Method for reducing transverse same-plate difference of silicon steel product

Abstract

The invention provides a method for reducing the transverse same-plate difference of a silicon steel product. The method comprises the following steps that S1, the original roller convexity of a cold-rolled silicon steel rolling mill is increased; s2, upper and lower middle rollers of the cold-rolled silicon steel rolling mill are moved, and the axial movement positions of the upper and lower middle rollers are determined according to the width of the strip steel; s3, adjusting the bending roller of the cold-rolled silicon steel rolling mill according to the rolling reduction rate: increasing the forward bending extension amount of the bending roller of the cold-rolled silicon steel rolling mill; s4, the total reduction rate of the cold-rolled silicon steel rolling mill is increased; s5, the strip steel tension of the cold-rolled silicon steel rolling mill is increased; and S6, the same-plate difference of the cold-rolled strip steel is reduced, and meanwhile the plate shape is improved. According to the method, the transverse same-plate difference of the silicon steel cold-rolled strip steel can be reduced to 0.0048-0.0051, and the requirements of manufacturers of motors, transformers and the like on the transverse same-plate difference of silicon steel products are met.

Description

Technical Field

[0001] The invention relates to the technical field of cold rolling technology, and in particular to a method for reducing the lateral plate difference of silicon steel products. Background Art

[0002] The same plate difference is the maximum value of the thickness difference between any two points of the same strip, which can be used to indicate the surface flatness and processing accuracy of the strip. The smaller the same plate difference, the higher the flatness of the strip and the higher the processing accuracy. In the process of hot rolling or cold rolling of electrical steel at home and abroad, the lateral thickness deviation of the strip is generally reduced by adjusting and controlling the convexity, edge drop and straightness of the strip, and the adjustment capacity is relatively limited. At present, the same plate difference of cold-rolled strip in China is between 0.008 and 0.01mm, while silicon steel products require the lateral same plate difference of the strip to be less than 0.007mm. Limited by many complex factors such as roll bounce, elastic deformation, uneven wear of rolls, thermal convexity, roll bending, roll shifting, uneven temperature along the width of the strip plate, uneven local deformation resistance caused by uneven strip material properties, it is very difficult to stably reduce the same plate difference of the strip to a lower level. Therefore, how to reduce / reduce the same plate difference has become a very important issue in the field of production research. Summary of the invention

[0003] According to the technical problem raised above, a method for reducing the lateral plate difference of silicon steel products is provided.

[0004] The technical means adopted by the present invention are as follows:

[0005] A method for reducing the transverse plate difference of silicon steel products comprises the following steps:

[0006] S1. Increase the original roll crown of the cold-rolled silicon steel mill;

[0007] S2, moving the upper and lower intermediate rollers of the cold-rolled silicon steel mill, and determining the axial movement positions of the upper and lower intermediate rollers according to the width of the strip;

[0008] S3. Adjust the bending roll of the cold-rolled silicon steel mill according to the rolling reduction rate: increase the positive bending extension of the bending roll of the cold-rolled silicon steel mill;

[0009] S4, increase the total reduction rate of the cold-rolled silicon steel mill;

[0010] S5, increase the strip tension of the cold-rolled silicon steel mill;

[0011] S6. Reduce the difference between cold-rolled strip and plate, and improve the plate shape.

[0012] Furthermore, in the step S1, the original roll crown of the cold-rolled silicon steel mill is 50 to 60 microns.

[0013] Further, in step S2, the smaller the strip width is, the greater the distance that the position of point A on the left side of the upper intermediate roller moves to the right of point L on the left side of the strip, and the greater the distance that the position of point B on the right side of the lower intermediate roller moves to the left of point R on the right side of the strip; the greater the strip width is, the smaller the distance that the position of point A on the left side of the upper intermediate roller moves to the right of point L on the left side of the strip, and the smaller the distance that the position of point B on the right side of the lower intermediate roller moves to the left of point R on the right side of the strip.

[0014] Furthermore, when the strip width is greater than 1200 mm and less than 1500 mm, the upper intermediate roll point A is located 10 mm to the left of the corresponding strip point L; the lower intermediate roll point B is located 10 mm to the right of the corresponding strip point R;

[0015] When the strip width is greater than 1100mm and less than 1200mm, point A of the upper intermediate roller is aligned with point L of the strip; point B of the lower intermediate roller is aligned with point R of the strip;

[0016] When the strip width is greater than 1000mm and less than 1100mm, the upper intermediate roller point A is 2mm to the right of the corresponding strip point L; the lower intermediate roller point B is 2mm to the left of the corresponding strip point R;

[0017] When the strip width is greater than 800mm and less than 1000mm, point A of the upper intermediate roller is 10mm to the right of point L of the corresponding strip; point B of the lower intermediate roller is 10mm to the left of point R of the corresponding strip.

[0018] Further, in step S3, when the total reduction ratio of the cold-rolled silicon steel mill is greater than 70% and less than 75%, the positive bend extension length is 18 mm;

[0019] When the total reduction ratio of the cold-rolled silicon steel mill is greater than 75% and less than 80%, the positive bend extension length is 26mm;

[0020] When the total reduction ratio of the cold-rolled silicon steel mill is greater than 80% and less than 85%, the positive bend extension length is 34mm;

[0021] When the total reduction rate of the cold-rolled silicon steel mill is greater than 85% and less than 89%, the positive bend extension length is 45mm.

[0022] Further, in step S4, the total reduction rate is the percentage of the ratio of the thickness of the incoming material before rolling minus the thickness after rolling to the thickness of the incoming material before rolling, and the total reduction rate satisfies the following formula: ε=(T1-T2)÷T1×100%, where ε is the total reduction rate, T1 is the thickness of the incoming material before rolling, and T2 is the thickness after rolling;

[0023] The difference between the same plate before rolling and the same plate after rolling is equal to the elongation coefficient of the strip steel. The elongation coefficient is the ratio of the incoming material thickness before rolling to the thickness after rolling. The elongation coefficient satisfies the following formula λ=T1 / T2=Δ / δ, and δ=Δ / λ=1 / (1-ε), where Δ is the difference between the same plate of the raw material and δ is the difference between the same plate after rolling.

[0024] It is concluded that the greater the total reduction rate ε, the greater the elongation coefficient λ, and the smaller the same-plate difference δ after rolling; by increasing the total cold rolling reduction rate, the transverse same-plate difference in the width direction of the strip, which is larger on one side and smaller on the other side, can be reduced, and the transverse same-plate difference in the width direction of the strip, which is higher in the middle and lower on both sides, can also be reduced.

[0025] Furthermore, in step S4, the method of increasing the total reduction ratio of the cold-rolled silicon steel mill includes:

[0026] S41, increasing the total reduction rate by increasing the incoming material thickness under the condition of constant rolling thickness;

[0027] S42, reducing the transmission load and rolling pressure by increasing the rolling passes;

[0028] S43. Determine the incoming material thickness according to different steel grades and rolling thickness.

[0029] Furthermore, in the step S5, the rear tension and the front tension of each rolling pass of the steel strip are increased, and the rear tension and the front tension are set for the added rolling passes.

[0030] Furthermore, in step S6, according to the difference value of the hot-rolled strip, each pass from the first to the Nth pass of rolling is corrected; from the N+1th pass to the last pass, the reduction rate of a single pass is reduced to adjust the plate shape; wherein, the N value is determined according to different incoming materials.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. Through the implementation of the method of the present invention, the transverse plate difference of silicon steel cold-rolled strip is reduced to 0.0048-0.0051, which meets the requirements of motor, transformer and other manufacturers for the transverse plate difference of silicon steel products.

[0033] 2. The present invention increases the original roll crown of the cold-rolled silicon steel mill, which is beneficial to reducing the harmful effects of the elastic bending deformation of the rolls during the rolling process on both sides of the strip and reducing the transverse plate difference in the width direction of the strip, which is higher in the middle and lower at both ends.

[0034] 3. The axial movement of the intermediate roller of the cold-rolled silicon steel mill of the present invention can reduce the elastic bending deformation of the working roller, and adjusting the moving position of the intermediate roller can reduce the transverse plate difference in the width direction of the strip, that is, the middle is higher and the two sides are lower.

[0035] 4. The present invention increases the positive bending extension of the bending cylinder of the cold-rolled silicon steel rolling mill to offset the bending deflection of the roll caused by the rolling pressure, reduce the effect of the roll on the edge of the strip, and thus reduce the transverse plate difference in the width direction of the strip, which is higher in the middle and lower on both sides.

[0036] 5. The present invention increases the cold rolling reduction rate to reduce the transverse plate difference in the width direction of the strip, which is larger on one side and smaller on the other side, and can also reduce the transverse plate difference in the width direction of the strip, which is higher in the middle and lower on both sides.

[0037] 6. The invention increases the strip tension of the cold-rolled silicon steel mill to keep the strip in a centered state, and is not prone to produce a transverse plate difference in which one side of the strip has a larger thickness and the other side has a smaller thickness in the width direction of the strip; increasing the strip tension can reduce the rolling pressure and reduce the elastic bending deformation of the rollers, thereby reducing the transverse plate difference in which the strip is higher in the middle and lower on both sides in the width direction. As the strip tension increases, the resistance to the longitudinal extension of the strip decreases, and the resistance to the extension in the width direction increases, which is also conducive to reducing the transverse plate difference in which the strip is higher in the middle and lower on both sides in the width direction of the strip.

[0038] 7. The present invention reduces the difference between cold-rolled strip and plate and improves the plate shape at the same time.

[0039] Based on the above reasons, the present invention can be widely promoted in the fields of cold rolling process and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 Flow chart of the method of the present invention.

[0042] Figure 2 The present invention is a schematic diagram of adjusting the position of the intermediate roller of a cold-rolled silicon steel mill, wherein (a) is a schematic diagram of the intermediate roller in the initial position, and b is a schematic diagram of the position of the intermediate roller after movement.

[0043] Figure 3 Schematic diagrams of large wedge-shaped incoming material and the upper roller being swung to an angle of 3°, the same as the upper surface of the strip, where (a) is a schematic diagram of large wedge-shaped incoming material, and b is a schematic diagram of the upper roller being swung to an angle of 3°, the same as the upper surface of the strip. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0047] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0048] Example 1

[0049] The present invention provides a method for reducing the transverse plate difference of silicon steel products, which can reduce the transverse plate difference of silicon steel products to below 0.006, comprising the following steps:

[0050] 1. Increase the original roll crown of the cold-rolled silicon steel mill;

[0051] The surface of the roll is a curve shape, and the roll crown is the difference between the diameter of the middle part of the roll and the diameter of the two ends of the roll. The original roll crown is the crown of the roll before it is put on the machine and not heated. Increasing the original roll crown of the cold-rolled silicon steel mill is conducive to reducing the harmful effects of the elastic bending deformation of the roll during the rolling process on both sides of the strip, and reducing the transverse plate difference in the width direction of the strip, which is high in the middle and low at the two ends.

[0052] 2. Adjust the position of the intermediate roller of the cold-rolled silicon steel mill;

[0053] The axial movement of the intermediate roll of the cold-rolled silicon steel mill can reduce the elastic bending deformation of the working roll. Adjusting the moving position of the intermediate roll can reduce the transverse plate difference in the width direction of the strip, where the middle is higher and the two sides are lower.

[0054] 3. Increase the positive bending extension of the bending roll of the cold-rolled silicon steel rolling mill;

[0055] Increasing the positive bending extension of the bending cylinder of the cold-rolled silicon steel rolling mill can offset the bending deflection of the roll caused by the rolling pressure, reduce the effect of the roll on the edge of the strip, and thus reduce the transverse plate difference in the width direction of the strip, where the middle is higher and the sides are lower.

[0056] 4. Increase the total reduction rate of cold-rolled silicon steel mill;

[0057] The total reduction rate is the percentage of the ratio of the thickness of the incoming material before rolling to the thickness after rolling; the total reduction rate satisfies the following formula: ε=(T1-T2)÷T1×100%, where ε is the total reduction rate, T1 is the thickness of the incoming material before rolling, and T2 is the thickness after rolling; the elongation coefficient is the ratio of the thickness of the incoming material before rolling to the thickness after rolling. According to the formula: the difference between the same plate before rolling divided by the difference between the same plate after rolling is equal to the elongation coefficient of the strip, that is: λ=Δ / δ, which is rearranged to obtain δ=Δ / λ=1 / (1-ε), where λ is the elongation coefficient; Δ is the difference between the same plate of the raw material; δ is the difference between the same plate after rolling. The greater the total reduction rate ε of cold rolling, the greater the elongation coefficient λ, and the smaller the difference between the same plate after rolling δ. Therefore, increasing the cold rolling reduction rate can reduce the transverse difference between the same plate in the width direction of the strip, which is large on one side and small on the other side, and can also reduce the transverse difference between the same plate in the width direction of the strip, which is high in the middle and low on both sides.

[0058] 5. Increase the strip tension of the cold-rolled silicon steel mill;

[0059] Increasing the strip tension of the cold-rolled silicon steel mill can keep the strip in a centered state, and it is not easy to produce a transverse plate difference in the width direction of the strip, where one side has a larger thickness than the other side; increasing the strip tension can reduce the rolling pressure and reduce the elastic bending deformation of the rollers, thereby reducing the transverse plate difference in the width direction of the strip, where the middle is higher and the two sides are lower; due to the increase in strip tension, the resistance to longitudinal extension of the strip is reduced, and the resistance to extension in the width direction is increased, which is also beneficial to reducing the transverse plate difference in the width direction of the strip, where the middle is higher and the two sides are lower.

[0060] 6. Reduce the difference between cold-rolled strip and improve the plate shape.

[0061] If the production method is not correct, a significant reduction in the plate difference in one pass of the hot-rolled material will cause the plate shape to deteriorate. Therefore, the cold rolling process needs to improve the plate shape while reducing the plate difference of the strip.

[0062] Example 2

[0063] The present invention provides a method for reducing the transverse plate difference of silicon steel products, comprising the following steps:

[0064] 1. Increase the original roll crown of the cold-rolled silicon steel mill

[0065] The original roller crown of the prior art cold-rolled silicon steel mill is 26 to 38 microns. The present invention increases the original roller crown of the cold-rolled silicon steel mill to 50 to 60 microns.

[0066] 2. Adjust the position of the intermediate roller of the cold-rolled silicon steel mill ( Figure 2 )

[0067] The position of the intermediate roller is adjusted according to the width of the strip. The smaller the width of the strip, the greater the elastic bending deformation of the roller, and the greater the transverse plate difference in the width direction of the strip, where the middle is higher and the two sides are lower. In the prior art, regardless of the width of the strip, the position of point A of the upper intermediate roller is aligned with the position of point L of the strip; the position of point B of the lower intermediate roller is aligned with the position of point R of the strip. The present invention determines the moving position of the intermediate roller based on the width of the strip. The smaller the width of the strip, the greater the distance that the position of point A of the upper intermediate roller moves to the right of point L of the strip, and the greater the distance that the position of point B of the lower intermediate roller moves to the left of point R of the strip. The greater the width of the strip, the smaller the distance that the position of point A of the upper intermediate roller moves to the right of point L of the strip, and the smaller the distance that the position of point B of the lower intermediate roller moves to the left of point R of the strip.

[0068] 1. Strip width is greater than 1200mm and less than 1500mm: Point A of the upper intermediate roller is 10mm to the left of point L of the corresponding strip; point B of the lower intermediate roller is 10mm to the right of point R of the corresponding strip.

[0069] 2. Strip width is greater than 1100mm and less than 1200mm: point A of the upper intermediate roller is aligned with point L of the strip; point B of the lower intermediate roller is aligned with point R of the strip.

[0070] 3. Strip width is greater than 1000mm and less than 1100mm: point A of the upper intermediate roller is 2mm to the right of point L of the corresponding strip; point B of the lower intermediate roller is 2mm to the left of point R of the corresponding strip.

[0071] 4. Strip width is greater than 800mm and less than 1000mm: point A of the upper intermediate roller is 10mm to the right of point L of the corresponding strip; point B of the lower intermediate roller is 10mm to the left of point R of the corresponding strip.

[0072] 3. Increase the positive bend extension of the bending roll of the cold-rolled silicon steel rolling mill

[0073] The cold rolling bending roll adjustment is based on the rolling reduction rate. The reduction rate is the percentage of the ratio of the thickness before rolling minus the thickness after rolling to the thickness before rolling (the percentage of the ratio of the thickness of the incoming material before rolling minus the thickness after rolling to the thickness of the incoming material before rolling).

[0074] 1. When the total reduction ratio of the cold-rolled silicon steel mill is greater than 70% and less than 75%, the positive bending extension length of the bending roll cylinder in the prior art is 12 mm, while the positive bending extension length of the present invention is 18 mm.

[0075] 2. When the total reduction rate of the cold-rolled silicon steel mill is greater than 75% and less than 80%, the positive bending extension length of the bending roll cylinder in the prior art is 18 mm; while the positive bending extension length of the present invention is 26 mm.

[0076] 3. When the total reduction rate of the cold-rolled silicon steel mill is greater than 80% and less than 85%, the positive bending extension length of the bending roll cylinder in the prior art is 26 mm; while the positive bending extension length of the present invention is 34 mm.

[0077] 4. When the total reduction rate of the cold-rolled silicon steel mill is greater than 85% and less than 89%, the positive bending extension length of the bending roll cylinder in the prior art is 36 mm; while the positive bending extension length of the present invention is 45 mm.

[0078] 4. Increase the total reduction rate of cold-rolled silicon steel mill

[0079] The first step to increase the total reduction rate of cold-rolled silicon steel mills: increase the total reduction rate by increasing the incoming material thickness under the condition of constant rolling thickness. The second step to increase the total reduction rate of cold-rolled silicon steel mills: reduce the transmission load and rolling pressure by increasing the number of rolling passes. The third step to increase the total reduction rate of cold-rolled silicon steel mills: determine the incoming material thickness according to different steel grades and rolling thicknesses.

[0080] 1. 50W470, 50W600, 50W800 grades of steel.

[0081] Existing technology: incoming material thickness 2.55mm; rolling thickness 0.495mm; total reduction rate 80.58%. Single-stand reversible rolling mill with 5 rolling passes.

[0082] The present invention has the following characteristics: the incoming material thickness is 2.72mm, the rolling thickness is 0.495mm, the total reduction ratio is 82%, and the single-stand reversible rolling mill has 6 rolling passes.

[0083] 2. 50W1000, 50W1300 grade steel.

[0084] Existing technology: incoming material thickness 2.55mm; rolling thickness 0.495mm; total reduction rate 80.58%. Single-stand reversible rolling mill with 5 rolling passes.

[0085] The present invention has the following characteristics: the incoming material thickness is 2.72mm, the rolling thickness is 0.495mm, the total reduction ratio is 82%, and the single-stand reversible rolling mill has 6 rolling passes.

[0086] 3. 50W800 grade steel.

[0087] Existing technology: incoming material thickness 2.9mm; rolling thickness 0.495mm; total reduction rate 82.93%. Single-stand reversible rolling mill with 6 rolling passes.

[0088] The present invention has the following characteristics: the incoming material thickness is 3.1 mm, the rolling thickness is 0.495 mm, the total reduction ratio is 84%, and the single-stand reversible rolling mill has 8 rolling passes.

[0089] 4. 50W1000, 50W1300 grade steel.

[0090] Existing technology: incoming material thickness 2.9mm; rolling thickness 0.495mm; total reduction rate 82.93%; single-stand reversible rolling mill with 6 rolling passes.

[0091] The present invention has the following characteristics: the incoming material thickness is 3.1 mm, the rolling thickness is 0.495 mm, the total reduction ratio is 84%, and the single-stand reversible rolling mill has 8 rolling passes.

[0092] 5. Increase the strip tension of cold-rolled silicon steel mill:

[0093] 1. 50W470, 50W600, 50W800 grade steel, 2.55mm, rolled 0.495mm.

[0094] Existing technology: the rear tension of the first pass rolled strip is 37.81KN and the front tension is 87.24KN; the rear tension of the second pass rolled strip is 87.24KN and the front tension is 131KN; the rear tension of the third pass rolled strip is 131KN and the front tension is 183KN; the rear tension of the fourth pass rolled strip is 183KN and the front tension is 200KN; the rear tension of the fifth pass rolled strip is 200KN and the front tension is 60KN.

[0095] The present invention: the rear tension of the rolled steel strip in the first pass is 40.62KN, and the front tension is 95.71KN; the rear tension of the rolled steel strip in the second pass is 95.71KN, and the front tension is 143KN; the rear tension of the rolled steel strip in the third pass is 143KN, and the front tension is 196KN; the rear tension of the rolled steel strip in the fourth pass is 196KN, and the front tension is 215KN; the rear tension of the rolled steel strip in the fifth pass is 215KN, and the front tension is 143KN; the rear tension of the rolled steel strip in the sixth pass is 143KN, and the front tension is 77KN.

[0096] 2. 50W1000, 50W1300 grade steel, 2.55mm, rolled 0.495mm.

[0097] Existing technology: the rear tension of the first pass rolled strip is 35.21KN and the front tension is 87.24KN; the rear tension of the second pass rolled strip is 87.24KN and the front tension is 131KN; the rear tension of the third pass rolled strip is 131KN and the front tension is 183KN; the rear tension of the fourth pass rolled strip is 183KN and the front tension is 199KN; the rear tension of the fifth pass rolled strip is 199KN and the front tension is 60KN.

[0098] The present invention: the rear tension of the rolled steel strip in the first pass is 40.62KN, and the front tension is 95.71KN; the rear tension of the rolled steel strip in the second pass is 95.71KN, and the front tension is 143KN; the rear tension of the rolled steel strip in the third pass is 143KN, and the front tension is 196KN; the rear tension of the rolled steel strip in the fourth pass is 196KN, and the front tension is 215KN; the rear tension of the rolled steel strip in the fifth pass is 215KN, and the front tension is 143KN; the rear tension of the rolled steel strip in the sixth pass is 143KN, and the front tension is 77KN.

[0099] 3. 50W800 steel grade. 2.9mm rolled to 0.495mm.

[0100] Existing technology: the tension after the first pass of rolling the strip is 32.64KN, and the front tension is 73.55KN; the tension after the second pass of rolling the strip is 73.55KN, and the front tension is 106KN; the tension after the third pass of rolling the strip is 106KN, and the front tension is 146KN; the tension after the fourth pass of rolling the strip is 146KN, and the front tension is 194KN; the tension after the fifth pass of rolling the strip is 194KN, and the front tension is 200KN; the tension after the sixth pass of rolling the strip is 200KN, and the front tension is 60KN.

[0101] The present invention: the tension after the first pass of rolling the strip is 40.2KN, and the front tension is 85.6KN; the tension after the second pass of rolling the strip is 85.6KN, and the front tension is 121KN; the tension after the third pass of rolling the strip is 121KN, and the front tension is 162KN; the tension after the fourth pass of rolling the strip is 162KN, and the front tension is 211KN; the tension after the fifth pass of rolling the strip is 211KN, and the front tension is 225KN; the tension after the sixth pass of rolling the strip is 225KN, and the front tension is 231KN; the tension after the seventh pass of rolling the strip is 231KN, and the front tension is 243KN; the tension after the eighth pass of rolling the strip is 243KN, and the front tension is 87KN;

[0102] 4. 50W1000, 50W1300 grade steel, 2.9mm, rolled 0.495mm.

[0103] Existing technology: the rear tension of the first pass of rolled strip is 30.96KN, and the front tension is 73.55KN; the rear tension of the second pass of rolled strip is 73.55KN, and the front tension is 106KN; the rear tension of the third pass of rolled strip is 106KN, and the front tension is 146KN; the rear tension of the fourth pass of rolled strip is 146KN, and the front tension is 194KN; the rear tension of the fifth pass of rolled strip is 194KN, and the front tension is 200KN; the rear tension of the sixth pass of rolled strip is 200KN, and the front tension is 60KN.

[0104] The present invention has the following characteristics: the rear tension of the rolled steel strip in the first pass is 40.2KN, and the front tension is 85.6KN; the rear tension of the rolled steel strip in the second pass is 85.6KN, and the front tension is 121KN; the rear tension of the rolled steel strip in the third pass is 121KN, and the front tension is 162KN; the rear tension of the rolled steel strip in the fourth pass is 162KN, and the front tension is 211KN; the rear tension of the rolled steel strip in the fifth pass is 211KN, and the front tension is 225KN; the rear tension of the rolled steel strip in the sixth pass is 225KN, and the front tension is 231KN; the rear tension of the rolled steel strip in the seventh pass is 231KN, and the front tension is 243KN; the rear tension of the rolled steel strip in the eighth pass is 243KN, and the front tension is 87KN.

[0105] 6. Reducing the difference between cold-rolled strip and improving the plate shape

[0106] 1. According to the difference value of the hot-rolled strip with the same plate, from the first pass to the fifth pass, each pass is corrected a little. If the correction is too large at one time, it will cause a larger wave shape, making rolling impossible.

[0107] 2. From the sixth to the seventh pass, reduce the reduction rate of each pass to adjust the plate shape.

[0108] 3. Take the cold rolling production method of hot-rolled large wedge-shaped incoming materials as an example. Figure 3 shown.

[0109] Large wedge-shaped incoming material refers to hot-rolled strip with one side thicker than the other. In order to obtain a good strip shape, the upper roll must be tilted at the same 3° angle as the upper surface of the strip, but it is not conducive to reducing the difference between the same strips; if the upper roll is tilted parallel to the roll gap, the difference between the same strips can be greatly reduced, but a large wave shape will appear on the higher side of the strip. In this case, it is necessary to consider both reducing the difference between the same strips and rolling out a good strip shape. By adjusting the tilt value of the roll:

[0110] In the first pass, the upper roller A side is pressed down 4 microns more than the upper roller B side, and a slight wave shape is allowed on the left side of the strip after it is rolled out;

[0111] In the second pass, the upper roll A side is pressed down 4 microns more than the upper roll B side, and a slight wave shape is allowed on the left side of the strip after it is rolled out;

[0112] In the third pass, the upper roller A side is pressed down 4 microns more than the upper roller B side, and a slight wave shape is allowed on the left side of the strip after it is rolled out;

[0113] In the fourth pass, the upper roll A side is pressed down 4 microns more than the upper roll B side, and a slight wave shape is allowed on the left side of the strip after it is rolled out;

[0114] In the fifth pass, the upper roll A side is pressed down 4 microns more than the B side, and a slight wave shape is allowed on the left side of the strip after it is rolled out;

[0115] The sixth and seventh passes use a small reduction rate, with the upper and lower rolls parallel to adjust the plate shape.

[0116] During the first to fifth rolling passes, if no single-sided wave shape appears on the left side of the strip, the difference between the rolled strip and the plate will not decrease.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 reducing the transverse plate difference of silicon steel products, characterized in that: The steps include: S1. Increase the original roll crown of the cold-rolled silicon steel mill; S2, moving the upper and lower intermediate rollers of the cold-rolled silicon steel mill, and determining the axial movement positions of the upper and lower intermediate rollers according to the width of the strip; S3. Adjust the bending roll of the cold-rolled silicon steel mill according to the rolling reduction rate: increase the positive bending extension of the bending roll of the cold-rolled silicon steel mill; S4, increase the total reduction rate of the cold-rolled silicon steel mill; S5, increase the strip tension of the cold-rolled silicon steel mill; S6. Reduce the difference between cold-rolled strip and plate, and improve the plate shape.

2. The method for reducing the transverse plate difference of silicon steel products according to claim 1, characterized in that: In the step S1, the original roll crown of the cold-rolled silicon steel mill is 50 to 60 microns.

3. The method for reducing the transverse plate difference of silicon steel products according to claim 1, characterized in that: In step S2, the smaller the strip width is, the greater the distance that the position of point A on the left side of the upper intermediate roller moves to the right of point L on the left side of the strip, and the greater the distance that the position of point B on the right side of the lower intermediate roller moves to the left of point R on the right side of the strip; The larger the strip width, the smaller the distance that point A on the left side of the upper intermediate roller moves to the right of point L on the left side of the strip, and the smaller the distance that point B on the right side of the lower intermediate roller moves to the left of point R on the right side of the strip.

4. The method for reducing the transverse plate difference of silicon steel products according to claim 3 is characterized in that: When the strip width is greater than 1200mm and less than 1500mm, the upper intermediate roller point A is 10mm to the left of the corresponding strip point L; the lower intermediate roller point B is 10mm to the right of the corresponding strip point R; When the strip width is greater than 1100mm and less than 1200mm, point A of the upper intermediate roll is aligned with point L of the strip; Point B of the lower middle roller is aligned with point R of the strip; When the strip width is greater than 1000mm and less than 1100mm, the upper intermediate roller point A is 2mm to the right of the corresponding strip point L; the lower intermediate roller point B is 2mm to the left of the corresponding strip point R; When the strip width is greater than 800mm and less than 1000mm, point A of the upper intermediate roller is 10mm to the right of point L of the corresponding strip; point B of the lower intermediate roller is 10mm to the left of point R of the corresponding strip.

5. The method for reducing the transverse plate difference of silicon steel products according to claim 1, characterized in that: In step S3, when the total reduction ratio of the cold-rolled silicon steel mill is greater than 70% and less than 75%, the positive bend extension length is 18 mm; When the total reduction ratio of the cold-rolled silicon steel mill is greater than 75% and less than 80%, the positive bend extension length is 26mm; When the total reduction ratio of the cold-rolled silicon steel mill is greater than 80% and less than 85%, the positive bend extension length is 34mm; When the total reduction rate of the cold-rolled silicon steel mill is greater than 85% and less than 89%, the positive bend extension length is 45mm.

6. The method for reducing the transverse plate difference of silicon steel products according to claim 1, characterized in that: In step S4, the total reduction rate is the percentage of the ratio of the thickness of the incoming material before rolling minus the thickness after rolling to the thickness of the incoming material before rolling, and the total reduction rate satisfies the following formula: ε=(T1-T2)÷T1×100%, where ε is the total reduction rate, T1 is the thickness of the incoming material before rolling, and T2 is the thickness after rolling; The difference between the same plate before rolling and the same plate after rolling is equal to the elongation coefficient of the strip steel. The elongation coefficient is the ratio of the incoming material thickness before rolling to the thickness after rolling. The elongation coefficient satisfies the following formula λ=T1 / T2=Δ / δ, and δ=Δ / λ=1 / (1-ε), where Δ is the difference between the same plate of the raw material and δ is the difference between the same plate after rolling. It is concluded that the greater the total reduction rate ε, the greater the elongation coefficient λ, and the smaller the same-plate difference δ after rolling; by increasing the total cold rolling reduction rate, the transverse same-plate difference in the width direction of the strip, which is larger on one side and smaller on the other side, can be reduced, and the transverse same-plate difference in the width direction of the strip, which is higher in the middle and lower on both sides, can also be reduced.

7. The method for reducing the transverse plate difference of silicon steel products according to claim 1 or 6, characterized in that: In step S4, the method of increasing the total reduction ratio of the cold-rolled silicon steel mill includes: S41, increasing the total reduction rate by increasing the incoming material thickness under the condition of constant rolling thickness; S42, reducing the transmission load and rolling pressure by increasing the rolling passes; S43. Determine the incoming material thickness according to different steel grades and rolling thickness.

8. The method for reducing the transverse plate difference of silicon steel products according to claim 7, characterized in that: In the step S5, the rear tension and the front tension of each rolling pass of the steel strip are increased, and the rear tension and the front tension are set for the increased rolling passes.

9. The method for reducing the transverse plate difference of silicon steel products according to claim 1, characterized in that: In step S6, according to the difference value of the hot-rolled strip, each pass from the first to the Nth pass of rolling is corrected; from the N+1th pass to the last pass, the reduction rate of each pass is reduced to adjust the plate shape; wherein, the N value is determined according to different incoming materials.

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