The slab soaking apparatus 18 is provided with a transfer table and a heating burner or an induction heater (not shown) inside an apparatus main body 23 in which the slab 2 can be installed. By heater
The slab 2 is soaked to a temperature suitable for rolling.

The total length of the slab soaking apparatus 18 is the first
Corresponds to the length (150 m to 170 m) of the slab 2 necessary for manufacturing the strip 4 for a plurality of coils to be wound by the winder 21 and the second winder 22.

A slab cutting device 24 is provided between the slab soaking device 18 and the continuous casting machine 1.

In the slab cutting device 24, cutting tools 25 are arranged above and below the slab 2 so as to be able to approach and separate from each other. When the cutting tools 25 are brought close to each other, the slab 2 is cut.

The first rolling mill group 19 includes a horizontal two-high rolling mill 27 having a pair of work rolls 26 and a pair of work rolls 1.
3 and a horizontal four-high rolling mill 15 provided with a counter roll 14. The horizontal two-high rolling mill 27 and the horizontal four-high rolling mill 15 successively roll-form the slab 2 as the strip 4, and perform slab soaking. When the thickness of the slab 2 fed from the forming device 18 is about 70 mm, the speed (100 m to 200 m /
A bar 34 having a thickness of about 20 mm is sent out from the horizontal four-high rolling mill 15.

A first scale removing device 28 for injecting high-pressure water into the slab 2 sent from the slab soaking device 18 is provided upstream of the first rolling mill group 19 in the slab moving direction. The scale (oxide) formed on the surface of the slab 2 is removed by the high-pressure water injected from the first scale removing device 28.

The second rolling mill group 20 includes six horizontal 4 rolls each having a pair of work rolls 13 and a counter roll 14.
The horizontal four-high rolling mills 15 sequentially roll-form the bars 34 fed from the first rolling mill group 19, and the speed (500 m to 950 m) according to the peripheral speed of the work roll 13. / Min) and a thickness of 1 mm to 12 m
m of strips 4 are delivered from a horizontal four-high rolling mill 15 located at the most downstream side in the strip moving direction.

A second scale removing device 29 for injecting high-pressure water into the bar 34 sent from the first rolling mill group 19 is provided upstream of the second rolling mill group 20 in the bar moving direction. The scale formed on the surface of the bar is removed by the high-pressure water injected from the second scale removing device 29.

Further, a coil box is provided between the second scale removing device 29 and the first rolling mill group 19 described above, and the bar delivered from the first rolling mill group 19 by the coil box. The bar 34 is rewound and the bar 34 is rewound to remove the second scale removing device 29 and the second rolling mill group 2.
It is also possible to adopt a configuration in which the data is transmitted to 0.

The strip cooling device 6 is configured to inject cooling water to the strip 4 sent from the second rolling mill group 20, and the strip water having a temperature suitable for rolling by the cooling water. 4 is cooled so as to exhibit predetermined material properties.

Further, the strip 4 delivered from the strip cooling device 6 is wound by a first winder 21 and a second winder 22 into a coil suitable for transport and storage.

The first winding machine 21 and the second winding machine 2
2 are arranged in series with respect to the strip moving direction.

A strip cutting device 30 is provided between the first winding machine 21 and the strip cooling device 6.

The strip cutting device 30 rotates the cutting tool 31 above and below the strip 4 synchronously at a high speed in a counterclockwise direction in FIG. 1 and in a clockwise direction in a lower position in FIG. Furthermore, the upper and lower cutting tools 31 are configured to be able to approach and separate from each other.
The moving strip 4 is cut.

In the figure, reference numerals 32, 33, and 35 denote a pair of pinch rolls.
Is provided on the upstream side in the strip moving direction of the first winding machine 21 so that the pinch roll 33 can be held in the thickness direction.
Is so arranged that the strip 4 can be clamped in the thickness direction.
Is provided on the upstream side in the strip moving direction of the winder 22 of
The pinch roll 35 is provided upstream of the strip cutting device 30 in the strip moving direction so that the strip 4 can be sandwiched in the thickness direction.

