KR20040059206A - Method for controlling width of slab in continuous rolling mill - Google Patents

Abstract

PURPOSE: A method for controlling width of slab in mini-mill continuous casting and continuous rolling mill is provided to minimize width defect of final products and improve actual yield by controlling the deviation through mold width control if finish rolling width margin deviation is 7 mm or more and controlling the deviation through dynamic width control if the finish rolling width margin deviation is 6 mm or less. CONSTITUTION: The method comprises first step of calculating an average value by receiving a target width margin deviation from hot rolling PLC using width of the strip measured in a strip width gauge after rolling strip in a finish rolling mill and a target width of the strip for satisfying width of the strip required by users; second step of judging whether the width of the strip required by users is changed or not or whether a finish rolling width margin deviation average value is large or not in operation instruction of the slab currently being proceeded and the succeeding slab; third step of transmitting the calculated mold width setting value to continuous casting/continuous rolling PLC by calculating a mold width setting value considering a finish rolling target width margin average if the width of the strip is changed or the finish rolling width margin deviation average value is 7 mm or more in operation instruction per slabs; fourth step of controlling mold width as a target mold width setting value in the continuous casting/continuous rolling PLC; fifth step of judging if the finish rolling width margin deviation average value is small such as within 6 to 3 mm; sixth step of calculating a rough rolling target width considering finish rolling target width margin average per slabs and width average measured in the width gauge if the width of the strip is not changed in operation instruction per slabs or if the finish rolling width margin deviation is small such as within 6 to 3 mm; seventh step of transmitting the rough rolling target width setting value calculated in the sixth step to the continuous casting/continuous rolling PLC; eighth step of controlling speed of rough rolling mill as a target width setting value in the continuous casting/continuous rolling PLC; and ninth step of performing dynamic width control to minimize the target width in the PLC and the width deviation measured in the slab width gauge.

Description

Method for controlling width of slab in continuous milling and mini mill performance

The present invention relates to a slab width control method in an inline strip plant type mini mill playing and continuous rolling equipment, and more specifically, using a strip width measured in a strip width meter after finishing rolling in a hot rolling equipment Deviation of the target width margin deviation of finishing rolling at the performance / continuous rolling PI and transmit to the performance / continuous rolling PS from the performance / continuous rolling PI to transmit the target width margin deviation when controlling slab width in the performance / continuous rolling equipment. The present invention relates to a method for controlling slab width in mini mills and continuous rolling equipment, which can be used to improve the final product width hit ratio.

In general, the conventional blast furnace mill hot rolling equipment to control the rough rolling width by predicting the slab entrance width and the exit width of the rough rolling mill measured in the slab width gauge before the rough rolling by the furnace extraction temperature as shown in FIG. As a method, Korean Patent Application No. 10-2001-8363 discloses a "width control technology considering heat input and exit width change by heating".

FIG. 2 is a flow chart of a rough rolling width control in the blast furnace hot rolling process of FIG. 1, in which the first process control system 330 uses the furnace loading side slab temperature 310 and the actual measurement data 320 of the width gauge. The furnace furnace temperature setting is controlled and the rough rolling width control setting is performed in the second process control system 335 to control the blast furnace mill hot rolling mill (350, 370) width control.

3 is a flow chart of the rough rolling control operation in the conventional blast furnace mill hot rolling process, the width control result in the rough rolling mill is finally determined in the finishing mill, considering the atmospheric temperature and the side width before rolling Calculating the rough rolling entrance width (410); and estimating a target width value of rough rolling and finishing rolling based on the control condition and the thickness and width conditions of the demand (420), and the entrance slab width and the rough rolling exit. Calculating a width spreading amount in consideration of the target width (430); calculating a width rolling amount in consideration of the width spreading amount and the heat correction factor (440); and calculating a pass width rolling amount in each rolling mill. (450), and step 460 to perform the width rolling transmission and width rolling control for each pass for each mill, the rough rolling width control, but in the case of mini mill equipment, the temperature generated after rough rolling due to the blast furnace mill and equipment conditions are differentAnd the width and the type of steel after the defective width spirit rolled to spread amount is different from the spirit of the rolling mill to generate a large amount of the.

4 is a configuration diagram of a conventional mini mill playing and continuous rolling equipment, in the case of conventional blast furnace rough rolling, the final width is determined immediately in finishing rolling after performing a reversible pass in the rough rolling mill several times. The mini mill rough mill 161 shown in FIG. 4 is rolled only once because the slab played is rough rolled immediately due to equipment characteristics.

