Method for improving section contour of cold-rolled raw material

Abstract

The invention provides a method for improving the section profile of a cold rolling raw material, which comprises the optimization of a convexity target value of a finishing mill group, a CVC roll shifting amount and a rack roll bending force parameter, and specifically comprises the following steps: if a wave shape and / or a high point appears in the middle of strip steel, reducing the convexity target value; if the edge of the strip steel is warped and / or warped in a cat ear shape, the convexity target value is increased; if waves and / or high points appear in the middle of the strip steel, the CVC roll shifting amount is reduced; if the edge of the strip steel is warped and / or warped in a cat ear shape, the CVC roll shifting amount is increased; after the strip shape is straightened, the roll bending force of a floating rack in the finishing mill group is adjusted, and if a wave shape and / or a high point appears in the middle of the strip steel, the roll bending force is reduced; if the edge of the strip steel is warped and / or warped in a cat ear shape, the roll bending force is improved; and the roll gap deviation or the roll bending force of the midstream frame is adjusted according to the actual strip shape of the strip steel. Adjustment of the plate shape and the section wheel is considered, and control over the effective section contour of the strip steel is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of hot-rolled strip technology, and more particularly to a method for improving the cross-sectional profile of cold-rolled raw materials. Background Technology

[0002] Hot-rolled strip profile control is a core technology for ensuring strip product quality. Without considering equipment factors, it involves the coordinated changes of multiple parameters such as crown, edge drop, and wedge shape. Currently, stable control of the hot-rolled strip profile is achieved through reasonable production planning, high-precision model prediction, and advanced shape control technologies such as CVC and PC. A good strip profile not only yields excellent physical strip shape but also facilitates downstream processing, ensuring the quality of the final product. However, due to the complex causes of poor strip profiles, relying solely on model adaptive adjustment is insufficient for rapid improvement. Manual intervention during the rolling process is necessary for rapid adjustment of the product's strip profile. Simultaneously, the results of manual intervention can be fed back into the model control system to assist in self-learning, thereby gradually improving the strip profile.

[0003] With industrial development, users have increasingly higher requirements for the quality of hot-rolled products. A good cross-sectional profile enables the production of high-quality products, meeting the diverse needs of different users in the automotive, construction, and machinery manufacturing industries, and enhancing the market competitiveness of products. Precise cross-sectional profile control ensures that the thickness, width, crown, and other indicators of hot-rolled products meet standard requirements, thereby improving the dimensional and shape accuracy of the products and reducing product defects caused by poor cross-sectional shape, such as edge thinning, central waviness, and "cat's ears" on both sides, thus improving product performance and usability. At the same time, reasonable cross-sectional profile control can make the rolling force distribution more uniform, reducing wear and uneven stress on equipment, thereby extending the service life of equipment components, reducing equipment maintenance costs and downtime, and improving equipment operating rate. Hot-rolled section profile control is generated during the rolling process and belongs to process quality control. Due to the characteristics of high temperature and high speed rolling in hot rolling production, the fitting calculation of secondary model parameters is particularly important for the control of hot-rolled section profile. However, in actual production, the adjustment speed of the model through instrument detection and model self-learning function is relatively slow. In order to reduce the section profile adjustment time and achieve fast and accurate section profile adjustment, manual intervention is required for correction, thereby achieving fast and accurate adjustment of section profile and promoting the model self-learning process. Summary of the Invention

[0004] Based on the aforementioned technical problems with existing hot-rolled cross-sectional profile control methods, this paper proposes a method to improve the cross-sectional profile of cold-rolled raw materials. This method deeply analyzes the control mechanism of hot-rolled strip cross-sectional profile, and obtains excellent physical strip shape by manually intervening in rolling process parameters and adjusting the shape control and proportional crown of each stand in the finishing mill. Simultaneously, advanced measuring equipment enables online and timely correction and control of the strip cross-sectional profile. Combined with scientifically sound judgment rules, the profile quality is graded to ensure the quality of hot-rolled products and reduce the probability of defective and scrap products.

[0005] The technical means employed in this invention are as follows: A method for improving the cross-sectional profile of cold-rolled raw materials includes optimizing the target crown value, CVC roll shifting amount, and stand bending roll force parameters of the finishing mill, specifically including: (1) Optimization of convexity target value: If wavy and / or high points appear in the middle of the strip, the convexity target value is reduced; if the edge of the strip shows upturn and / or cat ear-shaped warping, the convexity target value is increased. (2) Optimization of CVC roll shifting amount: If wavy and / or high points appear in the middle of the strip, reduce the CVC roll shifting amount; if the edge of the strip shows upturn and / or cat ear-shaped warping, increase the CVC roll shifting amount. (3) Optimization of bending roll force of the stand: After the strip is straightened, adjust the bending roll force of the mid-stream stand of the finishing mill: if the strip has a wave shape and / or high point in the middle, reduce the bending roll force; if the strip has a warping and / or cat ear shape at the edge, increase the bending roll force; and adjust the roll gap deviation or bending roll force of the mid-stream stand according to the actual strip shape.

