A method for determining false slabs of hot-rolled thin-gauge high-temperature coiled steel strip

Abstract

The present application relates to a kind of hot-rolled thin gauge high temperature coiling strip false slab judging method, belong to the technical field of hot continuous rolling plate production method.The technical scheme of the present application is: when high temperature coiling thin gauge strip rolling, on the basis of original 2# pyrometer detection, automatic control system increases the thickness of strip, coiling temperature target value and F7 finishing mill rolling signal to the true of strip in laminar cooling area It is judged, after the completion of the coiling of the strip, if F7 finishing mill loading signal is 0, when 2# pyrometer detects strip signal, it is judged as false slab, mathematical model does not set the parameters such as laminar cooling water, speed for the false slab.The present application expands the control function to automatic control system, increases the false slab identification function, can automatically identify false slab signal in production, does not cause the influence to the setting and control function of actual slab rolling parameter, without manual intervention, automatic control system runs stably and reliably.

Description

Technical Field

[0001] This invention relates to a method for determining false slabs in hot-rolled thin-gauge high-temperature coiled strip steel, belonging to the technical field of hot continuous rolling plate production methods. Background Technology

[0002] The 2250mm hot strip rolling production line has a high degree of automation and a fast production pace, placing high demands on the accuracy of on-site instrument measurements and the precision of the automatic control system. In the past two years, the hot rolling production pace has further accelerated, with the strip rolling time optimized from 115.4 seconds / coil to 106.72 seconds / coil. The original automatic control system could not adequately adapt to this fast-paced production. Two high-temperature gauges, #1 and #2, are installed at the coiler inlet to detect the strip temperature. The #1 gauge has a range of 100-700℃, and the #2 gauge has a range of 300-1100℃. For strip coiling targets below 500℃, the #1 gauge is used; for values ​​above 500℃, the #2 gauge is used. When the high-temperature gauge signal is 1 or the detected temperature is higher than the lower range, such as… Figure 1 As shown in the temperature measurement curve 1 of the #2 pyrometer, the CTC mathematical model generates the corresponding strip coil number and sets and controls the cooling water in the laminar flow cooling zone. The target coiling temperature for 8.0mm thin strip products is mostly above 650℃. During continuous, fast-paced strip production, the temperature of the laminar flow cooling zone rollers reaches above 300℃, which is higher than the low range of the #2 pyrometer. The hot rolling site experiences significant vibration, and during long-term production, the pyrometer frequently experiences measurement angle deviations due to vibration. During the gap between two strip coils being rolled, if the pyrometer scans the laminar flow cooling rollers, the CTC mathematical model triggers a false strip generation signal. The model sets and tracks this false strip. When the actual strip reaches the coiling entrance area, there is no corresponding coil information, and the model does not provide feedback control for the cooling water. The strip coiling temperature deviates from the target temperature, resulting in substandard product performance. Summary of the Invention

[0003] The purpose of this invention is to provide a method for identifying false slabs in hot-rolled thin-gauge high-temperature coiled strip steel. This method expands the control functions of the automatic control system, adding a function to identify false slabs. It judges false strip steel signals and blocks the generation of coil numbers. During high-temperature coiled thin-gauge strip rolling, based on the original detection by the No. 2 pyrometer, the automatic control system adds judgment on the authenticity of the strip steel in the laminar cooling zone based on strip thickness, target coiling temperature, and the rolling signal of the F7 finishing mill. After the upper coiled strip is coiled, if the loading signal of the F7 finishing mill is 0, the No. 2 pyrometer detects a strip steel signal and determines it as a false slab. The mathematical model does not set parameters such as laminar cooling water or speed for this false slab. In production, it can automatically identify false slab signals without affecting the setting and control functions of actual slab rolling parameters. No manual intervention is required, and the automatic control system operates stably and reliably, effectively solving the aforementioned problems in the background technology.

