A method for flattening a thin gauge hot-rolled high-strength strip having a shape defect

Abstract

This invention relates to the field of hot-rolled high-strength strip leveling technology, and discloses a leveling method for thin-gauge hot-rolled high-strength strip with poor shape. The method involves obtaining the coil thickness of the strip coil, dividing it into outer, middle, and inner coils based on the coil thickness, setting the operating parameters of the leveling machine, and performing multi-segment leveling of the strip coil in each zone. The uncoiling speed of each zone is adjusted regionally, and the uncoiling tension is adjusted based on the looseness of the inner coil. During the leveling process from the outer to the inner zone, the uncoiling tension increases sequentially. This method significantly reduces the probability of bruising, effectively controls poor shape such as waviness and warping in the inner zone, improves the problem of inner coil misalignment, and increases the yield and product quality of the leveled strip.

Description

Technical Field

[0001] This invention relates to the field of hot-rolled high-strength strip leveling technology, and in particular to a leveling method for thin-gauge hot-rolled high-strength strip with poor shape. Background Technology

[0002] Thin-gauge hot-rolled high-strength strip often exhibits the following issues during leveling: double-sided wavy patterns appear on the outer and middle coils during uncoiling, which can be leveled normally; however, the inner coil displays severe warping defects accompanied by significant abrasions, and deviation occurs during leveling, which is difficult to resolve using a leveling machine. Excessive bending roller force during leveling can also easily tear the strip, leading to scrap. Therefore, leveling operators often cut off 50-180 meters of the inner coil of the strip, which has the most severe shape and abrasion problems, significantly impacting the final yield. Existing technologies are continuously improving strip leveling shape control methods. For example, adjusting the bending roller force control quantity to regulate the output leveling control parameters solves the problem that manually setting leveling parameters cannot achieve good shape control. Alternatively, designed process flows can significantly improve the shape quality of high-strength steel open-faced sheets, reducing investment and processing costs. However, there is still a lack of a solution that can address both the flatness of thin-gauge hot-rolled high-strength strip and the control of inner ring scratches, while also effectively controlling defects in the inner ring such as large waviness and warping.

[0003] Therefore, there is a need in the existing technology to improve the leveling method for poor sheet shape of thin hot-rolled high-strength strip. Summary of the Invention

[0004] In view of this, the purpose of this invention is to propose a flattening method for thin-gauge hot-rolled high-strength strip with poor shape, which significantly reduces the probability of bruising, effectively controls the poor shape of the inner ring such as large waves and warping, improves the problem of inner ring deviation of strip coil, and improves the flattening yield and product quality.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for leveling thin-gauge hot-rolled high-strength strip with poor shape, comprising:

[0006] Obtain the winding thickness of the strip coil, and divide the strip coil into outer coil, middle coil and inner coil based on the winding thickness;

[0007] Set the operating parameters of the leveling machine and perform multi-segment leveling of the strip roll. Adjust the unwinding speed of each segment. Adjust the unwinding tension based on the looseness of the inner ring of the strip roll. During the segment leveling process from the outer ring to the inner ring, the unwinding tension increases sequentially.

[0008] In some implementations, the outer coil is the first 0-50m of the strip roll after it begins to flatten, the inner coil is the last 150m, and the remaining portion is the middle coil.

[0009] In some implementations, the unwinding speed V is used when flattening the outer coil. a The value range is 30~40m / min.

[0010] In some implementations, when flattening the outer coil, if the inner coil is not loose, the unwinding tension T a The value range is 25~35kN; if there is loose winding, the unwinding tension T a The value range is 15~25kN.

[0011] In some implementations, the unwinding speed V is used when flattening the middle coil. b The value range is 60~120m / min.

[0012] In some implementations, when flattening the middle coil, the unwinding tension T b The value range is 30~60kN.

[0013] In some implementations, the unwinding speed V is used when flattening the inner coil. c The value range is 30~50m / min.

[0014] In some implementations, when flattening the inner coil, the unwinding tension T c The value range is 90~130kN.

[0015] In some implementations, the leveling rolling pressure is 1000~7000KN during the leveling process.

[0016] In some implementations, the working roller of the leveling machine is a convex roller.

[0017] The present invention has at least the following beneficial technical effects:

[0018] When leveling thin-gauge hot-rolled high-strength strip, this invention effectively controls defects such as large waviness and warping on the inner ring, reducing the risk of deviation during leveling and allowing the strip to pass smoothly through the leveling machine. Simultaneously, it effectively controls inner ring scratches on the strip coil, reducing the area of ​​scratches occurring within the inner ring of the coil. This invention reduces abnormal cutting damage to the strip coil and significantly improves the yield of thin-gauge hot-rolled high-strength strip. Attached Figure Description

[0019] 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 only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the design of the leveling control strategy for this invention.

[0021] Figure 2 A comparison diagram of the unwinding tension curve of the entire flattening process and the original strategy provided in this embodiment of the invention;

[0022] Figure 3 A comparison diagram of the unwinding speed curve of the entire flattening process and the original strategy provided in this embodiment of the invention;

[0023] Figure 4 A comparison of the yield and scratch rate between the leveling control strategy provided in this embodiment of the invention and the original leveling control strategy. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0025] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0026] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] To control the flatness of hot-rolled steel sheets, shape control mills are typically used in the rolling process, and straightening or leveling machines are used in the finishing process. These methods or technologies have played a good role in controlling the flatness of hot-rolled steel sheets. However, in actual processes, defects such as inner ring scratches, large waviness, and warping often occur. This problem involves considering multiple factors, such as rolling force and the optimization of leveling process parameters. Therefore, this invention provides a leveling method for thin-gauge hot-rolled high-strength strips with poor sheet shape. The design steps are as follows: Figure 1 As shown, it specifically includes:

[0028] S1 obtains the winding thickness of the strip roll and divides the strip roll into outer coil, middle coil and inner coil based on the winding thickness;

[0029] S2 sets the operating parameters of the leveling machine and performs multi-segment leveling of the strip roll in sections. The unwinding speed of each section is adjusted regionally, and the unwinding tension is adjusted based on the looseness of the inner ring of the strip roll. During the section leveling process from the outer ring to the inner ring, the unwinding tension increases sequentially.

[0030] Furthermore, to ensure the leveling equipment is in good condition, set the leveling machine parameters to base values, and adjust the tension and speed of the thin-gauge hot-rolled high-strength strip during the uncoiling process according to different leveling stages.

[0031] Furthermore, in S1, the flat strip roll is divided into zones for leveling. The area within 0-50m from the start of leveling is the outer roll, the last 150m is the inner roll, and the remaining part is the middle roll.

[0032] Furthermore, in S2, when flattening the outer coil, the unwinding speed V a The value range is 30~40 m / min. When flattening the outer coil, if the inner coil is not loose, the unwinding tension T a The value range is 25~35kN; if there is loose winding, the unwinding tension T a The value range is 15~25kN. When flattening the middle coil, the unwinding speed V... b The value range is 60~120m / min. When leveling the middle coil, the unwinding tension T... b The value range is 30~60kN. When flattening the inner coil, the unwinding speed V... c The value range is 30~50 m / min. When flattening the inner coil, the unwinding tension T... c The value range is 90~130kN. During the leveling process, the leveling rolling pressure is 1000~7000kN. The working rolls of the leveling machine are convex rolls.

[0033] The present invention will be further explained below with reference to specific embodiments.

[0034] Keep the leveling equipment in good condition, set the leveling machine parameters to the base values, and adjust the tension and speed of the thin-gauge hot-rolled high-strength strip during the uncoiling process according to different leveling stages.

[0035] The flat strip roll is divided into sections for leveling. The first 50 meters of the leveled section is designated as the outer ring, the remaining 150 meters as the inner ring, and the rest of the middle length is designated as the middle ring.

