Device and method for controlling temperature uniformity of section of hot-rolled dual-phase steel

Abstract

The invention provides a hot-rolled dual-phase steel section temperature uniformity control device and method.The control device comprises a water spraying adjusting system and a rolling process parameter optimizing system, and the water spraying adjusting system comprises a strip steel cooling water collecting pipe between finishing mill racks and a finishing mill rack front end side water spraying collecting pipe; the strip steel cooling water collecting pipe between the finishing mill racks is used for cooling the strip steel between the finishing mill racks, so that the surface temperature of the strip steel finally reaches the target set temperature of a finishing mill outlet; the water spraying header at the front end side of the finishing mill frame is used for differentially adjusting the transverse temperature of the rolled piece, so that cooling water flow forms a uniform fan-shaped cooling area on the surface of strip steel, and the temperature balance of the cross section of the rolled piece is ensured; and the rolling process parameter optimization system is used for generating optimized rolling process parameters according to the initial parameters of the rolled piece and transmitting the optimized rolling process parameters to the rolling mill control system. The strip steel section temperature uniformity of hot-rolled dual-phase steel between finishing mill racks is effectively improved, it is guaranteed that the transverse section temperature difference is within the range of 13 DEG C, and the longitudinal temperature difference is controlled within the target value range of + / -15 DEG C.

Description

Technical Field

[0001] The present invention relates to the technical field of hot-rolled plate and strip rolling, and in particular to a device and method for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section. Background Art

[0002] Duplex steel combines high strength with excellent formability. Due to its excellent properties, it is widely used in many fields, including automotive manufacturing and mechanical engineering. Hot rolling is a key step in the production of duplex steel. The hot rolling process involves rolling the steel billet at high temperatures to achieve the desired shape and properties. Temperature control of the rolled piece is crucial during the hot rolling process, especially during the finishing stage, where temperature uniformity directly impacts the steel's microstructure, mechanical properties, and ultimately, product quality.

[0003] Currently, conventional methods for controlling rolling temperature in hot-rolled duplex steel production primarily involve simple adjustments to rolling speed, reduction, and cooling water. While these methods can control the temperature of the rolled piece to a certain extent, in actual production, significant temperature differences still exist across the cross-section of the duplex steel piece due to factors such as frictional heat generated between the workpiece and the rolls, deformation heat, and uneven distribution of the cooling medium. This temperature nonuniformity can lead to uneven microstructure in the steel, causing imbalances in the ratio and distribution of martensite and ferrite, which in turn affects the steel's mechanical properties, such as strength and toughness, failing to meet design requirements. Furthermore, this can make it difficult to maintain dimensional accuracy in the rolled piece, leading to shape defects such as camber and warping, significantly reducing product yield. During the downstream cold rolling process, frequent tension fluctuations can also occur, resulting in severely poor finished plate shape, leading to problems such as mill speed reduction and the risk of strip breakage.

[0004] However, existing conventional rolling temperature control methods struggle to effectively address the unique challenge of uneven cross-sectional temperatures in hot-rolled dual-phase steel. These methods are unable to precisely regulate the temperature of different sections of the rolled piece, nor can they dynamically adjust the temperature based on real-time temperature changes during the rolling process. Therefore, there is an urgent need to develop innovative technologies that can effectively improve the cross-sectional temperature uniformity of hot-rolled dual-phase steel during the rolling process, thereby improving product quality, reducing production risks, and meeting the stringent steel quality requirements of high-end applications. Summary of the Invention

[0005] To address the aforementioned technical issues, a device and method for controlling cross-sectional temperature uniformity of hot-rolled dual-phase steel strip are provided. This invention effectively improves cross-sectional temperature uniformity of hot-rolled dual-phase steel strip between finishing mill stands, ensuring that the transverse cross-sectional temperature difference is within 13°C and the longitudinal temperature difference is controlled within the target range of ±15°C. This eliminates frequent tension fluctuations during the downstream cold rolling process, improves finished strip shape, and mitigates the risk of mill speed reduction or strip breakage.