[0004] The technical solution of the present invention is: a method for judging false slabs of hot-rolled thin-gauge high-temperature coiled strip steel, comprising the following steps: (1) judging the target thickness of strip steel rolling during production, and applying the method for judging false slabs when rolling thin-gauge strip steel; (2) judging the target value of coiling temperature of high-temperature coiled strip steel, and calling the function when the temperature is higher than the set temperature; (3) collecting the application status of 1# pyrometer and 2# pyrometer, and identifying and shielding the false strip steel signal when using 2# pyrometer for detection; (4) tracking and detecting the rolling signal of F7 finishing mill and the length of strip head exiting F7 finishing mill, and judging whether there is strip steel in the laminar cooling area; (5) when 2# pyrometer detects that the temperature is higher than the low range, detecting the loading signal of F7 finishing mill, coiler loading signal and the length of strip head exiting F7 finishing mill, and judging whether the slab is a false slab; (6) shielding the error signal and transmitting it to the secondary CTC mathematical model.

[0005] In step (1), the three-level system in production issues slab PDI information, including slab rolling target thickness, width, final rolling temperature and coiling temperature information. After receiving the information, the second-level mathematical model transmits it to the first-level basic automation programmable controller. Based on the comparison between the target thickness and the program-designed thickness, if the target thickness is less than the set value, the false slab judgment function is called.

[0006] In step (2), after the programmable controller receives the slab PDI information, it retrieves the target value and target value code of the strip rolling coiling temperature, compares the target value with the design value in the program of the method, and applies the false slab judgment function when the target temperature is higher than the design temperature.

[0007] In step (3), the programmable controller judges the selection of 1# pyrometer and 2# pyrometer on site during strip rolling. During high-temperature coiling of strip rolling, the operator selects 2# pyrometer on the HMI operation interface to measure the coiling temperature and apply it to the feedback control of the CTC mathematical model.

[0008] In step (4), the programmable controller accumulates the loading signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill in each scanning cycle. This signal is used to accurately track the position of the strip head on the laminar cooling roller table, and the detection function of this signal is added on the basis of the original control.

[0009] In step (5), when the strip head reaches the roller table below the No. 2 pyrometer, the pyrometer detects a temperature higher than 300°C, and the heat detection signal changes from 0 to 1. At this time, the loading signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill are interlocked and controlled. That is, when the No. 2 pyrometer detects the strip head signal, the length of the strip head exiting the F7 finishing mill is detected simultaneously. If the strip tracking length is less than the distance between the No. 2 pyrometer and the F7 finishing mill, and the No. 2 pyrometer signal changes to 1, it is judged as an error signal.

[0010] In step (6), when the automatic control system determines that the signal of the strip head on the roller conveyor below the No. 2 high temperature meter is false, it automatically blocks the signal and sends it to the mathematical model. The CTC mathematical model does not generate the coil number or set the cooling manifold of the laminar cooling area. After the actual strip arrives at the area, the model automatically controls the strip.

[0011] The beneficial effects of this invention are as follows: By expanding the control functions of the automatic control system, the function of identifying false slabs is added, and the generation of steel coil numbers is blocked for judging false strip steel signals. When rolling thin strip steel at high temperature, based on the original detection of the No. 2 high temperature meter, the automatic control system adds the judgment of the authenticity of the strip steel in the laminar cooling zone by the strip steel thickness, the target value of the coiling temperature, and the rolling signal of the F7 finishing mill. After the upper strip steel is coiled, if the loading signal of the F7 finishing mill is 0, the strip steel signal detected by the No. 2 high temperature meter is judged as a false slab. The mathematical model does not set parameters such as laminar cooling water and speed for this false slab. In production, it can automatically identify false slab signals without affecting the setting and control function of actual slab rolling parameters. No manual intervention is required, and the automatic control system operates stably and reliably. Attached Figure Description

[0012] Figure 1 This is a false slab generation curve diagram of the background technology of this invention;