In particular, unlike the blast furnace mill hot rolling, the difference in equipment characteristics of the mini mill rough rolling has a wide variation in width depending on the casting speed and the amount of cooling in the player 154, and is wound up in the coiling station 171 after the rough rolling to hold the holding furnace 170 The temperature drop occurs while being transferred to the uncoiling station 181 of the hot rolling facility, the temperature is released by loosening the coil wound in the uncoiling station 181 of the hot rolling facility and subjected to finishing rolling in the finishing mill 182. There was a problem that a large change in width caused a large drop.

The conventional width control method has a problem that a large width defect occurs in the case of mini-mill, so the demand related to the width is frequent, and the error rate is also greatly reduced by managing the width margin largely to prevent the width defect. .

Therefore, the present invention has been made to solve the above problems, the present invention is to control the large deviation by mold width control that can change the slab width up to 50mm when the finishing rolling width margin deviation is greater than 7mm, the finishing rolling width If the margin deviation is less than 6mm, the width margin of the final product width is minimized and the width margin is minimized through the dynamic width control that controls the target width setting by the play / continuous rolling fish and the roughing speed by the play / continuous rolling fish. The purpose of the present invention is to provide a slab width control method for mini mill performance and continuous rolling equipment to minimize the error rate and improve the error rate.

1 is a schematic configuration diagram of a conventional blast furnace mill hot rolling facility

Figure 2 is a flow chart of the rough rolling width in the conventional blast furnace mill hot rolling process

3 is a flow chart of the rough rolling control in the conventional blast furnace mill hot rolling process

4 is a configuration diagram of a conventional mini mill playing and continuous rolling equipment

5 is a system configuration diagram for slab width control in the mini mill playing and continuous rolling equipment according to an embodiment of the present invention

Figure 6 is a rough rolling control flow chart for implementing the present invention

7 is a reference diagram showing a detailed calculation operation performed at each step of FIG.

<Explanation of symbols for the main parts of the drawings>

110: playing / continuous rolling fish 120: monitor

130: performance / continuous rolling piecy 140: hot rolling piecy

154: player 161: mini mill coarse mill

171: coiling station 170: holding furnace

181: uncoiling station 182: ideological tightness

In order to achieve the above object, the present invention calculates an average value by receiving a target width margin deviation using a width measured in a strip width gauge after rolling in hot rolling mill from a hot rolling mill and a target width to satisfy a demand width. A first step; A second step of judging whether the demand in the work order of the slab in progress and the trailing material slab is changed or if the mean of the rolling margin margin deviations is large; A third step of calculating the mold width setting value by reflecting the average rolling target width margin average when the change of the work instruction width for each slab is present or the average rolling width margin deviation is greater than 7 mm; A fourth step of controlling the mold width to a target mold width setting value in the play / continuous rolling PI; A fifth step of determining a case where the average rolling width margin deviation is less than or equal to 6 to 3 mm; The sixth step of calculating the rough rolling target width by reflecting the average rolling target width margin average by slab and the width average measured by the slab width gauge when there is no change of work order width by slab or the finishing roll width margin is small by 6-3mm. Wow; A seventh step of transmitting the rough rolling target width setting value calculated in the sixth step to the performance / continuous rolling PI; An eighth step of controlling the speed of the roughing milling to a target width setting value in the playing / continuous rolling PI; In order to minimize the width deviation measured by the target width and the slab width gauge in PIEL, it provides the width control method in the mini-mill performance and continuous rolling equipment consisting of the ninth step of dynamic width control.

The objects, features and advantages of the present invention will be more readily understood by reference to the accompanying drawings and the following detailed description.

Hereinafter, the configuration and operation of the present invention with reference to the accompanying drawings in detail as follows.

FIG. 5 is a system configuration diagram for slab width control in a mini mill playing and continuous rolling facility according to an embodiment of the present invention. The monitor 120 is provided in a performance / coordination cab to display a deviation of a rolling width margin and an average value. And a hot rolled pipe 140 installed in the hot rolled equipment and calculating the measured width deviation from the margin width considering the target width and transmitting to the performance / continuous rolled PI and controlling the thickness of the finishing mill. Control the mold width, control the target width and speed setting of the roughing mill, and control the roughing mill dynamically to collect the data from the PI through the network and transfer the collected data to the performance / continuous rolling fish. It is installed in the performance / continuous rolling PIC 130 and the performance / continuous rolling equipment to control the mold width setting and control the rough rolling thickness and width setting It comprises a performance / continuous rolling process 110 for transmitting to the monitor of the performance / rolling mill cab in order to display the deviation and the average value of the finishing rolling width margin.

