JP3465625B2 - Method for determining width of continuous casting slab - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the width of a slab for casting a slab corresponding to a steel product of an order with a continuous casting machine. The present invention relates to a method for determining the width of a slab that allows continuous casting of the slab to be cast while adopting the maximum possible casting width.

[0002]

2. Description of the Related Art In the pig iron integrated steel industry, various products are manufactured through the process shown in FIG. In the blast furnace 11, iron ore is reduced with coke to produce pig iron having a substantially constant composition. In the converter 12, the molten pig iron is blown with oxygen to produce molten steel having a predetermined composition so as to obtain a steel type corresponding to an ordered steel product. The operating mode of the converter 12 is a batch system, and the molten steel produced for each refining is tapped into a ladle. This refining for each time is called heat, and the amount of molten steel in one heat depends on the capacity of the converter.

The produced molten steel is cast by the continuous casting machine 13 to form a semi-finished product slab. In the normal continuous casting machine 13, in order to improve its productivity, so-called continuous casting is performed in which molten steel for several heats produced in the converter 12 is continuously cast. However, it is preferable that the heat cast by continuous casting is of the same steel type. In continuous casting of different steel types, it is necessary to scrap the joints of the steel types, which not only hinders productivity but also saves resources. Among the continuous casting machines 13, especially in the slab continuous casting machine, in order to further increase the number of heats from one continuous casting from the viewpoint of improving productivity, the casting mold short side is moved during casting to change the casting mold width, which is different. A so-called width change during casting is performed in which width slabs are also cast at one casting opportunity one after another. In the width change during casting, the maximum width change amount for one width change is usually about 50 mm in consideration of the shape of the tapered slab manufactured during the width change.

The manufactured slab is sent to the thick plate process 14 and the hot rolling process 15 according to the order. The rolled product in the thick plate process 14 is shipped to customers as a so-called thick plate, and the rolled product in the hot rolling process 15 is a hot rolled steel plate called a so-called hot coil, which is directly shipped as a product, or After the cold-rolling process 16 and the plating process 17 of the lower process, a cold-rolled steel plate or a surface-treated steel plate is shipped.

In the thick plate process 14, since the thick plate product is manufactured by rolling in the length direction and the width direction of the slab, the constraint of the slab width corresponding to the product size is extremely loose. Hot rolling process 15
Also, in recent years, a sizing press has been introduced, and a considerable amount of width rolling can be performed at the time of rolling, and the constraint of the slab width on the product size has become loose. For example, for a hot-rolled steel sheet having a width of a, a-50 mm to a + 25
There is also a hot rolling step 15 which allows slabs up to 0 mm. In this case, the width change during casting of the slab continuous casting machine is 50
If the pitch is mm, there will be a plurality of slab widths that can be cast within the allowable width range. Then, in a steel mill where a hot rolling step 15 equipped with a sizing press and a hot rolling step 15 not equipped with a sizing press are mixed,
Orders having different allowable slab widths are mixed, and it is particularly difficult to determine an appropriate slab width.

There are three attributes of the slab size that accompany an order: the slab nominal width, the maximum width that can be cast, and the minimum width that can be cast. Conventionally, an operator aims to increase the casting efficiency of a continuous casting machine. A large amount of time was spent deciding the slab width while looking at the list sorted by the slab nominal width so that the number of heats generated by one continuous casting increased and the width became as wide as possible within the allowable width range. .

[0007]

However, since the slab nominal width is set individually for each order, the overall connection is not taken into consideration. In the list arranged in the order of the slab nominal width, the maximum castable width is the slab nominal width. It was difficult to grasp the whole picture of the order because it was reversed from the width. Therefore, the operator did not always determine the slab width so that casting would be maximized one after another, and there was a loss.

The present invention has been made in view of the above circumstances.
The purpose is to provide a slab width determination method capable of improving the casting efficiency of a continuous casting machine by maximizing the number of heats for continuous casting in steel grade units while adopting the maximum possible casting width. Is.