[0006] The technical means adopted in the present invention are as follows:

[0007] A device for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section comprises a water spraying adjustment system and a rolling process parameter optimization system, wherein:

[0008] The water spray regulation system includes a strip cooling water manifold between the finishing mill stands and a water spray manifold at the front end of the finishing mill stand. The water spray manifold between the finishing mill stands is used to cool the strip between the finishing mill stands, so that the cooling water flows to form a uniform fan-shaped cooling area on the surface of the strip, thereby ensuring the consistency of the cooling effect of each part of the strip; the water spray manifold at the front end of the finishing mill stand is used to differentially adjust the transverse temperature of the rolled piece to ensure the temperature balance of the cross section of the rolled piece;

[0009] The rolling process parameter optimization system is used to generate optimized rolling process parameters according to the initial parameters of the rolled piece and transmit them to the rolling mill control system.

[0010] Furthermore, the strip cooling water header between the finishing mill stands includes a main body, multiple rows of branch pipes and branch pipe nozzles, wherein:

[0011] The main body is made of high-quality alloy steel, and multiple rows of branch pipes are symmetrically welded on the main body on both sides of the rolling line centerline. The branch pipe nozzles are distributed non-parallel to the running direction of the strip. The water spraying angle of the branch pipe nozzles forms a certain angle with the left and right sides of the strip in the horizontal direction, and sprays water in the opposite direction of the strip running, forming a certain angle in the longitudinal direction. The aperture size of the branch pipe nozzles changes symmetrically according to the distance from the rolling line centerline, with the largest aperture in the middle and the smallest on both sides, and the upper and lower surfaces are arranged symmetrically.

[0012] Furthermore, the front end side water spraying manifolds of the finishing mill stand include three groups of side water spraying manifolds, each group includes two water spraying manifolds, namely: two first side water spraying manifolds, two second side water spraying manifolds and two third side water spraying manifolds, wherein:

[0013] The two first-side water spray headers have the same structure and are respectively arranged at the front end of the F2 finishing mill stand and the F4 finishing mill stand. They each include a first header and three first water spray outlets. The three first water spray outlets are arranged in sequence on the first header and are arranged directly in the middle of the rolled steel strip.

[0014] The two second side water spray headers have the same structure and are respectively arranged at the front end of the F3 finishing rolling stand and the F5 finishing rolling stand. They each include a second header and four second water spray nozzles. The four second water spray nozzles are arranged in a front-to-back order on the second header, with two second water spray nozzles arranged directly opposite the front end of the rolled steel strip, and the other two second water spray nozzles arranged directly opposite the rear end of the rolled steel strip.

[0015] The two third-side water spray headers have the same structure and are respectively located at the front end of the F6 finishing mill stand and the F7 finishing mill stand. Each of them includes a third header and six third water spray nozzles. The six third water spray nozzles are arranged in sequence on the third header and are directly facing the entire strip area.

[0016] Each set of side water spray manifolds is equipped with an independent electrically controlled switching valve. The electrically controlled switching valve performs the switching function according to the instructions of the central processor, thereby realizing differentiated adjustment of the transverse temperature of the rolled piece and ensuring the temperature balance of the cross section of the rolled piece strip.

[0017] Furthermore, the rolling process parameter optimization system has a built-in hot-rolled dual-phase steel rolling process model constructed based on a large amount of experimental data and numerical simulation. The model covers the relationship between multiple variables such as the material properties of the rolled piece, rolling speed, reduction, and cooling strategy. The operator inputs the initial parameters of the rolled piece into the rolling process parameter optimization system, and the rolling process parameter optimization system automatically generates optimized rolling process parameters and transmits them to the rolling mill control system.

[0018] The present invention also provides a method for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section, which is implemented based on the above-mentioned control device and includes:

[0019] S1. Data Collection and Analysis: Before the steel strip enters the finishing mill for rolling, the temperature monitoring system collects the longitudinal and cross-sectional temperature distribution data of the steel strip in real time and transmits it to the central processing unit. The central processing unit pre-processes the data to obtain the initial parameters of the steel strip.

