A dynamic optimization method for width target value and trimming amount between process steps of plate and strip products

Abstract

The present invention discloses a method for dynamically optimizing the width target value and trimming amount between process steps of plate and strip products, and belongs to the technical field of plate and strip product production. The method for dynamically optimizing the width target value between process steps of plate and strip products of the present invention is to ensure the continued production of qualified steel coils after the same edge defects appear continuously in the hot rolling process. Based on the target width value originally designed for the order, according to the defect position information generated by the hot rolling process, and taking into account the actual trimming capacity and cutting cost of each unit, etc., the optimal disposal plan is calculated to guide the design of the width target value of the hot rolling process and subsequent processes. The method of the present invention quickly realizes online decision-making based on scientific calculations, avoids the risks brought by artificial and unfounded modification of the width target value, and not only improves production efficiency but also maximizes benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of plate and strip product production, and more specifically, relates to a method for dynamically optimizing width target values and trimming amounts between process steps of plate and strip products. Background Art

[0002] Width control for strip products is a crucial parameter. Strip processing involves multiple production steps: continuous casting, hot rolling, pickling, pickling, annealing / galvanizing, and recoiling. To achieve the desired width for the final product (the final process), target values are established for each process at the outset of design. Key considerations during the design process include edge quality, edge thickness reduction, and the trimming capabilities of each mill unit.

[0003] However, in actual production, various reasons often prevent production from meeting the original target. Edge defects during the hot rolling process, in particular, necessitate a change in the hot rolling process's target values, thereby eliminating defects during subsequent processing steps and preventing the coil from being reclassified. Blind widening can lead to various problems, such as insufficient widening, resulting in defects not being removed; excessive widening, exceeding the trimming capacity of subsequent processes; and excessive post-widening cutting losses, resulting in finished coil weights not meeting customer requirements. Therefore, how to rationally allocate the trimming requirements for plate and strip products across various processes to ultimately achieve the target width for the finished product is a highly relevant research topic.

[0004] After searching, the Chinese patent application number is: 202110251900.3, the application date is: March 8, 2021, and the name of the invention is: Method for deriving the nominal width of hot-rolled steel coils taking into account both cold-rolling yield and production stability. In this application, the necking amount of different processes in the cold-rolling area is first determined according to different steel grades and specifications, thereby obtaining the total necking amount of the cold-rolling process; considering the different trimming capabilities of the trimming shears in the cold-rolling post-treatment line and the pickling line, different minimum trimming capabilities of the trimming shears are used according to the changes in the trimming position when deriving the nominal width of the hot-rolled steel coil; the nominal width of the hot-rolled steel coil taking into account the cold-rolling delivery tolerance = the nominal width of the cold-rolled steel coil + the total necking amount of the cold-rolling process + the minimum trimming capacity of the trimming shear + the cold-rolling delivery tolerance. This application provides a method for deriving the nominal width of the hot-rolled steel coil, but for products with edge defects, the nominal width of the hot-rolled steel coil cannot guarantee that the hot-rolled edge defects will be removed, resulting in the inability to fulfill the order. Summary of the Invention

[0005] 1. Problem to be solved

[0006] In order to reduce the losses caused by the regrading of the supplied strip products due to hot-rolled edge defects, and at the same time avoid a series of problems such as the inability to trim the edges in the subsequent processes caused by blindly modifying the designed width value at the production site, the present invention provides a method for dynamically optimizing the width target value and trimming amount between processes of strip products. Adopting the technical solution of the present invention can effectively solve the above problems, and the dynamic optimization method can better meet the actual production and the adjustment requirements of the width trimming amount.

[0007] 2. Technical solution

[0008] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] A method for dynamically optimizing the width target value and trimming amount between processes of strip products according to the present invention includes the following steps:

[0010] Step 1: Determine whether there are batch edge defects in the hot-rolling process. For a certain batch of m hot-rolled coils produced, when the same edge defect appears in n consecutive coils, it is determined that there are batch edge defects in the hot-rolling process, and the design needs to be optimized immediately for the unproduced hot-rolled coils;

[0011] Step 2: Determine the maximum distance Qmax between the batch edge defect and the strip edge;

[0012] Step 3: Determine whether the edge defect can be removed under the equipment limit. The maximum trimming capacity of the pickling and cold rolling unit is Amax, the maximum trimming capacity of the finished product unit is Dmax, and the maximum trimming capacity of the recoiling unit is Tmax. Therefore, if the distance Qmax between the edge defect and the strip edge satisfies the inequality 2Qmax < Amax + b + c + Dmax + Tmax, it is determined that the edge defect can be removed, and thus proceed to the next step

[0013] Step 4: Determine whether the original designed hot-rolling target width value needs to be adjusted. The initial hot-rolling width target value of the current strip is Rw, and the width target value of the finished strip order is Tw.

[0014] If the inequality Rw - Tw > 2Qmax holds, there is no need to adjust the width target values of the subsequent processes, and the initial width target values of each process set currently can be used to remove the edge defect, that is, the currently set Rwnew still takes Rw. If the inequality is not satisfied, optimize the target width values of each process.

[0015] Step 5: Optimize and adjust the hot-rolling width target value.

[0016] Considering that the edge defect can be completely removed between the subsequent processes, the new width target value of the hot-rolling process needs to be adjusted, and the new strip hot-rolling width target value Rwnew = Tw + 2Qmax is set.

[0017] Step 6: Redesign of the width target value for the pickling and cold rolling process.

[0018] In Step 5, when the newly set hot rolling width target value is Rwnew, the actual width deviation of the hot rolling process is θ. Theoretically, the maximum trimming capacity of the pickling and cold rolling process is a, and a = Rwnew - Sw - b + θ, where the actual width deviation θ of the hot rolling process generally fluctuates within the range of 0 - 20 mm. Therefore, θ is generally taken as 0 - 20 mm; b is the necking amount of the pickling and cold rolling mill.

[0019] If a < Amax, it means that under the newly set hot rolling width target value Rwnew, the trimming capacity of the pickling and cold rolling mill is sufficient, and the width target value Sw of the pickling and cold rolling process and the target value Tw of the finished product process can cut off the edge defects without optimization, that is, Swnew = Sw.

[0020] If a ≥ Amax, it means that under the newly set hot rolling width target value Rwnew, the trimming amount a has exceeded the trimming capacity limit of the pickling and cold rolling mill, then the target value Sw of the pickling and cold rolling process also needs to be optimized. That is, Swnew is designed according to the trimming capacity limit of the pickling and cold rolling mill as: Swnew = Rwnew - Amax - b + θ.

[0021] Step 7: Redesign of the width target value for the finishing mill. After the new strip pickling width target value Swnew determined in Step 6, the theoretically trimming amount of the finishing mill is d, and d = Swnew - Tw - c, where c is the necking amount of the finishing mill.

[0022] If Dmin < d < Dmax, the Tw value does not need to be adjusted to meet the strip order width target Tw.

[0023] If d < Dmin, it means that under the newly designed pickling and cold rolling width target value Swnew, the trimming amount of the finishing mill is too small to trim the edge. At this time, adjust the trimming amount of the finishing mill to Dmin, then further modify Swnew in Step 6 as Swnew = Tw + c + Dmin. In the pickling process, appropriately reduce the trimming amount to ensure that the trimming amount of the finishing mill can reach the minimum trimming capacity limit of the finishing mill, avoiding the situation that the finishing mill cannot trim the edge, and finally meet the strip order width target Tw.

[0024] If d > Dmax, it means that the trimming capacity of the finishing mill has reached the limit, then the width target value of the finishing mill needs to be adjusted. Calculated according to the maximum capacity, set the width target value of the finishing mill as Twnew = Swnew - c - Dmax.

[0025] Step 8: Trimming in the recoiling mode. This process is mainly used to trim the finished product, so that the strip product can meet the order target and fulfill the order to meet the customer's needs.

[0026] By comparing the width of the strip after the finished product process with the order width target Tw, the width target value of the strip after trimming by the finished product unit is denoted as Twnew. When Twnew = Tw, it meets the order requirements, that is, the trimming amount t of the recoiling unit, t = Twnew - Tw = 0.

[0027] After correcting the Tw value to Twnew, that is, Twnew is greater than Tw, t = Twnew - Tw > 0, judge the value of t:

[0028] When Tmin < t < Tmax, the surface trimming amount t meets the trimming capacity of the recoiling unit, then trimming can be directly arranged, and the trimming amount is t. After trimming, the width of the strip can meet the order width target value Tw.

[0029] If t < Tmin, it means that under the new designed width target Twnew of the finished product unit, the trimming amount of the recoiling unit is too small to perform trimming. At this time, it is necessary to re-adjust the trimming amount of the finished product unit. By trimming slightly less width when trimming the finished product unit, to meet the limit that the trimming amount in the recoiling unit can meet the trimming of the recoiling unit, then correct Twnew in step seven as Twnew = Tw + Tmin, and then cut the difference between the corrected Twnew and the order width target Tw in the recoiling unit, and the order width target value Tw can be met.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] (1) A method for dynamically optimizing the width target value and trimming amount between processes of a strip product of the present invention can effectively remove the edge defects of the strip in the hot rolling process. By designing and dynamically optimizing the optimal width target values of each process, it avoids the losses caused by directly changing the order or blindly cutting according to experience, and has good economic benefits. [[ID=,17]]

[0032] (2) A method for dynamically optimizing the width target value and trimming amount between processes of a strip product of the present invention considers the trimming capacity of each process unit in the design, and reasonably distributes the trimming amounts of each process. It can not only effectively remove the edge defects generated by the hot rolled sheet, but also ensure the fulfillment of the order in the later stage, and has guiding significance for removing edge defects within different ranges. During production, according to the maximum value of the edge defect distance from the strip edge measured on the previous coil on site, the method of the present invention can be used to calculate in advance to adjust the width target values of each process in the production process of the next coil, and finally fulfill the order. Specific embodiments

[0033] In the production process of existing plate and strip products, when edge defects appear in a batch of strip steel that has completed the hot rolling process, the same edge defects are likely to appear in the strip steel of the same batch that has not yet been produced. Two treatment methods are usually adopted. One is to maintain the original design and production, which makes it impossible to remove the edge defects of the output strip steel and leads to a re-judgment, and the customer's order cannot be honored. The other method is to change the width target value of the designed hot rolling process, so as to remove the edge defects in the subsequent processing process. The latter method can avoid the losses caused by the re-judgment, but how to optimize the trimming amount and width target value between the subsequent processes is a difficult problem in the industry. The dynamic optimization method provided by the present invention can solve this problem, and it is more in line with actual production and the need to adjust the width trimming amount.

[0034] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. The following embodiments are used to illustrate the present invention. The initial order design information of the embodiments is as follows:

[0035]

[0036] The design capacity of the side trimming shears for each unit in this order is as follows:

[0037]

[0038] Example 1

[0039] When an edge defect occurs during the hot rolling process, and the maximum defect distance from the edge, Qmax, is 105mm, the width reduction at the shearing equipment's limit is calculated as Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205mm. Removing the edge defect requires at least twice the defect distance, or 2 * 105 = 210mm. Because 210mm > 205mm, the defect is considered unremovable. Therefore, when Qmax = 105mm, production of the order is temporarily suspended, and the slab is returned.

[0040] Example 2

[0041] When an edge defect occurs during the hot rolling process, and the maximum defect distance from the edge, Qmax, is 15mm, the width reduction at the equipment limit is calculated as Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205mm. However, to remove the edge defect, at least twice the defect distance is required, or 2 * 15 = 30mm. Since 30mm < 205mm, the defect is considered removable. Since the initial width reduction, Rw - Tw = 50mm, and 50mm > 30mm, when Qmax = 15mm, the target width for hot rolling does not need to be adjusted, and the target widths for pickling and annealing remain unchanged.

[0042] Example 3

[0043] When edge defects occur in the hot rolling process and the maximum value Qmax of the distance between the defect and the edge is 28 mm, calculate the width reduction amount in the extreme case of the equipment Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205 mm. And if the edge defect is to be removed, at least twice the defect distance is required, that is, 2 * 28 = 56 mm. Since 56 mm < 205 mm, it is determined that the defect can be removed. Since the initial width reduction amount Rw - Tw = 50 mm and 50 mm < 56 mm, it is necessary to recalculate the hot rolling width target value Rwnew. Rwnew = Tw + 2 * Qmax = 1200 + 2 * 28 = 1256 mm. The trimming amount a of the pickling and cold rolling mill = Rwnew - Sw - b + θ = 1256 - 1225 - 5 + θ. Since θ ∈ [0, 20], amax = 46 mm. Since 46 mm < Amax = 70 mm, when Qmax = 42 mm, the hot rolling width target value Rwnew is set to 1256 mm, and the pickling and cold rolling and continuous annealing width target values remain unchanged.

[0044] Example 4

[0045] When edge defects occur in the hot rolling process and the maximum value Qmax of the distance between the defect and the edge is 42 mm, calculate the width reduction amount in the extreme case of the equipment Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205 mm. And if the edge defect is to be removed, at least twice the defect distance is required, that is, 2 * 42 = 84 mm. Since 84 mm < 205 mm, it is judged that the defect can be removed. Since the initial width reduction amount Rw - Tw = 50 mm and 50 mm < 84 mm, it is necessary to recalculate the hot rolling width target value Rwnew. Rwnew = Tw + 2 * Qmax = 1200 + 2 * 42 mm = 1284 mm. The trimming amount a of the pickling and cold rolling mill = Rwnew - Sw - b + θ = 1284 - 1225 - 5 + θ. Since θ ∈ [0, 20], amax = 99 mm. Since 99 mm > Amax = 70 mm, it exceeds the trimming capacity of the pickling and cold rolling mill. Therefore, the width target value of the pickling and cold rolling mill is reset, Swnew = Rwnew - Amax - b + 20 = 1229 mm. The trimming amount d of the continuous annealing mill = Swnew - Tw - c = 1229 - 1200 - 5 = 24 mm. Since Dmin = 12 mm < 24 mm < Dmax = 65 mm, when Qmax = 42 mm, Rwnew = 1284 mm, Swnew = 1229 mm, and the Tw value remains unchanged.

[0046] Example 5

[0047] When edge defects occur in the hot rolling process and the maximum value Qmax of the defect distance from the edge is 35 mm, calculate the width reduction amount Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205 mm in the extreme case of the equipment. And if the edge defects need to be cut off, at least twice the defect distance is required, that is, 2 * 35 = 70 mm. Since 70 mm < 205 mm, it is judged that the defect can be cut off. Because the initial width reduction amount Rw - Tw = 50 mm and 50 mm < 70 mm, it is necessary to recalculate the hot rolling width target value Rwnew. Rwnew = Tw + 2 * Qmax = 1200 + 2 * 35 = 1270 mm. The edge cutting amount a of the pickling and cold rolling mill = Rwnew - Sw - b + θ = 1270 - 1225 - 5 + θ. Since θ ∈ [0, 20], amax = 85 mm. Since 85 mm > Amax = 70 mm, it exceeds the edge cutting capacity of the pickling and cold rolling mill. Therefore, the width target value of the pickling and cold rolling mill is reset, Swnew = Rwnew - Amax - b + 20 = 1215 mm. The edge cutting amount d of the continuous annealing mill = Swnew - Tw - c = 1215 - 1200 - 5 = 10 mm. Since 10 mm < Dmin = 12 mm, the continuous annealing mill cannot cut the edge. Redesign the width target value of the pickling and cold rolling mill Swnew = Tw + c + Dmin = 1200 + 5 + 12 = 1217 mm. Therefore, when Qmax = 35 mm, Rwnew = 1270 mm, Swnew = 1217 mm, and the Tw value remains unchanged.

[0048] Example 6

[0049] When edge defects occur in the hot rolling process and the maximum value Qmax of the defect distance from the edge is 75 m, calculate the width reduction amount Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205 mm in the case of equipment limit. And if the edge defects need to be removed, at least twice the defect distance is required, that is, 2 * 75 = 150 mm. Since 150 mm < 205 mm, it is judged that the defect can be removed. Because the initial width reduction amount Rw - Tw = 50 mm and 50 mm < 150 mm, it is necessary to recalculate the hot rolling width target value Rwnew. Rwnew = Tw + 2 * Qmax = 1200 + 2 * 75 = 1350 mm. The trimming amount a of the pickling and cold rolling mill = Rwnew - Sw - b + θ = 1350 - 1225 - 5 + θ. Since θ ∈ [0, 20], amax = 140 mm. Since 140 mm > Amax = 70 mm, it exceeds the trimming capacity of the pickling and cold rolling mill. Therefore, the pickling and cold rolling width target value is reset, Swnew = Rwnew - Amax - b + 20 = 1295 mm. The trimming amount d of the continuous annealing mill = Swnew - Tw - c = 1295 - 1200 - 5 = 90 mm. Since 90 mm > Dmax = 65 mm, the continuous annealing mill cannot trim. Redesign the Twnew of the continuous annealing mill = Swnew - c - Dmax = 1295 - 5 - 65 = 1225 mm. The trimming amount t of the recoiling mill = 1225 - 1200 = 25 mm. Since Tmin = 12 mm < 25 mm < Tmax = 60 mm, it meets the trimming design capacity of the recoiling mill. Therefore, when Qmax = 75 mm, Rwnew = 1350 mm, Swnew = 1295 mm, Twnew = 1225 mm, and t = 25 mm.

[0050] Example 7

[0051] When edge defects occur in the hot rolling process and the maximum value Qmax of the defect distance from the edge is 65 m, calculate the width reduction amount Amax + b + c + Dmax + Tmax = 70 + 5 + 5 + 65 + 60 = 205 mm in the case of the equipment limit. And if the edge defects need to be removed, at least twice the defect distance is required, that is, 2 * 65 = 130 mm. Since 130 mm < 205 mm, it is judged that the defect can be removed. Because the initial width reduction amount Rw - Tw = 50 mm and 50 mm < 130 mm, the hot rolling width target value Rwnew needs to be recalculated. Rwnew = Tw + 2 * Qmax = 1200 + 2 * 65 = 1330 mm. The edge trimming amount a of the pickling and rolling mill = Rwnew - Sw - b + θ = 1330 - 1225 - 5 + θ. Since θ ∈ [0, 20], amax = 120 mm. Since 120 mm > Amax = 70 mm, it exceeds the edge trimming capacity of the pickling and rolling mill. Therefore, the pickling and rolling width target value is reset, Swnew = Rwnew - Amax - b + 20 = 1275 mm. The edge trimming amount d of the continuous annealing unit = Swnew - Tw - c = 1275 - 1200 - 5 = 75 mm. Since 75 mm > Dmax = 65 mm, the continuous annealing unit cannot trim the edge. Redesign the continuous annealing unit Twnew = Swnew - c - Dmax = 1275 - 5 - 65 = 1205 mm. The edge trimming amount t of the recoiling mill = 1205 - 1200 = 5 mm. Since 5 mm < Tmin = 12 mm, the recoiling mill cannot trim the edge. Redesign the target width Twnew of the continuous annealing unit = Twaim + Tmin = 1200 + 12 = 1212 mm. Therefore, when Qmax = 65 mm, Rwnew = 1330 mm, Swnew = 1275 mm, Twnew = 1212 mm, and t = 12 mm.

[0052] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product, characterized by: The method includes the following steps: Step 1: When there are batch edge defects in the strip after the hot rolling process, measure the maximum distance Qmax from the edge defects of the strip to the strip edge; Step 2: When the edge defects of the strip can be cut off by the pickling and cold rolling mill, the finishing mill and the recoiling mill, then proceed to the next step to optimize the width target values of each process; otherwise, this order is not produced; Step 3: According to Qmax and the strip order width target value Tw, determine the strip hot rolling width target value Rwnew, where Rwnew = Rw or Rwnew = Tw + 2Qmax, and Rw is the initial strip hot rolling width target value; Step 4: According to the adjusted hot rolling width target value Rwnew and the trimming capacity of the pickling and cold rolling mill, determine the strip pickling and cold rolling width target value Swnew, where Swnew = Sw or Swnew = Rwnew - Amax - b, and Sw is the initial strip pickling and cold rolling width target value, Amax is the maximum trimming capacity of the pickling and cold rolling mill, and b is the necking amount of the pickling and cold rolling mill; Step 5: Adopt the newly determined pickling and cold rolling width target value Swnew in Step 4, and then combine with the trimming amount of the strip in the finishing mill and the minimum trimming capacity of the finishing mill itself to correct the pickling and cold rolling width target value Swnew, where Swnew = Tw + c + Dmin; Dmin is the minimum trimming capacity of the finishing mill, and c is the necking amount of the finishing mill; Step 6: According to the maximum trimming capacity of the finishing mill itself, correct the strip order width target value Tw to Twnew, where Twnew = Swnew - c - Dmax; Dmax is the maximum trimming capacity of the finishing mill; Step 7: Process the strip in the recoiling mill so that the finally obtained strip width hits Tw, and complete the order fulfillment.

2. A dynamic optimization method for the width target value and trimming amount between processes of a strip product according to claim 1, characterized in that in Step 2, the method for judging whether the edge defects of the strip can be cut off is as follows: When Qmax satisfies the formula 2Qmax < Amax + b + c + Dmax + Tmax, it is determined that the edge defect can be removed; otherwise, it cannot be removed. Among them, Amax is the maximum trimming capacity of the pickling and cold rolling mill, Dmax is the maximum trimming capacity of the finishing mill, Tmax represents the maximum trimming capacity of the recoiling mill, b represents the necking amount of the pickling and cold rolling mill, and c represents the necking amount of the finishing mill.

3. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product according to claim 1, characterized in that: In Step 3, when Qmax satisfies the formula Rw - Tw > 2Qmax, determine Rwnew = Rw; otherwise, determine Rwnew = Tw + 2Qmax.

4. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product according to claim 1, characterized in that: In Step 4, according to the strip hot rolling width target value Rwnew determined in Step 3, judge that the trimming amount a of the strip in the pickling and cold rolling mill is a = Rwnew - Sw - b. When a < Amax, determine Swnew = Sw; when a ≥ Amax, determine Swnew = Rwnew - Amax - b.

5. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product according to claim 4, characterized in that: Considering the actual width deviation amount θ of the strip during the hot rolling process, let this deviation amount be θ, and the trimming amount a of the strip in the pickling and cold rolling mill is a = Rwnew - Sw - b + θ; when a ≥ Amax, Swnew = Rwnew - Amax - b + θ.

6. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product according to claim 5, characterized in that: The value range of θ is 0 - 20 mm.

7. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product according to any one of claims 1 to 6, characterized in that: The method for correcting the width target value of the pickling and cold rolling mill and the width target value of the finishing mill is: Based on the newly determined Swnew in Step 4, the trimming amount d of the finished unit can be obtained, where d = Swnew - Tw - c; When the trimming amount d of the finished unit satisfies the formula Dmin ≤ d ≤ Dmax, Swnew = Rwnew - Amax - b, and Twnew = Tw; When the trimming amount d of the finished unit satisfies the formula d < Dmin, determine Swnew = Tw + c + Dmin, and Twnew = Tw; When the trimming amount d of the finished unit satisfies the formula d > Dmax, determine Swnew = Swnew, and Twnew = Swnew - c - Dmax; Among them, Dmin is the minimum trimming capacity of the finished unit, c is the necking amount of the finished unit, and Twnew is the new width target value of the finished unit.

8. A method for dynamically optimizing width target values and trimming amounts between process steps of a plate and strip product according to claim 7, characterized in that: The method for the recoiling unit to process the strip is as follows: When the strip is processed by the recoiling unit, the trimming amount t of the strip is t = Twnew - Tw. When t = 0, the recoiling unit does not need to trim the strip; When t > 0, when Tmin < t < Tmax, directly cut it off, and the trimming amount is t; when t < Tmin, it is necessary to correct Twnew = Tw + Tmin. When controlling the finished unit to cut, the width of the strip after cutting is Twnew, and then cut off the width part greater than the strip order width target value Tw in the recoiling unit to fulfill the order.

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