A control method for reducing the marking roll of a continuous rolling machine

Abstract

A control method for reducing the crescent mark of a rolling mill roller, the method comprising the steps of: reducing the edge rolling force according to the strip width; reducing the stress on the edge of the strip according to the roll shifting position; grinding the roller; and roughening the ground roller. The control method for reducing the crescent mark of a rolling mill roller provided by the application reduces the stress on the strip at the crescent position, avoids the crescent mark caused by the roller, enhances the wear resistance of the roller, and reduces the strip crescent mark defects. On the basis of ensuring customer product requirements, the RSK of the roller surface is negative, thereby improving the oil storage, oil uniformity, corrosion resistance, and apparent quality of the automobile sheet product. This has a very positive significance for optimizing the industrial structure, improving the brand effect, enhancing the quality of the automobile sheet product, especially the consistency of the product head and tail, reducing the strip performance defects, and improving the wear resistance of the roller.

Description

Technical Field

[0001] This invention belongs to the field of cold-rolled sheet production technology of continuous acid rolling mill, specifically relating to a control method for reducing crescent-shaped damage rolls in continuous rolling mills. Background Technology

[0002] During the transition between steel grades and specifications, especially when the strength of the steel grade changes significantly, a 60mm-90mm deep crescent-shaped groove needs to be cut near the weld to reduce stress concentration at the weld edge and prevent poor weld quality at the strip edge. However, after the weld crescent is cut, during the subsequent rolling process, due to significant changes in steel grade and rolling force, the strip at the crescent position is narrower, and the unit rolling force increases. When the strip edge is under greater stress, crescent marks in the width direction can easily be generated on the rolls, causing crescent damage. Rolls with crescent marks must be replaced immediately; otherwise, the roll surface defect will be reflected onto the subsequently rolled strip, causing product quality defects and resulting in scrap.

[0003] For cold continuous rolling mills, stands 1-5 bear approximately 1500t-2500t of rolling force during the rolling process, with a rolling force of approximately 15kN-25kN / mm per unit width. To ensure good strip shape on each stand, the principle of proportional crown adjustment must be followed, and the strip shape is ultimately adjusted through bending roll force. Theoretically, work roll bending, roll shifting in CVC mills, and rolling force all have a certain impact on the roll gap cross-sectional characteristics. The amount of work roll bending and roll shifting in CVC mills have a direct proportional change to the roll gap cross-sectional characteristics, while the rolling force has an inverse proportional change to the roll gap cross-sectional characteristics.

[0004] At the crescent-shaped section corresponding to the weld, the narrowing of the strip width leads to an increase in rolling force per unit width of approximately 10% to 20%. Simultaneously, since the bending force and roll profile settings of the work rolls and intermediate rolls remain constant, the roll deflection intensifies, resulting in increased stress on the strip's width edges. After the weld crescent is cut, during the subsequent rolling process, the rolling force varies significantly due to variations in steel grade. The strip is narrower at the crescent position, and when the edge of the strip experiences greater stress, a crescent imprint can easily form on the roll, causing damage. Because this is the weld crescent, the increased stress on the strip edge can cause the crescent imprint to be copied onto the roll, easily resulting in a crescent-shaped defect on the roll edge. This defect is then reflected back onto the strip, causing color differences on the strip surface. If a crescent imprint appears on the roll, it must be replaced immediately; otherwise, the roll surface defect will be reflected onto the subsequently rolled strip, leading to product quality defects and scrap. Summary of the Invention

[0005] In view of the above problems, the present invention provides a control method for reducing crescent-shaped damage rolls in continuous rolling mills to overcome or at least partially solve the above problems.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for controlling crescent-shaped damage rolls in continuous rolling mills, the method comprising the following steps:

[0007] Reduce the edge rolling force according to the strip width;

[0008] The stress on the edge of the strip is reduced by adjusting the position of the roller;

[0009] The rolls are ground.

[0010] The milled rolls are then roughened.

[0011] Preferably, the step of reducing the edge rolling force according to the strip width includes the following steps:

[0012] Obtain the width of the strip steel;

[0013] The number of bending rollers is increased according to a preset ratio based on the width.

[0014] Preferably, the step of reducing the edge stress of the strip steel according to the position of the shifting roller includes the following steps:

[0015] Get the set roller shift amount;

[0016] Obtain the actual amount of roller shifting;

[0017] Calculate the deviation between the set roll shifting amount and the actual roll shifting amount;

[0018] Calculate the bending roll force compensation value based on the deviation value;

[0019] The stress on the edge of the strip is reduced by the bending roll force compensation value.

[0020] Preferably, the grinding process of the roll includes the following steps:

[0021] The rolls are rough ground;

[0022] The rollers after rough grinding are then subjected to semi-finish grinding;

[0023] The semi-finished rolls are then finely ground.

[0024] Preferably, the semi-finishing of the rough-ground roll includes the following steps:

[0025] Set the grinding wheel speed to 22m / s~25m / s;

[0026] Set the Z-axis lateral traverse speed to 2400 mm / min ~ 2600 mm / min;

[0027] Set the X-axis feed rate to 0.006 mm / min.

[0028] Preferably, the finishing grinding of the semi-finished roll includes the following steps:

[0029] Set the Z-axis speed to 700 mm / min ~ 1800 mm / min;

[0030] Set the grinding wheel speed to 14m / s~20m / s;

[0031] Reduce the number of passes by one in each finishing grinding cycle;

[0032] Increase the grinding pressure by 2M% simultaneously for each pass;

[0033] The surface roughness of the rolls is controlled to be 0.60μm~0.70μm.

[0034] Preferably, the roughening treatment of the ground roll includes the following steps:

[0035] Adjust the position of the front and rear bearings of the EDM texturing equipment;

[0036] Set the roll texturing parameters;

[0037] Set the spindle speed of the rolls.

[0038] Preferably, adjusting the position of the front and rear supports of the electrical discharge texturing equipment includes the following steps:

[0039] The deviation between the workpiece center and the machine tool center should be less than or equal to 20μm;

[0040] The minimum clearance between the roll bearing and the bearing pad is controlled to be less than 10 μm.

[0041] Preferably, setting the roll texturing parameters includes the following steps:

[0042] The discharge current of the rolls is set to 2.3.

[0043] The energizing time of the rolls is set to 13.0.

[0044] The power-off time for the rolling mill rolls is set to 6.0 seconds.

[0045] Set the roll servo voltage to -6.5V;

[0046] Set the roll servo gain to 1.2;

[0047] The roll capacitance value is set to 22.

[0048] Set the roll charging voltage to 130.

[0049] Preferably, setting the spindle speed of the roll includes the following steps:

[0050] Set the main shaft speed of the rolls to 35 m / min;

[0051] The roll traverse speed is set to 75 m / min.

[0052] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages: The control method for reducing crescent mark damage to rolls in continuous rolling mills provided by this application reduces the stress on the strip at the crescent part, avoids damage to the roll due to the crescent mark, enhances the wear resistance of the roll, and reduces the crescent mark defect in the strip. While ensuring customer product requirements, it achieves a negative RSK value on the surface of the roll, thereby improving the oil retention, oil coating uniformity, corrosion resistance, and appearance quality of automotive steel products. It has a very positive significance for optimizing the industrial structure, enhancing brand effect, improving the quality of automotive steel products, especially the consistency of the beginning and end of the product, reducing strip performance defects, and improving the wear resistance of the roll. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0054] Figure 1a This is a diagram showing the position of the crescent shape of the weld seam under the same width condition in a control method for reducing crescent-shaped damage rolls in continuous rolling mills provided by an embodiment of the present invention.

[0055] Figure 1b This is a diagram showing the position of the crescent shape in the weld seam under the condition of width variation in a control method for reducing crescent-shaped damage rolls in continuous rolling mills provided by an embodiment of the present invention.

[0056] Figure 2a This is a schematic diagram of the transition region in the 3D microscopic morphology image corresponding to Figure 1;

[0057] Figure 2b This is a schematic diagram of the abnormal region in the 3D microscopic morphology image corresponding to Figure 1;

[0058] Figure 2c This is a schematic diagram of the normal region of the 3D microscopic morphology image corresponding to Figure 1;

[0059] Figure 3a for Figure 2a Corresponding two-dimensional data illustration;

[0060] Figure 3b for Figure 2b Corresponding two-dimensional data illustration;

[0061] Figure 3c for Figure 2c Corresponding two-dimensional data illustration;

[0062] Figure 4 A trend chart of unit rolling force, bending roll force, and width;

[0063] Figure 5 Schematic diagram of the setting value for the roll shifting amount of wide-specification strip steel;

[0064] Figure 6 This is a simulation diagram of the crescent-shaped area near the weld of the strip steel being rolled through stands 1-4. Detailed Implementation

[0065] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0066] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0067] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0068] In this application embodiment, the present invention provides a method for controlling crescent-shaped scratches on continuous rolling mill rolls, the method comprising the steps of:

[0069] S1: Reduce the edge rolling force according to the strip width;

[0070] In this embodiment of the application, the step of reducing the edge rolling force according to the strip width includes the following steps:

[0071] Obtain the width of the strip steel;

[0072] The number of bending rollers is increased according to a preset ratio based on the width.

[0073] In this embodiment, during the rolling process of the weld seam, the bending rolls on stands 1-5 automatically increase the bending force of the work rolls, thereby reducing the edge rolling force. Compensation is made according to the strip width; the strip width in the crescent section is reduced by 180mm. When the strip width is 18000mm, the unit rolling force increases by approximately 10%, or about 2000kN. At this point, the bending rolls are increased proportionally to reduce the edge rolling force; the bending roll force is increased by 5% of the rolling force, or about 100kN. This avoids the crescent mark on the roll caused by the increased rolling force in the crescent section of the strip edge due to insufficient bending roll force.

[0074] S2: Reduce the stress on the edge of the strip steel according to the position of the shifting roller;

[0075] In this embodiment of the application, the step of reducing the edge stress of the strip steel according to the position of the shifting roller includes the following steps:

[0076] Get the set roller shift amount;

[0077] Obtain the actual amount of roller shifting;

[0078] Calculate the deviation between the set roll shifting amount and the actual roll shifting amount;

[0079] Calculate the bending roll force compensation value based on the deviation value;

[0080] The stress on the edge of the strip is reduced by the bending roll force compensation value.

[0081] In this embodiment, when the roll shifting position does not reach the set value, the deviation between the set roll shifting amount and the actual roll shifting amount is divided by the roll shifting / rolling force conversion coefficient and multiplied by the bending roll / rolling force conversion coefficient to obtain the bending roll force compensation value required for the intermediate roll roll shifting deviation. By analyzing the influence of rolling force and work roll bending force, and rolling force and work roll roll shifting amount, the relationship between roll shifting amount and bending roll force is established, forming a strip shape control technology system for automatically compensating for roll shifting deviation by bending rolls of the work roll to reduce the force on the strip at the edge crescent position. For wide strip (above 1600mm), increasing the negative roll shifting amount of the intermediate roll is beneficial to reducing the peak of inter-roll contact pressure at the edge position of the strip. To reduce the influence of the intermediate roll CVC roll shape on the crescent mark defect and to reduce the degree of crescent mark defect in wide strip when the crescent passes through the rolling mill, corresponding intermediate roll roll shifting amount settings are given for strips of different widths. When the actual value of the roll shifting does not reach the set value, the roll shifting compensation technology of steel grade transition roll is adopted for control. After compensation, the stress on the edge of the strip is reduced, thereby avoiding crescent-shaped marks damaging the roll.

[0082] S3: Grinding the rolls;

[0083] In this embodiment of the application, the grinding process of the roll includes the following steps:

[0084] The rolls are rough ground;

[0085] The rollers after rough grinding are then subjected to semi-finish grinding;

[0086] The semi-finished rolls are then finely ground.

[0087] In the embodiments of this application, the RSK value of the roughened roll is approximately -0.2 to -0.1, which improves the wear resistance and hardness of the roll surface. According to the roll roughening theory, the lower the roughness of the roll roughening, the lower the grinding roughness of the required roughened base roll, and the more roll peaks are generated, which can effectively improve the roll roughening efficiency and increase the roll hardness and wear resistance.

[0088] In this embodiment of the application, the fine grinding of the semi-finely ground roll includes the following steps:

[0089] Set the Z-axis speed to 700 mm / min ~ 1800 mm / min;

[0090] Set the grinding wheel speed to 14m / s~20m / s;

[0091] Reduce the number of passes by one in each finishing grinding cycle;

[0092] Increase the grinding pressure by 2M% simultaneously for each pass;

[0093] The surface roughness of the rolls is controlled to be 0.60μm~0.70μm.

[0094] In this embodiment, when the semi-finished roll is fine-ground, in the rough grinding step, by increasing the grinding stroke by two passes and appropriately reducing the Z-axis traverse speed of the grinding machine, the grinding pressure of the roll is increased, which can effectively avoid transverse marking defects on the roll surface. In the semi-finish grinding step, the grinding wheel speed is set to 25-22 m / s and gradually decreases, the Z-axis traverse speed is controlled at 2600-2400 mm / min and gradually decreases, and the X-axis feed is controlled at 0.006 mm / min. In the fine grinding step, the Z-axis speed is 1800-700 mm / min and gradually decreases, the grinding wheel speed is set to 20-14 m / s and gradually decreases, each fine grinding stroke is reduced by one pass, and the grinding pressure of each pass is increased by 2M%, so that the surface roughness of the roll is controlled at about 0.65 μm.

[0095] S4: The ground roll is roughened.

[0096] In this embodiment, the center position of the front and rear bearings of the EDM texturing equipment is adjusted so that the deviation between the workpiece center and the machine tool center is controlled within 20μm; the roller bearing position is ground to make its surface smooth and without protrusions, and the micro gap between the roller bearing position and the bearing is less than 10μm, thereby increasing the sliding contact area and reducing vibration.

[0097] In this embodiment, the roll texturing parameters are set as follows: discharge current is set to 2.3, power-on time is set to 13.0, power-off time is set to 6.0, servo voltage is set to -6.5, servo gain is set to 1.2, capacitor value is 22, charging voltage is 130, and the texturing polarity is negative, which can achieve a negative RSK value and effectively improve the roll texturing efficiency, while avoiding problems such as roll texturing leakage or arc discharge.

[0098] In this embodiment, the main spindle speed of the roll is set to 35 m / min, and the lateral movement speed of the roll is set to 75 m / min. This can avoid the "arc" and "burn" phenomena on the roll surface caused by the mismatch between the roll speed and the lateral movement speed, and improve the lateral uniformity of the surface roughness of the roll.

[0099] In this embodiment of the application, the ultra-fine grinding pressure of the roughened roll is set to 0.6 Bar to increase the uniformity of the roll surface roughness and the roll wear resistance.

[0100] In the embodiments of this application, using this operation method can achieve a roughened roll RSK value of approximately -0.2 to -0.1 and a roll surface quality that is qualified without defects such as missing hair or black marks.

[0101] The present application will now be described in detail with reference to specific embodiments.

[0102] Figure 1a This diagram shows the position of the crescent shape of the weld seam when the seam width is the same. Figure 1b This is a diagram showing the position of the crescent shape of the weld seam under varying widths. A three-dimensional optical profilometer was used to inspect the normal areas, abnormal areas with crescent-shaped roller marks, and the transition between the normal and abnormal areas on both plates. Parameters related to the size and shape characteristics of the roughness peaks, such as numerical mean roughness Ra, root mean square roughness Rq, skewness Rsk, and kurtosis Rku, were compared and analyzed.

[0103] Figure 2 shows the 3D microscopic morphology image corresponding to Figure 1. Figure 2a As a transitional area, Figure 2b This is an abnormal area. Figure 2c This is a normal area. Figure 3a for Figure 2a The corresponding two-dimensional data, Figure 3b for Figure 2b The corresponding two-dimensional data, Figure 3c for Figure 2c The corresponding two-dimensional data. Figure 4 This is a trend chart of unit rolling force, bending roll force, and width. Figure 5 The set value for the amount of roll shifting for wide-gauge strip. Figure 6 This is a simulation diagram of the crescent-shaped area near the weld of the strip steel being rolled through stands 1-4.

[0104] In this embodiment, a three-dimensional optical profilometer is used to analyze the three-dimensional morphology of the strip with crescent-shaped defects, allowing for the observation and analysis of the microscopic differences between the crescent-shaped defect area and the normal area. Based on the three-dimensional morphology detection results of the crescent-shaped roll damage defect, it is inferred that the defect, which is then transferred onto the strip after the crescent-shaped roll damage, is caused by the destruction of the surface morphology of a local area on the roll during the process of the crescent passing through the roll gap in the continuous rolling mill, resulting in roll damage and transfer onto the surface of the strip.

[0105] In this embodiment, because the strip width narrows during the crescent-shaped rolling mill process, the unit rolling force increases. At this time, when the mill weld is being rolled, the bending rolls of stands 1-5 automatically increase the bending roll force of the work rolls, thereby reducing the edge rolling force. This avoids the increase in rolling force on the crescent-shaped part of the strip edge due to the small bending roll force, which would otherwise result in a crescent-shaped mark on the roll.

[0106] In the embodiments of this application, further data fitting reveals that the bending force FB of the work roll satisfies the formula for the unit rolling force FW:

[0107] k = dFB / dFW = f(W); (1-1)

[0108] In the formula: f(W) is a function of width.

[0109] While the model constructed in this way ensures the accuracy of the preset values, it cannot effectively adjust when the rolling force changes. Due to system limitations, the MTR (data tracking) cannot continue to receive preset values ​​after welding is completed. Therefore, it is also necessary to add a function to reduce the edge rolling force in the primary basic automation system so that the bending roll force can be adjusted in a timely manner when the rolling force changes.

[0110] In this embodiment, the mathematical model for reducing the edge rolling force of the crescent region in the weld area is as follows:

[0111] Once the strip begins rolling, the changes in rolling force of the hydraulic cylinders on stands 1-4 are calculated based on the fluctuations in the actual rolling force of the strip during the rolling process.

[0112] ; (1-2)

[0113] In the formula —The actual rolling force value for the i-th cycle;

[0114] —Estimated rolling force.

[0115] Rolling force variation Possible changes in convexity :

[0116] ; (1-3)

[0117] In the formula —The transverse stiffness value of the rolling mill roll gap;

[0118] B – The width of the strip.

[0119] eliminate The change in bending force of the work roll is :

[0120] (1-4)

[0121] In the formula — The efficiency coefficient for adjusting the bending force of the work roll.

[0122] Substituting equation 1-4 into equation 1-3, we get:

[0123] ; (1-5)

[0124] When the fifth stand uses a constant rolling force to level the strip, the roll deflection remains unchanged, and the bending roll force is not output at this time.

[0125] (1-6)

[0126] When the strip width changes during the transition between different steel grades and the crescent-shaped area of ​​the weld, the rolls will shift to maintain the strip shape and crown. During this shifting process, the crown of the strip cannot be maintained. Therefore, we need to bend the rolls in real time to compensate for the changes in the roll shifting and ensure that the roll gap crown remains unchanged. The calculation process mainly uses the following coefficients.

[0127] Based on the deviation between the set roll shifting amount and the actual roll shifting amount, divide by the roll shifting / rolling force conversion coefficient, and multiply by the bending roll / rolling force conversion coefficient to obtain the bending roll force compensation value required for the intermediate roll shifting deviation. The above four parts are superimposed to form the bending roll comprehensive value, which is output to L1 for control. The actual bending roll will undergo dead zone correction. The timing sequence of the bending roll compensation roll shifting control is as follows: when the weld seam passes through a certain stand, the bending roll compensation of that stand is triggered. For example, when the weld seam passes through stand #1, the roll shifting on stand #1 begins to shift, and the bending roll compensation roll shifting deviation compensation on stand #1 is triggered. Similarly, the same applies to stands #2-5.

[0128] In this embodiment, a steel grade and specification transition bend roll compensation roll shifting technology is established. By analyzing the influence of rolling force and bending forces of work rolls and intermediate rolls, as well as the influence of rolling force and intermediate roll shifting amount, the relationship between shifting amount and bending forces of work rolls and intermediate rolls is established, forming a strip shape control technology system that automatically compensates for shifting deviation of work roll bending rolls to reduce the stress on strip at the edge crescent position. For wide strip (above 1600mm), increasing the negative shifting amount of intermediate rolls helps to reduce the peak of inter-roll contact pressure at the edge position of the strip. To reduce the influence of intermediate roll CVC roll shape on crescent mark defects and alleviate the degree of crescent mark defects in wide strip when the crescent passes through the rolling mill, corresponding intermediate roll shifting amount settings are given for strips of different widths. When the actual value of the shifting amount does not reach the set value, the steel grade transition bend roll compensation roll shifting technology is used for control.

[0129] When the rolling mill changes specifications, the rolls will shift to maintain the strip shape and crown. However, during this shifting process, the crown of the strip cannot be maintained. Therefore, it is necessary to bend the rolls frequently to compensate for the changes in roll shifting and ensure that the roll gap crown remains unchanged. The calculation process mainly uses the following coefficients.

[0130] Based on the deviation between the set roll shifting amount and the actual roll shifting amount, divide by the roll shifting / rolling force conversion coefficient and multiply by the bending roll / rolling force conversion coefficient to obtain the required work roll and intermediate roll bending roll force compensation values ​​for the intermediate roll shifting deviation.

[0131] △WR=Again×Vgain×dwrbenddivshift / △SHIFT

[0132] △IMR = Again × Vgain × dwrbenddivshift / △SHIFT

[0133] In the formula:

[0134] Again: Proportional gain, set to 0.8;

[0135] Vgain: Speed ​​gain;

[0136] dwrbenddivshift=△WR / △SHIFT: Conversion coefficient between bending and shifting work rolls;

[0137] dwrbenddivshift=△IMR / △SHIFT: Conversion coefficient between intermediate roll bending and roll shifting;

[0138] △SHIFT1: Sets the difference between the actual and the shifted roller.

[0139] In this embodiment, the Rsk value can be positive or negative. This value is the main influencing factor on the roll hardness during the electrical discharge machining (EDM) texturing process. The magnitude of the roll's Rsk value mainly reflects the deviation of the rough peaks in the surface morphology from the centerline. A negative Rsk value indicates that more than 50% of the rough peaks are located above the centerline, and the surface rough peaks resemble ravines in a plateau. Therefore, when the roll's Rsk value is negative, the roll surface hardness is higher and more wear-resistant. The surface morphology of the strip is a reflection of the roll's surface morphology onto the strip, and the roll morphology exhibits characteristics opposite to those of the strip. Therefore, if the sheet material requires a positive Rsk value, the roll needs to be texturized to a negative Rsk value. The morphology and distribution of the roll surface are reflected onto the strip surface through the rolling force. Therefore, a negative Rsk value on the roll surface can improve the roll's wear resistance.

[0140] Grinding base roll roughness: According to the roll texturing theory, the lower the texturing roughness of the roll, the lower the grinding roughness of the required texturing base roll, and the more roll peaks are generated. This can effectively improve the texturing efficiency of the roll, and increase the roll hardness and wear resistance. Therefore, for texturing rolls with low roughness and high wear resistance, the preparation technology for high wear-resistant negative RSK rolls requires the roughness of the grinding base roll to be controlled below 0.3 μm. The specific grinding process parameters are shown in Table 1.

[0141] Table 1 Grinding process parameters for negative RSK roll preparation

[0142]

[0143] Table 2 shows the negative RSK roll preparation and chrome plating technology for rolls designed to improve roll hardness, enhance roll wear resistance, and prevent strip crescent marks from being imprinted onto the rolls and causing crescent mark damage.

[0144] Table 2 Texturing process parameters for negative RSK rolls

[0145]

[0146] Using this method, the RSK value of the roughened roll can be around -0.2 to -0.1, and the roll surface quality can be qualified without defects such as missing hair or black marks.

[0147] Steel coils produced using the negative RSK roll process, which involves the above-mentioned roll grinding and texturing processes, exhibit denser surface peaks with lower peak heights, resulting in enhanced wear resistance. While meeting customer requirements, this process achieves a negative RSK value on the roll surface, thereby improving the oil retention, oil coating uniformity, corrosion resistance, and appearance quality of automotive steel products. This is of great significance for optimizing industrial structure, enhancing brand effect, and improving operational efficiency. It also effectively avoids the crater-like marking effect on the strip steel surface.

[0148] This application provides a method for controlling crescent-shaped marks on strip rolls in continuous rolling mills. By reducing the stress on the strip at the crescent-shaped area, the method avoids damage to the roll due to crescent marks, enhances the wear resistance of the roll, and reduces crescent-shaped mark defects on the strip. While ensuring customer product requirements, it achieves a negative RSK value on the roll surface, thereby improving the oil retention, oil coating uniformity, corrosion resistance, and appearance quality of automotive steel products. This method has significant positive implications for optimizing industrial structure, enhancing brand effect, improving the quality of automotive steel products, especially the consistency of product head and tail, reducing strip performance defects, and improving roll wear resistance.

[0149] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The above descriptions are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

[0150] In summary, the above description is merely a preferred embodiment of the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling crescent-shaped damage rolls in continuous rolling mills, characterized in that, The method includes the following steps: Reduce the edge rolling force according to the strip width; The stress on the edge of the strip is reduced by adjusting the position of the roller; The rolls are ground. The milled rolls are then roughened.

2. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 1, characterized in that, The method of reducing the edge rolling force based on the strip width includes the following steps: Obtain the width of the strip steel; The number of bending rollers is increased according to a preset ratio based on the width.

3. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 1, characterized in that, The step of reducing the edge stress of the strip steel according to the position of the shifting roller includes the following steps: Get the set roller shift amount; Obtain the actual amount of roller shifting; Calculate the deviation between the set roll shifting amount and the actual roll shifting amount; Calculate the bending roll force compensation value based on the deviation value; The stress on the edge of the strip is reduced by the bending roll force compensation value.

4. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 1, characterized in that, The grinding process of the roll includes the following steps: The rolls are rough ground; The rollers after rough grinding are then subjected to semi-finish grinding; The semi-finished rolls are then finely ground.

5. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 4, characterized in that, The semi-finishing of the roll after rough grinding includes the following steps: Set the grinding wheel speed to 22m / s~25m / s; Set the Z-axis lateral traverse speed to 2400 mm / min ~ 2600 mm / min; Set the X-axis feed rate to 0.006 mm / min.

6. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 4, characterized in that, The fine grinding of the roll after the semi-fine grinding includes the following steps: Set the Z-axis speed to 700 mm / min ~ 1800 mm / min; Set the grinding wheel speed to 14m / s~20m / s; Reduce the number of passes by one in each finishing grinding cycle; Increase the grinding pressure by 2M% simultaneously for each pass; The surface roughness of the rolls is controlled to be 0.60μm~0.70μm.

7. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 1, characterized in that, The roughening treatment of the ground roll includes the following steps: Adjust the position of the front and rear bearings of the EDM texturing equipment; Set the roll texturing parameters; Set the spindle speed of the rolls.

8. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 7, characterized in that, The adjustment of the front and rear bearing positions of the electrical discharge texturing equipment includes the following steps: The deviation between the workpiece center and the machine tool center should be less than or equal to 20μm; The minimum clearance between the roll bearing and the bearing pad is controlled to be less than 10 μm.

9. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 7, characterized in that, The process of setting the roll texturing parameters includes the following steps: The discharge current of the rolls is set to 2.3I; The energizing time of the rolls is set to 13.0 seconds; The power-off time for the rolling mill rolls is set to 6.0 minutes. Set the roll servo voltage to -6.5V; Set the roll servo gain to 1.2%; The roll capacitance is set to 22A; Set the roll charging voltage to 130V.

10. The control method for reducing crescent-shaped damage rolls in continuous rolling mills according to claim 7, characterized in that, Setting the spindle speed of the rolls includes the following steps: Set the main shaft speed of the rolls to 35 m / min; The roll traverse speed is set to 75 m / min.

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