[0020] S2. Temperature prediction between finishing mill stands: Constructing a temperature drop model for the finishing mill stands to calculate the inlet and outlet temperatures of each stand;

[0021] S3. Finishing mill threading speed setting: determine the threading speed of the last stand and calculate the threading speed of other rolling mill stands based on the principle of equal flow rate per second;

[0022] S4, pre-control: the rolling process parameter optimization system generates optimized rolling process parameters according to the initial parameters of the rolled piece, and the rolling mill control system starts rolling according to the optimized rolling process parameters;

[0023] S5. Dynamic control: During the rolling process, the temperature monitoring system continuously monitors the temperature changes of the rolled piece at the outlet of the finishing stand, and transmits updated data to the central processing unit several times per second. Once the central processing unit determines that the temperature of a certain area of the rolled piece cross section deviates from the preset uniform temperature range, it immediately sends an instruction to the water spray regulation system. The rolling mill control system dynamically adjusts the rolling speed or the number of water spray groups and valve opening between stands according to the longitudinal temperature deviation to meet the target temperature control accuracy in the longitudinal direction of the finished rolling exit.

[0024] Furthermore, step S2 specifically includes:

[0025] S21. Calculate the inlet temperature of each rack using the following formula:

[0026] EntryTemp i =ExitTemp i-1 -SprayTemp i -RayTemp i

[0027] Among them, ExitTemp i-1 Indicates the outlet temperature of the previous rack; SprayTemp i Indicates the spray temperature drop between racks, SprayTemp i =Zla*Zba*f(1,2,3,…,7), Zla represents the long-term self-learning coefficient of the temperature drop model of the finishing mill stand, Zba represents the short-term self-learning coefficient of the temperature drop model of the finishing mill stand, and f(1,2,3,…,7) represents the stand; RayTemp i Indicates the radiation temperature drop between racks, RayTemp i =Zla*Zba*f(1,2,3,…,7);

[0028] S22. Calculate the outlet temperature of each rack using the following formula:

[0029] ExitTemp i =EntryTemp i -ContacTempDrop i -RollingTempDrop i

[0030] Among them, ContacTempDrop i Indicates the rack contact conduction temperature drop, ContacTempDrop i =f(1,2,3,…,7);RollingTempDrop i Indicates the rack deformation thermal temperature drop, RollingTempDrop i =f(1,2,3,…,7).

[0031] Furthermore, in step S3, the strip threading speed of each other rolling mill stand is calculated based on the principle of equal second flow rate, and the calculation formula is as follows:

[0032]

[0033] Among them, slip i Indicates finishing F i Rack front slide value; slip末 Indicates the forward slip value of the finishing mill stand; h i Indicates finishing F i Outlet thickness; h 末 Indicates the thickness of the finishing mill stand outlet; V i Indicates the strip threading speed of each rolling mill stand; v 末 Indicates the strip threading speed of the finishing rolling end stand.

[0034] Furthermore, step S5 specifically includes:

[0035] S51. During normal operation, the two third side water spray headers provided at the front ends of the F6 finishing mill stand and the F7 finishing mill stand are kept in an open state, so that the six third water spray ports spray water.

[0036] S52: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds 12°C (edge - center), the second side water spray header disposed at the front end of the F5 finishing mill stand is turned on to cause the four second water spray ports to spray water;

[0037] S53: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds 17°C (edge - center), the second side water spray header disposed at the front end of the F3 finishing mill stand is turned on to cause the four second water spray ports to spray water;

[0038] S54: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds -12°C (edge - center), the first side water spray header disposed at the front end of the F4 finishing mill stand is turned on to cause the three first water spray ports to spray water;

[0039] S55. When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds -17°C (edge - center), the first side water spray header disposed at the front end of the F2 finishing mill stand is turned on to cause the three first water spray ports to spray water.

[0040] S56. When the central processing unit determines that the longitudinal temperature detection value of the finished product at the finishing rolling exit is 8°C higher or lower than the target value, the water spraying amount of the strip cooling water manifold between the finishing rolling mill stands is controlled to be increased or decreased accordingly;

[0041] S57. When the central processing unit determines that the longitudinal temperature detection value of the finished rolling exit of the rolled piece deviates from the target value by more than 15°C, the speed of the rolling mill will participate in the temperature regulation, increasing or decreasing the speed to adjust the longitudinal temperature change of the rolled piece to meet the target temperature value.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] 1. The present invention effectively solves the problem of uneven temperature in the longitudinal and transverse sections of hot-rolled dual-phase steel, significantly improves the uniformity of the steel microstructure, stabilizes the mechanical properties, and controls the product strength fluctuation within a relatively small range of ±20 MPa, meeting the strict requirements of high-end applications for steel quality.

