A rolling method for optimizing the edge drop of non-oriented silicon steel

Abstract

The present application relates to a kind of rolling method of optimizing the edge drop of non-oriented silicon steel, using 5 machine frame continuous rolling rolling, meet the quality requirement that edge drop index is lower than 5um, the width range of inlet strip steel is in 1020~1300mm, the thickness range of inlet is in 2.2~2.8mm, the thickness range of outlet is in 0.45~0.55mm strip steel process system includes rolling load distribution relationship, tension setting, rolling force setting, 5 machine frame continuous rolling mill bending roll system, 5 machine frame continuous rolling mill roll roll system roll process parameters and rolling lubrication condition, from work roll roll, work roll bending, intermediate roll bending, rolling load distribution, tension, roll gap etc., formulate process system, realize non-oriented silicon steel in high speed stable rolling, realize non-oriented silicon steel in high speed stable rolling, meet the quality requirement that edge drop index is lower than 5um at the same time, under the premise of meeting the quality requirement, improve the economic benefit of production line.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal material forming, in particular to a rolling method for optimizing the edge drop of non-oriented silicon steel. BACKGROUND

[0002] Edge drop is a common problem encountered in the manufacturing process of cold-rolled silicon steel, and as the requirements for product quality continue to improve, the research and application of edge drop technology have also attracted increasing attention, involving a variety of process technologies that are constantly developing and innovating. One common process technology is the hydraulic bending roll system, which compensates for the bending of the work roll to reduce the thinning of the edge of the strip, while effectively improving the flatness of the product. However, in applications such as cold-rolled silicon steel, the effect of traditional bending roll compensation technology is relatively limited. In order to solve the problem of edge drop, the emergence of new generation high-tech rolling mills has gradually attracted attention, among which the HC rolling mill based on intermediate roll shifting is widely used. Through the shifting operation of the intermediate roll, harmful contact with the work roll is eliminated, reducing the deflection and flattening deformation of the work roll. At the same time, in combination with the bending operation of the work roll, control of the plate crown is achieved, and through the use of a smaller diameter work roll, the impact on edge drop is also reduced. Another common technology is the single taper work roll transverse shifting technology, which moves the tapered section of the work roll inward to compensate for the flattening deformation of the edge caused by the roll gap. At the same time, the shifting of the work roll and the intermediate roll reduces the contact between the backup roll and the work roll, thereby reducing the harmful bending moment generated by the roll on the strip. In practical applications, the single taper work roll transverse shifting technology often uses an optimized taper shape to achieve smooth transitions and improve the control effect of edge drop. There are other technologies, such as taper work roll transverse shifting and cross technology, work roll transverse shifting technology, and work roll local strengthening cooling technology, which have certain effects in reducing the edge drop of the strip, but each has some limitations. Therefore, in actual applications, steel enterprises will select appropriate edge drop process technology and equipment according to product requirements and process characteristics to improve product quality and production efficiency.

[0003] In summary, the development of cold-rolled strip edge drop technology has made certain progress, and technologies such as hydraulic bending roll systems, HC rolling mills, single taper work roll transverse shifting technology, and PC rolling mill cross technology are widely used and continuously innovated and improved to meet the requirements of high-quality products. Despite some technical and process challenges, with further research and technological progress, edge drop technology is expected to be further improved and bring more efficient and high-quality product solutions to the steel industry.

[0004] The paper "Research and application of EVC roll shape design and edge drop control model of cold rolled silicon steel" improves the edge thinning area of the strip, reduces the strip thickness difference and improves the qualified rate of electrical steel by using reasonable EVC roll shape and corresponding edge drop control model. However, the paper does not mention the specific cold continuous rolling process system and the process parameter value range of the work roll shifting.

[0005] The invention patent CN201410143167.3 provides a method for controlling the edge thinning of cold rolled strip by asymmetric shifting of work roll, but does not provide specific work roll shifting amount and important rolling parameter range.

[0006] The invention patent CN202010897197.9 provides a high-silicon non-oriented electrical steel and a production method thereof, which can prevent cold rolling breakage and achieve continuous high-speed rolling, thereby improving the efficiency of cold rolling production. However, the invention does not mention improving the edge drop of silicon steel products, and there is no related process system of work roll shifting in the given rolling parameters of cold continuous rolling. SUMMARY

[0007] The present application provides a rolling method for optimizing the edge drop of non-oriented silicon steel, which improves the edge drop defect of silicon steel products and enhances the quality stability and product quality of the products, thereby bringing huge economic benefits to enterprises.

[0008] To achieve the above purpose, the present application adopts the following technical solutions:

[0009] A rolling method for optimizing the edge drop of non-oriented silicon steel, the silicon steel is rolled by 5-stand continuous rolling, which meets the quality requirement of edge drop index below 5um, the inlet strip width range is 1020-1300mm, the inlet thickness range is 2.2-2.8mm, and the outlet thickness range is 0.45-0.55mm. The strip process system includes the following contents:

[0010] (1) Rolling load distribution relationship: the absolute values of the reduction rates of the 5 stands are 21-30%, 26-37%, 23-34%, 21-30% and 13-18%, respectively;

[0011] (2) Tension setting: the six unit tensions from the inlet of the first stand to the outlet of the fifth stand are set to 60-75MPa, 120-140MPa, 120-140MPa, 130-150MPa, 135-155MPa and 50-55MPa, respectively;

[0012] (3) Rolling force setting: the rolling force from the 1st stand to the 5th stand is set as 7.5-9.6 MN, 8.3-9.8 MN, 8.4-10.2 MN, 6.5-9.2 MN, 5.8-8.8 MN;

[0013] (4) 5-stand continuous rolling mill roll bending system: the work roll bending system from the 1st stand to the 5th stand is set as 700 KN, 700 KN, 700 KN, 650 KN, 306 KN; the intermediate roll bending system is set as 1000 KN, 1000 KN, 1000 KN, 900 KN, 1555 KN from the 1st stand to the 5th stand;

[0014] (5) 5-stand continuous rolling mill roll shifting system: the 5 roll shifting from the 1st stand to the 5th stand is set as 80-115 mm, 80-115 mm, 80-115 mm, 80-115 mm, 80-115 mm; the work roll shifting system is set as 60-75 mm, 45-65 mm, 5-15 mm, 0 mm, 0 mm from the 1st stand to the 5th stand;

[0015] (6) Roll process parameters: the surface roughness of the work roll of the stand is 0.7-1.0 um.

[0016] Further, the 1st to 3rd stands in the roll shifting adopt single taper work rolls, the taper section length is 150-160 mm, and the taper height is between 1 / 350 and 1 / 400 of the length, the 4th to 5th stands do not shift the work roll, and the taper section is a flat roll.

[0017] Further, it further comprises rolling lubrication conditions, and the emulsion concentration in the rolling process is set as 3.4-3.8%.

[0018] Further, the steel grade rolled by the 5-stand continuous rolling mill is 50w600, 50w800, 50w1000 and 50w1300.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1) Starting from the work roll shifting, the work roll bending, the intermediate roll bending, the rolling load distribution, the tension, the roll gap and the like, the process system is formulated to realize the high-speed stable rolling of the non-oriented silicon steel;

[0021] 2) The high-speed stable rolling of the non-oriented silicon steel is realized, and the quality requirement that the edge drop index is lower than 5 um is met;

[0022] 3) On the premise of meeting the quality requirement, the economic benefit of the production line is improved;

[0023] 4) The quality stability of the product is improved, and the product quality brings huge economic benefits to the enterprise. DETAILED DESCRIPTION

[0024] The specific embodiments of the present application are further described below in conjunction with the accompanying drawings:

[0025] The present application is a rolling method for optimizing the edge reduction of non-oriented silicon steel, which adopts five-stand continuous rolling for 50w600, 50w800, 50w1000, and 50w1300 silicon steel grades to meet the quality requirement of an edge reduction lower than 5 um. The process system of the strip steel with an inlet width range of 1020-1300 mm, an inlet thickness range of 2.2-2.8 mm, and an outlet thickness range of 0.45-0.55 mm includes the following contents:

[0026] (1) Rolling load distribution relationship: The five-stand cold continuous rolling mill is used for production, and the first stand to the fifth stand adopts a relatively balanced distribution mode of motor power, that is, the rolling reduction of each stand is determined according to the calculated value of the motor power model of each stand, and the absolute values of the rolling reduction of the five stands are 21-30%, 26-37%, 23-34%, 21-30%, and 13-18% respectively.

[0027] (2) Tension setting: Tension rolling is one of the most important controls in cold rolling production. Tension can reduce the rolling load, and at the same time, it can control the strip deviation and adjust the shape of the strip. The tension system of non-oriented silicon steel cold continuous rolling is that the six unit tensions from the inlet of the first stand to the outlet of the fifth stand are set to 60-75 MPa, 120-140 MPa, 120-140 MPa, 130-150 MPa, 135-155 MPa, and 50-55 MPa.

[0028] (3) Rolling force setting: Rolling force is one of the important parameters in cold rolling silicon steel production to ensure the thickness and rolling efficiency of the product. The rolling force system of the five-stand continuous rolling mill is that the rolling force from the first stand to the fifth stand is set to 7.5-9.6 MN, 8.3-9.8 MN, 8.4-10.2 MN, 6.5-9.2 MN, and 5.8-8.8 MN.

[0029] (4) 5-stand continuous rolling mill bending roll system: Bending roll is one of the most important means to ensure the shape of silicon steel in cold rolling production. The bending roll system of the five-stand continuous rolling mill is that the working roll 2 bending roll system from the first stand to the fifth stand is set to 700 KN, 700 KN, 700 KN, 650 KN, and 306 KN; and the intermediate roll bending roll system is set to 1000 KN, 1000 KN, 1000 KN, 900 KN, and 1555 KN from the first stand to the fifth stand.

[0030] (5) Roll shifting system of 5-stand tandem rolling mill: Roll shifting is one of the most important means to ensure the edge drop of silicon steel in cold rolling production. Single taper work rolls are used in the first to third stands, the length of taper section is 155 mm, and the taper height is between 1 / 350 and 1 / 400 of the length. The roll shifting system of the intermediate rolls in the 5-stand tandem rolling mill is set as 80-115 mm, 80-115 mm, 80-115 mm, 80-115 mm, and 80-115 mm from the first stand to the fifth stand. The roll shifting system of the work rolls is set as 60-75 mm, 45-65 mm, 5-15 mm, 0 mm, and 0 mm from the first stand to the fifth stand.

[0031] (6) Roll process parameters: The roll is a device directly acting on the strip steel in the cold rolling process. The technical parameters of the roll have a great influence on the rolling of non-oriented silicon steel cold rolling strip. The surface roughness of the work roll of the roll process parameter stand is 0.7-1.0 um.

[0032] (7) Rolling lubrication condition: In order to ensure the rolling lubrication condition, the rolling emulsion concentration is set as 3.4-3.8% in the rolling process.

[0033] The following examples are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following examples. The methods used in the following examples are all conventional methods unless otherwise specified.

[0034]

EXAMPLE

[0035] Taking steel grade 50w800 as an example, the product is rolled from raw material thickness of 2.5 mm to finished product thickness of 0.5 mm, the strip steel width is 1248 mm, the total compression ratio is 89%, and the actual average value of the outlet edge drop is 3.1 um, reaching the international leading level.

[0036] The six unit tensions from the first stand inlet to the fifth stand outlet are set as 65 MPa, 135 MPa, 135 MPa, 140 MPa, 150 MPa, and 52 MPa.

[0037] The rolling forces from the first stand to the fifth stand are set as 7.78 MN, 9.33 MN, 8.59 MN, 7.93 MN, and 6.19 MN.

[0038] The work roll bending from the first stand to the fifth stand is set as 700 KN, 700 KN, 700 KN, 650 KN, and 306 KN. The intermediate roll bending from the first stand to the fifth stand is set as 1000 KN, 1000 KN, 1000 KN, 900 KN, and 1555 KN.

