A method for improving rolling kilometers based on multi-parameter cooperative control

Abstract

The application discloses a kind of based on multi-parameter collaborative control method for improving rolling mileage, comprising the following steps: 1) preparation before production;Obtain the information to be generated order, prepare production plan;2) slab heating and temperature control optimization of conveying;3) optimization control in finishing process;Including finishing load distribution optimization;Rolling rhythm adaptive control;Finish before section roll surface temperature closed-loop regulation;4) on-line monitoring and early warning.The method of the application can effectively reduce roll wear and oxide film shedding, prolong the service life of the roll, thereby significantly improving the rolling mileage through finishing load distribution optimization, rolling rhythm adaptive control and whole-process temperature field collaborative control.

Description

Technical Field

[0001] This invention relates to hot rolling production technology, and more particularly to a method for increasing rolling mileage based on multi-parameter collaborative control. Background Technology

[0002] In the steel rolling industry, rolling mileage is a crucial indicator for measuring mill production efficiency and roll life. With the continuous growth in demand for steel products, increasing rolling mileage, reducing roll replacement frequency, and lowering production costs have become goals pursued by steel companies. However, in actual production, roll wear and oxide film peeling have consistently been key factors restricting the improvement of rolling mileage. Finishing mill work rolls operate under harsh conditions of high temperature, high speed, large reduction, and rapid heating and cooling, causing the oxide film on the roll surface to periodically endure enormous alternating stress. When the oxide film on the work roll surface reaches its fatigue limit, under the shear stress between the work roll and the strip during rolling, the oxide film is prone to peeling off. This not only accelerates roll wear but also affects the surface quality of the rolled product. Furthermore, unreasonable distribution of rolling load and improper control of rolling temperature can also exacerbate roll wear and oxide film peeling.

[0003] To improve rolling mileage, traditional methods mainly focus on single technologies such as online grinding roll technology, oxide film peeling control, process lubrication, and free rolling. These methods are insufficient to fundamentally solve the problem of increasing rolling mileage. A more comprehensive and systematic solution needs to be developed to address this issue at its root. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for increasing rolling mileage based on multi-parameter collaborative control, which addresses the deficiencies in the prior art.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for increasing rolling mileage based on multi-parameter collaborative control, comprising the following steps: 1) Preparations before production; Obtain information on orders to be generated, and formulate a production plan based on steel type, specifications, roll usage status, and process constraints; 2) Optimization of slab heating and conveying temperature control; 2.1) Set the target tapping temperature T of the heating furnace according to the thickness and strength grade of the strip to be rolled. out ; 2.2) Slab heating in the furnace; The slab is fed into the heating furnace and discharged at the preset furnace temperature T. out Closed-loop temperature control, real-time adjustment of heating power to ensure uniform temperature of the slab; 2.3) Out-of-furnace conveying and intermediate billet temperature control; After the slab exits the furnace, it enters the conveyor roller table. The conveying time Δt, heating power P, and rolling speed v are collected in real time. The intermediate slab temperature is calculated and dynamically verified. The intermediate slab temperature T is then... slab Stable control within the set range; 3) Optimization and control of the finishing rolling process; 3.1) Finishing mill load distribution optimization: In the finishing mill stage, a dynamic load distribution strategy of front heavy and rear light is adopted to move the rolling load forward, increase the reduction rate of the front stand and reduce the load of the rear stand; 3.2) Adaptive control of rolling rhythm Adaptive rolling rhythm control: Differentiated rolling rhythms are set according to the rolling mill status and product type to stabilize and protect the oxide film on the rolling mill surface; 3.3) Closed-loop regulation of surface temperature of rolls in the finishing mill front section Real-time monitoring of the temperature distribution of strip steel and roll width in F1 and F2 stands, dynamic adjustment of cooling water flow rate and spray position to maintain uniform roll surface temperature and keep the roll in the ideal working temperature window; 4) Online monitoring, early warning, and dynamic optimization; This includes monitoring and maintaining equipment status to avoid unplanned downtime; and fine-tuning rolling rhythm and heating power parameters based on feedback from equipment parameter fluctuations.

[0006] According to the above scheme, in step 2.1), the intermediate billet temperature T slab The calculation is as follows: T slab =T out -ɑ*Δt+β*P / v-γ*v, Where α is the temperature coefficient of radiation and convection heat loss, β is the power-velocity influence coefficient, and γ is the velocity-related temperature drop coefficient.

[0007] According to the above scheme, in step 3.1), for finishing mills F1 to Fn; For the front core stands: F1 and F2; reconfigure the load ratio, with the F1 stand significantly increasing the relative reduction rate to bear the main rolling deformation; the F2 stand moderately reduces the reduction rate to buffer the rolling impact brought by the heavy load at the front and ensure the stability of the first rolling pass. For the middle transition rack: F3 to F(n-1): the adaptation adjustments are as follows: Starting from F(n-1), select intervals, with F(n-1), F(n-3), ... as the stabilizing racks, and keep the original reduction rate parameters unchanged for the stabilizing racks; Using F(n-2), F(n-4), ... as transition frames, the reduction rate of the transition frames is lowered to reduce the load on the transition frames; For the tail-end finished product frame: Fn; slightly adjust the reduction rate to compensate for the overall deformation matching degree and ensure that the thickness accuracy and shape quality of the finished strip remain unchanged.

[0008] According to the above scheme, in step 3.1), for the front core rack: the relative reduction rate of rack F1 is increased by 5.5% to 7.0%; the reduction rate of rack F2 is reduced by 1.5% to 3.0%; the remaining reduction rate of the middle transition rack is reduced by 1.0% to 4.0%; and the reduction rate of the tail finished rack is adjusted from 0 to 1.0%.

[0009] According to the above plan, step 3.2) is as follows: 3.2.1) Collect rolling process data, including the roll number n, strip thickness H, and steel type; 3.2.2) Based on the collected rolling process data, the rolling process is divided into three segments: new roll preheating segment, pickling thin specification segment, and normal rolling segment; When n≤10, it is determined to be the new roller preheating section; When H≤2.5mm, it is determined to be a thin pickling section; When n > 10 and H > 2.5 mm, it is determined to be a normal rolling section; 3.2.3) Determine the lower limit of the corresponding rolling rhythm threshold based on the rolling process segmentation and different steel grades.

[0010] According to the above scheme, in step 3.2.3), the lower limit value that the rolling rhythm t must satisfy is defined by the following piecewise function: .

[0011] According to the above scheme, in step 3.3), if the temperature distribution of the strip and rolls in the width direction deviates from the ideal working temperature window beyond the set threshold range, the production rhythm will be adjusted as follows: If the temperature is higher than the maximum value of the ideal working temperature window, reduce the rolling speed.

[0012] According to the above plan, step 4) is as follows: 4.1) Equipment condition monitoring and maintenance; The sensor network continuously collects pressure, temperature, and vibration data from key equipment such as cooling water and descaling systems, and combines equipment digital twins with AI models to predict faults; when potential faults are detected, planned maintenance prompts are triggered in advance to avoid unplanned downtime. 4.2) Dynamic fine-tuning of parameters By combining feedback from temperature, roll condition, and equipment operation, the rolling rhythm and heating power parameters are finely adjusted based on feedback from equipment parameter fluctuations.

[0013] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described scheme.

[0014] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method in the above-described scheme.

[0015] The beneficial effects of this invention are: This invention effectively reduces roll wear and oxide film detachment and extends roll service life by optimizing finishing mill load distribution, adaptive control of rolling rhythm, and coordinated control of the temperature field throughout the entire process. It also features differentiated load distribution with heavier loads at the beginning and lighter loads at the end, rolling rhythm constraints, and full-range roll temperature regulation. This significantly increases the rolling mileage. At the same time, it ensures that the temperatures of slabs, intermediate slabs, and rolls remain within a stable process window for a long period, resulting in smaller fluctuations in rolling force on each stand, which is beneficial to improving the qualification rate of finished steel products. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a flowchart of a method according to an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] like Figure 1 As shown, a method for increasing rolling mileage based on multi-parameter collaborative control includes the following steps: 1) Preparations before production; Obtain information on orders to be generated, and formulate a production plan based on steel type, specifications, roll usage status, and process constraints; 2) Slab heating and conveying 2.1) Based on the thickness and strength grade of the strip to be rolled, the target tapping temperature T of the heating furnace is calculated and set using the temperature calculation formula. out ; T out =T base -k H *(HH) ref )+k S *(σ) S -σ ref ); Wherein: T base H is the reference furnace outlet temperature. ref For reference thickness, σ ref For reference strength, k H k is the thickness compensation coefficient. S This is the strength compensation coefficient; And T outThe value range is 1040℃~1100℃. When the calculated value exceeds the range, the endpoint value is used, but an alarm is triggered. If the calculated value is lower than the lower limit of 1040℃, the compensation coefficient is recalibrated, and a heat equalization strategy can be added if necessary. If the calculated value is higher than the upper limit of 1100℃, the production plan is rolled back, adjusted, and then re-executed. 2.2) Heating the slab in the furnace The slab is fed into the heating furnace and discharged at the preset furnace temperature T. out Closed-loop temperature control, real-time adjustment of heating power to ensure uniform temperature of the slab; 2.3) Out-of-furnace conveying and intermediate billet temperature control; After the slab exits the furnace, it enters the conveyor roller table. The conveying time Δt, heating power P, and rolling speed v are collected in real time. The intermediate slab temperature is calculated and dynamically verified. The intermediate slab temperature T is then... slab Stably controlled within the range of 880℃~920℃; T slab =T out -ɑ*Δt+β*P / v-γ*v, Where α is the temperature coefficient of radiation and convection heat loss (range 0.45~0.58℃ / s), β is the power-velocity influence coefficient (range 0.018~0.022℃*s / kW / m), and γ is the velocity-related temperature drop coefficient (range 9.5~10.5℃*s / m). 3) Optimization and control of the finishing rolling process; 3.1) Finishing mill load distribution optimization: In the finishing mill stage, a dynamic load distribution strategy of front heavy and rear light is adopted to move the rolling load forward, increase the reduction rate of the front stand and reduce the load of the rear stand; For finishing mills F1 to Fn; For the front core stands (F1, F2): the load ratio is reconfigured. The F1 stand significantly increases the relative reduction rate to bear the main rolling deformation. The F2 stand moderately reduces the reduction rate to buffer the rolling impact brought by the heavy load at the front and ensure the stability of the first rolling pass. Middle transition stands (F3 to F(n-1)): Differentiated adaptation and adjustment to reduce the load on non-core transition stands F3 and F5, while core stable stands F4 and F6 maintain the original reduction rate parameters, taking into account both rolling accuracy and load balance. Tail-end finished product frame (Fn): Slightly adjust the reduction rate to compensate for the overall deformation matching degree and ensure that the thickness accuracy and shape quality of the finished strip remain unchanged; In this embodiment, a seven-stand finishing mill is used. Precise process parameters are defined for the seven-stand finishing mill: F1=55%, F2≤48%, F3 / F5 decrease, F4 / F6 remain unchanged, and F7 slightly increase. This is combined with adjustments to the intermediate slab thickness to form a complete process. Specific details are as follows: F1 frame (the first main frame to be modified) Compared to the original process baseline reduction rate, the relative reduction rate is significantly increased. As the main deformation bearing stand of the entire unit, it concentrates on bearing most of the thickness reduction, realizing the forward shift of rolling load and reducing the rolling load and roll wear of the middle and rear stands from the source.

[0019] F2 rack (front stabilizing buffer rack) Compared to the original process baseline reduction rate, the relative reduction rate is reduced and an upper limit threshold is set to avoid excessive overall rolling stress after F1 heavy load, balance the rolling stability of the front part, and prevent stress concentration on the roll surface from damaging the oxide film.

[0020] F3 and F5 racks (central load-reducing racks) Compared to the original conventional process parameters of the production line, the overall relative reduction rate is lowered, continuously reducing the continuous stress and wear rate of the middle stand rolls, and the core achievement is to extend the life of the middle and rear rolls.

[0021] F4 and F6 racks (middle precision assurance racks) The relative reduction rate remains unchanged from the original process parameters, and the original mature rolling precision control parameters are retained to ensure that the dimensional accuracy and shape stability of the strip are not affected by load adjustments, thus avoiding the risk of quality fluctuations caused by process changes.

[0022] F7 rack (finished precision rack) Compared to the original process baseline reduction rate, the relative reduction rate is slightly increased, the deformation of the finished product pass is finely adjusted, and the overall rolling deformation deviation caused by the adjustment of the front load is compensated to ensure that the thickness and surface quality of the finished product meet the standards.

[0023] In actual control, for the front core rack: the relative reduction rate of rack F1 is increased by 5.5% to 7.0%; the reduction rate of rack F2 is reduced by 1.5% to 3.0%; the remaining reduction rate of the middle transition rack is reduced by 1.0% to 4.0%; and the reduction rate of the tail finished rack is adjusted from 0 to 1.0%.

[0024] The final optimized rolling load distribution results are shown in Table 1; Table 1 Optimization of Rolling Load Distribution

[0025] When optimizing the load distribution in finishing mills, it is necessary to ensure that the final thickness remains unchanged; Relative reduction ratio r i The percentage reduction in thickness for each rack is defined as follows: Where: i = 1, 2, ..., 7; represents the finishing mill stand number (F1 to F7); h i-1 h is the entrance thickness (mm) of the i-th rack. iThe thickness is the exit thickness (mm). For the finishing rolling stage, h0 is the intermediate billet thickness, which is 36 mm in the original process and 35 mm in the new process; h7 is the final thickness, which is constant at the target value of 2.0 mm.

[0026] The exit thickness of each rack is determined by the reduction ratio: h i = h i-1 *(1-r i To maintain the final thickness, the reduction rate must meet the following requirements: Optimize r i This constraint must hold in the given time.

[0027] 3.2) Adaptive control of rolling rhythm Adaptive rolling rhythm control: Differentiated rolling rhythms are set based on the roll's on-machine status and product type to stabilize and protect the oxide film on the roll surface; details are as follows: 3.2.1) Collect rolling process data, including the roll number n, strip thickness H, and steel type; 3.2.2) Based on the collected rolling process data, the rolling process is divided into three segments: new roll preheating segment, pickling thin specification segment, and normal rolling segment; When n≤10, it is determined to be the new roller preheating section; When H≤2.5mm, it is determined to be a thin pickling section; When n > 10 and H > 2.5 mm, it is determined to be a normal rolling section; 3.2.3) Determine the lower limit of the corresponding rolling rhythm threshold based on the segmentation of the rolling process and different steel grades; The lower limit that the rolling rhythm t must satisfy is defined by a piecewise function: ; 3.3) Closed-loop regulation of surface temperature of rolls in the finishing mill front section Real-time monitoring of the temperature distribution of strip steel and roll width in F1 and F2 stands, dynamic adjustment of cooling water flow rate and spray position to maintain uniform roll surface temperature and keep the roll in the ideal working temperature window; 4) Online monitoring, early warning, and dynamic optimization; 4.1) Equipment condition monitoring and maintenance; The sensor network continuously collects pressure, temperature, and vibration data from key equipment such as cooling water and descaling systems, and combines equipment digital twins with AI models to predict faults; when potential faults are detected, planned maintenance prompts are triggered in advance to avoid unplanned downtime. 4.2) Dynamic fine-tuning of parameters By combining feedback from temperature, roll condition, and equipment operation, the rolling rhythm and heating power parameters are finely adjusted based on feedback from equipment parameter fluctuations.

[0028] Example: Fluctuating descaling effect: Pressure is sufficient but descaling is incomplete (nozzle blockage / angle drift); Monitoring / Evidence: Descaling pressure is not bad, but the surface temperature field is uneven, the amount of scale residue is increased, the torque / current noise of the subsequent rack increases, and occasional "slippage / biting vibration" occurs. Fine-tuning method 1) Pace: Slightly reduce the bite and impact; Reduce the acceleration slope from the descaling box to R1 / R2 slightly, or lower the upper limit of the bite speed of the steel block by one gear.

[0029] 2) Heating side: The logic leans towards "getting closer to the upper limit but not exceeding it"; When the scale removal is poor, a feasible compensation is to make the billet surface "softer" to reduce the bite shear peak: the furnace exit target of the steel can be slightly raised by +5 to 10°C within the allowable window, and sufficient heat homogenization should be prioritized over "fast exit"; at the same time, the descaling system maintenance prompt should be triggered.

[0030] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for increasing rolling mileage based on multi-parameter collaborative control, characterized in that, Includes the following steps: 1) Preparations before production; Obtain information on orders to be generated and create a production plan; 2) Optimization of slab heating and conveying temperature control; 2.1) Set the target tapping temperature T of the heating furnace according to the thickness and strength grade of the strip to be rolled. out ; 2.2) Slab heating in the furnace; The slab is fed into the heating furnace and discharged at the preset furnace temperature T. out Closed-loop temperature control, real-time adjustment of heating power to ensure uniform temperature of the slab; 2.3) Out-of-furnace conveying and intermediate billet temperature control; After the slab exits the furnace, it enters the conveyor roller conveyor. The conveying time Δt, heating power P, and rolling speed v are collected in real time. The intermediate slab temperature is calculated and dynamically verified. The intermediate slab temperature T is then... slab Stable control within the set range; 3) Optimization and control of the finishing rolling process; 3.1) Finishing mill load distribution optimization: In the finishing mill stage, a dynamic load distribution strategy of front heavy and rear light is adopted to move the rolling load forward, increase the reduction rate of the front stand and reduce the load of the rear stand; 3.2) Adaptive control of rolling rhythm; Adaptive rolling rhythm control: Differentiated rolling rhythms are set according to the rolling mill status and product type to stabilize and protect the oxide film on the rolling mill surface; 3.3) Closed-loop regulation of the surface temperature of the rolls in the finishing mill front section; Real-time monitoring of the temperature distribution of strip steel and roll width in F1 and F2 stands, dynamic adjustment of cooling water flow rate and spray position to maintain uniform roll surface temperature and keep the roll in the ideal working temperature window; 4) Online monitoring and early warning; This includes monitoring and maintaining equipment status to avoid unplanned downtime.

2. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 1, characterized in that, In step 2.1), the intermediate billet temperature T slab The calculation is as follows: T slab =T out -ɑ*Δt+β*P / v-γ*v, Where α is the temperature coefficient of radiation and convection heat loss, β is the power-velocity influence coefficient, and γ is the velocity-related temperature drop coefficient.

3. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 1, characterized in that, In step 3.1), for finishing mills F1 to Fn; For the front core stands: F1 and F2; reconfigure the load ratio, increase the relative reduction rate of the F1 stand to bear the main rolling deformation; reduce the reduction rate of the F2 stand to buffer the rolling impact brought by the heavy load at the front and ensure the stability of the first rolling pass; For the middle transition rack: F3 to F(n-1): the adaptation adjustments are as follows: Starting from F(n-1), select intervals with F(n-1), F(n-3), ... as the stabilizing racks, and keep the original reduction ratio parameters unchanged for the stabilizing racks; Using F(n-2), F(n-4), ... as transition frames, reduce the transition frame reduction rate and decrease the load on the transition frames; For the tail-end finished product frame: Fn; slightly adjust the reduction rate to compensate for the overall deformation matching degree and ensure that the thickness accuracy and shape quality of the finished strip remain unchanged.

4. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 3, characterized in that, In step 3.1), for the front core rack: the relative reduction rate of rack F1 is increased by 5.5% to 7.0%; the reduction rate of rack F2 is reduced by 1.5% to 3.0%; the remaining reduction rate of the middle transition rack is reduced by 1.0% to 4.0%; and the reduction rate of the tail finished rack is adjusted from 0 to 1.0%.

5. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 1, characterized in that, Step 3.2) is as follows: 3.2.1) Collect rolling process data, including the roll number n, strip thickness H, and steel type; 3.2.2) Based on the collected rolling process data, the rolling process is divided into three segments: new roll preheating segment, pickling thin specification segment, and normal rolling segment; When n≤10, it is determined to be the new roller preheating section; When H≤2.5mm, it is determined to be a thin pickling section; When n > 10 and H > 2.5 mm, it is determined to be a normal rolling section; 3.2.3) Determine the lower limit of the corresponding rolling rhythm threshold based on the rolling process segmentation and different steel grades.

6. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 5, characterized in that, In step 3.2.3), the lower limit value that the rolling rhythm t must satisfy is defined by the following piecewise function: 。 7. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 1, characterized in that, In step 3.3), if the temperature distribution of the strip and rolls in the width direction deviates from the ideal operating temperature window beyond the set threshold range, the production rhythm will be adjusted as follows: If the temperature is higher than the maximum value of the ideal working temperature window, reduce the rolling speed.

8. The method for increasing rolling mileage based on multi-parameter collaborative control according to claim 1, characterized in that, Step 4) is as follows: 4.1) Equipment condition monitoring and maintenance; The sensor network continuously collects pressure, temperature, and vibration data of cooling water and key descaling equipment, and combines equipment digital twins and AI models to predict faults; when potential faults are detected, planned maintenance prompts are triggered in advance to avoid unplanned downtime. 4.2) Dynamic fine-tuning of parameters By combining feedback from temperature, roll condition, and equipment operation, the rolling rhythm and heating power parameters are finely adjusted based on feedback from equipment parameter fluctuations.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1 to 8.

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