[0044] 2. The present invention improves the plate shape accuracy of the rolled piece, reduces the occurrence rate of plate shape defects, and increases the yield rate through the optimization and dynamic adjustment of rolling process parameters. At the same time, on the basis of ensuring quality, it fully taps the production potential of the equipment and improves production efficiency.

[0045] 3. The present invention has strong versatility and can be applied to the rolling production of other similar dual-phase steels or high-strength steels with slight adjustments, providing strong support for technological upgrading in the steel industry.

[0046] Based on the above reasons, the present invention can be widely promoted in the fields of hot strip rolling and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0048] Figure 1 This is a schematic diagram of the temperature control device for the finished rolling area of the present invention.

[0049] Figure 2 This is a cross-sectional view of the water spray header between the stands of the finishing mill according to the present invention.

[0050] Figure 3 Schematic diagram of the first side water spray header of the present invention.

[0051] Figure 4 Schematic diagram of the second side water spray header of the present invention.

[0052] Figure 5 Schematic diagram of the third side water spray header of the present invention.

[0053] Figure 1 Middle: HR-TB, rolled product; FET, strip inlet temperature monitor; FSB, front-end bus; FDT, temperature monitoring point pyrometer; MFDI, multi-function detector; F1-F7, stands; ISC1-ISC6, strip cooling water headers between finishing mill stands; ISSW1 and ISSW3, first-side spray water headers; ISSW2 and ISSW4, second-side spray water headers; ISSW5 and ISSW6, third-side spray water headers. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0055] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0056] like Figure 1 As shown, the present invention provides a control device for cross-section temperature uniformity of hot-rolled dual-phase steel, characterized in that it includes: a water spray adjustment system and a rolling process parameter optimization system, wherein:

[0057] The water spray regulation system includes a strip cooling water manifold between the finishing mill stands and a water spray manifold on the front end of the finishing mill stand. The water spray manifold between the finishing mill stands is used to cool the strip between the finishing mill stands, so that the cooling water flows to form a uniform fan-shaped cooling area on the surface of the strip, thereby ensuring the consistency of the cooling effect of various parts of the strip, thereby improving the quality and performance of the strip; the water spray manifold on the front end of the finishing mill stand is used to differentially adjust the transverse temperature of the rolled piece to ensure the temperature balance of the cross section of the rolled piece;

[0058] The rolling process parameter optimization system is used to generate optimized rolling process parameters according to the initial parameters of the rolled piece and transmit them to the rolling mill control system.

[0059] In specific implementation, as a preferred embodiment of the present invention, the strip cooling water manifold between the finishing mill stands includes a main body, multiple rows of branch pipes and branch pipe nozzles, wherein:

[0060] Multiple rows of branch pipes are symmetrically welded on the main body on both sides of the rolling line centerline. The branch pipe nozzles are not parallel to the running direction of the strip. The water spraying angle of the branch pipe nozzles forms a certain angle with the left and right sides of the strip in the horizontal direction, and sprays water in the opposite direction of the strip running, forming a certain angle in the longitudinal direction. The aperture size of the branch pipe nozzles changes symmetrically according to the distance from the rolling line centerline. The aperture is the largest in the middle and the smallest on both sides. The upper and lower surfaces are symmetrically arranged. Figure 2 As shown, in this embodiment, 10 rows of branch pipes are provided, with each 5 rows in a group, and are symmetrically welded to the main body on both sides of the center line of the rolling line. The water spraying angle of the branch pipe nozzle forms an angle of 15° with the left and right sides of the strip in the horizontal direction, and water is sprayed in the opposite direction of the strip running direction, forming an angle of 15° in the longitudinal direction.

[0061] In specific implementation, as a preferred embodiment of the present invention, the front end side water spraying manifold of the finishing mill stand includes three groups of side water spraying manifolds, each group includes two water spraying manifolds, namely: two first side water spraying manifolds, two second side water spraying manifolds and two third side water spraying manifolds, wherein:

[0062] like Figure 3 As shown, the two first side water spray headers have the same structure and are respectively arranged at the front end of the F2 finishing mill stand and the F4 finishing mill stand. Each of them includes a first header and three first water spray outlets. The three first water spray outlets are arranged in sequence on the first header, and the three water spray outlets are arranged directly in the middle of the rolled steel strip.