6 is a flow control operation flow chart for implementing the present invention, the slab width control method in the mini mill playing and continuous rolling equipment according to the present invention is a strip width gauge after rolling from the hot rolling mill (182) to finishing mill (182) A first step (510) of receiving the finishing rolling width margin deviation using the width measured at 183 and a target width for satisfying the demand width, and calculating an average value thereof; A second step 520 of determining whether the demand changes in the required width or the finishing rolling target margin deviation is 7 mm or more in the work order of the slab in progress and the trailing material slab; A third step 530 of calculating a mold width setting value and transmitting the calculated width to the PSI 130 by reflecting the average rolling target width margin average when there is a change of the work instruction width for each slab; A fourth step 540 of controlling the width of the mold 153 to the target mold width setting value in the PSI 130; A fifth step 550 of determining a case in which the average rolling margin margin deviation is small within 6 to 3 mm; A sixth step 560 of calculating a trailing material slab target width setting value by reflecting the average rolling width margin deviation average and the slab width average measured by the slab width gauge 163 for each slab; A seventh step 570 of transmitting the rough rolling target width setting value calculated in the sixth step from the PS 110 to the PSI 130; An eighth step (580) of controlling a second roughness speed in order to control the first section of the trailing material slab with the slab target width set value received by the PSI 130 in the seventh step; In order to minimize the deviation between the slab target width set value received in the sixth step and the slab width generated by the rough rolling speed control in the seventh step, the slab width gauge 163 and the target width set value are different from each other. A ninth step 590 of controlling width is performed.

FIG. 7 is a reference diagram showing a detailed calculation operation performed in each step of FIG. 6, wherein the finishing rolling target width margin deviation calculation step 610 executed in the first step and the mold width setting performed in the third step are performed. A calculation process is shown in the value calculation step 620, the rough rolling target width calculation step 630 executed in the sixth step, and the PIC rough rolling dynamic width control value calculation step 640 executed in the ninth step. Doing.

The calculation process in the finishing rolling target width margin deviation calculation step 610 is a process of subtracting the actual measured width value (imaginary rolling side width gauge) from the value of the finishing rolling extraction target width and the margin width.

The calculation process in the mold width setting value calculating step 620 subtracts the difference between the next slab designation target width and the previous slab designation target width from the sum of the actual mold width of the previous steel sheet and the average rolling target width margin deviation value. Doing it is a process.

The calculation process in the rough rolling target width calculating step 630 includes a work instruction width of the trailing material slab, a mean rolling target width margin deviation value, and a width deviation (a difference value between the previous slab rough rolling target width and the previous slab measured width average). ) Is the process of adding

The calculation process in the PIC rough rolling dynamic width control value calculation step 640 is obtained by dividing the rough rolling exit speed by the rough rolling entrance speed (barrel rolling speed / bar rolling speed) and the target slab width and slab. It is a process of multiplying the difference between the measured width (the slab target width-slab measured width) by 1 and the rate of change of speed according to the width deviation.

Referring to the operation and effects of the present invention configured as described above are as follows.

When rolling with the hot rolling mill 182 in the hot rolling facility 180, the hot rolled piezo 140 measures the strip width meter 183 after finishing rolling by adding the margin width to the target rolling exit target width according to the order width. By subtracting the width 610, the target rolling margin deviation deviation is calculated and transmitted to the performance / continuous rolling PSI 130, and finally received by the performance / continuous rolling PSI 110.

The playing / continuous rolling fish 110 calculates an average value of the received finishing rolling target margin width deviations (510). The width margin average value and the instantaneous data are displayed on the performance / continuous rolling cab screen 120.

If the slab front end is sheared in the pendulum shear 162, it is determined whether there is a width change in the work order database for each slab (520).

If there is a width change in the work order, the width setting value of the mold 153 is calculated and transmitted to the PI 130 using the average rolling width margin deviation average received from the hot rolled PE 140 (530).

The mold width setting value is obtained by adding the work order width deviation of the front and back slab to the actual width of the previous slab, and adding the average deviation of the target width margin deviation of finishing rolling (180). (620) The work order width deviation is transferred from the next slab target width. Obtained by subtracting the slab indication target width.

The mold width is controlled by the target mold width set value received from the PS 110 in the PSI 130 (540).

