A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic induction grain-oriented silicon steel

Abstract

The present invention discloses a cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic induction grain-oriented silicon steel, belonging to the technical field of grain-oriented silicon steel manufacturing. By controlling the cold rolling process of low-temperature high-magnetic induction grain-oriented silicon steel, especially controlling the reduction rate of the first cold rolling pass according to the molten steel composition and the hot-rolled sheet thickness, the number of cold rolling aging times, the rolling speed of different passes, etc., while increasing the Si content to 3.6% - 3.9%, the rolling performance of thin-gauge low-temperature high-magnetic induction grain-oriented silicon steel with a finished thickness of 0.15 - 0.20 mm is improved, the cold rolling breakage rate is reduced, and its magnetic properties are improved at the same time.

Description

Technical Field

[0001] The present invention relates to a manufacturing method of low-temperature high-magnetic-induction grain-oriented silicon steel, and particularly to a cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel. Background Art

[0002] High-magnetic-induction grain-oriented silicon steel is an important soft magnetic material, which is widely used in power transmission and transformation industries such as large transformers. The transformer core is generally composed of grain-oriented silicon steel laminations. The lamination direction requires that the silicon steel sheet is easily magnetized and consistent with the magnetic field direction, and forms a circular loop. The smaller the resistance during core magnetization, the higher the transformer efficiency. Therefore, it is required that the grain-oriented silicon steel sheet for making the transformer core has high magnetic induction intensity and low iron loss.

[0003] The manufacturing process of low-temperature high-magnetic-induction grain-oriented silicon steel mainly includes: steelmaking, hot rolling, pickling and normalizing, cold rolling, decarburization annealing, nitriding, coating with magnesium oxide separator, high-temperature annealing, coating with insulation coating, temper stretching annealing, finishing, etc. In order to further improve the magnetic properties of low-temperature high-magnetic-induction grain-oriented silicon steel, during the manufacturing process of grain-oriented silicon steel, increasing the Si content in the steel and reducing the thickness of the steel sheet play an important role in improving the magnetic properties of the steel sheet. However, increasing the Si content and reducing the thickness of the steel sheet will both cause a sharp decline in the cold rolling performance of the strip steel, resulting in an increase in the frequency of cold rolling breakage, which seriously affects the production efficiency. Therefore, how to overcome the cold rolling problem in the production of high-Si thin-gauge grain-oriented silicon steel is of great significance.

[0004] Patent CN106583448A proposes a cold rolling method for ultra-thin-gauge high-magnetic-induction grain-oriented silicon steel, including the following steps: the thickness before rolling is 2.0 - 2.5 mm, pickling and normalizing; adopting a one-pass cold rolling method, and performing continuous reversible seven-pass cold rolling; using a rough surface work roll for the first five passes and a fine surface work roll for the last two passes; controlling the reduction rate of each pass, 30% - 45% for the first pass, 18% - 31% for the last pass, and 24% - 42% for the remaining passes; stabilizing the rolling speed at 600 - 800 m / min; using emulsion spraying for process lubrication and cooling, controlling the strip temperature to gradually rise to 200 - 230 °C in the first three passes; performing temperature reduction rolling in the fourth pass, and controlling the strip temperature in the subsequent passes at 60 - 80 °C, and the thickness of the rolled product is 0.15 mm - 0.20 mm. Using this method, the production efficiency of ultra-thin-gauge high-end silicon steel has been greatly improved, the product has no shape quality defects, and the surface quality is good. This method mainly considers the control of strip shape during the cold rolling process, reduces shape defects, and is for grain-oriented silicon steel containing 3.21% Si, and is not applicable to thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel products containing 3.5% - 3.9% Si.

[0005] Patent CN106591554A proposes a one-pass cold rolling method that can improve the magnetic properties of low-temperature high magnetic induction oriented silicon steel. The number of rolling passes is 5 - 7, and the steps are as follows: In the first pass, the rolling speed is controlled not to be lower than 200 m / min; the emulsion is sprayed unidirectionally, and the flow rate does not exceed 500 L / min; the rolling temperature is controlled not to be lower than 140 °C; from the second pass to the penultimate pass, the rolling speed is controlled at 400 - 600 m / min; during the rolling from the first pass to the third pass, the rolling temperature is positively correlated with the number of rolling passes; the emulsion is sprayed unidirectionally, and the flow rate is controlled at 1000 - 1500 L / min; the aging rolling temperature is 180 - 350 °C, the total aging time is 13 - 47 min, and the aging time in the range of 251 - 350 °C is extended to 7 - 37 min. The last two passes are in the ordinary rolling mode, which increases the finished product magnetic property B800 by 0.01 - 0.04 T. This method is for low-temperature high magnetic induction oriented silicon steel with a Si content of 3.3% - 3.5% and a conventional thickness (0.18 - 0.30 mm), and is not applicable to thin-gauge low-temperature high magnetic induction oriented silicon steel products with a Si content of 3.6% - 3.9%.