In FIG. 1, the slab cutting device 2
4. A slab soaking device 18 and a first rolling mill group 19 are shown, and a second rolling mill group 20, a strip cooling device 6, a strip cutting device 30, a first winding machine 21, and a second Are shown, the slab cutting device 24, the slab soaking device 18, the first rolling mill group 1
9, the second rolling mill group 20, the strip cooling device 6, the strip cutting device 30, the first winding machine 21, and the second winding machine 22 are usually arranged linearly in actual machines. .

Hereinafter, the operation of the hot rolling equipment shown in FIG. 1 will be described.

When manufacturing the strip 4 having a finished thickness of about 0.8 mm to 1.0 mm, the slab 2 is sent out from the continuous casting machine 1 and the slab 2 is stripped by the slab cutting device 24 into a plurality of strips. 4 is cut to a length required for the production of the slab 2, and the long slab 2 is
To the slab 2 for uniform heating.

Next, the soaked slab 2 is sent to the first rolling mill group 19, and the slab 2 is successively roll-formed as a bar 34 by the horizontal two-high rolling mill 27 and the horizontal four-high rolling mill 15, The bars 34 sent out from the first rolling mill group 19 are successively roll-formed by the horizontal four-high rolling mill 15 of the second rolling mill group 20.

At this time, the horizontal four-high rolling mill in the second rolling mill group 20 is designed so that the strip 4 sent out from the second rolling mill group 20 at the beginning of rolling has a finished thickness that can move in a stable state. The interval between the work rolls 13 above and below 15 is set, and the strip 4 is sent out from the second rolling mill group 20 without being folded or narrowed, thereby preventing a passing-through accident.

When the leading end of the strip 4 is sent out from the second rolling mill group 20, the first strip 4 is sent out from the second rolling mill group 20 so that the thickness of the strip 4 becomes the specified finished thickness. The interval between the upper and lower work rolls 26 of the horizontal two-high rolling mill and the upper and lower work rolls 13 of the horizontal four-high rolling mill 15 in the rolling mill group 19, and the upper and lower sides of the horizontal four-high rolling mill 15 in the second rolling mill group 20 Of the work roll 13 is adjusted.

The strip 4 sent out from the second rolling mill group 20 is cooled by the strip cooling device 6 so as to exhibit predetermined material characteristics, and is then coiled by the first winding machine 21. It is wound up.

The timing of adjusting the distance between the upper and lower work rolls 13 of the horizontal four-high rolling mill 15 in the second mill group 20 to make the thickness of the strip 4 thinner than the tip is determined by the thickness of the strip 4. When the leading end of the strip 4 has exited the second rolling mill group 20 based on the passing speed,
Alternatively, it may be either when the strip 4 is long enough to move in the cooling device 6 in a stable state, or when the leading end of the strip 4 reaches the first winder 21.

When the length of the strip 4 wound by the first winding machine 21 reaches a predetermined length, the strip 4 is cut by the strip cutting device 30 immediately before the first winding machine 21. The strip 4 following the part is coiled by a second winder 22.

Further, when the strip 4 to be wound by the second winding machine 22 reaches a predetermined length, the strip 4 is cut by the strip cutting device 30 immediately before the first winding machine 21. The strip 4 subsequent to the cut portion is wound again in a coil shape by the first winder 21, and the above-described procedure is sequentially repeated, whereby the strip 4 roll-formed from the long slab 2 is sequentially coiled. And roll it up.

As described above, in the hot rolling equipment shown in FIG. 1, the long slab 2 corresponding to the strips 4 of a plurality of coils sent from the continuous casting machine 1 is transferred to the first rolling mill group 19. And the second rolling mill group 20 continuously roll-forms the roll-formed strip 4 into a first winding machine 21
And the second winding machine 22 to form a coil, so that it is rolled and formed to be thicker than a specified finished thickness in order to prevent a threading accident, and is threaded in order to move in a stable state. Because the speed is reduced and the amount of cooling water is suppressed, the desired material properties are not maintained, and only the tip of the strip 4 is subjected to cutting and removal as a product defect. The ratio of the strip 4 having the specified finished thickness obtained from the slab 2, that is, the production yield of the strip 4 having a small finished thickness is remarkably improved.