If there is no work order width change per slab, the rough rolling target width is calculated by reflecting the target width margin by slab (182) and the average width measured by the slab width gauge (163). The slab rough rolling target width is calculated by adding the mean rolling target width margin deviation average value and adding the width deviation (630). The width deviation is calculated by subtracting the previous slab actual width average value from the previous slab rough rolling target width.

When the rough rolling target width calculated above is transmitted to the PSI 560, the PI performs dynamic width control to minimize the deviation between the rough rolling target width and the measured width measured by the slab width gauge 163. ) The PIC rough rolling dynamic width control value is obtained by dividing the exit rolling speed (161) exit speed by the rough rolling entrance speed, subtracting the slab measurement width from the slab target width of the current slab, and adding 1 to the product of the rate of change according to the width deviation. Find the product by multiplying (640)

As described above, the present invention reflects the target width margin deviation of the width measured by the measuring machine after finishing rolling in the hot rolling of the hot rolling process during the thickness rolling in the control of the mold width 153 and the rough rolling 161, and the slab If the work order width is different, the mold width is adjusted by reflecting the average value of the marginal rolling target width margin deviation, and in the slab having the same work order width, the actual measurement of the slab width gauge 163 to the target width in the PSI 130 is performed. Dynamic control is performed to minimize the deviation of the width, and the width is controlled by feeding back the exit width change value depending on the temperature drop and the steel grade after rough rolling, so that the width defect can be reduced and the width margin can be managed small.

According to the present invention, it is possible to reflect the actual target width margin deviation of the finishing rolling exit in the rough rolling, and to reduce the large width deviation by changing the mold width when there is a change in width between slabs in the work order, slab temperature and playing speed The measured width deviation with respect to the target width, which is a small width deviation in the slab, can be improved by precisely controlling the width width of the PS 130 using the rough rolling target width setting value of the PS 110 to improve the width hit ratio. By controlling it, it is possible to greatly improve the operation yield by managing the width margin to prevent the failure of the width 15mm or more to 10mm or less.

Claims (5)

A first step of receiving a target width margin deviation using a width measured in a strip width gauge after rolling in hot rolling mill from hot rolled carbon and a target width for satisfying a demand width; A second step of judging whether the demand in the work order of the slab in progress and the trailing material slab is changed or if the mean of the rolling margin margin deviations is large; A third step of calculating the mold width setting value by reflecting the average rolling target width margin average when the change of the work instruction width for each slab is present or the average rolling width margin deviation is greater than 7 mm; A fourth step of controlling the mold width to a target mold width setting value in the play / continuous rolling PI; A fifth step of determining a case where the average rolling width margin deviation is less than or equal to 6 to 3 mm; The sixth step of calculating the rough rolling target width by reflecting the average rolling target width margin average by slab and the width average measured by the slab width gauge when there is no change of work order width by slab or the finishing roll width margin is small by 6-3mm. Wow; A seventh step of transmitting the rough rolling target width setting value calculated in the sixth step to the performance / continuous rolling PI; An eighth step of controlling the speed of the roughing milling to a target width setting value in the playing / continuous rolling PI; Width control method of the mini-mill playing and continuous rolling equipment, characterized in that it comprises a ninth step of performing the dynamic width control to minimize the width deviation measured in the target width and the slab width gauge in the PI. The method of claim 1, wherein the first step, Mini-mill performance and continuous rolling equipment comprising a calculation process for calculating the finishing rolling target width margin deviation by subtracting the actual measured width value (imaginary rolling side-side gauge) from the value of the finishing rolling target width and margin width. Width control method The method of claim 1, wherein the third step, And calculating a mold width setting value by subtracting the difference between the next slab designation target width and the previous slab designation target width from the sum of the actual mold width of the previous steel sheet and the average deviation of the target rolling margin margin. Method of width control in mini mill and continuous rolling equipment. The method of claim 1, wherein the sixth step is It includes a calculation process that calculates the target rolling target width by adding the work instruction width of the trailing material slab, the mean rolling target width margin deviation value and the width deviation (the difference value between the previous slab rough rolling target width and the previous slab measured width average). Width control method in the mini mill playing and continuous rolling equipment, characterized in that. The method of claim 1, wherein the ninth step is The result obtained by dividing the rough rolling speed by the rough rolling speed (crude rolling speed / rough rolling speed) and the difference between the slab target width and slab actual width (slab target width-slab actual width) is 1 And a calculation process of multiplying the speed change rate according to the added value and the width deviation to calculate the PI rough rolling dynamic width control value.