A method for achieving narrow-range width control of hot-rolled strip steel
By using DOE experimental fitting formulas and automatic control correction methods, the model error problem in the width control of hot-rolled strip steel was solved, achieving narrow-range width control and high pass rate, reducing the frequency of manual intervention, and improving production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TANGSHAN IRON & STEEL GROUP
- Filing Date
- 2023-10-25
- Publication Date
- 2026-07-17
AI Technical Summary
In existing hot-rolled strip width control, the automatic width control model has control errors, leading to frequent manual intervention. This makes it unsuitable for small-batch, multi-variety, and multi-specification production, thus affecting product width quality.
An automatic control correction method is adopted, which calculates the width correction value through the DOE experimental fitting formula and compensates for the actual width deviation, thereby realizing automated width control and reducing the frequency of manual intervention.
It has achieved narrow-range width control of hot-rolled strip steel, with a width qualification rate of over 95%, reducing the labor intensity of operators and realizing standardized operation.
Smart Images
Figure CN117340013B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for controlling the narrow width of hot-rolled strip steel, belonging to the technical field of steel rolling control technology. Background Technology
[0002] The width accuracy of strip steel is a crucial indicator of hot-rolled product quality. Good width accuracy improves yield and provides better production conditions for downstream processes and hot-rolled product users. Strip steel width control on hot-rolling lines mainly consists of two parts: an automatic width control model and a manual correction function. The software portion of the automatic width control model is largely imported from abroad, and its underlying logic algorithm is a trade secret, often undecipherable by technical personnel, making model optimization extremely difficult. The manual correction function supplements the automatic width control model, acting as a "firefighter." Operators adjust the width of the next strip based on the current strip width deviation. If the model's accuracy is high, the frequency of operator intervention is low. However, in actual production, limitations in the accuracy of on-site detection components and environmental variations inevitably lead to control errors in the model. This often necessitates frequent operator intervention. Frequent manual correction is unsuitable for small-batch, multi-variety, and multi-specification production methods. Furthermore, since manual correction values are entirely based on operator experience, this inevitably leads to a decrease in the product width qualification rate, severely hindering the improvement of product width quality. Summary of the Invention
[0003] The purpose of this invention is to provide a method for narrow-range width control of hot-rolled strip steel. By adopting an automatic control correction method, the automatic width control model is compensated more accurately, and the width deviation is responded to quickly and accurately, thereby achieving narrow-range width control of hot-rolled strip steel and solving the problems existing in the background technology.
[0004] The technical solution of this invention is: A method for controlling the width of hot-rolled strip steel within a narrow range includes the following steps: S1. Collect online rolling temperature and corresponding finished product target width, target thickness and tensile strength data; S2. Before vertical roll rolling, perform a logical judgment: Is the current workpiece being rolled for the first time? If the judgment is "yes", proceed to step S3; if the judgment is "no", proceed to step S4. S3. Clear the data in the manual width correction window to zero, calculate the preset width correction value according to the formula obtained from the DOE test, use it as the width correction value, and go directly to step S6. S4. Collect the actual width of the finished product after rolling the previous piece in the same heat, and calculate the width deviation of the current piece. S5. Based on the width correction value change corresponding to the width deviation in the feedback control width correction table, compensate the current rolling mill's width correction value on the basis of the width correction value used in the previous rolling mill in the same heat. S6. Input the width correction value into the manual width correction window and save the data.
[0005] The initial rolling in step S2 includes the following situations: 1) After the rolling mill rolls are changed in the finishing or roughing mill, the first rolled piece that comes out of each heating furnace is the first rolling; 2) Production shall be restarted after the finishing mill or roughing mill has been stopped for more than 30 minutes. The first rolled piece from each heating furnace shall be the first rolled piece. 3) If the current rolled piece is compared with the previous rolled piece in the same heat, and the finished product thickness, width or tensile strength exceeds the limit, that is, the finished product width changes by more than 50 mm, or the finished product thickness changes by more than 0.24 mm, or the tensile strength changes by more than 50 MPa, it is considered as the first rolling.
[0006] The formula obtained from the DOE experiment in step S3 is: W set =C+0.02899·R m -0.049·T-0.0344·W t -0.5123·H-0.00002702·R m ·W t +0.001748·R m ·H+0.000040606·T·W t (1) In formula (1), 38.5≤C≤38.6, W set R is the preset width correction value (mm). m The tensile strength (MPa) corresponds to the steel grade, T is the highest temperature (°C) of the currently rolled piece as measured by RET, and W is the tensile strength (MPa) of the steel grade. t H represents the target width of the finished product (mm), and H represents the target thickness of the finished product (mm).
[0007] In formula (1) of step S3, C = 38.56.
[0008] The actual width W of the finished product in step S4 act The value is the average of all width data collected from the 20m to 60m position of the strip head; width deviation W dev The calculation formula is: W dev =W act -W t (2) In formula (2), W actW represents the actual width of the finished product (mm). t The target width of the finished product (mm).
[0009] The formula for calculating the compensation width correction value in step S5 is as follows: W cor =W b-cor +△w (3) In formula (3), W b-cor Δw represents the width correction value used for the previous rolled piece in the same furnace, where Δw is the change in the width correction value.
