JPH1034222A - Slab supply yard and slab suppl method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly and rapidly execute the supply for rolling slabs, storage of cold slabs, etc., in a hot strip mill by classifying the continuously cast slabs. SOLUTION: In this slab supply yard, the slabs are sorted into the slabs to be rolled and cold slabs to be stored and each sorted slab is respectively classified into a treatment necessitating slab and a treatment unnecessitating slab. The treatment unnecessitating slab transporting line 14 between a pallet yard 11 where the pallets on which classified slabs are respectively separately loaded are carried in and the charging sides of heating furnace 13-13c, and a treatment line 12 for the treatment necessitating slabs are connecting arranged in the pallet yard 11, slab forcedly cooling lines 23 are provide among the treatment unnecessitating slab transporting line 14, treatment line 12 and the cold slab yard 27 and also slab transfer devices 24 are provided among the treatment unnecessitating slab transporting line 14, treatment line 12 and slab forcedly cooling line 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a slab supply yard and a slab supply method.

[0002]

2. Description of the Related Art As a slab supply yard to a heating furnace for a slab conveyed to a hot rolling mill, a supply route to a heating furnace for heating a relatively high-temperature slab to a rolling temperature, and a slab supply yard from a cold storage yard. In addition to providing a supply route to the heating furnace that heats the low-temperature slab to the rolling temperature, the slab supply pitch to the heating furnace is set according to the relationship between the amount of slab (heating time) charged into each heating furnace and the rolling capacity. The adjustment of the ratio is disclosed in JP-A-3-106501.

[0003]

The slabs after the continuous casting are roughly classified into a serviced slab and a non-maintenance slab among the rolling slabs, and a serviced slab and a non-maintenance slab among the cold slab storage slabs. Such cast slabs are generally mixed and cast in continuous casting, sorted after continuous casting, and uncleaned slabs are transferred to a heating furnace and heated to a rolling temperature, and the well-maintained slabs have surface flaws and the like. In order to carry out maintenance to remove and remove the material, it is transported to a hot scarf facility, after which it is transported and charged into a heating furnace and heated to a rolling temperature. In addition, the unmaintained slab in the cold slab preserving slab is carried into the cold slab yard, and the well-maintained slab is transported to a hot scarf facility to perform maintenance for melting and removing surface flaws, etc.
Carry in cold slab yard and save. However, sorting slabs at the continuous casting unloading side or at the hot rolling mill entry side requires sorting and transporting while reloading with a hoist, forklift, etc., which requires a large amount of manpower, reduces work efficiency, and reduces productivity. Has also had a negative effect. Further, in the hot-rolled slab yard, the temperature of the slab decreases due to a long stagnation waiting for the rolling unit knitting. Also, the slabs are stacked and the temperature does not decrease so much because of the heat retention effect.However, the number of stacked slabs is reduced due to the rolling unit knitting, or the slabs are stuck together with low-temperature slabs that have stayed for a long time, etc. The temperature drops. Further, the unit time of the rolling lot cannot be secured and the temperature is reduced due to a long residence time, so that the heating time is increased, the productivity is reduced, and the energy cost is increased. Furthermore, if slabs having different temperatures are mixed and heated, it is difficult to uniformly bring the slab to the rolling temperature, and there is a problem that the quality such as the deterioration of the shape after rolling is adversely affected. The present invention has been made to advantageously solve such problems, and eliminates the handling of slabs by using a crane or the like, eliminates the slab transportation crossover, and further reduces the slab temperature and reduces the need for slabs and maintenance. It is an object of the present invention to provide a slab supply yard and a slab supply method that can uniformly heat a slab to a rolling temperature by reducing the temperature difference of the slab.

