JPH04158901A - Continuous hot rolling line and rolling method using same - Google Patents

Abstract

PURPOSE:To prevent temp. drop by a simple method by uncoiling and executing finish rolling after transporting a coil which is coiled with a coil box to a proximity un-coiler. CONSTITUTION:The coil which is coiled with the coiler 4 of the coil box 3 is once transported to the un-coiler 5. The coil on the un-coiler 5 is raised upwards with a coil elevating device 12 and transported above the proximity un-coiler 15 with rails 13 and wheels. The coil which is transported above the proximity un-coiler 15 is lowered with the coil elevating device 12 and uncoiled. A rolled stock which is uncoiled is rolled with a finishing mill 10 and made into a prescribed product. In this way, rolling can be done using the same rolling line and finish rolling can be executed while the temp. drop is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a continuous hot rolling line and a rolling method using the same. In particular, the present invention relates to a continuous hot rolling line and a rolling method using the continuous hot rolling line that can suitably perform hot finish rolling of continuously rolled material and discontinuously rolled material on the same rolling line.

(Prior art) Conventionally, in hot rolling lines, slabs extracted from continuous casting equipment or heating furnaces, that is, plate thicknesses of 200 to 300 fi
111, board width 600-2000+lll, length 5-12
Slabs of about one end were rolled discontinuously one by one. However, in such discontinuous rolling, the yield is lowered due to poor sheet thickness accuracy, sheet width accuracy, and poor characteristics due to temperature fluctuations, particularly at the leading and trailing ends of the rolled material.

In recent years, for the purpose of solving this problem, for example, Japanese Patent Application Laid-Open No. 57
A continuous finish rolling method shown in Japanese Patent No. 109504 has been proposed.

Figure 3 shows a continuous hot rolling line used in this method. In Figure 0, a rolled material 2 with a plate thickness of 15 to 45-1 rolled by a rough rolling mill 1 is rolled by a winder 4 in a coil box 3. Taken,
The wound coil is then unwound in an unwinding machine 5.6. The leading end of the trailing rolled material 7 and the rear end of the preceding rolled material 8, which have been unwound in sequence in this way, are joined by a joining machine 9, and the rolled material continuous in this way is transferred to a finishing mill 10. rolled continuously.

There are the following two methods for joining the preceding rolled material and the subsequent rolled material to perform such continuous rolling.

The welding machine 9 uses a running welding method that synchronizes with the traveling speed of the preceding rolled material 8 and joins it in a running state, and the welding machine 9 is fixedly placed.
This is a stop joining method in which the intermediate portion in the longitudinal direction of the pre-rolled material 8 is appropriately stored in the looper 11, and the rear end portion is stopped for a while at the position of the joining machine and joined during that time.

(Plot B to be solved by the invention) The time required to join such leading and trailing rolled materials is normally several seconds to several seconds, but Including the time to set the tip and the joining position, the total joining time is about 20 to 50 seconds.

By the way, the rolling material speed at the entry side of the finishing rolling machine is 40 to 60 m.
/min, the traveling distance of the running splicer is required to be 13 to 50 m. In addition, in the case of the stop joining method, the amount of looper plate storage is 1
Since 3 to 5 loops are required, a large looper is required.

Further, a descaler, edger-1, various measuring instruments, etc. are arranged between the coil box and the finishing mill, and the distance between the coil box and the finishing mill becomes considerably long.

To carry out continuous rolling, it is necessary to rearrange the rolled materials (slabs) extracted from the continuous casting equipment or heating furnace in order of ease of continuous rolling, and to adjust the timing of rolling. In other words, since a large number of materials are rolled for each roll, the rolling operation becomes quite complicated when these rollings are taken into account.

In addition, it is expected that jamming will occur when the rolled material gets caught in the finish rolling mill, so the initial rolling material speed is slower than the steady rolling material speed, and the plate gets caught in all stands during finish rolling. The rolling material speed is gradually increased until the
The speed can be increased to the rolling material speed at steady state. In continuous rolled materials, the individual rough rolled materials are connected continuously and there is no leading end, so the rolling material speed at the entrance of the finishing mill during steady state is relatively high as mentioned above, but with discontinuous materials In this case, the threading speed at the tip of the rolled material in the finishing mill is slow (because each rolled material has a tip, if the distance between the coil box and the finishing mill is long, the temperature drop of the rolled material will be large, It may become impossible to secure the finish rolling temperature.