The hot rolling method and the hot rolling equipment according to the present invention are not limited to the above-described embodiment, but the number of winders may be increased as appropriate, Needless to say, the number of rolling mills and the number of stages of each horizontal rolling mill can be appropriately changed, and various changes can be made without departing from the scope of the present invention.

[0053]

As described above, the hot rolling method and the hot rolling equipment of the present invention can provide various excellent effects as described below.

(1) In the hot rolling method according to the first aspect of the present invention, the interval between the work rolls of the rolling mill group can be moved in a state where the strip roll-formed from the slab by the rolling mill group is stable. A long slab with uniform thickness is set and sent to the rolling mill group, and the number of times the strip passes through the rolling mill group is reduced, so that a passing accident can be prevented. After the leading end of the strip is sent out from the group, the interval between the work rolls of the rolling mill group is adjusted so that the thickness of the strip sent out from the rolling mill group is reduced, and the strip is cut for each finished length. Since it is wound in a coil shape, a portion where desired material properties are not maintained due to the finished thickness, the passing speed, etc., is formed only slightly on the strip, and the production yield of the strip having a small finished thickness is improved. It can be achieved.

(2) In the hot rolling apparatus according to the second aspect of the present invention, the interval between the work rolls of the group of rolling mills is set such that the thickness of the strip roll-formed from the slab by the group of rolling mills is specified. It is set to have a thickness, and the long slab soaked by the slab soaking device is sent to the rolling mill group, and the number of times the strip passes through the rolling mill group is reduced. After the end of the strip is sent out from the rolling mill group, the interval between the work rolls in the rolling mill group is adjusted so that the thickness of the strip sent out from the rolling mill group is reduced, and the finished length is adjusted by the strip cutting device. Since the strip cut every time is wound into a coil by a winder, only a small portion of the strip does not retain the desired material properties due to the finished thickness of the strip, the passing speed, etc. Made is no longer, it is possible to improve the production yield of finished thickness is thin strip.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of an embodiment of a hot rolling facility of the present invention.

FIG. 2 is a conceptual diagram showing an example of a conventional hot rolling facility.

[Explanation of symbols]

 Reference Signs List 1 continuous casting machine 2 slab 4 strip 6 strip cooling device 13 work roll 18 slab soaking device 19 first rolling mill group 20 second rolling mill group 21 first winding machine 22 second winding machine 24 Slab cutting device 26 Work roll 30 Strip cutting device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location B21B 37/00 B21B 37/00 113Z

Claims (2)

[Claims] 1. A group of rolling mills for equalizing a long slab corresponding to a plurality of strips of coils so that the thickness of a strip roll-formed from the slab by the group of rolling mills has a specified finished thickness. After setting the interval between the work rolls, send the soaked long slab to the rolling mill group,
After the end of the strip is sent by a predetermined length from the rolling mill group, the interval between the work rolls of the rolling mill group is adjusted so that the thickness of the strip sent from the rolling mill group is reduced,
Further, a hot rolling method is characterized in that a strip sent from a group of rolling mills is cooled, and the strip is cut into finished lengths and wound into a coil shape. 2. A slab cutting device for cutting a slab sent from a continuous casting machine, a slab soaking device for equalizing a slab cut by the slab cutting device, and a slab soaking device. A group of rolling mills for rolling and forming the slab to be rolled into strips, a strip cooling device for cooling the strips sent from the rolling mill group, and a plurality of windings for winding the strips sent from the strip cooling device in a coil shape A strip cutting device for cutting the strip between the strip cooling device and the winder, and the entire length of the slab soaking device is reduced by a plurality of coils to be wound by the winder. A hot-rolling plant characterized in that it corresponds to the length of a slab required for strip rolling.