[0006] Patent CN112916615A discloses a cold rolling process for high-performance oriented silicon steel, including one-pass cold rolling and two-pass cold rolling. In one-pass cold rolling, 4 or 5 passes of rolling are used, rolling to a thickness of 0.60 - 0.62 mm, and the rolling temperature is 100 °C - 105 °C; in two-pass cold rolling, 2 passes of rolling are used, rolling to a thickness of 0.24 - 0.26 mm, and the rolling temperature is 95 °C - 100 °C. This method ensures that the Goss texture content in the two-pass cold rolled sheet is 0.8 - 1.5%, and the rolling stability is high. This method is for oriented silicon steel with thicknesses of 0.27 mm and 0.30 mm, and is not applicable to thin-gauge low-temperature high magnetic induction oriented silicon steel products with a Si content of 3.6% - 3.9%.

[0007] Patent 102560235A discloses a manufacturing method of high magnetic induction oriented silicon steel. One-pass cold rolling reversible rolling is adopted, and 3 - 5 passes of reversible rolling are carried out. The total reduction ratio of one-pass cold rolling is 70% - 80%, and the reduction ratio per pass is controlled at 33% - 37%. This method is for oriented silicon steel with a conventional thickness and is not applicable to thin-gauge low-temperature high magnetic induction oriented silicon steel products with a finished thickness of 0.20 mm and below.

[0008] Patent 101748257A discloses a production method of grain-oriented electrical steel, which adopts a three-time cold rolling and two-time intermediate annealing process. The reduction rate of the first cold rolling is 39%-44%, the first intermediate annealing process is at 830-880°C, the time is 2-5 minutes, the dew point is 35-45°C, the carbon content is controlled at 200-300 ppm, the reduction rate of the second cold rolling is 45%-50%, the second intermediate annealing process is at 800-830°C, the time is 3-5 minutes, the dew point is 40-50°C, and the carbon content is reduced to below 30 ppm. The reduction rate of the third cold rolling is 58%-63%. This invention is aimed at ordinary grain-oriented electrical steel products and is not applicable to low-temperature high magnetic induction grain-oriented electrical steel products.

[0009] Patent CN1059369A discloses a method for producing silicon steel with a large and small grain configuration by a pre-aging method. The silicon steel is produced by a single cold rolling method. Before cold rolling, a pre-aging treatment is carried out for more than 5 s and less than 10 h, and the process is constituted by aging-cold rolling-aging-cold rolling-aging... until the final finished thickness is rolled. This method believes that aging treatment should be carried out before rolling and between each pass, which can improve the magnetic properties of the finished high magnetic induction grain-oriented electrical steel. However, this method requires additional heating and heat preservation and cannot meet the requirements of high-efficiency continuous production.

[0010] Patent CN104894354A discloses a production method of thin-gauge high magnetic induction grain-oriented electrical steel prepared from a low-temperature hot-rolled sheet. In the cold rolling process, the hot-rolled sheet is finally rolled into a cold-rolled sheet with a thickness of 0.16-0.18 mm through 6-8 cold rolling passes. Among them, the reduction rate of each cold rolling pass is 20%-40%, and an aging heat treatment with heat preservation at 240-250°C for 5-10 minutes is carried out between the cold rolling passes. This method requires additional heating and heat preservation and cannot meet the requirements of high-efficiency continuous production.

[0011] Patent CN102127709A discloses a low-temperature slab heating high magnetic induction grain-oriented electrical steel and its manufacturing method. In the cold rolling process, a single cold rolling process is adopted, and it is cold rolled to the target thickness through 5-7 passes. The average reduction rate of each pass is 25%-33%, and the total reduction rate is 82%-90%. In the previous several passes, the temperature of the cold-rolled strip is raised to about 200°C by the deformation heat during rolling. This method does not require aging passes and time, which is not conducive to improving the magnetic level of the steel plate. Summary of the Invention

[0012] In view of the deficiencies of the prior art, the present invention provides a cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic induction oriented silicon steel. By controlling the cold rolling process of low-temperature high-magnetic induction oriented silicon steel, especially controlling the reduction ratio of the first cold rolling pass according to the molten steel composition and the thickness of the hot-rolled sheet, as well as the number of cold rolling aging times, the rolling performance of thin-gauge low-temperature high-magnetic induction oriented silicon steel with a Si content of 3.6% - 3.9% and a finished thickness of 0.15 - 0.20 mm is improved, its cold rolling breakage rate is reduced, and its magnetic properties are simultaneously improved.

[0013] The technical solution of the present invention is as follows:

[0014] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic induction oriented silicon steel, comprising the following steps:

[0015] (1) Smelting the molten steel in a converter and continuous casting to obtain a slab; hot rolling to obtain a hot-rolled sheet with a thickness of 1.8 - 2.3 mm, and performing normalizing pickling;

[0016] (2) Primary cold rolling, with 6 rolling passes, and the primary cold rolling comprises the following steps:

[0017] S1: First-pass rolling: Controlling the reduction ratio to be 20 - 26%, setting the rolling speed to be 350 - 450 m / min, and controlling the temperature of the steel sheet to be 100 - 150 °C;

[0018] S2: The reduction ratio from the second pass to the fifth pass is 30 - 39%, and the rolling speed is 450 - 600 m / min;

[0019] S3: The sixth pass is rolled at a general rolling temperature of about 80 °C, the reduction ratio is 35 - 42%, and the rolling speed is 600 - 700 m / min;

[0020] (4) Decarburization annealing, nitriding annealing, coating with a magnesium oxide annealing isolation agent, high-temperature annealing, coating with a tension coating, stretcher leveling and magnetic domain refinement to obtain high-silicon thin-gauge low-temperature high-magnetic induction oriented silicon steel.