[0010] The beneficial effects of this invention are: without increasing equipment investment, the precise calculation equation for the first rolling is obtained by fitting the DOE test, the manual correction rules for non-first rolling are summarized, the manual width correction method is transformed into an automatic correction method, the labor intensity of employees is reduced, standardized operation is achieved, and the pass rate of the narrow range of target width ±3mm can reach more than 95%. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the process of the present invention; Figure 2 This is a process layout diagram of the hot rolling line of the present invention. Detailed Implementation
[0012] The invention will be further described below with reference to the accompanying drawings and examples.
[0013] A method for controlling the width of hot-rolled strip steel within a narrow range includes the following steps: S1. Collect online rolling temperature and corresponding finished product target width, target thickness and tensile strength data.
[0014] S2. Before vertical roll rolling, perform a logical judgment: Is the current workpiece being rolled for the first time? If the judgment is "yes", proceed to step S3; if the judgment is "no", proceed to step S4. The initial rolling process includes the following situations: 1) After the rolling mill rolls are changed in the finishing or roughing mill, the first rolled piece that comes out of each heating furnace is the first rolling; 2) Production shall be restarted after the finishing mill or roughing mill has been stopped for more than 30 minutes. The first rolled piece from each heating furnace shall be the first rolled piece. 3) If the finished product specifications or tensile strength of this steel bar exceed the limit range (i.e., the finished product width changes by more than 50 mm, or the finished product thickness changes by more than 0.24 mm, or the tensile strength changes by more than 50 MPa) compared with the previous rolled piece in the same heat, it is considered as the first rolling.
[0015] S3. Clear the data in the manual width correction window to zero, calculate the preset width correction value according to the following formula (1) obtained from the DOE test, use it as the width correction value, and go directly to step S6. W set =C+0.02899·R m -0.049·T-0.0344·W t -0.5123·H-0.00002702·R m ·W t +0.001748·R m ·H+0.000040606·T·W t (1) In formula (1), 38.5≤C≤38.6, W set R is the preset width correction value (mm). m The tensile strength (MPa) corresponds to the steel grade, T is the highest temperature (°C) of the currently rolled piece as measured by RET, and W is the tensile strength (MPa) of the steel grade. t H represents the target width of the finished product (mm), and H represents the target thickness of the finished product (mm).
[0016] S4. Collect the actual width (W) of the finished product after rolling the previous piece in the same heat. act The value of W is the average of all width data collected from the 20m to 60m position of the strip head. The width deviation (W) is calculated according to the following formula (2). dev ); W dev =W act -W t (2) In formula (2), W act W represents the actual width of the finished product (mm). t The target width of the finished product (mm).
[0017] S5. Based on the width correction value change corresponding to the width deviation in the feedback control width correction table, calculate the width correction value of the current rolling piece according to the compensation width correction value calculation formula (3) based on the width correction value used in the previous rolling piece in the same furnace. Formula for calculating compensation width correction value: W cor =W b-cor +△w (3) In formula (3), W b-cor Δw represents the width correction value used for the previous rolled piece in the same furnace, where Δw is the change in the width correction value.
[0018] S6. Input the width correction value into the manual width correction window and save the data.
[0019] In this embodiment, as Figure 2 As shown, after the heated rolled workpiece exits the furnace, it undergoes post-furnace descaling (TSB) and temperature monitoring via RET. The vertical rolls and roughing mill then roll it into an intermediate workpiece. The coil is conveyed to the finishing mill, where it is rolled, cooled, and coiled to obtain the final finished product. The vertical rolls control the width of the finished product. During width control, as... Figure 1 As shown, a method for controlling the width of hot-rolled strip steel within a narrow range includes the following steps: S1. When all the heated rolled pieces pass through the furnace descaling outlet high temperature gauge (RET) detection point, the highest temperature detected by RET is collected, and the target width, target thickness and tensile strength data of the finished product to be rolled are collected. S2. When the head of the current rolled piece reaches the area of the front guide plate of the roughing mill, perform a logical judgment: whether the current rolled piece is being rolled for the first time. If the judgment is "yes", execute step S3; if the judgment is "no", execute step S4. The initial rolling process includes the following situations: 1) After the rolling mill rolls are changed in the finishing or roughing mill, the first rolled piece that comes out of each heating furnace is the first rolling; 2) Production shall be restarted after the finishing mill or roughing mill has been stopped for more than 30 minutes. The first rolled piece from each heating furnace shall be the first rolled piece. 3) If the finished product specifications or tensile strength of this steel bar exceed the limit range (i.e., the finished product width changes by more than 50 mm, or the finished product thickness changes by more than 0.24 mm, or the tensile strength changes by more than 50 MPa) compared with the previous rolled piece in the same heat, it is considered as the first rolling. S3. Clear the data in the manual width correction window to zero, calculate the preset width correction value according to the following formula (1), use it as the width correction value, and go directly to step S6. W set =C+0.02899·R m -0.049·T-0.0344·W-0.5123·H-0.00002702·R m ·W t +0.001748·R m ·H+0.000040606·T·W t (1) In formula (1), 38.5≤C≤38.6, W set R is the preset width correction value. m The tensile strength (MPa) corresponds to the steel grade, T is the highest temperature (°C) of the currently rolled piece as measured by RET, and W is the tensile strength (MPa) of the steel grade. t H represents the target width of the finished product (mm), and H represents the target thickness of the finished product (mm).