[0009]

[0010]

Means for Solving the Problems] width determination method of engaging Ru continuously cast slab to a first aspect of the present invention, the order granted manufacturing specifications
-From the order DB that stores information,
The order information is read by the knitting unit connected to
The knitting section based on the read order information.
Used, the slab corresponding to each individual order the order group to be aggregated to the same steel species, advance and castable maximum width wide order of castable maximum width allowed classified into broad order of castable minimum width in the same range first, castable maximum width and the width of the castable minimum width minimum slab, decide castable width a is a maximum width of the slab, then the slab next to the width a and the previous SL slabs order of the slab In the case where the difference between the maximum width that can be cast and the maximum width change amount α in one continuous casting width change of the continuous casting machine is less than or equal to the maximum slab width that can be cast for the slab , the difference between the casting possible maximum width of the slab next to the width a of the previous Symbol slabs order of the slab,
When the maximum width change amount α is exceeded, the slabs including adjacent slabs can be cast until the slab with the wider maximum width is castable, and the slab is cast within the range between the maximum castable width and the minimum castable width. A slab whose width can be set wider than the width A by the maximum width change amount α is found, and the width of the found slab is defined as a value obtained by adding the maximum width change amount α to the width A. as to the width of the slab next to the slab to determine the width and order Tsugike' constant follow the above in, out of the width of the determined slab
It is characterized by making them work.

[0011] the width determination method for engaging Ru continuously cast slab in the second invention, Oite the first inventions, the maximum width change amount alpha 5
It is characterized in that it is 0 mm.

In the present invention, while maintaining the width of each slab within the range of the maximum castable width and the minimum castable width of each slab, the width of the slab to be continuously cast is determined by the continuous casting machine 1
Since the maximum width change amount α of the continuous casting width change is less than or equal to α, the continuous casting machine can perform continuous casting width change while maximizing continuous casting in units of steel types, and the casting efficiency of the continuous casting machine is improves. Furthermore, since the maximum castable width of the slab is adopted as the slab width as much as possible, the casting amount per unit time can be increased, and the casting efficiency of the continuous casting machine is further improved.

Further, the maximum width change amount α during one width change during casting
Since the taper slab manufactured during width change during casting has a difference in width between the leading end side and the trailing end side of casting of 50 mm or less, the taper slab is It can be easily rolled into a hot coil having a uniform width with the rear end.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of the exchange of order information related to the slab width determination method according to the present invention. First, the exchange of order information related to the slab width determination will be described with reference to FIG.

The ordering department 1 provided at the head office or the like receives orders for thin steel sheet products from customers. The order information at this stage includes contents such as product standard, product width, total weight, and delivery date. Such order information is transmitted to each steel mill on a regular basis, for example, once a week.

In the product design department 2 of each steel mill, quality design and manufacturing method design are carried out for orders from each customer. At this stage, information on the steel grade and the slab nominal width, the maximum castable width, and the minimum castable width of the slab corresponding to the ordered product is given. The slab nominal width is obtained by adding the yield loss after the hot rolling process to the product width, and usually the product width and the slab nominal width are substantially the same. The maximum castable width and the minimum castable width are calculated from the capability of the width rolling machine or the width pressing machine of the hot rolling factory where the slab is rolled. Recently, the width rolling mill (Ve
Most of the hot rolling plants are capable of straightening the slab width by arranging vertical scale breaker (abbreviated name VSB) and sizing press. Incidentally, the width rolling mill has a castable width range of 150 mm and the sizing press has a castable width range of 300 mm.

The order information given the manufacturing specifications in the product design department 2 is collected by steel type and transmitted to the production planning department 3. The production planning department 3 is a department that determines the type of steel to be manufactured, its quantity, and its manufacturing time based on the order information, and finally determines the width of the slab corresponding to the order. FIG. 2 is a flowchart showing a slab width determining method according to the present invention, which is performed in the production planning department 3, and hereinafter, referring to FIG.
Maximum width change amount α during width change during casting is set to 50 mm 2
The present invention relates to the present invention in a steel mill having a strand type slab continuous casting machine and two hot rolling mills in which a width rolling mill is installed in one hot rolling mill and a sizing press is installed in the other hot rolling mill. A method for determining the width of the slab will be described. still,
In FIG. 2, W (I) is the slab width of the registration number I, and W
max (I) is the maximum castable width of registration number I. Here, the registration number is a number for identifying the slab and is a serial number given to each slab corresponding to the order.

The production planning department 3 is an order DB for storing order information given manufacturing specifications in the product design department 2.
4, the knitting unit 5 connected to the order DB 4 reads all order information of a certain steel type. An example of the read order is shown in FIG. FIG. 3 shows all 39 slabs corresponding to the order in order of the slab nominal width from the slab nominal width to the narrow slab nominal width, and shows the maximum castable width and the minimum castable width of each slab together. . As shown in FIG. 3, it can be confirmed that a wide casting range and a narrow casting range coexist.