[0063] like Figure 4 As shown, the two second side water spray headers have the same structure and are respectively arranged at the front end of the F3 finishing mill stand and the F5 finishing mill stand. They each include a second header and four second water spray outlets. The four second water spray outlets are arranged in sequence on the second header, and two of the second water spray outlets are arranged directly opposite the front end of the rolled steel strip, and the other two second water spray outlets are arranged directly opposite the rear end of the rolled steel strip.

[0064] like Figure 5 As shown, the two third side water spray headers have the same structure and are respectively arranged at the front end of the F6 finishing rolling stand and the F7 finishing rolling stand. Each includes a third header and six third water spray nozzles. The six third water spray nozzles are arranged in sequence on the third header, and the six third water spray nozzles are arranged directly facing the entire rolled strip area.

[0065] Each set of side water spray manifolds is equipped with an independent electrically controlled switching valve. The electrically controlled switching valve performs the switching function according to the instructions of the central processor, thereby realizing differentiated adjustment of the transverse temperature of the rolled piece and ensuring the temperature balance of the cross section of the rolled piece strip.

[0066] In specific implementation, as a preferred embodiment of the present invention, the rolling process parameter optimization system has a built-in hot-rolled dual-phase steel rolling process model constructed based on a large amount of experimental data and numerical simulation. The model covers the relationship between multiple variables such as the material properties of the rolled piece, rolling speed, reduction, and cooling strategy. The operator inputs the initial parameters of the rolled piece into the rolling process parameter optimization system, and the rolling process parameter optimization system automatically generates the optimized rolling process parameters and transmits them to the rolling mill control system.

[0067] The present invention also provides a method for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section based on the above-mentioned control device, comprising:

[0068] S1. Data collection and analysis: Before the steel strip enters the finishing mill for rolling, the temperature monitoring system collects the longitudinal and cross-sectional temperature distribution data of the steel strip in real time and transmits it to the central processing unit. The central processing unit pre-processes the data to obtain the initial parameters of the steel strip. In this embodiment, see Figure 1 , using strip entrance temperature monitoring (FET) and multi-function detector (MFDI) to collect real-time temperature distribution data of the rolled piece in the longitudinal and cross-section.

[0069] S2. Temperature prediction between finishing mill stands: Constructing a temperature drop model for the finishing mill stands to calculate the inlet and outlet temperatures of each stand;

[0070] S3. Finishing mill threading speed setting: determine the threading speed of the last stand and calculate the threading speed of other rolling mill stands based on the principle of equal flow rate per second;

[0071] S4, pre-control: the rolling process parameter optimization system generates optimized rolling process parameters according to the initial parameters of the rolled piece, and the rolling mill control system starts rolling according to the optimized rolling process parameters;

[0072] S5. Dynamic Control: During the rolling process, the temperature monitoring system continuously monitors the temperature changes of the rolled piece at the outlet of the finishing mill stand, and transmits updated data to the central processing unit several times per second. Once the central processing unit determines that the temperature of a certain area of the rolled piece cross section deviates from the preset uniform temperature range, it immediately sends a command to the water spray control system. The rolling mill control system then dynamically adjusts the rolling speed or the number of water spray groups and valve opening between stands according to the longitudinal temperature deviation to meet the target temperature control accuracy in the longitudinal direction of the finished rolling mill outlet. In this embodiment, continue to refer to Figure 1 , the temperature monitoring system uses a temperature monitoring point pyrometer (FDT) and a multi-function detector (MFDI).

[0073] In specific implementation, as a preferred embodiment of the present invention, step S2 specifically includes:

[0074] S21. Calculate the inlet temperature of each rack using the following formula:

[0075] EntryTemp i =ExitTemp i-1 -SprayTemp i -RayTemp i

[0076] Among them, ExitTemp i-1 Indicates the outlet temperature of the previous rack; SprayTemp i Indicates the spray temperature drop between racks, SprayTemp i =Zla*Zba*f(1,2,3,...,7), Zla represents the long-term self-learning coefficient of the temperature drop model of the finishing mill stand, Zba represents the short-term self-learning coefficient of the temperature drop model of the finishing mill stand, and f(1,2,3,...,7) represents the stand; RayTemp i Indicates the radiation temperature drop between racks, RayTemp i =Zla*Zba*f(1,2,3,…,7);

[0077] S22. Calculate the outlet temperature of each rack using the following formula:

[0078] ExitTemp i =EntryTemp i -ContacTempDrop i -RollingTempDrop i

[0079] Among them, ContacTempDrop i Indicates the rack contact conduction temperature drop, ContacTempDrop i =f(1,2,3,…,7);RollingTempDrop i Indicates the rack deformation thermal temperature drop, RollingTempDrop i =f(1,2,3,…,7).