[0020] S4. Collect the actual width (W) of the finished product after rolling the previous piece in the same heat. act The value of W is the average of all width data collected from the 20m to 60m position of the strip head. The width deviation (W) is calculated according to the following formula (2). dev ); W dev =W act -W t (2) In formula (2), W act W represents the actual width of the finished product (mm). t Target width of the finished product (mm); S5. Based on the width correction value change corresponding to the width deviation in the feedback control width correction table (Table 1), calculate the width correction value of the current rolling piece according to the compensation width correction value calculation formula (3) based on the width correction value used in the previous rolling piece in the same furnace.
[0021] Table 1 Formula for calculating compensation width correction value: W cor =W b-cor +△w (3) In formula (3), W b-cor Δw represents the width correction value used for the previous rolled piece in the same furnace, and Δw represents the change in the width correction value.
[0022] S6. Input the width correction value into the manual width correction window and save the data.
[0023] Examples 1-16 were produced according to the above implementation method. Examples 1-7 are width correction examples when tapping steel from a single furnace, as shown in Table 2. Examples 8-16 are width correction examples when tapping steel from two furnaces alternately, as shown in Table 3.
[0024] Table 2
[0025] Table 3
[0026] This invention addresses the issue of manual correction affecting width pass rate. Based on the analysis of the correlation between manual correction data and process parameters, it transforms the manual correction method into an automatic control method. This allows for more precise compensation of the automatic width control model and a rapid and accurate response to width deviations, thereby achieving narrow-range width control of hot-rolled strip. Without increasing equipment investment, the invention uses DOE experiments to fit a precise calculation equation for the first rolling, summarizes the manual correction patterns for subsequent rolling, and transforms the manual width correction method into an automatic one. This reduces the labor intensity of workers, achieves standardized operations, and enables a narrow-range width pass rate of over 95% within a target width of ±3mm.
Claims
1. A method for controlling the width of hot-rolled strip steel within a narrow range, characterized in that... It includes the following steps: S1. Collect online rolling temperature and corresponding finished product target width, target thickness and tensile strength data; S2. Before vertical roll rolling, perform a logical judgment: Is the current workpiece being rolled for the first time? If yes, proceed to step S3; if no, proceed to step S4. S3. Clear the data in the manual width correction window to zero, calculate the preset width correction value according to the formula obtained from the DOE test, use it as the width correction value, and go directly to step S6. S4. Collect the actual width of the finished product after rolling the previous piece in the same heat, and calculate the width deviation of the current piece. S5. Based on the width correction value change corresponding to the width deviation in the feedback control width correction table, compensate the current rolling mill's width correction value on the basis of the width correction value used in the previous rolling mill in the same heat. S6. Input the width correction value into the manual width correction window and save the data; The initial rolling in step S2 includes the following situations: 1) After the rolling mill rolls are changed in the finishing or roughing mill, the first rolled piece that comes out of each heating furnace is the first rolling; 2) Production shall be restarted after the finishing mill or roughing mill has been stopped for more than 30 minutes. The first rolled piece from each heating furnace shall be the first rolled piece. 3) If the current rolled piece is compared with the previous rolled piece in the same heat, and the finished product thickness, width or tensile strength exceeds the limit, that is, the finished product width changes by more than 50 mm, or the finished product thickness changes by more than 0.24 mm, or the tensile strength changes by more than 50 MPa, it is considered as the first rolling. The formula obtained from the DOE experiment in step S3 is: W set =C+0.02899·R m -0.049·T-0.0344·W t -0.5123·H-0.00002702·R m ·W t +0.001748·R m ·H+0.000040606·T·W t (1) In formula (1), 38.5≤C≤38.6, W set R is the preset width correction value. m The tensile strength corresponds to the steel grade, T is the highest temperature of the rolled piece measured by RET, and W... t H represents the target width of the finished product, and H represents the target thickness of the finished product.
2. The method for controlling the narrow width of hot-rolled strip steel according to claim 1, characterized in that: In formula (1) of step S3, C = 38.
56.
3. The method for controlling the narrow width of hot-rolled strip steel according to claim 1, characterized in that: The actual width W of the finished product in step S4 act The value is the average of all width data collected from the 20m to 60m position of the strip head; width deviation W dev The calculation formula is: IN dev =W act -IN t (2) In formula (2), W act W represents the actual width of the finished product. t This represents the target width of the finished product.
4. A method for controlling the narrow width of hot-rolled strip steel according to claim 1, characterized in that: The formula for calculating the compensation width correction value in step S5 is as follows: IN cor =W b-cor +△w (3) In the official (3), W b-cor Δw represents the width correction value used for the previous rolled piece in the same furnace, where Δw is the change in the width correction value.