[0013] Figure 2 This is a flowchart of the process of this invention;

[0014] In the figure: Temperature measurement curve 1 of 2# pyrometer, thermal detection curve 2 of laminar flow cooling area. Detailed Implementation

[0015] To make the purpose, technical solutions, and advantages of the invention's embodiments clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only a small part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0016] A method for determining false slabs of high-temperature coiled strip steel of thin specifications includes the following steps: (1) the target thickness of strip steel rolling is judged during production, and the method for determining false slabs is applied when thin strip steel is rolled; (2) the target value of coiling temperature of high-temperature coiled strip steel is judged, and the function is called when it is higher than the set temperature; (3) the application status of 1# pyrometer and 2# pyrometer is collected, and the system identifies and shields the false strip steel signal when 2# pyrometer is used for detection; (4) the rolling signal of F7 finishing mill and the length of strip head exiting F7 finishing mill are tracked and detected to determine whether there is strip steel in the laminar cooling area; (5) when 2# pyrometer detects that the temperature is higher than the low range, the loading signal of F7 finishing mill, coiler loading signal and the length of strip head exiting F7 finishing mill are detected to determine whether the slab is a false slab; (6) the erroneous signal is shielded and transmitted to the secondary CTC mathematical model.

[0017] In step (1), the three-level system in production issues slab PDI information, including slab rolling target thickness, width, final rolling temperature and coiling temperature information. After receiving the information, the second-level mathematical model transmits it to the first-level basic automation programmable controller. Based on the comparison between the target thickness and the program-designed thickness, if the target thickness is less than the set value, the false slab judgment function is called.

[0018] In step (2), after the programmable controller receives the slab PDI information, it retrieves the target value and target value code of the strip rolling coiling temperature, compares the target value with the design value in the program of the method, and applies the false slab judgment function when the target temperature is higher than the design temperature.

[0019] In step (3), the programmable controller judges the selection of 1# pyrometer and 2# pyrometer on site during strip rolling. During high-temperature coiling of strip rolling, the operator selects 2# pyrometer on the HMI operation interface to measure the coiling temperature and apply it to the feedback control of the CTC mathematical model.

[0020] In step (4), the programmable controller accumulates the loading signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill in each scanning cycle. This signal is used to accurately track the position of the strip head on the laminar cooling roller table, and the detection function of this signal is added on the basis of the original control.

[0021] In step (5), when the strip head reaches the roller table below the No. 2 pyrometer, the pyrometer detects a temperature higher than 300°C, and the heat detection signal changes from 0 to 1. At this time, the loading signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill are interlocked and controlled. That is, when the No. 2 pyrometer detects the strip head signal, the length of the strip head exiting the F7 finishing mill is detected simultaneously. If the strip tracking length is less than the distance between the No. 2 pyrometer and the F7 finishing mill, and the No. 2 pyrometer signal changes to 1, it is judged as an error signal.

[0022] In step (6), when the automatic control system determines that the signal of the strip head on the roller conveyor below the No. 2 high temperature meter is false, it automatically blocks the signal and sends it to the mathematical model. The CTC mathematical model does not generate the coil number or set the cooling manifold of the laminar cooling area. After the actual strip arrives at the area, the model automatically controls the strip.

[0023] In practical applications, this invention optimizes control parameters by modifying the programmable logic controller (PLC) control program and method to achieve accurate identification of false slabs during high-temperature coiling of thin strip steel, including the following process:

[0024] 1. Information on high-temperature coiling of thin-gauge strip steel issued

[0025] In hot rolling production, the production plan for the third-level hot rolling line includes a large amount of basic information such as the chemical composition, target width and thickness, target final rolling temperature and coiling temperature, and spray code for each slab. This information is sent to the database of the second-level system. After receiving the slab information, the mathematical model calculates the corresponding control parameters. For thin strip steel with a specification of less than 8.0 mm, the mathematical model generates thickness codes of 1-13, and for coiling temperatures of 650℃ and above, the mathematical model generates temperature codes ctIdx of 5-9. When rolling strip steel of this specification, the third level sends this information to the automatic control system.