[0006] Furthermore, when optimizing the convexity target value, if a wave-like shape and / or high point appears in the middle of the strip, the convexity target value will be reduced by 10μm~20μm; if a warping and / or cat-ear-shaped warping appears at the edge of the strip, the convexity target value will be increased by 10μm~20μm.

[0007] Furthermore, when optimizing the CVC roll shifting amount, if wavy and / or high points appear in the middle of the strip, the CVC roll shifting amount should be reduced by 20mm to 50mm based on the preset CVC roll shifting amount in the finishing rolling process; if the strip edge shows upturn and / or cat ear-shaped warping, the CVC roll shifting amount should be increased by 20mm to 50mm based on the preset CVC roll shifting amount in the finishing rolling process.

[0008] Furthermore, when optimizing the bending roll force of the stand, the bending roll force of the mid-stream stand of the finishing mill is adjusted: if a wave-like shape and / or a high point appears in the middle of the strip, the bending roll force is reduced by 10% to 30% based on the preset bending roll force; if the edge of the strip shows upturn and / or cat-ear-shaped warping, the bending roll force is increased by 10% to 30% based on the preset bending roll force.

[0009] Furthermore, adjust the roll gap deviation or bending roll force of the midstream stand according to the actual strip shape: if the strip has a single-sided waviness, reduce or increase the roll gap at the corresponding position of the single-sided waviness by 0.1~0.3mm; if the strip has a double-sided waviness, reduce the bending roll force by 10%~20% based on the preset bending roll force; if the strip has a middle waviness, increase the bending roll force by 10~20% based on the preset bending roll force.

[0010] Furthermore, if the finishing mill includes seven stands (F1-F7), when optimizing the bending roll force of the stands: after the strip shape is straightened, adjust the bending roll force of stands F4-F5 of the finishing mill, and adjust the roll gap deviation and / or bending roll force of stands F5-F6 according to the actual strip shape.

[0011] Furthermore, if the finishing mill includes five stands (F1-F5), when optimizing the bending roll force of the stands: after the strip shape is straightened, adjust the bending roll force of stands F3-F4 of the finishing mill, and adjust the roll gap deviation and / or bending roll force of stands F4-F5 according to the actual strip shape.

[0012] Compared with the prior art, the present invention has the following advantages: The method for improving the cross-sectional profile of cold-rolled raw materials provided by this invention adjusts the crown, CVC roll shifting, and midstream stand bending roll force to adjust the proportional crown set in the model. Combined with the strip shape control strategy, it adjusts the roll gap deviation and bending roll force control of the downstream stand, taking into account both the strip shape and the adjustment of the cross-sectional wheel. This ensures the effective control of the strip's cross-sectional profile, minimizes the generation of defective products, and effectively improves the cross-sectional profile and actual strip shape of hot-rolled products. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 The cross-sectional profile of cold-rolled raw material that was not produced using the method described in this invention.

[0015] Figure 2 The cross-sectional profile of the cold-rolled raw material is improved using the method described in Example 1 of this invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This invention provides a method for improving the cross-sectional profile of cold-rolled raw materials, including optimizing the target crown value, CVC roll shifting amount, and stand bending roll force parameters of the finishing mill, specifically including: (1) Optimization of crown target value: Based on the location of the defective cross-sectional profile of the cold-rolled raw material, the crown target value is adjusted to achieve rapid improvement; in the finishing rolling process, the preset crown target value is 40μm~60μm; if wavy and / or high points appear in the middle of the strip, the crown target value is reduced; if the edge of the strip is raised and / or cat ear-shaped warping, the crown target value is increased; by increasing the proportional crown of the upstream stand, the wear of the roll edge can be compensated, and the purpose of rapidly improving the cross-sectional profile can be achieved. (2) Optimization of CVC roll shifting amount: When the cold-rolled raw material has poor cross-sectional profile, the crown can be improved by adjusting the roll shifting amount, and the cross-sectional profile can be controlled; if the strip has wavy and / or high points in the middle, the CVC roll shifting amount should be reduced; if the strip has raised and / or cat ear-shaped warping at the edge, the CVC roll shifting amount should be increased to improve the effective crown range of the strip. (3) Optimization of bending roll force of stand: For poor cross-sectional profile of cold rolled raw material, the bending roll force of the mid-stream stand can be manually intervened; after the strip shape is straightened, the bending roll force of the mid-stream stand of the finishing mill is adjusted: if the strip has a wave shape and / or high point in the middle, the bending roll force is reduced; if the strip edge has a warping and / or cat ear shape, the bending roll force is increased; and the roll gap deviation or bending roll force of the mid-stream stand is adjusted according to the actual strip shape to realize the adjustment method that combines the cross-sectional profile and the strip shape control strategy, taking into account both the cross-sectional profile and the straightness of the strip.