First, these slabs are sorted in the order of the largest castable maximum width and in the order of the smallest castable minimum width within the same range of the castable maximum width, ignoring the slab nominal width. The rearranged data is shown in FIG. Figure 4
Does not display the slab nominal width. If the difference in the maximum width that can be cast between adjacent slabs that have been rearranged is less than or equal to the maximum width change amount α for one change in width during casting, in this example, 50 mm or less, while changing the width during casting in a continuous casting machine. Casting is possible, the maximum casting width of each slab is determined as the width of each slab, and the width setting work is completed. However, in the example of FIG. 4, 250m between the registration numbers 26 and 27.
There is a difference of m, and between the registration number 36 and the registration number 37 is 150
There is a difference of mm, and thus it is usually impossible to continuously cast all the slabs with the maximum possible width.

Therefore, among the rearranged slabs, the slab having the smallest maximum castable width and the minimum castable width, in this example, the slab width of the registration number 39 corresponding to the 39th slab of the 39 total slabs. Is determined to be 1050 mm which is the maximum castable width of the slab. Next, the width of the slab (registration number 38) adjacent to the slab (registration number 39 in the example of FIG. 4) thus determined is determined. At that time, whether the difference between the maximum castable width of the adjacent slab (registration number 38) and the width of the already determined slab (registration number 39) is less than or equal to the maximum width change amount α of one width change during casting. There are two ways to determine the width.

In the example of FIG. 4, the maximum castable width of the registration number 38 is the same as the slab width of the registration number 39, so the slab width of the registration number 38 can be determined to be 1050 mm. That is, when the difference between the maximum castable width of the slab whose width is newly determined and the width of the slab whose width has already been determined between adjacent slabs is less than or equal to the maximum width change amount α during one width change during casting. Is
The width of the slab that determines the new width is the maximum castable width of the slab. The width of the registration number 37 is similarly determined based on the width of the registration number 38, and the maximum casting width of the registration number 37 is 1050.
Since it is mm, the slab width of the registration number 37 can be determined to be 1050 mm.

On the other hand, the difference between the slab width of the registration number 37 and the maximum castable width of the registration number 36 is 150 mm, which exceeds the maximum width change amount α for one width change during casting. From the maximum width change amount α of the width change during casting in (3), it is necessary to change the width during casting three times in order to perform continuous casting. Since the example shown in FIG. 4 is a two-strand type continuous casting machine, two slabs are required for one width change during casting, so that the slab width is changed from 1050 mm to 1200 mm by 50 m.
A total of 6 slabs are required to spread at m intervals. Therefore, the slabs ahead of the six slabs are descent, and it is examined whether all the six slabs are permissible with respect to the width change. In the example shown in FIG. 4, the registration numbers 36 and 35 are provisionally set to 1100 mm, the registration numbers 34 and 33 are set to 1150 mm, and the registration numbers 32 and 31 are set to 1200 mm. Since it is within the range between the maximum castable width and the minimum castable width, the slab width can be determined as it is. Since the maximum casting widths of the registration numbers 27 to 30 are equal to the slab width of the registration number 31, the registration numbers 30 to 27 can be reduced to 1200 mm width.

The difference between the slab width of the registration number 27 and the maximum castable width of the registration number 26 is 250 mm, and it is necessary to change the width during casting 5 times in order to continuously cast the slab. Therefore, the slab width is 1200 mm. A total of 10 slabs are required to spread from 1450 mm to 1450 mm at 50 mm intervals. In this case as well, the slab width is provisionally set in the same manner as above, but when the registration number 26 and the registration number 25 are provisionally set to 1250 mm,
Registration number 25 becomes less than the minimum width that can be cast, and the width cannot be set. In FIG. 4, within the range in which the maximum castable width is the same, the minimum castable width is arranged in the descending order. Therefore, it is impossible to set the width of 1250 mm for the registration numbers 18 to 24 where the maximum casting width is 1450 mm. Is. Therefore, registration number 1
Go back to 7 or earlier and secure a slab that can be cast with a width of 1250 mm. In the example shown in FIG. 4, the registration number 17 can be cast at 1250 mm, and the registration number 17 is determined to be 1250 mm wide.

The minimum castable width of registration number 25 is 1350 mm
Therefore, it is impossible to set the width of 1300 mm. Therefore, as when securing a slab with a width of 1250 mm,
Secure two slabs that can be cast with a width of 1300 mm before registration number 16. In the example shown in FIG. 4, registration number 15 and registration number 16
Since it is possible to cast with 1300 mm, the registration number 15 and the registration number 16 are determined to be 1300 mm. After that, return to the registration number 25, and change the registration number 25 and the registration number 24 to 1350 mm width, registration number 2
3 and the registration number 22 have a width of 1400 mm, and the registration number 21 has a maximum castable width of 1450 mm. And the registration number 18
Up to 1450mm width.