[0021] Furthermore, by mass percentage, the molten steel comprises the following chemical components: C: 0.04 - 0.06%, Si: 3.6 - 3.9%, Mn: 0.09 - 0.15%, S: 0.003 - 0.008%, Als: 0.020 - 0.035%, N: 0.006 - 0.01%, and the balance is Fe and unavoidable impurities.

[0022] Furthermore, in step S1, the reduction ratio, the thickness of the hot-rolled sheet, and the Si content in the silicon steel satisfy the following relational formula I:

[0023] 17 + 30 / d 2- 90[Si] ≤ β ≤ 18 + 35 / d 2 - 65[Si] (Ⅰ)

[0024] Where: β is the reduction ratio of the first pass, unit, %; d is the thickness of the hot-rolled sheet, unit, mm; [Si] represents the Si content in the steel, expressed as a percentage.

[0025] Furthermore, aging rolling is carried out during the second pass to the fifth pass.

[0026] Furthermore, the aging rolling starts when the rolling temperature reaches 200°C, and the temperature of the aging rolling is 200 - 350°C, and the time is 5 - 8 min.

[0027] Furthermore, the number of times of aging rolling between the second pass and the fifth pass satisfies the following relational expression Ⅱ:

[0028] n = 7 - ln([Als] - 27[N] / 14) (Ⅱ)

[0029] Where: n is the number of times of aging rolling between the second pass and the fifth pass, rounded to an integer, and the number of aging times is not less than 1 time; [Als] is the content of Als in the steel, ppm; [N] is the content of N in the steel, ppm.

[0030] Furthermore, in step S3, in the sixth pass rolling, the temperature of the steel plate is controlled ≤ 80°C.

[0031] Furthermore, the temperature refers to the temperature of the steel plate, which is controlled by the amount and temperature of the emulsion.

[0032] Furthermore, in step (2), the difference between the maximum rolling speed and the minimum rolling speed in the first to sixth passes does not exceed 350 m / min.

[0033] Furthermore, the thickness of the high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel is 0.15 - 0.2 mm.

[0034] A high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel prepared by the above cold rolling method.

[0035] The beneficial technical effects of the present invention are as follows:

[0036] (1) By regulating the content of Si element in the grain-oriented silicon steel, the magnetic property level of the grain-oriented silicon steel product is improved. By increasing the Si content in the grain-oriented silicon steel, the density of the (110)

[001] on the surface layer of the hot-rolled sheet can be increased. Combined with cold rolling with a large reduction ratio, the iron loss can be effectively reduced and the magnetic induction can be improved.

[0037] (2) By controlling the reduction rate of the first cold rolling pass and the number of cold rolling aging treatments, the present invention can achieve the preparation of low-temperature high magnetic induction oriented silicon steel with a high silicon content and a relatively thin finished thickness. At the same time, it can improve the rolling performance of the prepared silicon steel, reduce the cold rolling breakage rate, improve the magnetism of the finished silicon steel, and reduce the iron loss.

[0038] (3) In the cold rolling process of the present invention, by controlling the reduction rate of the first pass, it is proposed to determine the reduction rate of the first pass through the hot-rolled sheet thickness and the silicon content, which is beneficial to improving the local elongation rate of the steel strip after rolling and reducing the probability of micro-cracks easily appearing at the edges during rolling, avoiding frequent breakage during subsequent cold rolling or coiling.

[0039] (4) Through the cold rolling aging treatment between the second pass and the fifth pass, the content of dissolved C and N in the silicon steel increases, and the unstable carbides and nitrides existing in the steel dissolve during the aging treatment. During cold rolling, the dissolved C and N accumulate at dislocations, hindering the movement of dislocations, promoting the formation of more transition zones, changing the recrystallization texture during cold rolling, and being beneficial to the formation of more fine AlN, thereby strengthening the inhibitory force, being beneficial to the reduction of the secondary recrystallization size, and improving the magnetism of the finished oriented silicon steel; at the same time, through the cold rolling aging treatment between the second pass and the fifth pass, it is beneficial to the perfection of secondary recrystallization. If the number of aging treatments is too small, the effect of cold rolling aging weakens, which is not conducive to the perfection of secondary recrystallization, and the magnetism of the finished oriented silicon steel decreases; if the number of aging treatments is too large, it leads to changes in the recrystallization texture, which is not conducive to the perfection of secondary recrystallization, and also causes the magnetism of the finished oriented silicon steel to decrease.

[0040] (5) By controlling the maximum rolling speed difference in one coil not exceeding 350 m / min, it is beneficial to the stability of the primary grain size, thereby being beneficial to improving the stability of the steel plate magnetism. The rolling speed cannot be too low, as too low will affect the primary grain size after cold rolling, being not conducive to secondary recrystallization and affecting the steel plate magnetism; the rolling speed cannot be too high, as too high will cause the surface of the steel strip to be easily damaged and the plate thickness to fluctuate greatly. Detailed Embodiments

[0041] The present invention will be specifically described below in conjunction with embodiments.

[0042] The present invention provides a cold rolling method applicable to high-silicon thin-gauge low-temperature high magnetic induction oriented silicon steel, and the high-silicon thin-gauge low-temperature high magnetic induction oriented silicon steel obtained by this preparation method.

[0043] Example 1:

[0044] A cold rolling method applicable to high-silicon thin-gauge low-temperature high magnetic induction oriented silicon steel, comprising the following steps:

[0045] (1) The molten steel is smelted in a converter and continuously cast. The cast slab is heated to 1250 °C, then conventionally hot-rolled. The thickness of the hot-rolled sheet is 1.8 mm, and normalizing pickling is carried out. Among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.5%, Mn: 0.09%, S: 0.003%, Als: 0.020%, N: 0.006%, and the balance is composed of Fe and inevitable impurities.

[0046] (2) Then, a 20-high rolling mill is used to carry out one-pass cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0047] The reduction rate in the first pass is 25%, the rolling speed is 350 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0048] The reduction rate in the second to fifth passes is 30 - 39%, the rolling speed is 450 - 600 m / min. The temperature of the steel plate is controlled by controlling the flow rate of the emulsion. According to the empirical formula of the number of aging rolling times and the contents of Als and N in the steel, 3 times of aging rolling are carried out between the second and fifth passes. When the rolling temperature reaches 200 °C, it enters the aging rolling state. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min. The last pass uses ordinary normal-temperature rolling, the reduction rate is 40%, the temperature of the steel plate is controlled not to be higher than 80 °C, the rolling speed is 700 m / min, and it is rolled to the finished thickness of 0.15 mm.

[0049] (3) Finally, decarburization and nitriding annealing are carried out; conventionally, magnesia annealing isolating agent is coated, and final high-temperature annealing is carried out; a tension coating is coated, and stretch leveling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0050] Example 2:

[0051] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel, comprising the following steps:

[0052] (1) The molten steel is smelted in a converter and continuously cast. The cast slab is heated to 1250 °C, then conventionally hot-rolled. The thickness of the hot-rolled sheet is 2.3 mm, and normalizing pickling is carried out. Among them, by mass percentage, the composition of the molten steel is: 0.04%, Si: 3.7%, Mn: 0.09%, S: 0.003%, Als: 0.030%, N: 0.0085%, and the balance is composed of Fe and inevitable impurities.

[0053] (2) Then, a 20-high rolling mill is used to carry out one-pass cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0054] The reduction ratio of the first pass is 20%, the rolling speed is 400 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0055] The reduction ratio of the second to the fifth passes is 30 - 39%, the rolling speed is 450 - 600 m / min, and the temperature of the steel plate is controlled by adjusting the flow rate of the emulsion. According to the empirical formula of the number of aging rolling passes, the content of Als in the steel, and the content of N in the steel, 2 aging rolling passes are carried out between the second and the fifth passes. When the rolling temperature reaches 200 °C, the aging rolling state is entered. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min. In the last pass, normal temperature rolling is adopted, the reduction ratio is 40%, the temperature of the steel plate is controlled not to exceed 80 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.18 mm.

[0056] (3) Finally, decarburization and nitriding annealing are carried out; magnesia annealing isolating agent is coated and final high-temperature annealing are carried out conventionally; a tension coating is coated and stretch leveling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0057] Example 3:

[0058] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel, comprising the following steps:

[0059] (1) The molten steel is smelted in a converter and continuously cast, and the cast slab is heated to 1250 °C and conventionally hot-rolled. The thickness of the hot-rolled plate is 2.0 mm, and normalizing and pickling are carried out. Among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.6%, Mn: 0.09%, S: 0.003%, Als: 0.035%, N: 0.01%, and the balance is Fe and inevitable impurities.

[0060] (2) Then, a 20-high rolling mill is used to carry out one cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6, and the steps are as follows:

[0061] The reduction ratio of the first pass is 24%, the rolling speed is 450 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0062] The reduction ratio for the second to the fifth passes is 30 - 39%, the rolling speed is 450 - 600 m / min, the temperature of the steel plate is controlled by regulating the emulsion flow rate, and according to the empirical formula of the number of aging rolling passes and the Als and N contents in the steel, 2 aging rolling passes are carried out between the second and the fifth passes. When the rolling temperature reaches 200 °C, the aging rolling state is entered, the aging rolling temperature is 200 - 350 °C, and the aging time is 5 min; in the last pass, normal room-temperature rolling is adopted, the reduction ratio is 40%, the temperature of the steel plate is controlled at 80 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.15 mm.

[0063] (3) Finally, decarburization and nitriding annealing are carried out; magnesium oxide annealing isolation agent is coated and final high-temperature annealing is carried out conventionally; a tension coating is coated and temper rolling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0064] Example 4:

[0065] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel, comprising the following steps:

[0066] (1) Molten steel is smelted in a converter and continuously cast, the cast slab is heated to 1250 °C, and normal hot rolling is carried out. The thickness of the hot-rolled sheet is 2.20 mm, and normalizing pickling is carried out; among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.9%, Mn: 0.09%, S: 0.003%, Als: 0.028%, N: 0.0075%, and the balance is Fe and inevitable impurities.

[0067] (2) Then, a 20-high rolling mill is used to carry out one cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6, and the steps are as follows:

[0068] The reduction ratio in the first pass is 20.5%, the rolling speed is 400 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0069] The reduction ratio for the second to the fifth passes is 30 - 39%, the rolling speed is 450 - 600 m / min, the temperature of the steel plate is controlled by regulating the emulsion flow rate, and according to the empirical formula of the number of aging rolling passes and the Als and N contents in the steel, 2 aging rolling passes are carried out between the second and the fifth passes. When the rolling temperature reaches 200 °C, the aging rolling state is entered, the aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min; in the last pass, normal room-temperature rolling is adopted, the reduction ratio is 37.5%, the temperature of the steel plate is controlled at 80 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.15 mm.