[0018] Furthermore, when optimizing the convexity target value, if a wave-like shape and / or high point appears in the middle of the strip, the convexity target value will be reduced by 10μm~20μm; if a warping and / or cat-ear-shaped warping appears at the edge of the strip, the convexity target value will be increased by 10μm~20μm.

[0019] Furthermore, when optimizing the CVC roll shifting amount, if wavy and / or high points appear in the middle of the strip, the CVC roll shifting amount should be reduced by 20mm to 50mm based on the preset CVC roll shifting amount in the finishing rolling process; if the strip edge shows upturn and / or cat ear-shaped warping, the CVC roll shifting amount should be increased by 20mm to 50mm based on the preset CVC roll shifting amount in the finishing rolling process.

[0020] Furthermore, when optimizing the bending roll force of the stand, the bending roll force of the mid-stream stand of the finishing mill is adjusted: if a wave-like shape and / or a high point appears in the middle of the strip, the bending roll force is reduced by 10% to 30% based on the preset bending roll force; if the edge of the strip shows upturn and / or cat-ear-shaped warping, the bending roll force is increased by 10% to 30% based on the preset bending roll force.

[0021] Furthermore, adjust the roll gap deviation or bending roll force of the midstream stand according to the actual strip shape: if the strip has a single-sided waviness, reduce or increase the roll gap at the corresponding position of the single-sided waviness by 0.1~0.3mm; if the strip has a double-sided waviness, reduce the bending roll force by 10%~20% based on the preset bending roll force; if the strip has a middle waviness, increase the bending roll force by 10~20% based on the preset bending roll force.

[0022] Furthermore, if the finishing mill includes seven stands (F1-F7), when optimizing the bending roll force of the stands: after the strip shape is straightened, adjust the bending roll force of stands F4-F5 of the finishing mill, and adjust the roll gap deviation and / or bending roll force of stands F5-F6 according to the actual strip shape.

[0023] Furthermore, if the finishing mill includes five stands (F1-F5), when optimizing the bending roll force of the stands: after the strip shape is straightened, adjust the bending roll force of stands F3-F4 of the finishing mill, and adjust the roll gap deviation and / or bending roll force of stands F4-F5 according to the actual strip shape.

[0024] Furthermore, in the finishing rolling process, the preset CVC roll shifting amount, stand bending roll force and roll gap deviation can all be calculated using a two-stage rolling model. The specific calculation method is a well-known technical means to those skilled in the art, and will not be elaborated upon in this invention.

[0025] Furthermore, the detection methods for whether there are wavy patterns, high points, edge warping, or cat-ear-shaped warping on the strip are existing technologies. For example, wavy patterns can be detected by plate rolls or laser scanning methods, high points can be detected by laser displacement sensors or confocal white light sensors, edge warping can be detected by dual-sided laser displacement sensors, and cat-ear-shaped warping can be detected by three-dimensional laser scanning cameras. This invention will not elaborate on these methods.

[0026] The method for improving the cross-sectional profile of cold-rolled raw materials described in this invention adjusts the proportional crown setting based on changes in the cross-sectional profile, combining optimization of the crown target value, adjustment of CVC roll shifting amount, and manual intervention of the bending roll force of the midstream stand, while taking into account the shape control strategy. This improves the control of the cross-sectional profile and the shape of the actual product, further enhancing product quality and minimizing defective products.

[0027] For different steel grades, different adjustment ranges can be determined by combining model settings. At the same time, the model's self-learning parameters can be adjusted to allow the biased model to quickly adapt to the control of the cross-sectional profile under the current working conditions. Considering that there are areas with poor cross-sectional profiles in the whole coil, rework and leveling can effectively improve the original cross-sectional profile and eliminate the impact on subsequent production processes.