The slab following the registration number 18 is the registration number 14,
Since the difference between the slab width of the registration number 18 and the maximum castable width of the registration number 14 is 50 mm, the registration number 14 can be set to the maximum castable width of 1500 mm. Then, it goes down to the registration number 1 with a width of 1500 mm and outputs the determined width. Figure 4
In the figure, the slab width determined in this way is indicated by ▲.
FIG. 5 is a diagram in which the slabs corresponding to the order are rearranged in order from the widest slab width based on the determined slab width. Incidentally, the slab width is determined in the production planning department 3 automatically by the knitting unit 5, and there is no need to show it as shown in FIGS. 4 and 5. In addition, if there is no order of suitable size and continuous casting cannot be continued even by changing the width during casting, give up continuous casting and divide the cast into the maximum possible width as much as possible. Determine the width so that

As described above, in the present invention, the number of slabs corresponding to the minimum number of strands in each width is secured to change the width during casting.
Since the width is determined so that it can be cast by one continuous casting as a whole and the maximum possible casting width is adopted as much as possible, the casting efficiency of the continuous casting machine can be improved.

In the above description, the order information is sent and received in three steps.
Although the description is made by dividing into two departments, the present invention is not limited to the above, and any number of intervening departments may be used as long as the order information is transmitted according to the above.
Further, in the above description, when the slabs corresponding to the orders are sorted in the order of the widest castable maximum width and in the order of the widest castable minimum width within the same range of the castable maximum width, the maximum castable width and the minimum castable width. Although the slab with the smallest value was described as the Nth among the N pieces, the slabs with the smallest possible castable width and the smallest possible castable width were set in the completely opposite order.
As the second, the second and subsequent ones may be sequentially determined according to the above description.

[0028]

According to the present invention, the width is determined so that casting can be continuously performed once, and the maximum possible width is adopted as much as possible, so that the casting efficiency of the continuous casting machine is improved. It becomes possible and brings an industrially beneficial effect.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of exchange of order information relating to a slab width determination method according to the present invention.

FIG. 2 is a flowchart showing a slab width determining method according to the present invention.

FIG. 3 is a diagram showing an example of read orders in the order of slab designation widths.

FIG. 4 is a diagram in which the orders shown in FIG. 3 are rearranged in the order of widest castable maximum width and in the order of widest castable minimum width within the same range of castable maximum width.

FIG. 5 is a diagram in which the orders shown in FIG. 3 are rearranged in the order of slab width determined by the present invention.

FIG. 6 is a manufacturing process diagram of a steel product in an integrated pig iron manufacturing industry.

[Explanation of symbols]

1 Order department 2 Product design department 3 Production Planning Department 4 Order DB 5 formation department

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP 62-263857 (JP, A) JP 9-314299 (JP, A) JP 57-94449 (JP, A) JP 7- 214268 (JP, A) JP-A-8-174171 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22D 11/15 106 B22D 11/05

Claims (2)

(57) [Claims] 1. The order information provided with manufacturing specifications
From the order DB to be paid, connect to the order DB
Read the order information by the knitting unit and read it
Based on the ordered information,
For each individual order in the order group that is aggregated into one steel type
Suitable slabs can be cast in ascending order of maximum width
If the maximum width is within the same range,
First, the maximum width that can be cast and the minimum that can be cast
The width of the smallest slab is the maximum castable width of that slab.
Then the width A of the slab and the width A
The difference between the maximum castable width of the adjacent slab in the order of love,
Maximum width change amount α or less for one width change during casting of continuous casting machine
In the case of, the width of the adjacent slab is set to the
On the other hand, the width A of this slab and the order of the slabs
The difference between the maximum slab width of the adjacent slab and the maximum width
If the change amount α is exceeded, the above-mentioned slab including the adjacent slab
Capable of casting in the order of love.
Slab width within the range of maximum and minimum casting width
To be wider than the width A by the maximum width change amount α.
Slab width that can be found and found
Is the value obtained by adding the maximum width change amount α to the width A, and
The width of the slab next to the slab whose width was determined by
To output the determined slab width.
A method for determining the width of a continuously cast slab , characterized by: 2. The maximum width change amount α should be 50 mm.
The method for determining the width of a continuously cast slab according to claim 1, wherein: