A feedback type low alloy steel high speed bar performance control method and system based on multi-parameter coupling

Abstract

The present application relates to a kind of feedback type low alloy steel high-speed bar performance control method and system based on multi-parameter coupling, belong to low alloy steel high-speed bar production technical field in steel metallurgical industry.The method includes: to the double line of the first steel after being cut, collect its temperature data before finish rolling and finish rolling unit each rack motor current data, calculate the temperature difference before finish rolling of double line and motor current difference;When any difference exceeds preset threshold value, adjust instruction to the cooling parameter before finish rolling of next steel is output through first coupling model;Collect the temperature of first steel after finish rolling, temperature on cooling bed, mechanical property and microstructure data, calculate the difference of each parameter of double line and organization qualified determination;When any parameter difference exceeds preset threshold value or organization is unqualified, adjust instruction to the cooling parameter after finish rolling of next steel is output through second coupling model;Repeat the above steps to realize iterative closed-loop control, significantly improve control precision and product stability.

Description

Technical Field

[0001] This invention belongs to the field of high-speed low-alloy steel bar production technology in the iron and steel metallurgical industry, and relates to a feedback-based method and system for controlling the performance of high-speed low-alloy steel bars based on multi-parameter coupling. Background Technology

[0002] Low-alloy steel is widely used in high-rise buildings, bridges, railways, and rail transit. As the most important product of low-alloy steel, rebar's mechanical properties and surface quality are crucial to the quality and safety of major national projects such as bridges, railways, and rail transit. With the implementation of the new national standard GB / T1499.2-2024 "Steel for Reinforced Concrete - Part 2", higher requirements have been placed on the metallographic structure of rebar, explicitly prohibiting the presence of tempered martensite on the base circle. Therefore, rebar produced using residual heat treatment processes contains tempered martensite, which does not meet the national standard requirements; microalloying production leads to a significant increase in production costs; achieving high-strength, high-stability rebar production through controlled rolling and controlled cooling technology, meeting national standard requirements while reducing alloy costs, is an important direction for future development.

[0003] As a low-alloy steel bar production process that has developed and been applied rapidly in recent years, the high-speed bar production line can achieve temperature control through water tanks and recovery sections before and after the finishing mill, and achieve low-temperature high-reduction rolling through modular finishing mills, ultimately obtaining low-alloy steel, especially rebar bar products with qualified quality and microstructure, while significantly reducing the content of alloying elements.

[0004] To further increase the output and surface quality of low-alloy steel in high-speed bar production lines, improve mill utilization, and appropriately reduce alloy costs, some steel mills have adopted a dual high-speed bar rolling method. A typical process, as shown in Chinese patent CN114405992B, involves splitting the bar in a pre-finishing mill to form two independent rolled sections, which then enter two separate finishing mills for subsequent rolling and cooling. While this dual-line parallel production method significantly increases output, it also presents new technical challenges: (1) Due to the inherent differences in physical position, operating conditions of surrounding equipment and cooling conditions of the two rolled pieces after splitting, the rolling load of the double-line finishing mill is inconsistent, which in turn affects the rolling stability and product dimensional accuracy. (2) The slight difference in the entry temperature of the double-line finishing mill will be amplified after multiple rolling and cooling passes, resulting in significant differences in the grain size and microstructure (such as the ratio of ferrite / pearlite and the probability of martensite) of the final product. This directly causes instability and inconsistency in the mechanical properties of the double-line product, and in severe cases, even abnormal structures that do not meet the national standards.

[0005] To address the aforementioned issues, existing technologies, such as CN119857735A, disclose a bar mill temperature control method. This method achieves precise closed-loop control of the temperature of a single rolled bar by establishing a mill temperature control model and a performance prediction model. However, this method primarily focuses on the real-time adjustment of the temperature of a single rolled bar and does not solve the long-term, cumulative performance drift and inconsistency problems caused by differences in equipment and operating conditions between the two mills. Another example is CN110814053B, which discloses a trial-and-error water tank reverse self-decision temperature control method. Its core is to use model self-learning to make the cooling path of the rolled bar conform to a preset CCT curve. This is a feedforward model optimization and similarly fails to provide a feedback control method that dynamically couples multiple parameters with the ultimate goal of ensuring consistency between the two mill products.

[0006] Therefore, there is an urgent need in this field for a control system and method that can comprehensively consider the parameters of the dual-line process and the final result parameters, and can achieve dynamic balance of the dual-line process and ensure long-term high consistency of product performance. Summary of the Invention

[0007] In view of this, the present invention aims to solve the problem of cumulative differences and inconsistencies in product performance and microstructure between the two lines of a dual high-speed bar production line caused by long-term drift in equipment and operating conditions. It provides a feedback-based microstructure and performance control medium, system, and method for producing high-speed low-alloy steel bars based on multi-parameter coupling. Through the mutual coupling and feedback control of the dual-line motor current, rolled piece temperature, rolled piece surface quality, and mechanical property results, stable production of the dual-line low-alloy steel bar production line is achieved. This effectively improves the stability of process control, mechanical property stability, surface quality stability, passability, and microstructure reliability of the two lines of the dual-line high-speed bar production line. Simultaneously, it improves rolling production stability, increases average hourly output, reduces operating costs, and enhances economic efficiency.

[0008] The performance control described in this invention refers to the comprehensive control of the mechanical properties (including but not limited to yield strength, tensile strength, elongation, and total elongation at maximum force) and microstructure (including but not limited to the morphology, proportion, and distribution of ferrite, pearlite, and martensite) of low-alloy steel high-speed bars.

[0009] To achieve the above objectives, On one hand, this invention provides a feedback-based method for controlling the performance of high-speed low-alloy steel bars based on multi-parameter coupling, comprising the following steps: S1: According to the initial process requirements, the first steel strip after being cut is subjected to pre-finishing cooling, finishing mill rolling, post-finishing cooling and cooling bed operation on both wires. S2: Collect the temperature data before finishing rolling of the first steel bar and the motor current data of each stand of the finishing mill during the rolling process, and calculate the first difference value of the temperature data before finishing rolling of the two lines. The second difference value of the motor current data () and the motor current data ); S3: When the first difference value ( ) greater than the first preset threshold ( ), or the second difference value ( ) greater than the second preset threshold ( When ), the first difference value ( ) and the second difference value ( Input a preset first coupling model, and the first coupling model outputs an adjustment command for the cooling parameters of the A line and / or B line before finishing rolling of the next steel. S4: Collect the temperature data after finishing rolling, upper cooling bed temperature data, surface quality data, mechanical property data, and microstructure data of the first steel strip after rolling and cooling, and calculate the third difference value of the finishing rolling temperature data of the two lines ( ), and the fourth difference value of the upper cooling bed temperature data ( The fifth difference value of the mechanical property data and the qualification judgment result of the microstructure data. ); S5: When the third difference value ( ) greater than the third preset threshold ( The fourth difference value ( ) greater than the fourth preset threshold ( The condition that at least one of the fifth difference value is greater than the fifth preset threshold is met, or the condition that the microscopic tissue data is qualified is determined. When the third difference value is unqualified, the third difference value ( ), fourth difference value ( The fifth difference value and microstructure data are input into the preset second coupling model, and the second coupling model outputs the adjustment command for the cooling parameters of the A line and / or B line after finishing rolling of the next steel. S6: Based on the adjustment instructions output in step 3 and / or step 5, execute the production of the next steel piece and repeat steps 2 to 6 to achieve feedback closed-loop control.

[0010] Preferably, the adjustment instructions for the cooling parameters before finishing milling in step 3 include the water volume adjustment range and water pressure adjustment threshold of the water tank before finishing milling, wherein the water volume adjustment range is 5%-35% and the water pressure adjustment threshold is 0.3MPa-1.5MPa; the adjustment instructions for the cooling parameters after finishing milling in step 5 include the water volume adjustment range and water pressure adjustment threshold of the water tank after finishing milling, wherein the water volume adjustment range is 5%-35% and the water pressure adjustment threshold is 0.3MPa-1.5MPa.

[0011] Preferably, the first coupling model is a two-level coupling model constructed based on the roll pass material calculation model and the mill current calculation model; the second coupling model is a two-level coupling model constructed based on the water cooling parameter calculation model, the microstructure transformation model and the mechanical property calculation model.

[0012] Preferably, in step 3, the first coupling model applies the first difference value ( ) and second difference value ( The processing of the third difference value ( ) adopts a preset first weight ratio, where the weight ratio is 3 for temperature data and 7 for motor current data. In step 5, the second coupling model processes the third difference value ( ) ), fourth difference value ( The processing of the fifth difference value and microstructure data adopts a preset second weighting ratio, which is 2 for the temperature data after finishing rolling, 2 for the microstructure data, and 6 for the mechanical property data.

[0013] Preferably, the mechanical property data includes yield strength ( ), elongation after fracture ( ) and total elongation at maximum force ( The fifth difference value includes intensity difference (); ), Elongation difference after fracture ( ) and the difference in total elongation at maximum force ( The fifth preset threshold includes an intensity difference threshold (); =15MPa, threshold for difference in elongation after fracture ( =4% and the threshold for the difference between the total elongation rate and the maximum force ( =4%.

[0014] Preferably, the qualification judgment result of the microscopic tissue data ( A result of ) is considered unqualified when the microstructure contains more than 5% martensite or tempered martensite, or when a closed martensite ring of ≥180° appears on the outer periphery of the base circle.

[0015] Preferably, in steps 2 and 4, the collected data is subjected to denoising processing, which includes using a wavelet threshold denoising algorithm, with the threshold set to 0.05 times the signal standard deviation.

[0016] Preferably, the noise reduction process further includes: removing interference data during the workpiece biting and tailing stages; the interference data refers to the data occurring before and after the workpiece biting and tailing time points. Data within seconds, of which = , The distance between the nth stand rolling mill and the (n+1)th stand rolling mill is expressed in meters. This represents the mill exit speed corresponding to the nth stand, expressed in meters per second.

[0017] Preferably, the first preset threshold ( The temperature is 20℃, and the second preset threshold ( ) is 3% of the motor's rated current value ( The third preset threshold ( The fourth preset threshold is 20℃. The temperature is 20℃.

[0018] Preferably, the finishing mill is a 4-stand or 6-stand mill, and its arrangement includes: (1) Centralized layout, using a 45° top-crossing cantilever mill; (2) Separate arrangement, divided into finishing mill group 1 and finishing mill group 2 along the running direction of the rolled piece. Finishing mill group 1 consists of 2 stands or 4 stands, and finishing mill group 2 consists of 4 stands or 2 stands. When finishing mill group 1 has 2 stands and finishing mill group 2 has 4 stands, finishing mill group 1 is a flat-vertical short stress line mill, a flat-vertical cantilever mill, or a 45° top-crossing cantilever mill, and finishing mill group 2 is a 45° top-crossing cantilever mill; when finishing mill group 1 has 4 stands and finishing mill group 2 has 2 stands, the first two stands of finishing mill group 1 are flat-vertical short stress line mills, flat-vertical cantilever mills, or 45° top-crossing cantilever mills, and the last two stands of finishing mill group 1 and finishing mill group 2 are 45° top-crossing cantilever mills.

[0019] Preferably, in steps 2 and 4, the thermometer collects temperature data 10 to 100 times per second, and the motor current collects data 20 to 200 times per second.

[0020] Preferably, when the red rust area in the surface quality data is >5% and the martensite or tempered martensite content in the microstructure data is >3%, the first coupled model in step 3 outputs an adjustment command to increase the cooling intensity of the water tank before finishing milling, and controls the temperature adjustment range of the finishing mill inlet to within ≤50℃.

[0021] On the other hand, the present invention also provides a feedback-based low-alloy steel high-speed bar performance control system based on multi-parameter coupling for performing the above-described method, comprising: The rolling mill consists of a slitting unit, a pre-finishing water tank and recovery section, a pre-finishing flying shear, a finishing mill, a post-finishing water tank and recovery section, a high-speed flying shear, a tail brake, a high-speed upper steel drum, and a cooling bed, arranged sequentially along the rolling direction. At least two independent rolling branches are formed after the slitting unit. Each rolling branch is equipped with the pre-finishing water tank and recovery section, the finishing mill, and the post-finishing water tank and recovery section. The multiple temperature measuring instruments installed on each rolling branch line include at least a pre-finishing temperature measuring instrument installed before the entrance of the finishing mill, a post-finishing temperature measuring instrument installed after the exit of the finishing mill, and a rotary drum entrance temperature measuring instrument installed at the entrance of the cooling bed after the upper cooling bed. Current sensors are installed on the main motors of each stand of the finishing mill unit; Surface quality testing instrument installed at the cooling bed; Offline or online mechanical property testing instruments and microstructure testing instruments; and The central controller is connected to the thermometer, current sensor, surface quality detector, mechanical property detector and microstructure detector respectively, and is configured to perform the method described in any one of the above.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The invention achieves high consistency control of the performance and structure of dual-line products by coupling and feeding back process parameters (temperature, current) with result parameters (performance, structure) in multiple parameters, avoiding random deviations caused by taking only one result, and effectively avoiding product quality problems caused by differences between the two lines.

[0023] (2) This invention adopts an iterative feedback logic that optimizes the production of the next steel bar based on the data of the previous steel bar. This effectively overcomes the lag of single-time, single-parameter adjustment, compensates for the impact of long-term equipment drift, and ensures the long-term stability of the production process. By coupling the motor current parameter for feedback before finishing rolling, the random deviation caused by a single temperature parameter is avoided, and the number of unnecessary adjustments is reduced.

[0024] (3) This invention introduces motor current as a feedback parameter that comprehensively reflects the rolling state. Combined with wavelet threshold denoising algorithm and head and tail interference data removal technology, the control system can more accurately perceive the real working conditions of the production line and improve the intelligence of decision-making. High-frequency sampling of temperature measuring instrument and current sensor ensures the accuracy of data acquisition.

[0025] (4) This invention not only stabilizes mechanical properties, but also achieves comprehensive optimization of product appearance (adjustment triggered when red rust area > 5%) and internal quality (adjustment triggered when martensite content > 3%) by coupling surface quality and microstructure data. Through refined graded feedback control (before finishing rolling group 1, before finishing rolling group 2, and after finishing rolling), it can meet the personalized process requirements of different steel grades and specifications.

[0026] (5) Through the feedback control of this invention, the number of scrap and downgraded products caused by product performance fluctuations is reduced, and the yield is improved. At the same time, by precisely controlling the cooling parameters, the content of alloying elements can be appropriately reduced, realizing alloy reduction production and significantly reducing production costs. Industrial trials show that after adopting the method of this invention, the production cost per ton of steel is reduced, the rolling operation rate is improved, and significant economic benefits are achieved.

[0027] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 The process layout is a 4-stand centralized finishing mill; wherein, 101-slitting rolling mill, 102-finishing mill front water tank and recovery section, 103-finishing mill front flying shear, 104-4-stand finishing mill, 105-finishing mill rear water tank and recovery section, 106-high-speed flying shear, 107-tail brake, 108-high-speed upper steel drum, 109-cooling bed; Figure 2 The 6-stand finishing mill is arranged in a "2+4" separate process layout; namely, 201 - slitting rolling mill, 202 - front water tank and recovery section of finishing mill, 203 - front flying shear of finishing mill group 1, 204 - 2-stand finishing mill group 1, 205 - rear water tank and recovery section of finishing mill group 1, 206 - front flying shear of finishing mill group 2, 207 - 4-stand finishing mill group 2, 208 - rear water tank and recovery section of finishing mill group 1, 209 - high-speed flying shear, 2010 - tail brake, 2011 - high-speed upper steel drum, 2012 - cooling bed; Figure 3 The 6-stand finishing mill is arranged in a "4+2" separate process layout; namely, 301-slitting rolling mill, 302-finishing mill front water tank and recovery section, 303-finishing mill group 1 front flying shear, 304-4-stand finishing mill group 1, 305-finishing mill group 1 rear water tank and recovery section, 306-finishing mill group 2 front flying shear, 307-2-stand finishing mill group 2, 308-finishing mill group 1 rear water tank and recovery section, 309-high-speed flying shear, 3010-tail brake, 3011-high-speed upper steel drum, and 3012-cooling bed; Figure 4 This is a system architecture diagram of the present invention; Figure 5This section describes the temperature measurement, surface inspection, mechanical property, and microstructure testing units corresponding to the process layout scheme of a 4-stand centralized finishing mill. Specifically, T11 is the temperature measuring instrument in the water tank room of the pre-finishing water-cooling section; T12 is the pre-finishing temperature measuring instrument (near the finishing mill inlet); T13 is the post-finishing temperature measuring instrument; T14 is the temperature measuring instrument in the water tank room of the post-finishing water-cooling section; T15 is the post-finishing water-cooling section temperature measuring instrument (near the high-speed flying shear); T16 / T17 is the temperature measuring instrument at the inlet of the rotating hub after the upper cooling bed; I11~I14 are current sensors; S11 is a surface quality inspector; M11 is a mechanical property inspector; and P11 is a microstructure inspector. Figure 6 This section describes temperature measurement, surface inspection, mechanical property testing, and microstructure testing units for the "2+4" and "4+2" separate process layout schemes of the 6-stand finishing mill. Specifically, it includes temperature measuring instruments in the water tank room of the front water-cooling section of finishing mill group T21 / T31, the front temperature measuring instrument of finishing mill group T22 / T32 (near the entrance of finishing mill group T1), the rear temperature measuring instrument of finishing mill group T23 / T33, the water tank room of the rear water-cooling section of finishing mill group T24 / T34, and the front temperature measuring instrument of finishing mill group T25 / T35 (near the entrance of finishing mill group T2). T26 / T36 - Temperature measuring instrument after finishing mill group 2; T27 / T37 - Temperature measuring instrument in water tank room of water cooling section after finishing mill group 2; T28 / T38 - Temperature measuring instrument after water cooling section of finishing mill group 2 (near high-speed flying shear); T29 / T39 and T2010 / T3010 - Temperature measuring instrument at the inlet of the rotating hub after the upper cooling bed; I21~I26 and I31~I36 - Current sensor; S21 / S31 - Surface quality inspector; M21 / M31 - Mechanical property inspector; P21 / P31 - Microstructure inspector. Figure 7 This is a simplified flowchart of the feedback control system of the present invention. Detailed Implementation

[0029] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0031] It should be noted that in the description of this invention, the terms "first," "second," etc., are used only for descriptive purposes and to distinguish similar objects; there is no order between them, nor should they be construed as indicating or implying relative importance. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0032] Example 1 provides a feedback microstructure and performance control system based on multi-parameter coupling, which adopts a process layout scheme of a 4-stand centralized finishing mill and is used for the production of high-speed low-alloy steel bars in a dual-line process.

[0033] like Figure 1 As shown, the main equipment of the 4-stand centralized finishing mill in this embodiment, along the rolling direction, includes: (1) The splitting rolling mill 101 is used to split a single rolled piece after intermediate rolling into two independent rolled pieces, line A and line B. After splitting rolling, the diameter of the double-line rolled pieces is 18.7 mm, the rolling speed is 15.5 m / s, and the rolling temperature is 950℃~980℃.

[0034] (2) The pre-rolling water tank and recovery section 102 includes two independently controlled water tanks, which are used for pre-rolling temperature control and cooling of lines A and B, respectively. The surface temperature of the rolled piece at the outlet after cooling by the first water tank is 860℃~880℃. After cooling by the second water tank after passing through the recovery section, the surface temperature of the rolled piece at the inlet of the finishing mill is required to be controlled at 880℃~900℃.

[0035] (3) The flying shear 103 before finishing rolling is used to cut the head and tail of the cooled double-line rolled piece to ensure that the head of the rolled piece is regular and can smoothly enter the finishing mill.

[0036] (4) The 4-stand centralized finishing mill 104 adopts a 45° top-crossing cantilever mill to finish the A and B double-line rolled pieces after controlled cooling in 4 passes. The compression ratios of the 4 passes are 1.297, 1.266, 1.268 and 1.239 respectively. After 4 passes of rolling, the diameter of the finished product is 12mm and the running speed of the finished product is 40m / s.

[0037] (5) Finishing water tank and recovery section 105, including two independently controlled water tanks, which are used for temperature control and cooling of line A and line B after finishing rolling. The surface temperature of the rolled piece after cooling by the first water tank is 840℃~860℃. After cooling by the second water tank after the recovery section, the surface temperature of the rolled piece on the cooling bed is required to be controlled at 850℃~870℃.

[0038] (6) High-speed flying shear 106, tail brake 107, high-speed steel loading hub 108 and cooling bed 109 are used for multiple-length flying shear shearing, tail brake, steel loading on hub and cooling bed process of rolled workpiece after water tank controlled cooling after precision rolling.

[0039] like Figure 4 As shown, the system also includes a central controller, which comprises a data extraction unit, a data analysis unit, a calculation model unit, a result data distribution unit, and a system optimization processing unit.

[0040] To achieve multi-parameter coupled feedback, the system is equipped with the following detection elements at key locations, such as... Figure 5 (Process layout of a 4-stand centralized finishing mill) is shown below: (1) Temperature detection unit: Temperature measuring instrument T11 in the water tank room of the water cooling section before finishing mill: It is set between the water tank before finishing mill and the water tank of recovery section 102 to collect the intermediate temperature of lines A and B during the water cooling process.

[0041] T12 temperature measuring instrument before finishing mill (near the finishing mill inlet): It is set in front of the 104 inlet of the finishing mill unit and is used to collect the final temperature of lines A and B before they enter the finishing mill.

[0042] T13, a temperature measuring instrument after finishing rolling: is installed after the 104 outlet of the finishing mill and is used to collect the temperature of lines A and B immediately after finishing rolling.

[0043] Temperature measuring instrument T14 in the water tank room of the water cooling section after finishing rolling: It is set between the water tank after finishing rolling and the water tank of the recovery section 105 to collect the intermediate temperature of lines A and B during the water cooling process after rolling.

[0044] Temperature measuring instrument T15 after the water cooling section of the finishing mill (near the high-speed flying shear): It is set after the water tank and recovery section 105 after the finishing mill and before the high-speed flying shear 106, and is used to collect the temperature of the rolled piece after the final cooling is completed.

[0045] Temperature measuring instruments T16 and T17 at the inlet of the rotating drum after the cooling bed: are set at the inlet of the cooling bed 109 or the inlet of the high-speed steel rotating drum 108, respectively, to collect the final temperature of the A and B line rolled pieces before they are placed on the cooling bed.

[0046] (2) Current detection unit: Current sensors I11~I14: Installed on the main motors of each stand in the finishing mill (104 units), used to collect motor current data in real time. The sampling frequency of the current sensors is set to 20~200 times / second to ensure that dynamic changes in current during the rolling process can be captured.

[0047] (3) Surface quality inspection unit: Surface quality inspector S11: Located above or to the side of the cooling bed 109, it is used to inspect the surface color, defects, and red rust of rolled parts. Individual defects include peeling, scabs, folds, roll marks, indentations, pits, spots, and iron oxide scale; strip-shaped defects include scratches, cracks, and black lines.

[0048] (4) Offline detection unit: M11 Offline Mechanical Property Tester: Used to test the mechanical properties of rolled steel samples taken from the alignment roller table of the cooling bed. For different grades of steel bars, the test indicators include: yield strength, tensile strength, elongation after fracture (A), and total elongation at maximum force (Agt), etc.

[0049] Offline microstructure analyzer P11: Used for metallographic analysis of rolled parts sampled from the alignment roller table of the cooling bed. The analysis includes: microstructure composition data, such as the proportion of ferrite and pearlite; identification of abnormal structures, including the presence of tempered martensite, and the content of martensite.

[0050] Taking the Φ12mm HRB400E as an example, this paper demonstrates a feedback control method based on multi-parameter coupling.

[0051] Step 1: Initial rolling and data acquisition.

[0052] The slitting unit 101 slits the rolled piece into A and B double lines. According to the initial process settings, the first steel is rolled through the pre-finishing water tank and recovery section 102, the finishing mill 104, and the post-finishing water cooling and recovery section 105.

[0053] During the rolling process, the data extraction unit of the central controller collects the following data in real time: ① Temperature data before finishing rolling: Temperature values ​​of lines A and B collected by T12 , .

[0054] ② Finishing mill motor current data: Current values ​​collected from I11~I14 for each stand of lines A and B during the stable rolling stage. , , where i=1,...,4.

[0055] ③Temperature data after finishing rolling: Temperature values ​​of lines A and B collected by T13 , .

[0056] ④ Cooling bed temperature data: Temperature values ​​of lines A and B collected from T16 and T17. , .

[0057] ⑤ Surface quality data: The surface image data of lines A and B collected by S11 are analyzed to obtain the surface defect type and area, red rust area ratio, etc.

[0058] ⑥ Mechanical property data: Yield strength of the first steel samples (A and B lines) tested by M11. , Tensile strength, elongation after fracture , and maximum total elongation , .

[0059] ⑦ Microstructure data: Metallographic structure of the first steel A and B line samples detected by P11, especially the presence and content of tempered martensite.

[0060] Step 2: Data processing and eigenvalue calculation.

[0061] The data analysis unit preprocesses the collected raw data: (1) Denoising: For all time series data, wavelet threshold denoising algorithm is used to remove high-frequency noise in the signal. The threshold is set to 0.05 times the standard deviation of the signal to improve the signal-to-noise ratio of the data.

[0062] (2) Eliminate head and tail interference: accurately eliminate interference data during the biting and tailing stages of the rolled piece.

[0063] For the nth stand, the head interference data is the time before and after the workpiece bite-in point. Data within seconds, = ,in, The distance (in meters) between the nth rack and the (n+1)th rack. Let n be the exit speed of the nth rack (m / s).

[0064] Similarly, data from the tail end of the rolling process were removed. Only data from the stable rolling stage was retained for subsequent calculations.

[0065] (3) Eigenvalue calculation: Calculate the average values ​​of various parameters of lines A and B during the stable rolling stage, and then obtain the following difference values: Motor current difference ,in, This is the rated current of the motor; Temperature difference before finishing rolling ; Temperature difference after finishing rolling ; upper cooling bed temperature difference ; Difference in strength ; poor elongation ; Total elongation at maximum force 。

[0066] Qualification determination of microstructure : If martensite or tempered martensite with a content > 5% appears in the microstructure, or a closed martensite ring with ≥ 180° appears around the base circle, it is determined as unqualified. ; Otherwise, it is qualified. 。

[0067] Step 3: Feedback adjustment of cooling parameters before finish rolling.

[0068] The calculation model unit will and be compared with the preset threshold values.

[0069] In this embodiment, the preset threshold values are respectively , 。

[0070] A (no adjustment required): If and , it indicates that the process parameters of the two lines are basically the same, and no adjustment is required for the cooling before finish rolling.

[0071] B (adjustment required): If , the feedback adjustment is triggered.

[0072] The calculation model unit activates a preset first coupling model, which is a secondary coupling model constructed based on the pass rolling stock shape calculation model and the mill current calculation model. In this embodiment, the model calculates comprehensively according to the and values, and uses a preset first weight ratio. In this embodiment, the first weight ratio is 3 for temperature data weight and 7 for motor current data weight; it determines which line (usually the line with lower temperature and smaller current) needs to be adjusted and how to adjust the cooling parameters before finish rolling. The model outputs an adjustment instruction for the second strand of steel, for example: "Increase the water volume in the water tank before finish rolling of line B by 20%, and adjust the water pressure to 1.2 MPa". The water volume adjustment range is between 5% - 35%, and the water pressure is within the range of 0.3 MPa - 1.5 MPa. The result data distribution unit distributes the instruction to the basic automation PLC system to complete the parameter setting before the second strand of steel enters.

[0073] Step 4: Feedback adjustment of cooling parameters after finish rolling.

[0074] Meanwhile, the calculation model unit will 、 、 、 、 and Compare with their respective preset thresholds.

[0075] In this embodiment, the preset thresholds are respectively , , , , .

[0076] C (No adjustment needed): If and and and and and This indicates that the product parameters are qualified and consistent, and no adjustment is needed for cooling after finishing rolling.

[0077] D (Needs Adjustment): If any of the above conditions are not met, feedback adjustment will be triggered.

[0078] The computational model unit initiates a preset second coupled model, which is a two-level coupled model constructed based on the water-cooling parameter calculation model, the microstructure transformation model, and the mechanical property calculation model. In this embodiment, the model is based on... , , , and The system performs comprehensive calculations using a preset second weighting ratio. In this embodiment, the second weighting ratio is 2 for the temperature data after finishing rolling, 2 for the microstructure data, and 6 for the mechanical property data. It outputs adjustment instructions for the cooling parameters after finishing rolling of the second steel bar. For example, if the model determines that the cooling of line B needs to be strengthened due to excessive strength and temperature differences, it outputs the instruction: "Increase the water volume in the water tank after finishing rolling of line B by 15%, and adjust the water pressure to 1.0 MPa." Similarly, the adjustment range and threshold are within the preset range. The result data distribution unit sends the instructions to the PLC system for execution.

[0079] Step 5: Iterative optimization.

[0080] Following the adjustment instructions output in steps 3 and / or 4, the production of the second steel strip is executed. During the rolling process of the second steel strip, the central controller repeats steps 1-4 above, collects various data, and determines whether the parameters of the third steel strip need to be adjusted. This cycle repeats continuously, forming a dynamic, iterative closed-loop control system that constantly fine-tunes the process parameters of both lines to combat long-term production drift and ensure a high degree of consistency in the performance and structure of the products from both lines.

[0081] Figure 7This is a simplified flowchart of the feedback control system of the present invention, fully demonstrating the iterative feedback control logic based on multi-parameter coupling. As shown in the figure, after the rolled piece is cut into two lines, A and B, it sequentially undergoes the following processes: water tank cooling and recovery, pre-finishing temperature detection and processing, finishing mill rolling, water tank cooling and recovery, high-speed loading onto the cooling bed, temperature measurement on the cooling bed, surface quality inspection on the cooling bed, and product performance and microstructure inspection. After the pre-finishing temperature detection and processing, the system determines the temperature and current differences between the two lines: if the temperature difference between the two lines is ≤20℃ and the current difference between the two lines is ≤3% of the rated current value, the subsequent processes continue; otherwise, the "next piece adjustment" path is triggered, and the pre-finishing cooling parameters of the next piece of steel are adjusted through model calculation and cooling process optimization and distribution. After surface quality inspection and product performance and microstructure testing on the cooling bed, the system comprehensively judges the differences in temperature after twin-line rolling, temperature difference on the upper cooling bed, strength difference, elongation at fracture difference, and total elongation at maximum force difference. If all differences are within the threshold range, the product quality is qualified and no adjustment is required. If any one of them exceeds the threshold, the "next adjustment" path is triggered. Through model calculation and controlled cooling process optimization, the system adjusts the cooling parameters after finishing rolling of the next steel. This process is repeated to form a dynamic, iterative closed-loop control system.

[0082] In actual production, red rust on the product surface and internal martensitic structure are often correlated. Based on this, and building upon Example 1, further collaborative control of red rust and martensite is achieved. Specifically, when the surface quality inspector S11 detects that the red rust area on the rolled piece surface is >5%, and the microstructure inspector P11 detects that the martensite (including tempered martensite) content is >3%, the central controller determines that both the product surface quality and internal structure need to be optimized simultaneously. At this time, the calculation model unit generates an instruction to increase the cooling intensity of the pre-finishing water tank according to preset rules, lowering the pre-finishing inlet temperature (adjustment range ≤50℃), adjusting the water volume of the pre-finishing water tank to the range of 5%-35%, and adjusting the water pressure to the range of 0.3MPa-1.5MPa.

[0083] Different grades (such as HRB400E, HRB500E, 20CrMnTi) or different specifications (such as Φ12mm, Φ25mm, Φ40mm) of low-alloy steel bars have different requirements for rolling processes. To adapt to this diversity, based on Example 1, the central controller's preset database can store multiple sets of control parameters, which can be automatically called according to the production plan. Specifically, for large-specification bars, since their core temperature is more difficult to control, the temperature difference threshold can be appropriately relaxed; for steel grades sensitive to microstructure, the weight of microstructure data can be appropriately increased in the second coupling model; the maximum water volume adjustment range of the model output can be dynamically limited according to the characteristics of the steel grade. When the MES system issues a production plan, the central controller automatically calls the control parameter set corresponding to the steel grade and specification to achieve adaptive multi-parameter coupled feedback control.

[0084] Example 2 provides a feedback-based microstructure and performance control system based on multi-parameter coupling, employing a 6-stand "2+4" split finishing mill process layout for the production of high-speed low-alloy steel bars on a dual-line basis. Compared to the centralized layout of Example 1, this example achieves refined segmented control of the rolling process by dividing the finishing mill into finishing mill group 1 and finishing mill group 2.

[0085] like Figure 2 As shown, the main equipment of the 6-stand "2+4" split finishing mill in this embodiment, along the rolling direction, includes as follows: (1) Splitting Rolling Mill 201: Used to split a single rolled piece after intermediate rolling into two independent rolled pieces, line A and line B. After splitting rolling, the diameter of the double-line rolled pieces is 25.5 mm, the rolling speed is 9.10 m / s, and the rolling temperature is 950℃~980℃.

[0086] (2) Pre-rolling water tank and recovery section 202: includes two independently controlled water tanks, which are used for temperature control and cooling of line A and line B before finishing rolling, respectively. The process requirements are the same as in Example 1.

[0087] (3) Pre-flying shear 203 of the finishing mill group: used to cut the head and tail of the cooled double-line rolled piece.

[0088] (4) 2-stand finishing mill group 204: A flat-vertical short stress line mill, a flat-vertical cantilever mill, or a 45° top-crossing cantilever mill are used to roll the A and B double-line rolled pieces after controlled cooling in two passes. The compression ratios of the two passes are 1.257 and 1.231, respectively. After two passes, the diameter of the rolled piece is 20.5 mm, and the running speed of the rolled piece is 14.07 m / s.

[0089] (5) Water tank after finishing milling and recovery section 205: includes two independently controlled water tanks, which are used for temperature control and cooling of lines A and B after finishing milling. The process requirements are the same as in Example 1.

[0090] (6) Flying shear 206 before finishing mill group 2: used to cut the head and tail of the rolled piece after cooling after finishing mill group 1.

[0091] (7) 4-stand finishing mill group 207: A 45° top-crossing cantilever mill is used to finish the A and B double-line rolled pieces after controlled cooling in 4 passes. The compression ratios of the 4 passes are 1.343, 1.302, 1.277 and 1.273 respectively. After 4 passes, the diameter of the finished product is 12 mm and the running speed of the finished product is 40 m / s.

[0092] (8) Finishing mill set 208: includes two independently controlled water tanks, which are used for temperature control and cooling of A line and B line after finishing milling. The process requirements are the same as in Example 1.

[0093] (9) High-speed flying shear 209, tail brake 2010, high-speed steel rotating hub 2011 and cooling bed 2012: used to complete subsequent processes.

[0094] like Figure 4 and Figure 6 As shown, the detection element in this embodiment is configured as follows: (1) Temperature detection unit: Temperature measuring instrument T21 in the water tank room of the pre-cooling section of the finishing mill: It is installed between the water tank in the pre-cooling section of the finishing mill and the water tank in the recovery section 202.

[0095] Temperature measuring instrument T22 before finishing mill group 1 (near the entrance of finishing mill group 1): is set in front of the 204 entrance of finishing mill group 1.

[0096] Temperature measuring instrument T23 after finishing mill group 1: installed after the 204 outlet of finishing mill group 1.

[0097] Temperature measuring instrument T24 in the water tank room of the water cooling section after the finishing mill group: It is installed between the water tank after the finishing mill group and the water tank of the recovery section 205.

[0098] Temperature measuring instrument T25 before finishing mill group 2 (near the entrance of finishing mill group 2): is set in front of entrance 207 of finishing mill group 2.

[0099] Temperature measuring instrument T26 after finishing mill group 2: installed after outlet 207 of finishing mill group 2.

[0100] Temperature measuring instrument T27 in the water tank room of the water cooling section after the finishing mill group 2: It is installed between the water tank of the water tank after the finishing mill group 2 and the water tank of the recovery section 208.

[0101] Temperature measuring instrument T28 after the water cooling section of the finishing mill group 2 (near the high-speed flying shear): It is set after the water tank and recovery section 208 of the finishing mill group 2 and before the high-speed flying shear 209.

[0102] Temperature measuring instruments T29 and T2010 at the inlet of the cooling bed: These instruments are installed at the inlet of the cooling bed 2012 or the inlet of the high-speed steel rolling drum 2011, and are used to collect the final temperature of the rolled pieces on lines A and B before they are placed on the cooling bed.

[0103] (2) Current detection unit: Current sensors I21~I22: installed on the main motors of each stand of the finishing mill group 204.

[0104] Current sensors I23~I26: installed on the main motors of each stand 207 in the finishing mill group 2. The sampling frequency of all current sensors is set to 20~200 times / second.

[0105] (3) Surface quality testing unit and offline testing unit: surface quality tester S21, mechanical property tester M21, microstructure tester P21, the setup method is the same as in Example 1.

[0106] Its control logic correspondingly evolves into a hierarchical feedback control for the two finishing rolling stages: 1) Feedback before finishing mill group 1: Based on the temperature difference before finishing mill group 1 The current difference between the set of motors in the precision rolling mill The cooling parameters of the pre-rolling water tank and recovery section 202 are adjusted through the first coupling model.

[0107] 2) Feedback before finishing mill group 2: Based on the temperature difference after finishing mill group 1, i.e., the temperature difference before finishing mill group 2. The current difference between the two groups of motors in the finishing mill The cooling parameters of the water tank and recovery section 205 after the finishing mill are adjusted by the first coupling model or the independent third coupling model.

[0108] 3) Feedback after finishing rolling: The control process is the same as step 4 of Example 1. The cooling parameters of the water tank and recovery section 208 after finishing rolling are adjusted based on the final product parameters.

[0109] This graded control method is more refined and can precisely control the temperature in segments during the rolling process, making it especially suitable for steel grades with more stringent requirements for temperature and deformation.

[0110] Example 3 is basically the same as Example 2, except that the finishing mill is arranged in a "4+2" separate configuration, such as... Figure 3 As shown.

[0111] Its hardware configuration has been adjusted accordingly: The slitting rolling mill unit 301, the water tank and recovery section before the finishing mill 302, and the flying shear before the first set of finishing mills 303.

[0112] The 4-stand finishing mill for 304 stainless steel uses a 45° top-crossing cantilever mill to roll the A and B twin-line rolled pieces in four passes after controlled cooling. The compression ratios for the four passes are 1.257, 1.231, 1.343, and 1.302, respectively. After four passes, the diameter of the rolled piece is 15.5 mm, and the rolling speed is 24.61 m / s.

[0113] The water tank and recovery section 305 of the first finishing mill, and the front flying shear 306 of the second finishing mill.

[0114] 2-stand finishing mill, group 2, 307: A 45° top-crossing cantilever mill is used to finish the A and B double-line rolled pieces after controlled cooling in two passes. The compression ratios for the two passes are 1.277 and 1.273, respectively. After two passes, the finished product diameter is 12 mm, and the running speed is 40 m / s.

[0115] The finishing mill second group's rear water tank and recovery section 308, high-speed flying shear 309, tail brake 3010, high-speed upper steel drum 3011, and cooling bed 3012.

[0116] like Figure 4 and Figure 6 As shown, the configuration of the detection elements is similar to that of Example 2, except that the current sensors are set as follows: I31~I34 are set on each stand of 304 in the first group of finishing mill, and I35~I36 are set on each stand of 307 in the second group of finishing mill.

[0117] (1) Temperature detection unit: Temperature measuring instrument T31 in the water tank room of the pre-cooling section of the finishing mill: It is installed between the water tank in the pre-cooling section of the finishing mill and the water tank in the recovery section 302.

[0118] Temperature measuring instrument T32 before finishing mill group 1 (near the entrance of finishing mill group 1): is set in front of the 304 entrance of finishing mill group 1.

[0119] Temperature measuring instrument T33 after finishing mill group 1: installed after the 304 outlet of finishing mill group 1.

[0120] Temperature measuring instrument T34 in the water tank room of the water cooling section after the finishing mill group: It is installed between the water tank after the finishing mill group and the water tank of the recovery section 305.

[0121] Temperature measuring instrument T35 before finishing mill group 2 (near the entrance of finishing mill group 2): is installed before the 307 entrance of finishing mill group 2.

[0122] Temperature measuring instrument T36 after finishing mill group 2: installed after outlet 307 of finishing mill group 2.

[0123] Temperature measuring instrument T37 in the water tank room of the water cooling section after finishing mill group 2: It is installed between the water tank of the water tank of finishing mill group 2 and the water tank of recovery section 308.

[0124] Temperature measuring instrument T38 after the water cooling section of the finishing mill group 2 (near the high-speed flying shear): It is set after the water tank and recovery section 308 of the finishing mill group 2 and before the high-speed flying shear 309.

[0125] Temperature measuring instruments T39 and T3010 at the inlet of the rotating drum after the cooling bed: are set at the inlet of the cooling bed 3012 or the inlet of the high-speed steel rolling drum 3011, respectively, to collect the final temperature of the A and B line rolled pieces before they are placed on the cooling bed.

[0126] (2) Current detection unit: Current sensors I31~I34: installed on the main motors of each stand of the finishing mill group 304.

[0127] Current sensors I35~I36: installed on the main motors of each stand 307 in the finishing mill group 2. The sampling frequency of all current sensors is set to 20~200 times / second.

[0128] (3) Surface quality inspection unit and offline inspection unit: The surface quality tester S31, mechanical property tester M31, and microstructure tester P31 are set up in the same way as in Example 1.

[0129] The control logic of this embodiment is the same as that of Embodiment 2, and it also includes three graded control stages: pre-feedback of finishing mill group 1, pre-feedback of finishing mill group 2, and post-feedback of finishing mill.

[0130] The test results show that, using the method of Example 1, a one-month industrial-scale test was conducted on a double-high-strength bar production line in a steel plant. The test steel grade was HRB400E, with specifications ranging from Φ12mm to Φ18mm. Production data shows that the yield strength difference of the double-strength products was ≤12MPa (better than the threshold of 15MPa), the elongation difference was ≤3% (better than the threshold of 4%), the microstructure consisted entirely of ferrite and pearlite, and no martensitic closed-loop structure was found, with a pass rate of 100%. Using the method of Example 2, a one-month industrial-scale test was conducted on a double-high-strength bar production line in a steel plant. The test steel grade was HRB400E, with specifications ranging from Φ16mm to Φ25mm. Production data shows that the yield strength difference of the double-strength products was ≤10MPa (better than the threshold of 15MPa), the elongation difference was ≤3% (better than the threshold of 4%), the microstructure pass rate was ≥99.8%, and no martensitic closed-loop structure was found. Using the method described in Example 3, a one-month industrial trial was conducted on a double-strength bar production line at a steel plant. The test steel was HRB500E, with specifications ranging from Φ18mm to Φ22mm. Production data showed that the yield strength difference between the two lines was ≤14MPa (better than the threshold of 15MPa), the elongation difference was ≤3.6% (better than the threshold of 4%), the microstructure qualification rate was ≥99.8%, and no martensitic closed-loop structure was found.

[0131] In summary, this invention solves the problem of inconsistent performance and microstructure of dual-line products through multi-parameter coupling and cross-rolling iterative feedback. It can effectively control the performance differences between dual-line products, ensure qualified microstructure, reduce scrap and downgraded products, improve control accuracy and product stability, and achieve significant economic benefits.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A feedback-based method for controlling the performance of high-speed low-alloy steel bars based on multi-parameter coupling, characterized in that, Includes the following steps: S1: According to the initial process requirements, the first steel strip after being cut is subjected to pre-finishing cooling, finishing mill rolling, post-finishing cooling and cooling bed operation on both wires. S2: Collect the temperature data before finishing rolling of the first steel bar and the motor current data of each stand of the finishing mill during the rolling process, and calculate the first difference value of the temperature data before finishing rolling of the two lines. The second difference value of the motor current data () and the motor current data ); S3: When the first difference value ( ) greater than the first preset threshold ( ), or the second difference value ( ) greater than the second preset threshold ( When ), the first difference value ( ) and the second difference value ( Input a preset first coupling model, and the first coupling model outputs an adjustment command for the cooling parameters of the A line and / or B line before finishing rolling of the next steel. S4: Collect the temperature data after finishing rolling, upper cooling bed temperature data, surface quality data, mechanical property data, and microstructure data of the first steel strip after rolling and cooling, and calculate the third difference value of the temperature data after finishing rolling of the two lines. ), and the fourth difference value of the upper cooling bed temperature data ( The fifth difference value of the mechanical property data and the qualification judgment result of the microstructure data. ); S5: When the third difference value ( ) greater than the third preset threshold ( The fourth difference value ( ) greater than the fourth preset threshold ( The condition that at least one of the fifth difference value is greater than the fifth preset threshold is met, or the condition that the microscopic tissue data is qualified is determined. When the third difference value is unqualified, the third difference value ( ), fourth difference value ( The fifth difference value and microstructure data are input into the preset second coupling model, and the second coupling model outputs the adjustment command for the cooling parameters of the A line and / or B line after finishing rolling of the next steel. S6: Based on the adjustment instructions output in step 3 and / or step 5, execute the production of the next steel piece and repeat steps 2 to 6 to achieve feedback closed-loop control.

2. The method according to claim 1, characterized in that, The adjustment instructions for the cooling parameters before finishing milling in step 3 include the adjustment range of water volume and water pressure threshold of the water tank before finishing milling, wherein the water volume adjustment range is 5%-35% and the water pressure adjustment threshold is 0.3MPa-1.5MPa; the adjustment instructions for the cooling parameters after finishing milling in step 5 include the adjustment range of water volume and water pressure threshold of the water tank after finishing milling, wherein the water volume adjustment range is 5%-35% and the water pressure adjustment threshold is 0.3MPa-1.5MPa.

3. The method according to claim 1, characterized in that, The first coupling model is a two-level coupling model constructed based on the roll pass material calculation model and the mill current calculation model; the second coupling model is a two-level coupling model constructed based on the water cooling parameter calculation model, the microstructure transformation model and the mechanical property calculation model.

4. The method according to claim 1, characterized in that, In step 3, the first coupling model applies the first difference value ( ) and second difference value ( The processing of temperature data adopts a preset first weight ratio, which is 3 for temperature data and 7 for motor current data.

5. The method according to claim 1, characterized in that, In step 5, the second coupling model applies the third difference value ( ), fourth difference value ( The processing of the fifth difference value and microstructure data adopts a preset second weighting ratio, which is 2 for the temperature data after finishing rolling, 2 for the microstructure data, and 6 for the mechanical property data.

6. The method according to claim 1, characterized in that, The mechanical property data includes yield strength ( ), elongation after fracture ( ) and total elongation at maximum force ( The fifth difference value includes intensity difference (); ), Elongation difference after fracture ( ) and the difference in total elongation at maximum force ( The fifth preset threshold includes an intensity difference threshold (); =15MPa, threshold for difference in elongation after fracture ( =4% and the threshold for the difference between the total elongation rate and the maximum force ( =4%.

7. The method according to claim 1, characterized in that, The qualification judgment result of the microstructure data ( A result of ) is considered unqualified when the microstructure contains more than 5% martensite or tempered martensite, or when a closed martensite ring of ≥180° appears on the outer periphery of the base circle.

8. The method according to claim 1, characterized in that, In steps 2 and 4, the collected data is denoised. The denoising process includes using a wavelet threshold denoising algorithm, with the threshold set to 0.05 times the signal standard deviation.

9. The method according to claim 8, characterized in that, The noise reduction process further includes: removing interference data during the workpiece biting and tailing stages; the interference data refers to the data occurring before and after the workpiece biting and tailing time points. Data within seconds, of which = , The distance between the nth stand rolling mill and the (n+1)th stand rolling mill is expressed in meters. This represents the mill exit speed corresponding to the nth stand, expressed in meters per second.

10. The method according to claim 1, characterized in that, The first preset threshold ( The temperature is 20℃, and the second preset threshold ( ) is 3% of the motor's rated current value ( The third preset threshold ( The fourth preset threshold is 20℃. The temperature is 20℃.

11. The method according to claim 1, characterized in that, The finishing mill is a 4-stand or 6-stand mill, and its arrangement includes: (1) Centralized layout, using a 45° top-crossing cantilever mill; (2) Separate arrangement, divided into finishing mill group 1 and finishing mill group 2 along the running direction of the rolled piece. Finishing mill group 1 consists of 2 stands or 4 stands, and finishing mill group 2 consists of 4 stands or 2 stands. When finishing mill group 1 has 2 stands and finishing mill group 2 has 4 stands, finishing mill group 1 is a flat-vertical short stress line mill, a flat-vertical cantilever mill, or a 45° top-crossing cantilever mill, and finishing mill group 2 is a 45° top-crossing cantilever mill; when finishing mill group 1 has 4 stands and finishing mill group 2 has 2 stands, the first two stands of finishing mill group 1 are flat-vertical short stress line mills, flat-vertical cantilever mills, or 45° top-crossing cantilever mills, and the last two stands of finishing mill group 1 and finishing mill group 2 are 45° top-crossing cantilever mills.

12. The method according to claim 1, characterized in that, In steps 2 and 4, the thermometer collects temperature data 10 to 100 times per second, and the motor current collects data 20 to 200 times per second.

13. The method according to claim 1, characterized in that, When the red rust area in the surface quality data is >5% and the martensite or tempered martensite content in the microstructure data is >3%, the first coupled model in step 3 outputs an adjustment command to increase the cooling intensity of the water tank before finishing milling, and controls the temperature adjustment range of the finishing mill inlet to within ≤50℃.

14. A feedback-based dual-wire bar rolling microstructure and property control system based on multi-parameter coupling for performing the method according to any one of claims 1-13, characterized in that the system include: The rolling mill is arranged in sequence along the rolling direction as follows: a slitting mill (101, 201, 301), a pre-finishing water tank and recovery section (102, 202, 302), a pre-finishing flying shear (103, 203, 303), a finishing mill (104, 204+207, 304+307), a post-finishing water tank and recovery section (105, 205+208, 305+308), a high-speed flying shear (106, 209, 309), a tail brake (107, 2010, 3010), a high-speed upper steel drum (108, 2011, 3011), and a cooling bed (109, 2012, 3012). At least two independent rolling branches are formed after the slitting mill. Each rolling branch is equipped with the pre-finishing water tank and recovery section, the finishing mill, and the post-finishing water tank and recovery section. Multiple temperature measuring instruments installed on each rolling branch line include at least the pre-finishing temperature measuring instrument (T12, T22, T32) installed before the entrance of the finishing mill, the post-finishing temperature measuring instrument (T13, T23, T33) installed after the exit of the finishing mill, and the post-cooling drum inlet temperature measuring instrument (T16, T17, T29, T2010, T39, T3010) installed at the entrance of the cooling bed. Current sensors (I11~I14, I21~I26, I31~I36) are installed on the main motors of each stand of the finishing mill. Surface quality inspection instruments (S11, S21, S31) are installed at the cooling bed. Mechanical property testing instruments (M11, M21, M31) and microstructure testing instruments (P11, P21, P31) that can be set up offline or online. The central controller is connected to the thermometer, current sensor, surface quality detector, mechanical property detector and microstructure detector respectively, and is configured to perform the method according to any one of claims 1-13.

15. The system according to claim 14, characterized in that, The temperature measuring instrument also includes: Temperature measuring instruments (T11, T21, T31) are installed between the water tanks in the pre-finishing water cooling section and the water tanks in the recovery section (102, 202, 302) of the finishing mill. Temperature measuring instruments (T14, T24, T27, T34, T37) are installed between the water tanks in the finishing mill and the recovery section (105, 205+208, 305+308) in the water cooling section after finishing mill. Temperature measuring instruments (T15, T28, T38) are installed after the finishing mill water tank and recovery section and before the high-speed flying shear in the finishing mill water cooling section.

16. The system according to claim 14, characterized in that, When the finishing mill is arranged separately, the temperature measuring instrument also includes: Temperature measuring instruments (T23, T33) are installed after the exit of the finishing mill group (204, 304). Temperature measuring instruments (T25, T35) are installed before the entrance of the second finishing mill (207, 307). Temperature measuring instruments (T26, T36) are installed after the exit of the finishing mill group 2 (207, 307). Temperature measuring instruments (T24, T34) are installed between the water tanks of the water cooling section after the finishing mill and the water tanks of the recovery section (205, 305). Temperature measuring instruments (T27, T37) are installed between the water tanks of the water cooling section of the second finishing mill and the water tanks of the recovery section (208, 308). Temperature measuring instruments (T28, T38) are installed after the water tank and recovery section of the finishing mill group and before the high-speed flying shear in the water cooling section of the finishing mill group.

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