[0026] 2. Function call for judging thin strip steel coiling at high temperature

[0027] After receiving the slab PDI information, the programmable logic controller (PLC) retrieves the target value and target value code of the strip rolling coiling temperature, compares the target value with the design value in the program, and determines that the high-temperature coiling of thin strip is in progress when the target thickness of the strip is less than 8.0 mm and the system detects that the coiling temperature is higher than 650℃. At this time, the system adds a judgment on the authenticity of the strip in the laminar cooling zone on the basis of the original detection and control.

[0028] 3. Selection of a high-temperature meter for laminar flow cooling zone

[0029] Two pyrometers are installed in the laminar flow cooling zone to measure different strip temperatures. Pyrometer #1 has a measurement range of 100-700℃, and pyrometer #2 has a measurement range of 300-1100℃. During production, the pyrometer is selected based on the target strip coiling temperature. For target coiling temperatures below 500℃, pyrometer #1 is used; for target coiling temperatures above 500℃, pyrometer #2 is used for measurement and control system tracking. The secondary database receives high-temperature coiling strip rolling information and displays the rolling plan on the HMI. Operators pre-select pyrometer #2 for coiling temperature measurement and feedback control applied to the CTC mathematical model during rolling according to this plan.

[0030] 4. Strip head length inspection at F7 finishing mill

[0031] After the strip head is rolled by the F1-F7 finishing mills, the system tracks and detects the length of the strip head exiting the F7 finishing mill. The programmable logic controller (PLC) calculates and accumulates the loading signal of the F7 finishing mill, the length of the strip head exiting the F7 finishing mill, the time of the PLC scan cycle, and the instantaneous speed of the strip within each scan cycle. The distance between the F7 finishing mill and the No. 2 pyrometer is 142 meters. When this length is between 0 and 142 meters, the strip head is located in the laminar cooling zone before the No. 2 pyrometer.

[0032] 5. Identification of Fake Thin-Dimensional Slabs from High-Temperature Coiling

[0033] The original control method assumed the strip was being rolled when the signal from the #2 pyrometer changed from 0 to 1, simultaneously triggering a coil generation signal in the CTC mathematical model. The new control method simultaneously detects the strip head's length L1 exiting the F7 finishing mill when the #2 pyrometer signal is detected. When L1 is greater than or equal to 142 meters, the automatic control system determines that the strip has reached below the #2 pyrometer. At this point, the communication signal L\TN_ROT_CT between the first-level programmable logic controller (PLC) and the second-level CTC mathematical model becomes 1. The mathematical model generates a coil number corresponding to the FDTC mathematical model and sets and controls the parameters of the strip. If the #2 pyrometer signal changes from 0 to 1 and the detected strip head's length L1 exiting the F7 finishing mill is less than 142 meters, the PLC determines the strip information as false.

[0034] 6. Handling false signals in slabs

[0035] The automatic control system, after determining that the slab information is false based on the No. 2 pyrometer and the strip length exiting the F7 finishing mill, outputs a false strip signal. This signal interrupts the programmable logic controller (PLC) to send a strip generation signal to the CTC mathematical model. The CTC mathematical model does not generate the coil number or set the cooling manifold for the laminar cooling zone. When the actual strip reaches the roller table below the No. 2 pyrometer, both the pyrometer signal and the strip head exiting the F7 finishing mill length signal simultaneously meet the control method's setting requirements. At this time, L\TN_ROT_CT is 1, and the corresponding coil number is automatically generated in the CTC mathematical model. The model sets the number of opening branches and the opening mode of the laminar cooling manifold based on the strip coiling temperature target value, thus achieving normal strip setting and rolling.