[0080] In specific implementation, as a preferred embodiment of the present invention, in step S3, the strip threading speed of each other rolling mill stand is calculated based on the principle of equal second flow rate, and the calculation formula is as follows:

[0081]

[0082] Among them, slip i Indicates finishing F i Rack front slide value; slip 末 Indicates the forward slip value of the finishing mill stand; h i Indicates finishing F i Outlet thickness; h末 Indicates the thickness of the finishing mill stand outlet; V i Indicates the strip threading speed of each rolling mill stand; v 末 Indicates the threading speed of the final stand of the finishing mill. In this embodiment, the threading speed of the final stand determines the flow rate per second during threading. When setting this speed, in addition to cooling performance and production capacity, factors such as threading on the finishing stand and runout rollers, transport stability, and coiler power must also be considered. The threading speed of the final stand of the finishing mill is set using an automatic calculation method. Since the finishing process is a continuous rolling process, once the threading speed of the final stand is determined, the threading speeds of the remaining stands can be calculated based on the principle of equal flow rates per second.

[0083] In specific implementation, as a preferred embodiment of the present invention, step S5 specifically includes:

[0084] S51. During normal operation, the two third side water spray headers provided at the front ends of the F6 finishing mill stand and the F7 finishing mill stand are kept in an open state, so that the six third water spray ports spray water.

[0085] S52: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds 12°C (edge - center), the second side water spray header disposed at the front end of the F5 finishing mill stand is turned on to cause the four second water spray ports to spray water;

[0086] S53: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds 17°C (edge - center), the second side water spray header disposed at the front end of the F3 finishing mill stand is turned on to cause the four second water spray ports to spray water;

[0087] S54: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds -12°C (edge - center), the first side water spray header disposed at the front end of the F4 finishing mill stand is turned on to cause the three first water spray ports to spray water;

[0088] S55. When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds -17°C (edge - center), the first side water spray header disposed at the front end of the F2 finishing mill stand is turned on to cause the three first water spray ports to spray water.

[0089] S56. When the central processing unit determines that the longitudinal temperature detection value of the finished product at the finishing rolling exit is 8°C higher or lower than the target value, the water spraying amount of the strip cooling water manifold between the finishing rolling mill stands is controlled to be increased or decreased accordingly;

[0090] S57. When the central processing unit determines that the longitudinal temperature detection value of the finished rolling exit of the rolled piece deviates from the target value by more than 15°C, the speed of the rolling mill will participate in the temperature regulation, increasing or decreasing the speed to adjust the longitudinal temperature change of the rolled piece to meet the target temperature value.

[0091] In this embodiment, for example, during the production of hot-rolled dual-phase steel DP590, side water spraying is activated at F6 and F7 during normal operation. When the cross-sectional temperature difference exceeds 12°C (edge-to-center), the front-side water spraying of the F5 finishing stand is activated; when the cross-sectional temperature difference exceeds 17°C (edge-to-center), the front-side water spraying of the F3 finishing stand is activated. Conversely, when the cross-sectional temperature difference exceeds -12°C (edge-to-center), the front-side water spraying of the F4 finishing stand is activated; and when the cross-sectional temperature difference exceeds -17°C (edge-to-center), the front-side water spraying of the F2 finishing stand is activated. The mill control system dynamically adjusts the rolling speed, the number of interstand water spray (ISC) groups activated, and the valve opening based on the longitudinal temperature deviation to coordinately balance the cross-sectional temperature of the rolled product. For example, if the longitudinal temperature (FDT) at the finish rolling exit of hot-rolled dual-phase steel DP590 is 8°C higher or lower than the target of 880°C, the water spray volume between the stands will be increased or decreased accordingly. If the deviation from the target is more than 15°C, the speed of the rolling mill will be involved in temperature regulation, increasing or decreasing the speed to adjust the longitudinal temperature change of the rolled piece to meet the target temperature value.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section, characterized in that: include: Water spray adjustment system and rolling process parameter optimization system, including: The water spray regulation system includes a strip cooling water manifold between the finishing mill stands and a water spray manifold at the front end of the finishing mill stand. The water spray manifold between the finishing mill stands is used to cool the strip between the finishing mill stands, so that the cooling water flows to form a uniform fan-shaped cooling area on the surface of the strip, thereby ensuring the consistency of the cooling effect of each part of the strip; the water spray manifold at the front end of the finishing mill stand is used to differentially adjust the transverse temperature of the rolled piece to ensure the temperature balance of the cross section of the rolled piece; The rolling process parameter optimization system is used to generate optimized rolling process parameters according to the initial parameters of the rolled piece and transmit them to the rolling mill control system.