[0070] (3) Finally, decarburizing nitriding annealing is carried out; magnesia annealing isolating agent is coated and final high-temperature annealing is carried out conventionally; a tension coating is coated and stretch leveling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0071] Example 5:

[0072] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel includes the following steps:

[0073] (1) The molten steel is smelted in a converter and continuously cast, the cast slab is heated to 1250 °C, and conventional hot rolling is carried out. The thickness of the hot-rolled plate is 2.20 mm, and normalizing pickling is carried out. Among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.9%, Mn: 0.09%, S: 0.003%, Als: 0.033%, N: 0.007%, and the balance is Fe and inevitable impurities.

[0074] (2) Then, a 20-high rolling mill is used to carry out primary cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0075] The reduction rate of the first pass is 23.7%, the rolling speed is 350 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0076] The reduction rates of the second to fifth passes are 30-39%, the rolling speeds are 450-600 m / min, the temperature of the steel plate is controlled by controlling the flow rate of the emulsion, and 2 times of aging rolling are carried out between the second and fifth passes according to the empirical formula of the number of aging rolling times and the Als and N contents in the steel. When the rolling temperature reaches 200 °C, it enters the aging rolling state. The aging rolling temperature is 200-350 °C, and the aging time is 5-8 min; the last pass uses ordinary normal-temperature rolling, the reduction rate is 37.9%, the temperature of the steel plate is controlled at 70 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.18 mm.

[0077] (3) Finally, decarburizing nitriding annealing is carried out; magnesia annealing isolating agent is coated and final high-temperature annealing is carried out conventionally; a tension coating is coated and stretch leveling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0078] Example 6:

[0079] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel includes the following steps:

[0080] (1) The molten steel is smelted in a converter and continuously cast. The cast slab is heated to 1250 °C, then conventionally hot-rolled. The thickness of the hot-rolled sheet is 2.30 mm, and normalizing pickling is carried out. Among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.6%, Mn: 0.09%, S: 0.003%, Als: 0.021%, N: 0.0083%, and the balance is Fe and inevitable impurities.

[0081] (2) Then, a 20-high rolling mill is used to carry out one-pass cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0082] The reduction rate in the first pass is 21.7%, the rolling speed is 450 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0083] The reduction rates from the second pass to the fifth pass are 30 - 39%, the rolling speeds are 450 - 600 m / min, and the temperature of the steel plate is controlled by controlling the flow rate of the emulsion. According to the empirical formula of the number of aging rolling passes and the contents of Als and N in the steel, 3 times of aging rolling are carried out between the second pass and the fifth pass. When the rolling temperature reaches 200 °C, it enters the aging rolling state. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min. The last pass uses ordinary normal-temperature rolling, the reduction rate is 41.2%, the temperature of the steel plate is controlled at 70 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.15 mm.

[0084] (3) Finally, decarburization and nitriding annealing are carried out; conventionally, magnesia annealing isolation agent is applied and final high-temperature annealing is carried out; a tension coating is applied and stretch leveling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0085] Example 7:

[0086] A cold rolling method suitable for high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel, comprising the following steps:

[0087] (1) The molten steel is smelted in a converter and continuously cast. The cast slab is heated to 1250 °C, then conventionally hot-rolled. The thickness of the hot-rolled sheet is 1.80 mm, and normalizing pickling is carried out. Among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.8%, Mn: 0.09%, S: 0.003%, Als: 0.035%, N: 0.0081%, and the balance is Fe and inevitable impurities.

[0088] (2) Then, a 20-high rolling mill is used to carry out one-pass cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0089] The reduction ratio in the first pass is 25.0%, the rolling speed is 350 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0090] The reduction ratios from the second pass to the fifth pass are 30 - 39%, the rolling speeds are 450 - 600 m / min, and the temperature of the steel plate is controlled by adjusting the flow rate of the emulsion. According to the empirical formula of the number of aging rolling passes, the content of Als in the steel, and the content of N in the steel, 2 aging rolling passes are carried out between the second pass and the fifth pass. When the rolling temperature reaches 200 °C, the steel plate enters the aging rolling state, the aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min. In the last pass, normal temperature rolling is adopted, the reduction ratio is 37.9%, the temperature of the steel plate is controlled at 80 °C, the rolling speed is 650 m / min, and the steel plate is rolled to the finished thickness of 0.18 mm.

[0091] (3) Finally, decarburization and nitriding annealing are carried out; magnesia annealing isolation agent is coated and final high-temperature annealing are carried out routinely; a tension coating is coated and temper rolling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0092] Example 8:

[0093] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel, comprising the following steps:

[0094] (1) The molten steel is smelted in a converter and continuously cast, and the cast slab is heated to 1250 °C and subjected to conventional hot rolling. The thickness of the hot-rolled plate is 2.00 mm, and normalizing pickling is carried out. Among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.9%, Mn: 0.09%, S: 0.003%, Als: 0.03%, N: 0.007%, and the balance is Fe and inevitable impurities.