[0028] Comparative Example 1 The comparative example uses a finishing mill consisting of seven stands (F1-F7). The target crown value in the finishing mill is 40 μm, the CVC roll shifting amount is 45.5 mm, and the bending roll force in the mid-stands is 800 kN. The resulting cross-sectional profile is as follows: Figure 1 As shown.

[0029] Example 1 Based on Comparative Example 1, this embodiment uses the method described in this invention for improving the cross-sectional profile of cold-rolled raw materials to optimize the target crown value, CVC roll shifting amount, and stand bending roll force parameters of the finishing mill, specifically including: (1) The target convexity value is 60 μm after optimization; (2) The optimized CVC roll shifting amount is 80mm; (3) The optimized bending force of the frame roller is 915KN.

[0030] The strip cross-sectional profile obtained in Example 1 is as follows: Figure 2 As shown, comparison Figure 1 As can be seen, the method described in this invention can effectively improve the original cross-sectional profile and enhance the quality of the cross-sectional profile of cold-rolled raw materials.

[0031] 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 them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for improving the cross-sectional profile of cold-rolled raw materials, characterized in that, This includes optimizing the crown target value, CVC roll shifting amount, and stand bending roll force parameters of the finishing mill, specifically including: (1) Optimization of convexity target value: If wavy and / or high points appear in the middle of the strip, the convexity target value is reduced; if the edge of the strip shows upturn and / or cat ear-shaped warping, the convexity target value is increased. (2) Optimization of CVC roll shifting amount: If wavy and / or high points appear in the middle of the strip, reduce the CVC roll shifting amount; if the edge of the strip shows upturn and / or cat ear-shaped warping, increase the CVC roll shifting amount. (3) Optimization of bending roll force of the stand: After the strip is straightened, adjust the bending roll force of the mid-stream stand of the finishing mill: if the strip has a wave shape and / or high point in the middle, reduce the bending roll force; if the strip has a warping and / or cat ear shape at the edge, increase the bending roll force; and adjust the roll gap deviation or bending roll force of the mid-stream stand according to the actual strip shape.

2. The method for improving the cross-sectional profile of cold-rolled raw materials according to claim 1, characterized in that, When optimizing the convexity target value, if wavy and / or high points appear in the middle of the strip, the convexity target value will be reduced by 10μm~20μm; If the strip edge shows warping and / or cat-ear shaped warping, the convexity target value will be increased by 10μm~20μm.

3. The method for improving the cross-sectional profile of cold-rolled raw materials according to claim 1, characterized in that, When optimizing the CVC roll shifting amount, if wavy and / or high points appear in the middle of the strip, the CVC roll shifting amount should be reduced by 20mm to 50mm based on the preset CVC roll shifting amount in the finishing rolling process. If the strip edge warps and / or has a cat-ear shape, the CVC roll shifting amount should be increased by 20mm to 50mm based on the preset CVC roll shifting amount in the finishing rolling process.

4. The method for improving the cross-sectional profile of cold-rolled raw materials according to claim 1, characterized in that, When optimizing the bending roll force of the stand, adjust the bending roll force of the mid-stream stand of the finishing mill: if the strip has a wave-like shape and / or high point in the middle, reduce the bending roll force by 10% to 30% based on the preset bending roll force; if the strip has a warping and / or cat ear-shaped warping at the edge, increase the bending roll force by 10% to 30% based on the preset bending roll force.

5. The method for improving the cross-sectional profile of cold-rolled raw materials according to claim 1, characterized in that, Adjust the roll gap deviation or bending roll force of the midstream stand according to the actual strip shape: if the strip has a single-sided waviness, reduce or increase the roll gap at the corresponding position of the single-sided waviness by 0.1~0.3mm; if the strip has a double-sided waviness, reduce the bending roll force by 10%~20% based on the preset bending roll force; if the strip has a middle waviness, increase the bending roll force by 10~20% based on the preset bending roll force.

6. The method for improving the cross-sectional profile of cold-rolled raw materials according to claim 1, characterized in that, If the finishing mill includes seven stands (F1-F7), when optimizing the bending roll force of the stands: after the strip shape is straightened, adjust the bending roll force of stands F4-F5 of the finishing mill, and adjust the roll gap deviation and / or bending roll force of stands F5-F6 according to the actual strip shape.

7. The method for improving the cross-sectional profile of cold-rolled raw materials according to claim 1, characterized in that, If the finishing mill unit includes five stands (F1-F5), when optimizing the bending roll force of the stands: after the strip shape is straightened, adjust the bending roll force of stands F3-F4 of the finishing mill unit, and adjust the roll gap deviation and / or bending roll force of stands F4-F5 according to the actual strip shape.

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