2. The device for controlling cross-section temperature uniformity of hot-rolled dual-phase steel according to claim 1, characterized in that: The strip cooling water header between the finishing mill stands includes a main body, multiple rows of branch pipes and branch pipe nozzles, wherein: Multiple rows of branch pipes are symmetrically welded on the main body on both sides of the rolling line centerline. The branch pipe nozzles are distributed non-parallel to the running direction of the strip. The water spraying angle of the branch pipe nozzles forms a certain angle with the left and right sides of the strip in the horizontal direction, and sprays water in the opposite direction of the strip running, forming a certain angle in the longitudinal direction. The aperture size of the branch pipe nozzles changes symmetrically according to the distance from the rolling line centerline, with the largest aperture in the middle and the smallest on both sides, and the upper and lower surfaces are arranged symmetrically.

3. The device for controlling cross-section temperature uniformity of hot-rolled dual-phase steel according to claim 1, characterized in that: The front end side water spraying manifolds of the finishing mill stand include three groups of side water spraying manifolds, each group includes two water spraying manifolds, namely: two first side water spraying manifolds, two second side water spraying manifolds and two third side water spraying manifolds, wherein: The two first-side water spray headers have the same structure and are respectively arranged at the front end of the F2 finishing mill stand and the F4 finishing mill stand. They each include a first header and three first water spray outlets. The three first water spray outlets are arranged in sequence on the first header and are arranged directly in the middle of the rolled steel strip. The two second side water spray headers have the same structure and are respectively arranged at the front end of the F3 finishing rolling stand and the F5 finishing rolling stand. They each include a second header and four second water spray nozzles. The four second water spray nozzles are arranged in a front-to-back order on the second header, with two second water spray nozzles arranged directly opposite the front end of the rolled steel strip, and the other two second water spray nozzles arranged directly opposite the rear end of the rolled steel strip. The two third-side water spray headers have the same structure and are respectively located at the front end of the F6 finishing mill stand and the F7 finishing mill stand. Each of them includes a third header and six third water spray nozzles. The six third water spray nozzles are arranged in sequence on the third header and are directly facing the entire strip area. Each set of side water spray manifolds is equipped with an independent electrically controlled switching valve. The electrically controlled switching valve performs the switching function according to the instructions of the central processor, thereby realizing differentiated adjustment of the transverse temperature of the rolled piece and ensuring the temperature balance of the cross section of the rolled piece strip.

4. The device for controlling cross-section temperature uniformity of hot-rolled dual-phase steel according to claim 1, characterized in that: The rolling process parameter optimization system has a built-in hot-rolled dual-phase steel rolling process model. The model covers the relationship between multiple variables such as the material properties of the rolled product, rolling speed, reduction, and cooling strategy. The operator inputs the initial parameters of the rolled product into the rolling process parameter optimization system, and the rolling process parameter optimization system automatically generates optimized rolling process parameters and transmits them to the rolling mill control system.