[0095] (2) Then, a 20-high rolling mill is used to carry out one cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6, and the steps are as follows:

[0096] The reduction ratio in the first pass is 23.5%, the rolling speed is 450 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0097] The reduction ratio for the second to the fifth passes is 30 - 39%, the rolling speed is 450 - 600 m / min, the temperature of the steel plate is controlled by controlling the emulsion flow rate, and according to the empirical formula of the number of aging rolling times and the Als and N contents in the steel, 2 times of aging rolling are carried out between the second pass and the fifth pass. When the rolling temperature reaches 200 °C, it enters the aging rolling state. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min; in the last pass, normal room-temperature rolling is adopted, the reduction ratio is 37.5%, the temperature of the steel plate is controlled at 70 °C, the rolling speed is 700 m / min, and it is rolled to the finished thickness of 0.2 mm.

[0098] (3) Finally, decarburization and nitriding annealing are carried out; magnesia annealing isolation agent is coated and final high-temperature annealing is carried out conventionally; a tension coating is coated and temper rolling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0099] Example 9:

[0100] A cold rolling method applicable to high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel, comprising the following steps:

[0101] (1) The molten steel is smelted in a converter and continuously cast, the cast slab is heated to 1250 °C, and normal hot rolling is carried out. The thickness of the hot-rolled plate is 1.80 mm, and normalizing pickling is carried out; among them, by mass percentage, the composition of the molten steel is: C: 0.04%, Si: 3.7%, Mn: 0.09%, S: 0.003%, Als: 0.034%, N: 0.0077%, and the balance is composed of Fe and inevitable impurities.

[0102] (2) Then, a 20-high rolling mill is used to carry out one-time cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0103] The reduction ratio for the first pass is 23.3%, the rolling speed is 350 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0104] The reduction ratio for the second to the fifth passes is 30 - 39%, the rolling speed is 450 - 600 m / min, the temperature of the steel plate is controlled by controlling the emulsion flow rate, and according to the empirical formula of the number of aging rolling times and the Als and N contents in the steel, 2 times of aging rolling are carried out between the second pass and the fifth pass. When the rolling temperature reaches 200 °C, it enters the aging rolling state. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min; in the last pass, normal room-temperature rolling is adopted, the reduction ratio is 35.5%, the temperature of the steel plate is controlled at 80 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.2 mm.

[0105] (3) Finally, decarburizing and nitriding annealing is carried out; magnesia annealing release agent is coated and final high-temperature annealing is carried out conventionally; a tension coating is coated and stretch leveling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0106] Comparative Example 1:

[0107] The chemical composition of the molten steel is C: 0.04%, Si: 3.6%, Mn: 0.09%, S: 0.003%, Als: 0.020%, N: 0.006%, and the balance is Fe and inevitable impurities. The molten steel is smelted by a converter and continuously cast, the billet is heated to 1250 °C, and conventional hot rolling is carried out. The thickness of the hot-rolled plate is 1.8 mm, and normalizing pickling is carried out.

[0108] Then, a 20-high rolling mill is used to carry out single-pass cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0109] The reduction rate of the first pass is 26.7%, the rolling speed is 350 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0110] The reduction rates of the second to fifth passes are 30 - 42%, the rolling speeds are 450 - 600 m / min, the temperature of the steel plate is controlled by controlling the flow rate of the emulsion, and 3 times of aging rolling are carried out between the second and fifth passes. When the rolling temperature reaches 200 °C, it enters the aging rolling state. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min; the last pass adopts ordinary normal-temperature rolling, the reduction rate is 40%, the temperature of the steel plate is controlled not to be higher than 80 °C, the rolling speed is 700 m / min, and it is rolled to the finished thickness of 0.15 mm.

[0111] Then, decarburizing and nitriding annealing is carried out; magnesia annealing release agent is coated and final high-temperature annealing is carried out conventionally; a tension coating is coated and stretch leveling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0112] Comparative Example 2:

[0113] The chemical composition of the molten steel is C: 0.04%, Si: 3.7%, Mn: 0.09%, S: 0.003%, Als: 0.030%, N: 0.0085%, and the balance is Fe and inevitable impurities. The molten steel is smelted by a converter and continuously cast, the billet is heated to 1250 °C, and conventional hot rolling is carried out. The thickness of the hot-rolled plate is 2.3 mm, and normalizing pickling is carried out.

[0114] Then, a 20-high rolling mill is used to carry out single-pass cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0115] The reduction rate in the first pass is 20%, the rolling speed is 400 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0116] The reduction rates in the second to fifth passes are 30 - 42%, the rolling speeds are 450 - 600 m / min, and the temperature of the steel plate is controlled by adjusting the flow rate of the emulsion. Three times of aging rolling are carried out between the second and fifth passes. When the rolling temperature reaches 200 °C, the aging rolling state is entered. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min. In the last pass, normal temperature rolling is adopted, the reduction rate is 40%, the temperature of the steel plate is controlled not to exceed 80 °C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.18 mm.

[0117] Then decarburization and nitriding annealing are carried out; magnesium oxide annealing release agent is coated and final high-temperature annealing are carried out conventionally; a tension coating is coated and stretch leveling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0118] Comparative Example 3:

[0119] The chemical composition of the molten steel is C: 0.04%, Si: 3.6%, Mn: 0.09%, S: 0.003%, Als: 0.035%, N: 0.01%, and the balance is Fe and inevitable impurities. The molten steel is smelted in a converter and continuously cast. The casting blank is heated to 1250 °C and conventionally hot-rolled. The thickness of the hot-rolled plate is 2.0 mm, and normalizing pickling is carried out.