[0004]

The present invention is characterized in that it is divided into a rolled slab and a cold slab storage slab, and each of the divided slabs is classified into a carved slab and a non-care slab. The unmaintained slab transfer line is connected between the pallet yard for loading the pallets and the heating furnace loading side, and the care line for the maintenance slab is connected to the pallet yard. A slab supply yard comprising: a slab forced cooling line provided between cold slab yards; and a slab transfer device provided between an unmaintained slab transport line, a care line, and a slab forced cooling line. And while dividing the continuous cast slab into rolled slabs and cold slab storage slabs, each of the divided slabs is classified into cared slabs and uncarried slabs, respectively.
Each pallet is sorted and loaded on a pallet according to its classification, and then the pallets stacked and loaded are transported to the pallet yard of the hot-rolling plant by a self-propelled trackless truck, and the slabs of the maintenance slabs and the slabs of the maintenance slabs in the rolling slabs are respectively processed. Through a maintenance line and a maintenance-free slab transfer line for maintenance-free slabs, a heating piece slab is charged into a heating furnace at a temperature difference of 100 ° C or less between the maintenance slab and the maintenance-free slab, and heated to a rolling temperature. Is a slab supply method.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When a continuous cast slab is hot-rolled at a hot rolling mill, which is the next hot rolling step, generally, the slab after casting is charged into a heating furnace at about 800 ° C. to perform rolling. It is heated to a suitable temperature of 1200 to 1300 ° C. and supplied to a hot rolling line. The so-called hot charge rolling is performed to save energy and improve the heating furnace capacity by charging at a high temperature. In continuous casting, one charge of molten steel refined in a steelmaking furnace is cast into a ladle and continuously cast while exchanging a ladle filled with molten steel. Few. Therefore, among the cast slabs for one charge of molten steel, there is a cold strip preserving slab that is carried into a cold strip slab yard of a hot rolling mill and a rolled steel strip that is rolled into a product and stored until a customer order is received. . In addition, some of such rolled slabs and cold slab storage slabs become untreated slabs after casting, and surface flaws occur due to various factors during casting, and surface cracks occur during casting. There are some well-maintained slabs that require surface care.

[0006] Thus, the slab is cast by the continuous casting apparatus, and the various slabs cut into a predetermined length as described above are moved to, for example, a carry-out yard adjacent to the continuous casting apparatus, sorted, and sorted into pallets by classification. . In addition to such a classification, for example, the ultra low carbon steel of C: 0.0002 to 0.008% and the low carbon Al killed steel of C: 0.02 to 0.10% are classified and stacked to be hot rolled. This is preferable because the heating temperature in the heating furnace of the factory can be precisely controlled.

[0007] The pallets on which the slabs are stacked in this way are mounted on a self-propelled trackless bogie, carried into the yard on the entrance side of the next process hot rolling mill, and firstly, the maintenance slab in the rolling slab is moved to, for example, a surface defect position. After being carried out to a maintenance line consisting of a detector, a hot scarf device and a grinder, and subjected to maintenance such as removal of surface flaws, it is carried out to a maintenance-free slab transportation line by a transfer device such as a hoist, turntable, etc., to a heating furnace. After being transported and charged to a rolling temperature, the material is supplied to a rolling line including a rough rolling mill and a finishing rolling mill. On the other hand, at the same time, the unmaintained slab in the rolling slab is carried out of the pallet yard to the unmaintained slab transfer line, similarly transferred and charged into a heating furnace, heated to the rolling temperature, and then supplied to the rolling line. Since the temperature of such a slab during transport decreases, for example, by covering the stacked slab with an insulating box, the temperature can be effectively prevented from lowering.

[0008] As described above, the maintenance slab is preferentially carried out to the maintenance line and the slab surface is repaired so that the waiting time in the pallet yard is reduced, the temperature of the slab is prevented from lowering as much as possible, and the maintenance-free slab is prevented. To reduce the temperature difference. That is, since the temperature of the maintenance slab is reduced by the time required for maintenance, the standby time in the yard is reduced as much as possible, and the maintenance processing time is shortened to prevent the temperature of the slab from lowering. The temperature difference between the slab with care and the slab without care at the time can be made 100 ° C. or less, uniform heating can be performed in a heating furnace, and shape deterioration during rolling can be prevented. Also, even if the cared slab and the uncarried slab are mixed into the heating furnace, the heating time can be shortened because the temperature is high and the temperature difference is small, and the productivity can be improved and energy can be saved. .

[0009] On the other hand, the slab of the cold slab preserving slab, which is unmaintained, is transported from the yard to the cold slab yard and stored for waiting for an order. In addition, the maintenance slab in the cold flake preservation slab is carried out from the yard to the maintenance line, and after treating the slab surface flaws, it is transferred to the slab forced cooling line by the transfer device and cooled to almost room temperature, Carry in the cold slab yard and wait for orders.