[0039] The work rolls of the first to third stands are single-tapered work rolls, the length of the tapered section is 155 mm, the height of the taper is 1 / 400 of the length, the roll shifting settings of the five work rolls from the first stand to the fifth stand are: 65 mm, 52 mm, 10 mm, 0 mm, 0 mm; the roll shifting settings of the intermediate roll 1 from the first stand to the fifth stand are: 95 mm, 95 mm, 95 mm, 95 mm, 95 mm;

[0040] The surface roughness of the work roll of the first stand is 0.9 um, the surface roughness of the work roll of the second to fifth stands is 0.8 um, and the rolling emulsion concentration of the first to fifth stands is 3.5%.

[0041] The 50w800 product is rolled by using the above rolling process method, the rolling process parameters are shown in Table 1, the exit speed of the rolling process reaches 100% of the maximum value, the rolling force is less than 9.5 MN, the thickness deviation of the rolled strip steel is 0.08%, and the average value of the edge drop control precision is 3.2 I. According to the actual rolling process parameters, it can be analyzed that the 50w800 product is rolled from 2.5 mm to 0.5 mm, under the condition of the limit compression ratio of similar products, the stable rolling can be realized by using the above process optimization method, the rolling mill load meets the equipment requirements, and the product quality meets the standard.

[0042] Table 1 Rolling process parameters of cold-rolled non-silicon steel 50w800 strip steel

[0043]

Claims

1. A rolling method for optimizing the edge drop of non-oriented silicon steel, characterized in that, The silicon steel grade is rolled using a 5-stand continuous rolling mill, meeting the quality requirement of a strip drop index of less than 5µm. The strip process system for which the entry strip width ranges from 1020 to 1300 mm, the entry thickness ranges from 2.2 to 2.8 mm, and the exit thickness ranges from 0.45 to 0.55 mm includes the following: (1) Rolling load distribution relationship: The absolute values ​​of the reduction rates of the 5 stands are 21-30%, 26-37%, 23-34%, 21-30%, and 13-18%, respectively; (2) Tension setting: The six unit tensions from the inlet of the first rack to the outlet of the fifth rack are set to 60-75MPa, 120-140MPa, 120-140MPa, 130-150MPa, 135-155MPa, and 50-55MPa; (3) Rolling force setting: The rolling force is set from the 1st stand to the 5th stand as 7.5-9.6MN, 8.3-9.8MN, 8.4-10.2MN, 6.5-9.2MN, and 5.8-8.8MN; (4) Bending roll system of 5-stand continuous rolling mill: The bending roll system of the work rolls is set to 700KN, 700KN, 700KN, 650KN, and 306KN from the 1st stand to the 5th stand; the bending roll system of the intermediate rolls is set to 1000KN, 1000KN, 1000KN, 900KN, and 1555KN for the 5 bending rolls from the 1st stand to the 5th stand. (5) Roll shifting system for 5-stand continuous rolling mill: The five intermediate rolls from the 1st stand to the 5th stand are set to 80-115mm, 80-115mm, 80-115mm, 80-115mm, 80-115mm; The work roll shifting system is set to 60-75mm, 45-65mm, 5-15mm, 0mm, 0mm for the five intermediate rolls from the 1st stand to the 5th stand. (6) Roll process parameters: The surface roughness of the work rolls on the roll stand is 0.7 to 1.0 μm; (7) Rolling lubrication conditions: The emulsion concentration during the rolling process is set to 3.4-3.8%.

2. The rolling method for optimizing the edge drop of non-oriented silicon steel according to claim 1, characterized in that, In the roller shifting process, frames 1 to 3 use single-tapered work rollers with a tapered section length of 150-160mm and a tapered height between 1 / 350 and 1 / 400 of the length. Frames 4 and 5 do not perform work roller shifting and are flat rollers without tapered sections.

3. The rolling method for optimizing the edge drop of non-oriented silicon steel according to claim 1, characterized in that, The silicon steel grades produced by the 5-stand continuous rolling mill are 50W600, 50W800, 50W1000, or 50W1300.

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