[0120] Then, a 20-high rolling mill is used to carry out one-time cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6, and the steps are as follows:

[0121] The reduction rate in the first pass is 24%, the rolling speed is 300 m / min, and the temperature of the steel plate is controlled at 100 °C.

[0122] The reduction rates in the second to fifth passes are 30 - 42%, the rolling speeds are 450 - 600 m / min, and the temperature of the steel plate is controlled by adjusting the flow rate of the emulsion. According to the empirical formula of the number of aging rolling times and the Als and N contents in the steel, two times of aging rolling are carried out between the second and fifth passes. When the rolling temperature reaches 200 °C, the aging rolling state is entered. The aging rolling temperature is 200 - 350 °C, and the aging time is 5 - 8 min. In the last pass, normal temperature rolling is adopted, the reduction rate is 40%, the temperature of the steel plate is controlled not to exceed 80 °C, the rolling speed is 700 m / min, and it is rolled to the finished thickness of 0.15 mm.

[0123] Then decarburization and nitriding annealing are carried out; magnesium oxide annealing release agent is coated and final high-temperature annealing are carried out conventionally; a tension coating is coated and stretch leveling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0124] Comparative Example 4:

[0125] The chemical composition of the molten steel is C: 0.04%, Si: 3.5%, Mn: 0.09%, S: 0.003%, Als: 0.03%, N: 0.0079%, and the balance is Fe and inevitable impurities. The molten steel is smelted in a converter and continuously cast. The cast slab is heated to 1250°C, hot-rolled conventionally, the thickness of the hot-rolled plate is 1.8 mm, and normalizing and pickling are carried out;

[0126] Then, a 20-high rolling mill is used to perform a single cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0127] The reduction rate in the first pass is 22.2%, the rolling speed is 400 m / min, and the temperature of the steel plate is controlled at 100°C.

[0128] The reduction rates from the second pass to the fifth pass are 30 - 42%, the rolling speeds are 450 - 600 m / min, and the temperature of the steel plate is controlled by controlling the flow rate of the emulsion. According to the empirical formula of the number of aging rolling passes and the Als and N contents in the steel, 2 aging rolling passes are carried out between the second pass and the fifth pass. When the rolling temperature reaches 200°C, it enters the aging rolling state. The aging rolling temperature is 200 - 350°C, and the aging time is 5 - 8 min; the last pass uses ordinary normal-temperature rolling, the reduction rate is 37.5%, the temperature of the steel plate is controlled not to be higher than 80°C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.2 mm.

[0129] Then decarburizing and nitriding annealing are carried out; magnesia annealing isolation agent is coated conventionally, and finally high-temperature annealing is carried out; a tension coating is coated, and stretch leveling is carried out. The magnetic properties of the obtained finished steel plate are shown in Table 2.

[0130] Comparative Example 5:

[0131] The chemical composition of the molten steel is C: 0.04%, Si: 4.0%, Mn: 0.09%, S: 0.003%, Als: 0.036%, N: 0.0065%, and the balance is Fe and inevitable impurities. The molten steel is smelted in a converter and continuously cast. The cast slab is heated to 1250°C, hot-rolled conventionally, the thickness of the hot-rolled plate is 2.0 mm, and normalizing and pickling are carried out;

[0132] Then, a 20-high rolling mill is used to perform a single cold rolling according to the rolling processes in Table 1-1, Table 1-2, Table 1-3, and Table 1-4. The number of rolling passes is 6 passes, and the steps are as follows:

[0133] The reduction rate in the first pass is 21%, the rolling speed is 350 m / min, and the temperature of the steel plate is controlled at 100°C.

[0134] The reduction ratio for the second to the fifth passes is 30 - 42%, the rolling speed is 450 - 600 m / min, the steel plate temperature is controlled by controlling the emulsion flow rate, and according to the empirical formula of the number of aging rolling times and the Als and N contents in the steel, 2 aging rolling operations are carried out between the second and the fifth passes. When the rolling temperature reaches 200°C, the aging rolling state is entered, the aging rolling temperature is 200 - 350°C, and the aging time is 5 - 8 min; the last pass adopts ordinary normal temperature rolling, the reduction ratio is 37.5%, the steel plate temperature is controlled not to be higher than 70°C, the rolling speed is 650 m / min, and it is rolled to the finished thickness of 0.2 mm.

[0135] Decarburizing and nitriding annealing are carried out afterwards; magnesia annealing separator is conventionally coated and final high-temperature annealing is carried out; a tension coating is coated and stretch leveling is carried out, and the magnetic properties of the obtained finished steel plate are shown in Table 2.

