A method for early warning of cold-rolled steel strip rib formation based on strip cross-sectional feature recognition

Abstract

This invention relates to a cold-rolling rib formation early warning method based on strip cross-sectional feature recognition, comprising steps such as data acquisition, region division, and separate judgment of each region. This invention's cold-rolling rib formation early warning method based on strip cross-sectional feature recognition can not only identify and warn of rib formation risks in cold-rolled coils, but also locate the specific length position and width range of the rib formation through this design content rule, providing a good early warning and reference function for subsequent cold-rolling processes.

Description

Technical Field

[0001] This invention relates to a method for early warning of cold-rolled steel strip rib formation based on the identification of cross-sectional features, belonging to the field of metal smelting technology. Background Technology

[0002] During the rolling process, due to factors such as the transverse flow of metal within the strip and uneven distribution of reduction, the strip exhibits uneven thickness distribution and longitudinal extension along its width, resulting in defects such as localized high points and localized deformation. These localized defects accumulate layer by layer during strip coiling, forming raised ridges on the surface of the coil, a phenomenon known as rib formation. Depending on their location on the coil surface, ribs can be further classified into center ribs and edge ribs. The direct consequence of rib formation is the formation of additional waviness in the strip after uncoiling, leading to product downgrading. Specifically, rib formation is essentially a buckling and post-buckling deformation behavior under the stress distribution pattern within the strip.

[0003] Ribbing defects caused by rib formation are a significant factor affecting the quality of cold-rolled products. The direct consequence is the formation of additional waviness on the strip surface after uncoiling, severely impacting the product's appearance and performance, leading to downgrading or even scrapping. Ribbing defects are more pronounced during cold rolling and annealing coiling, and their formation mechanism is complex. In terms of processes, both hot rolling and cold rolling can be important factors influencing rib formation. Existing research has found a relatively clear correspondence between the location of rib formation and the location of local high points in the cross-sectional profile of hot-rolled strip. Therefore, before the cold rolling process, a corresponding method for identifying defects in the strip cross-sectional profile can be designed to understand the cross-sectional quality of the coil to be rolled in advance, and to locate and identify areas prone to rib formation defects, thus serving as a warning for cold rolling.

[0004] There are several technical challenges in identifying cross-sectional profile defects along the entire length of the coil to be rolled: (1) Since the cold-rolled coil to be rolled is a hot-rolled finished coil, its relevant quality data are stored in the hot rolling production line. The basic data for defect identification and the identification time correspond to different production lines. Data transmission is a prerequisite for realizing this method. (2) It is necessary to conduct a detailed analysis of the cold-rolled coil with existing rib defects, and it is not limited to a single process. This workload is relatively large. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the above-mentioned technologies and provide a method for dividing the cross-sectional profile of the strip steel according to the cross-sectional profile thickness data of the strip steel throughout the entire length of the hot rolling process, designing relevant defect identification methods, and providing effective early warning of the rib formation defects that may occur in the strip steel after cold rolling.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is: a cold-rolled steel strip cross-sectional feature recognition early warning method, comprising the following steps:

[0007] (1) Read the crown data of the strip steel to be cold rolled at the exit of the hot rolling mill along the entire length of the strip steel. Wedge data W i 40 (i = 1, 2, 3, ... n), cross-sectional thickness data 1, 2, 3, ... n; j = 5, 10, 15, ... m); where the convexity data and wedge data are positions 40 mm from the edge of the strip in the width direction; in the cross-sectional thickness data, i is the position in the length direction and j is the position in the width direction;

[0008] (2) The strip is divided in the width direction, with the centerline of the strip length as the reference. The 15% width range on both sides of the center is the middle section, the 25% width range outside the middle on both sides is the intermediate section, and the distance from the intermediate section to the edge of the strip is the edge section; then T i 5 ~T i [0.1m] and T i [0.9m]+5 ~T i m For the cross-sectional thickness data of the edge, T i [0.1m]+5 ~T i [0.35m] and T i [0.65m]+5 ~T i [0.9m] For the cross-sectional thickness data of the interstitial section, T i [0.35m]+5 ~T i [0.65m] This refers to the cross-sectional thickness data for the middle section;

[0009] (3) At position i along the length of the strip, take any data within an 80mm range of the cross-sectional thickness data at the middle section, and calculate the maximum and minimum values:

[0010]

[0011]

[0012] (4) The risk identification condition for point j within the 80mm range selected in step (3) is as follows: When this condition is met, it is considered that there is a risk of reinforcement at point j, where T set The nominal thickness of the strip steel;

[0013] (5) Among the cross-sectional thickness data at position i along the length of the strip, take data within an arbitrary range of 80mm on both the drive side and the operating side, and calculate the maximum and minimum values ​​of the data on the drive side:

[0014]

[0015]

[0016] Calculate the maximum and minimum values ​​of the inter-operational data:

[0017]

[0018]

[0019] (6) For point j within the 80mm range of the transmission side selected in step (5), if the wedge data at this position is positive, the rib risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j; if the wedge data at this location is negative, the rib forming risk identification condition is: When this condition is met, point j is considered to have a risk of rib formation; for point j within the 80mm range of the operating side selected in step (5), if the wedge data at this position is positive, the rib formation risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j; if the wedge data at this position is negative, then the rib forming risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j;

[0020] (7) Among the thickness of the edge cross section at position i along the length of the strip, take data within an arbitrary range of 80mm on both the drive side and the operating side, and calculate the maximum and minimum values ​​of the data on the drive side:

[0021]

[0022]

[0023] Calculate the maximum and minimum values ​​of the data on the operational side:

[0024]

[0025]

[0026] (8) For point j within the 80mm range of the transmission side selected in step (7), the risk identification condition for the reinforcing rib is: When this condition is met, point j is considered to have a risk of rib formation; for point j within the 80mm range of the operating side selected in step (7), the rib formation risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j;

[0027] (9) Repeat steps (3) to (8) until all points along the entire length and width of the strip are identified.

[0028] The further improvement of the above scheme is that the distance between two adjacent positions in the convexity data and wedge data in the length direction is 1m, the distance between two adjacent positions in the cross-sectional thickness data in the length direction is 1m, the distance between two adjacent positions in the width direction is 5mm, and the j value gradually increases from the transmission side to the operation side.

[0029] This invention provides a cold-rolled rib formation early warning method based on strip cross-sectional feature recognition. The strip cross-section is divided into three regions: edge, middle, and center. Data from the entire length of the coil to be rolled is used to identify the specific rib formation risk locations in both the length and width directions. First, the thickness data of each region on the cross-sectional profile is processed. Then, the cross-sectional profile data of the center and middle regions are combined with the contribution of convexity and wedge shape at corresponding locations to the rib formation risk. A comprehensive rule for identifying rib formation risks caused by local high points and convexity / wedge shape contributions in different regions of the cross-sectional profile is designed. This method not only identifies and warns of rib formation risks in the cold-rolled coil but also uses this designed rule to pinpoint the specific length location and width range of the rib formation, providing a good early warning and reference for subsequent cold-rolling processes. Detailed Implementation

[0030] Example

[0031] The cold-rolled steel strip cross-sectional feature recognition-based early warning method for rib formation in this embodiment includes the following steps:

[0032] (1) Read the crown data of the strip steel to be cold rolled at the exit of the hot rolling mill along the entire length of the strip steel. Wedge data W i 40 (i = 1, 2, 3, ... n), cross-sectional thickness data In this data, the convexity data and wedge data are both located at a position 40mm from the edge of the strip in the width direction, and the distance between two adjacent positions in the length direction is 1m; in the cross-sectional thickness data, i represents the position in the length direction, with a 5mm interval between two positions; j represents the position in the width direction, with a 1m interval between two data points.

[0033] (2) The strip is divided in the width direction, with the centerline of the strip length as the reference. The 15% width range on both sides of the center is the middle section, the 25% width range outside the middle on both sides is the intermediate section, and the distance from the intermediate section to the edge of the strip is the edge section; then T i 5 ~T i [0.1m] and T i[0.9m]+5 ~T i m For the cross-sectional thickness data of the edge, T i [0.1m]+5 ~T i [0.35m] and T i [0.65m]+5 ~T i [0.9m] For the cross-sectional thickness data of the interstitial section, T i [0.35m]+5 ~T i [0.65m] This refers to the cross-sectional thickness data for the middle section;

[0034] (3) At position i along the length of the strip, take any data within an 80mm range of the cross-sectional thickness data at the middle section, and calculate the maximum and minimum values:

[0035]

[0036]

[0037] (4) The risk identification condition for point j within the 80mm range selected in step (3) is as follows: When this condition is met, it is considered that there is a risk of reinforcement at point j, where T set The nominal thickness of the strip steel;

[0038] (5) Among the cross-sectional thickness data at position i along the length of the strip, take data within an arbitrary range of 80mm on both the drive side and the operating side, and calculate the maximum and minimum values ​​of the data on the drive side:

[0039]

[0040]

[0041] Calculate the maximum and minimum values ​​of the inter-operational data:

[0042]

[0043]

[0044] (6) For point j within the 80mm range of the transmission side selected in step (5), if the wedge data at this position is positive, the rib risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j; if the wedge data at this location is negative, the rib forming risk identification condition is: When this condition is met, point j is considered to have a risk of rib formation; for point j within the 80mm range of the operating side selected in step (5), if the wedge data at this position is positive, the rib formation risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j; if the wedge data at this position is negative, then the rib forming risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j;

[0045] (7) Among the thickness of the edge cross section at position i along the length of the strip, take data within an arbitrary range of 80mm on both the drive side and the operating side, and calculate the maximum and minimum values ​​of the data on the drive side:

[0046]

[0047]

[0048] Calculate the maximum and minimum values ​​of the data on the operational side:

[0049]

[0050]

[0051] (8) For point j within the 80mm range of the transmission side selected in step (7), the risk identification condition for the reinforcing rib is: When this condition is met, point j is considered to have a risk of rib formation; for point j within the 80mm range of the operating side selected in step (7), the rib formation risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j;

[0052] (9) Repeat steps (3) to (8) until all points along the entire length and width of the strip are identified.

[0053] Taking an actual production process as an example, the basic information of a strip steel in a certain production plan is as follows: the length of this steel coil is 1200m, the width is 1000mm, and the nominal thickness is 2.2mm. According to the above, i represents the position in any length direction, and j represents the position in any width direction. Based on the detection frequency and accuracy of the detection equipment, the distance between two adjacent positions in the length direction is usually 1m, and the distance between two adjacent positions in the width direction is usually 5mm. The maximum value of i for this steel coil is 1200, and the maximum value of j is 1000.

[0054] (1) Obtain the full-length crown, wedge data and cross-sectional thickness data of the hot-rolled material in the length direction from the hot-rolled data acquisition and storage platform;

[0055] (2) Before identifying the risk of rib tufting caused by local high points in certain locations along the length of the strip, it is necessary to divide the cross-sectional profile of the strip. Taking the middle of the strip cross-section as the reference, the middle section is defined as the range of 15% of the width on both sides, the middle section is defined as the range of 25% outward from the middle on both sides, and the edge section is defined as the range of 10% outward from the middle on both sides. If the width of this coil is 1000mm, then T i 5 ~T i 100 and T i 905 ~T i 1000 For the thickness data of the edge, T i 105 ~T i 350 and T i 655 ~T i 900 For the thickness data of the interstitial portion, T i 355 ~T i 650 The thickness data is for the middle section;

[0056] (3) Pay attention to the thickness data within any 80mm range in the middle of the cross section. Taking one as an example, such as at 83m in the length direction, the thickness of the cross section T i 405 ~T i 480 The location, and the maximum and minimum values ​​are calculated as follows:

[0057]

[0058]

[0059] (4) Determine whether there is a risk of rib formation caused by local high points in the middle of a cross section along the length of the strip. The risk of rib formation in the middle is also affected by the superposition effect of convexity, and the influence of convexity on it must also be considered. Therefore, based on the risk identification criteria for reinforcing bars in the middle of the cross-section:

[0060]

[0061] 0.01T set =0.01×2200=22μm;

[0062] 35.4μm ≥ 22μm;

[0063] Therefore, there is a risk of ribs forming in the middle of the cross-section of the strip at position 83m.

[0064] (5) Pay attention to the thickness data within any 80mm range between the two sections of the cross section. Taking one of them as an example, such as at 186m along the length direction, the thickness data of the cross section T i 205 ~T i 280 The maximum and minimum values ​​of the thickness data for the transmission side interbody section calculated based on the position are as follows:

[0065]

[0066]

[0067] (6) Determine whether there is a risk of rib formation caused by local high points in the middle of a certain cross section along the length of the strip. The risk of rib formation in the middle section also has the superposition effect of wedges, and the influence of wedges may also need to be considered. If the wedge data at this position is negative, then the following judgment can be made:

[0068]

[0069] 2239-2203=33μm≥22μm;

[0070] Therefore, there is a risk of ribs forming in the cross section of the strip at position 186m on the transmission side.

[0071] (7) Pay attention to the thickness data within any 80mm range between the two sections of the cross section. Taking one of them as an example, such as at 466m along the length direction, the thickness data of the cross section T i 25 ~T i 100 The maximum and minimum values ​​of the thickness data for the transmission side edge calculated for the position are as follows:

[0072]

[0073]

[0074] (8) Determine whether there is a risk of rib bulging caused by local high points at the edge of a cross section along the length of the strip. The risk identification conditions are as follows:

[0075] 2242-2216=26μm≥22μm;

[0076] Therefore, there is a risk of ribs forming on the transmission side of the strip cross section at position 466m.

[0077] (9) In summary, this strip steel has the risk of rib formation. There is a risk of rib formation in the middle of the cross section at position 83m, a risk of rib formation in the middle of the transmission side of the cross section at position 186m, and a risk of rib formation in the edge of the transmission side of the cross section at position 466m.

Claims

1. A method for early warning of cold-rolled steel strip rib formation based on strip cross-sectional feature recognition, characterized in that, Includes the following steps: (1) Read the crown data of the strip steel to be cold rolled at the exit of the hot rolling mill along the entire length of the strip steel. wedge data Cross-sectional thickness data In this context, the convexity data and wedge data both refer to the position 40mm from the edge of the strip in the width direction; in the cross-sectional thickness data, i represents the position in the length direction, and j represents the position in the width direction. (2) The strip is divided in the width direction, with the centerline of the strip length direction as the reference. The 15% width range on both sides of the center is the middle section, the 25% width range outside the middle on both sides is the intermediate section, and the distance from the intermediate section to the edge of the strip is the edge section; then and This refers to the cross-sectional thickness data at the edge. and The data pertains to the cross-sectional thickness of the intermediate section. This refers to the cross-sectional thickness data for the middle section; (3) At position i along the length of the strip, take any data within an 80mm range of the cross-sectional thickness data at the middle section, and calculate the maximum and minimum values: ； ； (4) The risk identification condition for point j within the 80mm range selected in step (3) is as follows: When this condition is met, it is considered that there is a risk of rib forming at point j. The nominal thickness of the strip steel; (5) Among the cross-sectional thickness data at position i along the length of the strip, take any data within an 80mm range on both the drive side and the operating side, and calculate the maximum and minimum values ​​of the data on the drive side: ； ； Calculate the maximum and minimum values ​​of the data on the operational side: ； ； (6) For point j within the 80mm range of the transmission side selected in step (5), if the wedge data at this position is positive, the rib risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j; if the wedge data at this position is negative, the rib forming risk identification condition is: When this condition is met, point j is considered to have a risk of rib formation; for point j within the 80mm range of the operating side selected in step (5), if the wedge data at this position is positive, the rib formation risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j; if the wedge data at this position is negative, then the rib forming risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j. (7) Among the thickness of the edge cross section at position i along the length of the strip, take data within an arbitrary range of 80 mm on both the drive side and the operating side, and calculate the maximum and minimum values ​​of the data on the drive side: ； ； Calculate the maximum and minimum values ​​of the data on the operational side: ； ； (8) For point j within the 80mm range of the transmission side selected in step (7), the risk identification condition for the reinforcing rib is: When this condition is met, point j is considered to have a risk of rib forming; for point j within the 80mm range of the operating side selected in step (7), the rib forming risk identification condition is: When this condition is met, it is considered that there is a risk of rib forming at point j. (9) Repeat steps (3) to (8) until all points along the entire length and width of the strip are identified.

2. The cold-rolled steel strip cross-sectional feature recognition early warning method according to claim 1, characterized in that: The distance between two adjacent positions in the convexity data and wedge data along the length direction is 1m. The distance between two adjacent positions in the cross-sectional thickness data along the length direction is 1m. The distance between two adjacent positions in the width direction is 5mm. The value of j gradually increases from the transmission side to the operation side.

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