An object of the present invention is to provide a method for ensuring a finish rolling temperature when rolling a discontinuous material on a continuous hot rolling line.

(Means for Solving the Problems) In order to achieve the above object, the inventor of the present invention has made various studies and has focused on the fact that the temperature drop in the coil state is very small. It has been found that a rolling line equipped with an unwinding machine (hereinafter referred to as a close unwinding machine) can most effectively solve the problems of the prior art.

In addition, using such a rolling line, after winding the discontinuous material in a coil box, the coil is transferred to the above-mentioned proximity unwinding machine, and the rolled material is unwound from this proximity unwinding machine for finish rolling. The present inventors have discovered that the temperature drop during the process can be minimized, and have completed the present invention.

That is, the present invention provides a hot rolling line that connects the trailing end of the preceding rolled material and the leading end of the trailing rolled material after rough rolling and continuously performs finish rolling, which is provided on the exit side of the rough rolling mill. A coil box consisting of a winding machine and a plurality of unwinding machines, a joining machine, a proximity unwinding machine located close to a finishing rolling machine, and a coil transport installed between the coil box and the proximity unwinding machine. This is a continuous hot rolling line equipped with equipment.

From yet another aspect, the present invention provides, in the continuous hot rolling line described above, the finish continuously rolled material is wound in the coil box and then unwound by the unwinding machine of the coil box, and the discontinuously rolled material is After winding with the coil box winding machine,
This is a rolling method using a continuous hot rolling line, characterized in that unwinding and finish rolling are performed by the close unwinding machine installed close to the finishing rolling machine.

Thus, according to the present invention, both continuously rolled and discontinuously rolled materials can be rolled on the same rolling line, and in particular, discontinuously rolled materials can be finished while minimizing temperature drop. Rolling can be performed.

Further, according to the present invention, even if the joining timing is shifted and the preceding rolled material and the succeeding rolled material cannot be joined, it is possible to continue rolling by transferring the coil to a nearby unwinding machine, Significant improvements can be seen in this respect as well.

(effect) The present invention will now be described in further detail with reference to the accompanying drawings.

FIG. 1 and FIG. 2 (b) are schematic illustrations of a continuous hot rolling line and a coil transfer device of the present invention. Identical members are designated by the same reference numerals.

First, referring to FIG. 1, a rolling operation for rolling a continuously rolled material will be explained.

The rolled material 2 rolled by the rough rolling mill 1 is a coiled material.

The coil 3 is wound by a winding machine 4, and the wound coil is transferred to an unwinding machine 5 to prepare for unwinding.

When the rewinding is completed by the front rewinding machine 6, the rewinding 115
The rolled material is rewound from there, and the rear end of the leading material and the leading end of the trailing material are joined by a joining machine 9. In this example, joining is performed using a running joining method.

As the winder 4, the unwinder 1R5, and the splicer 9, conventional devices are used, and the present invention is not limited thereto.

After joining, the coil of the unwinding machine 5 is unwound while being unwinded by the unwinding machine 6.
will be transferred to. After the coil on the unwinding machine 5 is transferred,
The next coil is transferred from the winder 4 to the unwinder 5.

During such continuous rolling, the coil threading speed of the finish rolling mill 10 is rolled at a constant speed without being reduced. Therefore,
The temperature drop of the rolled material between the coil box 3 and the finishing mill 10 is small.

Next, a rolling operation when rolling a discontinuously rolled material in FIG. 1 will be explained.

First, the coil wound up by the winding machine 4 of the coil box 3 is once transferred to the unwinding machine 5. The coil 16 on the unwinding machine 5 is lifted upward by the coil lifting device 12, as shown in detail in FIGS. is transported above the The coil 16 transferred above the close unwinding 11115 is moved to the close unwinding 11 by the coil heating device 12.
15 and is rewound. The rewound rolled material is rolled in a finishing mill IO to form a predetermined product.

After placing the coil in the proximity unwinding *tS, the coil lifting device 12 returns to above the coil box 30 and the unwinding machine 5, and prepares for the next coil transfer.

