Rolling method of ultra-thin precision alloy steel strip

Abstract

The invention discloses a rolling method of an ultra-thin precision alloy steel strip, and belongs to the technical field of steel rolling. An alloy steel strip with the thickness of 0.25-0.3 mm is selected as a raw material, a large-roller-diameter four-roller or 12-roller rolling mill is adopted, and the ultra-thin precision alloy steel strip with the thickness of 0.05-0.12 mm is obtained through rolling by adjusting parameters such as rolling passes, rolling reduction and tension. According to the rolling method for the ultra-thin precision alloy steel strip, the limitation of the minimum rolling thickness of a large-roller-diameter rolling mill is broken through, under the condition that safe and stable work of the rolling mill is guaranteed, by adjusting control parameters in the rolling process, the ultra-thin precision alloy steel strip with the thickness ranging from 0.05 mm to 0.12 mm can be rolled through a large-roller-diameter four-roller or even 12-roller rolling mill, and the rolling quality of the ultra-thin precision alloy steel strip is improved. And the range of types for rolling the ultra-thin steel strip is widened, the utilization rate of a large-roller-diameter rolling mill is improved, and huge economic benefits are brought to enterprise production. The method is suitable for a large-roller-diameter rolling mill (the roller diameter is larger than 45 mm) to roll the ultra-thin steel strip.

Description

Technical Field

[0001] The invention belongs to the technical field of steel rolling, and relates to a cold rolling process for an ultra-thin steel strip, in particular to a rolling method for an ultra-thin precision alloy steel strip. Background Art

[0002] Ultra-thin precision alloy steel strips with a thickness of 0.05-0.12mm are widely used in new energy, medical equipment, household appliances, precision machinery manufacturing, building decoration, automobiles and other industries. Currently, only a few steel mills in the world can stably supply qualified products for ultra-thin precision alloy steel strips, and the rolling technology of ultra-thin precision alloy steel strips is also a high-end technology in China.

[0003] Among all types of rolling mills, 20-roll mills with small working roll diameters (roller diameters are mostly in the range of 20-45mm) are usually used to roll ultra-thin precision alloy steel strips with a rolling thickness of less than 0.1mm. For 4-roll mills and even 12-roll mills, the working roll diameters are mostly greater than 60mm, and the minimum rollable thickness in the mill design is also greater than 0.1mm, so they are usually used to roll medium-thick alloy steel strip products. Limited by the rolling mill model and the minimum rollable thickness, manufacturers with only 4-roll or even 12-roll mill models cannot produce ultra-thin precision alloy steel strips, which has a huge impact on corporate benefits. Summary of the invention

[0004] The purpose of the present invention is to provide a method for rolling an ultra-thin precision alloy steel strip, so as to solve the problem in the prior art that a rolling mill with a large roller diameter cannot be used to roll an ultra-thin precision alloy steel strip.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A method for rolling an ultra-thin precision alloy steel strip comprises the following steps: S1. Material selection: Select alloy steel strip with a thickness of 0.25-0.3mm as raw material; S2. Rolling: The total reduction is 60%-82%, designed according to 1-2 rolling passes, each rolling pass has 4-6 passes, the first pass reduction of each rolling pass is ≥20%, and the remaining passes reduction decreases; the last pass of each rolling pass is rolled with M2 rolls, and the remaining passes are rolled with D2 rolls; The first pass tension of each rolling process is 130-300N / mm 2 , the tension of the remaining passes increases by 15%-22%; Use full-flow rolling oil for lubrication, keep the oil temperature at 40-43℃, and halve the rolling oil flow in the last two passes of each rolling process; Annealing during rolling process, annealing temperature is 1050℃; The thickness of the ultra-thin precision alloy steel strip is 0.05-0.12 mm; the hardness of the M2 roller is 62-64 HRC, and the surface roughness Ra is 0.1-0.2 um; the hardness of the D2 roller is 61-62 HRC, and the surface roughness Ra is 0.12-0.23 um.

[0006] As a limitation, the rolling adopts a 4-roller or 12-roller rolling mill; the rolling mill frame stiffness value is 1mm / 500T-1mm / 1000T.

[0007] As another limitation, the alloy steel strip includes a SUS 200 series steel strip, a SUS 300 series steel strip, a SUS 400 series steel strip, an iron-nickel alloy steel strip, or an iron-chromium alloy steel strip.

[0008] Due to the adoption of the above technical solution, the present invention has the following technical advances compared with the prior art: The present invention provides a method for rolling an ultra-thin precision alloy steel strip. After a large number of experimental studies, the method has broken through the limitation of the minimum rollable thickness of a large-diameter rolling mill (roller diameter>45mm). Under the condition of ensuring the safe and stable operation of the rolling mill, by adjusting the control parameters of the rolling process, a 4-roller or even 12-roller rolling mill with a large roller diameter can achieve the rolling of an ultra-thin precision alloy steel strip with a thickness of 0.05-0.12mm, thereby broadening the range of machine models for rolling ultra-thin steel strips, improving the utilization rate of large-diameter rolling mills, and bringing huge economic benefits to enterprise production. The rolling process is simple and suitable for industrial production. DETAILED DESCRIPTION

[0009] The present invention is further described in detail below by specific examples. It should be understood that the described examples are only used to explain the present invention, and are not intended to limit the present invention.

[0010] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art.

[0011] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0012] Example 1 This embodiment discloses a method for rolling an ultra-thin precision alloy steel strip, which specifically includes the following steps: S1. Material selection An iron-chromium alloy steel coil with a thickness of 0.3 mm and a width of 280 mm was selected as the raw material; S2. Rolling A 4-roller reversible rolling mill is used. The working roll diameter of the rolling mill is 170mm. In order to reduce the elastic flattening of the roll system, the frame stiffness value is 1mm / 500T. The last rolling pass uses M2 rolls with a hardness of 62HRC and a surface roughness Ra of 0.1um. The remaining rolling passes use D2 rolls with a hardness of 61HRC and a surface roughness Ra of 0.12um to ensure the roundness, concentricity, hardness layer and dimensional accuracy along the roll body of the roll, reduce the elastic flattening of the roll system, so as to improve and ensure the straightness and thickness accuracy of the rolled ultra-thin precision alloy steel strip. The target finished product thickness is 0.12mm, and the total reduction is 60%. This rolling is designed according to one rolling process, with a first-pass reduction of 25%, and the remaining passes with decreasing reductions. After 6 passes, the raw material thickness is rolled from 0.3mm to 0.12mm; Due to the large roller diameter and high rolling force, high tension rolling is adopted in the process, and the first pass tension is 130N / mm 2 The tension of the remaining passes increases by 15%, and the tension is adjusted to 530-630N / mm during the entire rolling process. 2 Within the range, the rolling force is adjusted to 900-1600KN; In order to ensure the surface quality of the finished steel strip, rolling oil lubrication is adopted, the oil temperature is maintained at 40℃, and full flow rolling oil lubrication is adopted for rolling. When the rolling conditions are stable, the rolling oil flow of the last two passes is halved, and low flow rolling is implemented, which has good effects on oil saving, rolling lubrication, surface quality of ultra-thin precision alloy steel strips and overall plate shape control.

[0013] After rolling, the technical indicators of the finished steel strip were tested using the conventional industry tapered scale (accuracy 0.1mm) and a handheld digital thickness micrometer (accuracy 0.001mm). The results are as follows: 1) Thickness deviation: 0.12±0.002mm; 2) The edge wave height of the steel strip is less than 0.2mm; 3) The ratio of the steel strip edge wave height to the edge wave length, that is, the steepness is less than 0.5%; 4) There are no defects such as oblique ribs, spots, scratches, etc. on the surface of the steel belt.

[0014] Example 2 This embodiment discloses a method for rolling an ultra-thin precision alloy steel strip, which specifically includes the following steps: S1. Material selection An iron-nickel alloy steel coil with a thickness of 0.25 mm and a width of 300 mm is selected as the raw material; S2. Rolling A 4-roller reversible rolling mill is selected. The working roll diameter of the rolling mill is 145mm. The minimum thickness of the rolled product in the original design of the rolling mill is 0.1mm. In order to reduce the elastic flattening of the roll system, the frame stiffness value is 1mm / 800T. The last rolling pass uses M2 rolls with a hardness of 64HRC and a surface roughness Ra of 0.2um. The remaining rolling passes use D2 rolls with a hardness of 62HRC and a surface roughness Ra of 0.23um to ensure the roundness, concentricity, hardness layer and dimensional accuracy along the roll body of the roll, reduce the elastic flattening of the roll system, so as to improve and ensure the straightness and thickness accuracy of the rolled ultra-thin precision alloy steel strip; The target finished product thickness is 0.08mm, and the total reduction is 68%. This rolling is designed according to one rolling process, with a first-pass reduction of 20%, and the remaining passes with decreasing reductions. After five passes, the raw material thickness is rolled from 0.25mm to 0.08mm. Due to the large roller diameter and high rolling force, high tension rolling is adopted in the process, and the first pass tension is 155N / mm 2 The tension of the remaining passes increases by 22%. The tension is adjusted to 550-650N / mm during the entire rolling process. 2 Within the range, the rolling force is adjusted to 800-1500KN; In order to ensure the surface quality of the finished steel strip, rolling oil lubrication is adopted, the oil temperature is maintained at 43°C, and full flow rolling oil lubrication is adopted for rolling. When the rolling conditions are stable, the rolling oil flow of the last two passes is halved, and low flow rolling is implemented, which has good effects on oil saving, rolling lubrication, surface quality of ultra-thin precision alloy steel strips, and overall plate shape control.