[0036] This invention addresses the problem of slab misdetection that occurs during high-temperature strip steel production in a fast-paced process. It optimizes the control system, improves the control accuracy of the automatic control system, eliminates the generation of false slabs and prevents slab scrap accidents caused by the lack of setting in the timing model when the real slab reaches the No. 2 high temperature, and effectively improves the first-grade product rate and efficiency of hot-rolled products.

Claims

1. A method for determining false slabs in hot-rolled thin-gauge high-temperature coiled strip steel, characterized in that... The process includes the following steps: (1) Determine the target thickness of the strip during production. When rolling thin strip, use the false slab judgment method; (2) Determine the target value of the high-temperature coiling temperature of the strip. If the temperature is higher than the set temperature, call the false slab judgment function; (3) Collect data on the application of 1# and 2# high-temperature gauges. When using 2# high-temperature gauge for detection, the system identifies and shields the false strip signal; (4) Track and detect the rolling signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill to determine whether there is strip in the laminar cooling area; (5) If the temperature detected by 2# high-temperature gauge is higher than the low range, apply the above-mentioned F7 finishing mill loading signal and coiler loading signal. The signal and the length of the strip head exiting the F7 finishing mill are detected to determine whether the slab is a false slab. When the strip head reaches the roller table below the No. 2 high temperature meter, the high temperature meter detects a temperature higher than 300℃, and the heat detection signal changes from 0 to 1. At this time, the loading signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill are interlocked. That is, when the No. 2 high temperature meter detects the strip head signal, the length of the strip head exiting the F7 finishing mill is detected simultaneously. When the length of the strip head exiting the F7 finishing mill is less than the distance between the No. 2 high temperature meter and the F7 finishing mill, if the No. 2 high temperature meter signal changes to 1, it is judged as an error signal. (6) Shield the error signal and transmit it to the secondary CTC mathematical model.

2. The method for determining false slabs of hot-rolled thin-gauge high-temperature coiled strip steel according to claim 1, characterized in that: In step (1), the three-level system in production issues slab PDI information, including slab rolling target thickness, width, final rolling temperature and coiling temperature information. After receiving the information, the second-level mathematical model transmits it to the first-level basic automation programmable controller. Based on the comparison between the target thickness and the program-designed thickness, if the target thickness is less than the set value, the false slab judgment function is called.

3. The method for determining false slabs in hot-rolled thin-gauge high-temperature coiled strip steel according to claim 1, characterized in that: In step (2), after receiving the slab PDI information, the programmable controller retrieves the target value and target value code of the strip rolling and coiling temperature, compares the target value with the design value in the set temperature method program, and applies the false slab judgment function when the target temperature is higher than the set temperature.

4. The method for determining false slabs of hot-rolled thin-gauge high-temperature coiled strip steel according to claim 1, characterized in that: In step (3), the programmable controller judges the selection of 1# pyrometer and 2# pyrometer on site during strip rolling. During high-temperature coiling of strip rolling, the operator selects 2# pyrometer on the HMI operation interface to measure the coiling temperature and apply it to the feedback control of the CTC mathematical model.

5. The method for determining false slabs of hot-rolled thin-gauge high-temperature coiled strip steel according to claim 1, characterized in that: In step (4), the programmable controller accumulates the loading signal of the F7 finishing mill and the length of the strip head exiting the F7 finishing mill in each scanning cycle. This signal is used to accurately track the position of the strip head on the laminar cooling roller table, and the detection function of this signal is added on the basis of the original control.

6. The method for determining false slabs in hot-rolled thin-gauge high-temperature coiled strip steel according to claim 1, characterized in that: In step (6), when the automatic control system determines that the signal of the strip head on the roller conveyor below the No. 2 high temperature meter is false, it automatically blocks the signal and sends it to the mathematical model. The CTC mathematical model does not generate the coil number or set the cooling manifold of the laminar cooling area. After the actual strip arrives at the area, the model automatically controls the strip.

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