In this example, a coil transfer device consisting of rails 13 and wheels 14 has been described, but other devices using a dedicated crane may be used. The installation location of the proximity unwinding machine 15 may be as close to the finishing rolling mill 10 as possible; in other words, it may be located at an appropriate location as long as a temperature drop is not observed.

In the case of continuously rolled material, the threading speed must be slowed down for the first rolled material, but in this case, the thicker rolled material is used as the first rolled material, and the rolling material from the second wood onward is By changing the thickness of the material during running in the finishing mill, it is possible to ensure the finishing temperature from the first rolled material of the first grain.

When starting rolling, it is preferable to use a rolled material with a thick plate thickness. This is because the thicker the material, the slower the cooling rate, and the slower the temperature drop.

Next, the present invention will be explained in more detail with reference to Examples.

(Example) In this example, continuously rolled material and discontinuously rolled material are processed by using a device using a coil transfer device shown in FIGS. 2(a) and (b) on the hot finish rolling line shown in FIG. 1. Finish rolling was performed on each.

The distance between the unwinding 115 of the coil box 3 and the first stand of the finishing rolling mill 10 is 6 mm, and the close unwinding 1115 and finishing rolling! ! ! The distance between the first stand of 10 is 10
I was overwhelmed with m.

First, as a comparative example, a rolled material having a plate thickness of 30II1 m and a plate width of 1250 mm after rough rolling was continuously and discontinuously finished rolled to a plate thickness of 1.81 mm using a finishing mill.

In the case of continuous rolling, the rolling material speed at the entrance of the finishing mill is 60 m.
/min (finishing mill exit speed is 1000+n/min) and -4
The temperature drop between the coil box 3 and the finishing rolling mill IO was 70°C.

On the other hand, in the case of discontinuously rolled material, the rolling material speed at the entry side of the finishing mill is usually 36
The temperature drop between the coil box 3 and the finishing mill 10 was as large as 124° C. because the temperature was kept at about 100 m/min (600 m/min at the exit speed of the finishing mill). Therefore, a predetermined finish rolling temperature could not be ensured, resulting in a significant yield loss from the tip to the middle of the rolled material until the rolling material speed reached a steady state.

Next, according to the method of the present invention, the coil 16 wound in the coil box 3 was transferred to the nearby unwinding machine 15 as shown in FIG. 2, and was unwound at a rolling material speed of 36 m/min to perform finish rolling. However, the temperature drop between the close unwinding 1115 and the finishing mill 10 was as small as 38°C, and even when the temperature drop of 11°C during coil transfer was added, the temperature drop was significantly improved to 49"C.

In this example, no special measures were taken to keep the coil warm during the coil transfer, but by taking such measures, the temperature drop during the transfer can be further controlled.

(Effects of the Invention) Since the present invention is configured as described above, it has the effect of preventing temperature drop, which is a problem when rolling a discontinuous material on a continuous hot rolling line, in a simple manner. It is extremely useful in industry.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a continuous hot finishing rolling line according to the present invention; FIG. 2(a) is a front view of the coil transfer device, FIG. 2(b) is a side view; and FIG. 3 is a conventional FIG. 2 is a schematic explanatory diagram of a hot finish rolling line. 1: Rough rolling mill 2, 7, 8: Rolled material 3: Coil box 4: Winding machine 5.6: Unwinding machine
9: Joining machine 10: Finish rolling 41! i15; Proximity unwinding machine 12: Coil lifting device

Claims (2)

[Claims] (1) A hot rolling line that connects the rear end of the preceding rolled material after rough rolling and a part of the tip of the trailing rolled material and continuously performs finish rolling, and the winding line is installed on the exit side of the rough rolling mill. a coil box consisting of a machine and a plurality of unwinding machines, a joining machine, a proximity unwinding machine located close to the finishing rolling machine, and a coil conveying device installed between the coil box and the proximity unwinding machine. Continuous hot rolling line equipped with (2) In the continuous hot rolling line according to claim 1,
The finishing continuous rolled material was wound in the coil box and then unwound in the coil box unwinding machine, and the discontinuously rolled material was wound in the coil box winding machine and then installed close to the finishing rolling machine. A rolling method using a continuous hot rolling line, characterized in that unwinding and finish rolling are performed by the close unwinding machine.