[0015] After rolling, the technical indicators of the finished steel strip were tested using the conventional industry tapered scale (accuracy 0.1mm) and a handheld digital thickness micrometer (accuracy 0.001mm). The results are as follows: 1) Thickness deviation: 0.08±0.001mm; 2) The edge wave height of the steel strip is less than 0.2mm; 3) The ratio of the steel strip edge wave height to the edge wave length, that is, the steepness is less than 0.5%; 4) There are no defects such as oblique ribs, spots, scratches, etc. on the surface of the steel belt.

[0016] Example 3 This embodiment discloses a method for rolling an ultra-thin precision alloy steel strip, which specifically includes the following steps: S1. Material selection SUS 304 stainless steel coil with a thickness of 0.28 mm and a width of 250 mm was selected as the raw material; S2. Rolling A 12-roller KT rolling mill was selected. The working roll diameter of the rolling mill is 65mm, the frame stiffness value is 1mm / 1000T, and the minimum thickness of the rolled product in the original design of the rolling mill is 0.1mm. The target finished product thickness is 0.05mm, and the total reduction is 82%. This rolling is designed according to two rolling processes: the intermediate rolling process, the reduction is 64%, the first pass reduction is 29%, and the remaining passes reduction decreases. After 5 passes, the raw material thickness is rolled from 0.28mm to 0.1mm; the finished product rolling process, the reduction is 50%, the first pass reduction is 20%, and the remaining passes reduction decreases. After 4 passes, the raw material thickness is rolled from 0.1mm to 0.05mm. Annealing process is carried out between the two rolling processes, and the annealing temperature is 1050℃; In the middle rolling process, the first pass tension is 160N / mm 2 The tension of the remaining passes increases by 20%, and the rolling force is adjusted to 520-620KN during the entire rolling process; in the finished rolling process, the tension of the first pass is 300N / mm 2 The tension of the remaining passes increases by 18%, and the tension is adjusted to 550-650N / mm during the entire rolling process. 2 Within the range, the rolling force is adjusted to 1080-1680KN; The last pass of each rolling process uses M2 rollers with a hardness of 63HRC and a surface roughness of Ra of 0.15um, and the remaining passes use D2 rollers with a hardness of 61HRC and a surface roughness of Ra of 0.2um to ensure the roundness, concentricity, hardness layer and dimensional accuracy along the roller body, reduce the elastic flattening of the roller system, so as to improve and ensure the straightness and thickness accuracy of the rolled ultra-thin precision alloy steel strip; In order to ensure the surface quality of the finished steel strip, rolling oil lubrication is adopted, the oil temperature is maintained at 42°C, and full flow rolling oil lubrication is adopted for rolling. Under the condition of stable rolling conditions, the rolling oil flow of the last two passes of each rolling process is halved, and low flow rolling is implemented, which has good effects on oil saving, rolling lubrication, surface quality of ultra-thin precision alloy steel strips and overall plate shape control.

[0017] After rolling, the technical indicators of the finished steel strip were tested using the conventional industry tapered scale (accuracy 0.1mm) and a handheld digital thickness micrometer (accuracy 0.001mm). The results are as follows: 1) Thickness deviation: 0.05±0.001mm; 2) The wave height of the steel strip edge is less than 0.3mm; 3) The ratio of the steel strip edge wave height to the edge wave length, that is, the steepness is less than 0.5%; 4) There are no defects such as oblique ribs, spots, scratches, etc. on the surface of the steel belt.

Claims

1. A method for rolling an ultra-thin precision alloy steel strip, characterized in that: The following steps are involved: S1. Material selection: Select alloy steel strip with a thickness of 0.25-0.3mm as raw material; S2. Rolling: The total reduction is 60%-82%, designed according to 1-2 rolling passes, each rolling pass has 4-6 passes, the first pass reduction of each rolling pass is ≥20%, and the remaining passes reduction decreases; the last pass of each rolling pass is rolled with M2 rolls, and the remaining passes are rolled with D2 rolls; The first pass tension of each rolling process is 130-300N / mm 2 , the tension of the remaining passes increases by 15%-22%; Use full-flow rolling oil for lubrication, keep the oil temperature at 40-43℃, and halve the rolling oil flow in the last two passes of each rolling process; Annealing during rolling process, annealing temperature is 1050℃; The thickness of the ultra-thin precision alloy steel strip is 0.05-0.12 mm; the hardness of the M2 roller is 62-64 HRC, and the surface roughness Ra is 0.1-0.2 um; the hardness of the D2 roller is 61-62 HRC, and the surface roughness Ra is 0.12-0.23 um.

2. The method for rolling an ultra-thin precision alloy steel strip according to claim 1, characterized in that: The rolling adopts a 4-roller or 12-roller rolling mill; the rolling mill frame rigidity value is 1mm / 500T-1mm / 1000T.

3. A method for rolling an ultra-thin precision alloy steel strip according to claim 1 or 2, characterized in that: The alloy steel strip includes a SUS 200 series steel strip, a SUS 300 series steel strip, a SUS 400 series steel strip, an iron-nickel alloy steel strip or an iron-chromium alloy steel strip.