[0036] Furthermore, the unwinding speed V of the outer ring of the flat sheet coil a The value is 40 m / min.

[0037] Furthermore, when flattening the outer ring of the sheet roll, the unwinding tension T a The value is 25kN.

[0038] Furthermore, the unwinding speed V of the flat sheet coil is... b The value is 90 m / min.

[0039] Furthermore, the uncoiling tension T of the flat sheet coil is... b The value range is 50kN.

[0040] Furthermore, when the flattened sheet is rolled into the inner ring, the unwinding speed V c Value taken as 50 m / min

[0041] Furthermore, when flattening the inner coil of the sheet metal roll, the unwinding tension T c Increased to 110kN.

[0042] The leveling method for thin-gauge hot-rolled high-strength strip with poor shape, provided by an embodiment of the present invention, was applied to a leveling unit on a production line. For example... Figure 2 The figure shows a comparison between the unwinding tension curve of the original production line strategy and the unwinding tension curve provided by the present invention. Figure 3 The figure shows a comparison between the unwinding speed curve of the original strategy and the unwinding speed curve provided by this invention. Figure 4 The diagram shows a comparison of yield and scratch rate between the original leveling control strategy and the leveling control strategy provided by this invention when leveling similar quantities and specifications of strip coils. It can be seen that the strategy provided by this invention can significantly improve the yield of leveling thin-gauge hot-rolled high-strength strip, reduce the probability of scratches on the inner ring of the strip coil, thereby reducing resource consumption in the production process and improving the economic efficiency of the production line. The original strategy often generates large waves when leveling the inner ring, causing the strip to twist and deviate, making it impossible to level on the leveling machine, and in severe cases, even tearing the strip. The strategy of this invention significantly improves the shape of the inner ring of the strip coil, allowing all leveled thin-gauge hot-rolled high-strength strip to smoothly enter the leveling machine for leveling, thus improving product quality.

[0043] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0044] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0045] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0046] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for leveling thin-gauge hot-rolled high-strength strip with poor sheet shape, characterized in that, include: Obtain the winding thickness of the strip roll, and divide the strip roll into outer coil, middle coil and inner coil based on the winding thickness; Set the operating parameters of the leveling machine and perform multi-segment leveling of the strip roll in sections. Adjust the unwinding speed of each section in a regional manner. Adjust the unwinding tension based on the loosening condition of the inner strip roll. During the section leveling process from the outer ring to the inner ring, the unwinding tension increases sequentially. When flattening the outer coil, if the inner coil is not loose, the unwinding tension T a The value range is 25~35kN; if there is loose winding, the unwinding tension T a The value range is 15~25kN; When flattening the middle coil, the unwinding tension T b The value range is 30~60kN; When flattening the inner coil, the unwinding tension T c The value range is 90~130kN.

2. The method for leveling thin-gauge hot-rolled high-strength strip with poor shape according to claim 1, characterized in that, The outer coil is the first 0-50m of the strip roll after it begins to flatten, the inner coil is the last 150m, and the rest is the middle coil.

3. The method for leveling thin-gauge hot-rolled high-strength strip with poor shape according to claim 1, characterized in that, When flattening the outer coil, the unwinding speed V a The value range is 30~40m / min.

4. The method for leveling thin-gauge hot-rolled high-strength strip with poor shape according to claim 1, characterized in that, When flattening the middle coil, the unwinding speed V b The value range is 60~120m / min.

5. The method for leveling thin-gauge hot-rolled high-strength strip with poor shape according to claim 1, characterized in that, When flattening the inner coil, the unwinding speed V c The value range is 30~50m / min.

6. The method for leveling thin-gauge hot-rolled high-strength strip with poor shape according to claim 1, characterized in that, During the leveling process, the leveling rolling pressure is 1000~7000KN.

7. The method for leveling thin-gauge hot-rolled high-strength strip with poor shape according to claim 1, characterized in that, The working roller of the leveling machine is a convex roller.

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