5. A method for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section, implemented based on the control device according to any one of claims 1 to 4, characterized in that: include: S1. Data Collection and Analysis: Before the steel strip enters the finishing mill for rolling, the temperature monitoring system collects the longitudinal and cross-sectional temperature distribution data of the steel strip in real time and transmits it to the central processing unit. The central processing unit pre-processes the data to obtain the initial parameters of the steel strip. S2. Temperature prediction between finishing mill stands: Constructing a temperature drop model for the finishing mill stands to calculate the inlet and outlet temperatures of each stand; S3. Finishing mill threading speed setting: determine the threading speed of the last stand and calculate the threading speed of other rolling mill stands based on the principle of equal flow rate per second; S4, pre-control: the rolling process parameter optimization system generates optimized rolling process parameters according to the initial parameters of the rolled piece, and the rolling mill control system starts rolling according to the optimized rolling process parameters; S5. Dynamic control: During the rolling process, the temperature monitoring system continuously monitors the temperature changes of the rolled piece at the outlet of the finishing stand, and transmits updated data to the central processing unit several times per second. Once the central processing unit determines that the temperature of a certain area of the rolled piece cross section deviates from the preset uniform temperature range, it immediately sends an instruction to the water spray regulation system. The rolling mill control system dynamically adjusts the rolling speed or the number of water spray groups and valve opening between stands according to the longitudinal temperature deviation to meet the target temperature control accuracy in the longitudinal direction of the finished rolling exit.

6. The method for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section according to claim 5, characterized in that: Step S2 specifically includes: S21. Calculate the inlet temperature of each rack using the following formula: EntryTemp i =ExitTemp i-1 -SprayTemp i -RayTemp i Among them, ExitTemp i-1 Indicates the outlet temperature of the previous rack; SprayTemp i Indicates the spray temperature drop between racks, SprayTemp i =Zla*Zba*f(1,2,3,…,7), Zla represents the long-term self-learning coefficient of the temperature drop model of the finishing mill stand, Zba represents the short-term self-learning coefficient of the temperature drop model of the finishing mill stand, and f(1,2,3,…,7) represents the stand; RayTemp i Indicates the radiation temperature drop between racks, RayTemp i =Zla*Zba*f(1,2,3,…,7); S22. Calculate the outlet temperature of each rack using the following formula: ExitTemp i =EntryTemp i -ContacTempDrop i -RollingTempDrop i Among them, ContacTempDrop i Indicates the rack contact conduction temperature drop, ContacTempDrop i =f(1,2,3,…,7);RollingTempDrop i Indicates the rack deformation thermal temperature drop, RollingTempDrop i =f(1,2,3,…,7).

7. The method for controlling the temperature uniformity of a hot-rolled dual-phase steel cross section according to claim 5, characterized in that: In step S3, the strip threading speed of each other rolling mill stand is calculated based on the principle of equal second flow rate. The calculation formula is as follows: Among them, slip i Indicates finishing F i Rack front slide value; slip 末 Indicates the forward slip value of the finishing mill stand; h i Indicates finishing F i Outlet thickness; h 末 Indicates the thickness of the finishing mill stand outlet; V i Indicates the strip threading speed of each rolling mill stand; v 末 Indicates the strip threading speed of the finishing rolling end stand.

8. The method for controlling cross-section temperature uniformity of hot-rolled dual-phase steel according to claim 5, characterized in that: Step S5 specifically includes: S51. During normal operation, the two third side water spray headers provided at the front ends of the F6 finishing mill stand and the F7 finishing mill stand are kept in an open state, so that the six third water spray ports spray water. S52: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds 12°C, the second side water spray header provided at the front end of the F5 finishing mill stand is turned on to cause the four second water spray ports to spray water; S53: When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds 17° C., the second side water spray header provided at the front end of the F3 finishing mill stand is opened so that the four second water spray ports spray water; S54. When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds -12°C, the first side water spray header provided at the front end of the F4 finishing mill stand is turned on to spray water from the three first water spray ports. S55. When the central processing unit determines that the temperature difference in the cross-sectional area of the rolled steel strip exceeds -17°C, the first side water spray header disposed at the front end of the F2 finishing mill stand is turned on to cause the three first water spray ports to spray water. S56. When the central processing unit determines that the longitudinal temperature detection value of the finished product at the finishing rolling exit is 8°C higher or lower than the target value, the water spraying amount of the strip cooling water manifold between the finishing rolling mill stands is controlled to be increased or decreased accordingly; S57. When the central processing unit determines that the longitudinal temperature detection value of the finished rolling exit of the rolled piece deviates from the target value by more than 15°C, the speed of the rolling mill will participate in the temperature regulation, increasing or decreasing the speed to adjust the longitudinal temperature change of the rolled piece to meet the target temperature value.

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