[0010]

Next, examples of the present invention will be described. In FIG. 1, a slab is cast by a continuous casting apparatus 1, the slab is moved from a strand table 2, 2 a via a traverse car 3 to a weighing machine 4 and weighed. Inspection, and then, when the slab is carried out to the slab unloading yard 8 via the slab receiving stand 7 by the slab lifter 6, the slab is classified into a rolled slab and a cold slab storage slab,
Furthermore, after sorting these slabs according to the slab width and rolling unit of the slab with care and the slab without care, slabs having a surface temperature of about 800 ° C. are pallets 9, 9a, 9b, and 9 respectively.
c, respectively. The pallet 9d, among other pallets 9, 9a, 9b, and 9c, always waits for one of the pallets 9, 9a, 9b, and 9c as a spare so that the pallet 9d can be quickly loaded onto the carrier pallet 9d after the pallet 9d satisfies the required transport amount to the yard of the hot rolling mill. Let it. The pallet 9 that has satisfied the required transport amount
... are self-propelled trackless bogies 10, 10a, 10b, 10
c and then transported to the pallet yard of the hot rolling mill.

That is, as shown in FIG. 2, the pallet is carried into a pallet yard 11 on the entrance side of a hot rolling mill, and the slab (about 800 ° C.) in the rolling slab is preferentially connected to the yard 11 in the yard 11. To the maintenance line 12, and at the same time, the maintenance-free slab (about 800 ° C.) in the rolling slab is transferred to the maintenance-free slab transfer line 14 disposed between the loading side of the heating furnaces 13, 13 a, 13 b, and 13 c and the pallet yard 11. After being unloaded, the slabs are sequentially charged into heating furnaces 13, 13a, 13b, and 13c and heated to a rolling temperature of 1250 ° C., extracted, and passed through a table 15 to a rough rolling mill 16 and a finishing rolling mill 17.
Is supplied to a rolling line 18 consisting of On the other hand, the maintenance slab in the rolled slab carried out to the maintenance line 12 confirms the surface flaw position with the surface flaw position detector 19, removes the surface flaw with the hot scarf 20, and then removes the surface flaw. After inspecting the presence or absence of residual flaws at 21, the residual flaws are removed by a grinder 22 if necessary, and the slab transfer device 24 provided between the unmaintained slab transport line 14, the care line 12, and the slab forced cooling line 23. The slab whose temperature has been reduced to 750 ° C. is transferred to the unmaintained slab transfer line 14 by a (hoist), and transferred to the heating furnaces 13, 13 a, 13 b, and 13 c together with the unmaintained slab, and the rolling temperature (1250 ° C.) is reached. After heating, it is supplied to a rolling line 18.

The unmaintained slab in the cold slab storage slab carried into the pallet yard 11 is carried into the cold slab yard 27 via the cold slab transfer line 25 and waits for an order. On the other hand, the maintenance slab in the cold slab storage slab is carried out from the pallet yard 11 to the maintenance line 12, and the flaw position is confirmed by the surface flaw position detecting device 19, the surface flaw is removed by the hot scarf 20, and the residual flaw is inspected as described above. After inspecting the residual flaws with the device 21, the grinder 22 is used if necessary.
To remove residual flaws, and then the slab transfer device 24
After being carried into the slab forced cooling line 23 and rapidly cooled to almost normal temperature by water cooling, it is re-inspected at the inspection line 26, and if necessary, is cared for.

[0013]

According to the present invention, the slabs after continuous casting are classified and sorted in advance, stacked on a pallet, and conveyed to a hot rolling mill in the next step. In the yard configured as the route, the slab is processed and supplied to the rolling line, and the cold slab storage slab is carried into the cold slab yard, so that there is almost no slab crossing. Accordingly, the slab temperature during heating does not greatly vary, and the slab can be uniformly heated to the rolling temperature, and the rolling shape can be improved to increase the yield. Further, the supply of the slab can be ensured, the rolling lot unit volume can be expanded and knitted, and the productivity can be improved and the labor can be saved. Further, energy saving can be achieved.
Furthermore, by separating and loading the slabs after continuous casting on a pallet and transporting them to a hot rolling plant, it is possible to prevent a reduction in the rolling unit amount due to the maintenance slabs that occur during continuous casting and a decrease in the heating furnace capacity due to a decrease in temperature. In addition, in the hot-rolling plant slab yard, it is possible to omit the operation of rearranging the rolling units and the supplying operation, thereby achieving an excellent effect such as a significant rationalization of personnel.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention.

FIG. 2 is a flowchart showing an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 9 pallet 9a pallet 9b pallet 9c pallet 11 yard 12 care line 13 heating furnace 13a heating furnace 13b heating furnace 13c heating furnace 14 unmaintained slab transfer line 23 forced slab cooling line 24 slab transfer device 26 inspection line 27 cold slab yard

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[Procedure amendment]

[Submission date] September 6, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007] The pallets on which the slabs are stacked in this way are mounted on a self-propelled trackless bogie, carried into the yard on the entrance side of the next process hot rolling mill, and firstly, the maintenance slab in the rolling slab is moved to, for example, a surface defect position. After taking out to a maintenance line consisting of a detector, a hot scarf device and a grinder, and performing care such as removing surface flaws, it is carried out to a maintenance-free slab transfer line by a transfer device such as a hoist, turntable, etc. And heated to a rolling temperature, and then supplied to a rolling line including a rough rolling mill and a finishing rolling mill. On the other hand, at the same time, the unmaintained slab in the rolling slab is carried out of the pallet yard to the unmaintained slab transfer line, similarly transferred and charged into a heating furnace, heated to the rolling temperature, and then supplied to the rolling line. Since the temperature of such a slab during transport decreases, for example, by covering the stacked slab with an insulating box, the temperature can be effectively prevented from lowering.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009] On the other hand, non-care slab in a cold piece storage slab, and save transported from the pallet yard to cold strip slab yard and orders waiting. In addition, the maintenance slab in the cold flake preservation slab is carried out from the yard to the maintenance line, and after treating the slab surface flaws, it is transferred to the slab forced cooling line by the transfer device and cooled to almost room temperature, Carry in the cold slab yard and wait for orders.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010]

Next, examples of the present invention will be described. In FIG. 1, a slab is cast by a continuous casting apparatus 1, the slab is moved from a strand table 2, 2 a via a traverse car 3 to a weighing machine 4 and weighed. Inspection, and then, when the slab is carried out to the slab unloading yard 8 via the slab receiving stand 7 by the slab lifter 6, the slab is classified into a rolled slab and a cold slab storage slab,
Furthermore, after sorting these slabs according to the slab width and rolling unit of the slab with care and the slab without care, slabs having a surface temperature of about 800 ° C. are pallets 9, 9a, 9b, and 9 respectively.
c, respectively. Pallet 9d is another pallet 9, 9a, 9b, in the 9c, next to met conveyance necessary amount to yard hot rolling plants, rapidly pallet 9
One is always on standby as a standby so that it can be loaded on d . The pallet 9 that fulfills the required amount of transport
Are sequentially mounted on the self-propelled trackless carriages 10, 10a, 10b, and 10c and transported to a pallet yard of a hot rolling plant.

Claims (3)

[Claims] 1. A pallet yard for separating a rolled slab and a cold slab storage slab, classifying each of the divided slabs as a carved slab and an uncarried slab, and carrying a pallet into which the classified slabs are stacked. An unmaintained slab transfer line is connected and installed between the furnace loading side and a maintenance line for the preparatory slab at the pallet yard.
A slab forced cooling line is provided between the unmaintained slab transfer line and the care line and the cold slab yard, and a slab transfer device is provided between the unmaintained slab transfer line, the care line, and the slab forced cooling line. Slab supply yard. 2. A continuous cast slab is divided into a rolled slab and a cold slab storage slab, and each of the divided slabs is classified into a carved slab and an uncarried slab, and each slab is separately loaded on a pallet according to the classification. The loaded pallets are transported to the pallet yard of the hot rolling mill by a self-propelled trackless bogie, and the maintenance slabs in the rolling slabs and the maintenance slabs are respectively transported. A slab supply method comprising: charging a hot slab with a temperature difference of 100 ° C. or less between a treated slab and an untreated slab into a heating furnace through a line, and heating the slab to a rolling temperature. 3. Conveying the unmaintained slab of the cold slab from the pallet yard to the cold slab yard,
The slab supply method according to claim 2, wherein the slab is maintained and forcibly cooled and transported to a cold slab yard.