[0136] Table 1-1 Cold rolling reduction ratios (%) of examples and comparative examples

[0137]

[0138]

[0139] Table 1-2 Temperatures (unit: °C) of cold rolling of examples and comparative examples

[0140] First pass Second pass Third pass Fourth pass Fifth pass Sixth pass Example 1 100 200 350 250 85 60 Example 2 100 200 350 125 100 80 Example 3 100 200 350 125 100 80 Example 4 100 200 350 125 100 80 Example 5 100 200 350 125 100 70 Example 6 100 200 350 250 100 70 Example 7 100 200 350 125 100 80 Example 8 100 200 350 125 100 70 Example 9 100 200 350 125 100 80 Comparative example 1 100 200 350 250 85 60 Comparative example 2 100 200 350 225 100 80 Comparative example 3 100 200 350 125 100 80 Comparative example 4 100 200 350 125 100 80 Comparative example 5 100 200 350 125 100 70

[0141] Table 1-3 Aging times (min) of examples and comparative examples

[0142]

[0143]

[0144] Table 1-4 Rolling speeds (m / min) of cold rolling of examples and comparative examples

[0145] First pass Second pass Third pass Fourth pass Fifth pass Sixth pass Example 1 350 500 450 480 600 700 Example 2 400 500 450 480 600 650 Example 3 450 500 450 480 600 650 Example 4 400 500 450 480 600 650 Example 5 350 500 450 480 600 650 Example 6 450 500 450 480 600 650 Example 7 350 500 450 480 600 650 Example 8 450 500 450 480 600 700 Example 9 350 500 450 480 600 650 Comparative example 1 350 500 450 480 600 700 Comparative example 2 400 500 450 480 600 650 Comparative example 3 300 500 450 480 600 700 Comparative example 4 400 500 450 480 600 650 Comparative example 5 350 450 450 480 600 650

[0146] Table 2 Comparison of silicon steel parameters and properties of examples and comparative examples

[0147]

[0148]

[0149] As can be seen from Table 2, when the cold rolling process meets the scope of the technical solution of the present invention, the rolling performance of thin-gauge low-temperature high magnetic induction grain-oriented silicon steel with a Si content of 3.6% - 3.9% and a thickness of 0.15 - 0.20 mm can be improved, its cold rolling breakage rate can be reduced, and at the same time, a thin-gauge low-temperature high magnetic induction grain-oriented silicon steel product with excellent magnetic properties can be obtained.

[0150] The first pass reduction rate in Comparative Example 1 does not satisfy the relationship between the first pass reduction rate and the hot-rolled plate thickness and the Si content in the steel proposed in the present invention, resulting in a high strip breakage rate in the subsequent coiling process, affecting production efficiency.

[0151] In Comparative Example 2, the number of aging rolling passes between the second and fifth passes does not satisfy the relationship between the number of aging rolling passes and the Als content and the N content in the steel proposed in the present invention, and the improvement of secondary recrystallization is not utilized, resulting in reduced magnetic properties of the oriented silicon steel product.

[0152] In Comparative Example 3, the maximum rolling speed difference in one roll is 400m / min, which exceeds 350m / min, which is not conducive to the stability of the initial grain size. In addition, the first rolling speed is too low, which affects the initial grain size after cold rolling and is not conducive to secondary recrystallization, resulting in reduced magnetic properties of the finished steel plate.

[0153] The mass percentage of silicon content in a coil in Comparative Example 4 is 3.5%, which is lower than the characteristic range of 3.6% to 3.9%. The recrystallized structure cannot be improved by rolling and aging using the method of the present invention, and the performance of the product is poor.

[0154] In Comparative Example 5, the mass percentage of silicon content in a coil is 4.0%, which is higher than the characteristic range of 3.6% to 3.9%. The first rolling adopts the relationship between the first pass reduction rate proposed in the present invention and the hot-rolled plate thickness and the Si content in the steel. The steel coil breaks frequently during the rolling process, seriously affecting production.

[0155] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A cold rolling method applicable to high-silicon thin-gauge low-temperature high magnetic induction oriented silicon steel, characterized in that, It includes the following steps: (1) Smelt molten steel in a converter, continuously cast to obtain a billet; hot roll to obtain a hot-rolled sheet with a thickness of 1.8 - 2.3 mm, and perform normalizing pickling; (2) First cold rolling, with 6 rolling passes, and the first cold rolling includes the following steps: S1: First-pass rolling: Control the reduction ratio, set the rolling speed to 350 - 450 m / min, and control the steel plate temperature to 100 - 150 °C; S2: The reduction ratio for the second to fifth passes is 30 - 39%, and the rolling speed is 450 - 600 m / min; S3: The reduction ratio for the sixth pass is 35 - 42%, and the rolling speed is 600 - 700 m / min; (3) Decarburization annealing, nitriding annealing, after coating with magnesium oxide annealing isolation agent, high-temperature annealing, coating with a tension coating, stretch leveling and magnetic domain refinement to obtain high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel; In step S1, the reduction ratio, the thickness of the hot-rolled sheet, and the Si content in the silicon steel satisfy the following relational formula I: 17 + 30 / d 2 - 90[Si] ≤ β ≤ 18 + 35 / d 2 - 65[Si] (Ⅰ) In the formula: β is the reduction ratio of the first pass, unit: %; d is the thickness of the hot-rolled sheet, unit: mm; [Si] represents the Si content in the steel, expressed as a percentage.

2. The cold rolling method according to claim 1, characterized in that, By mass percentage, the molten steel includes the following chemical components: C: 0.04 - 0.06%, Si: 3.6 - 3.9%, Mn: 0.09 - 0.15%, S: 0.003 - 0.008%, Als: 0.020 - 0.035%, N: 0.006 - 0.01%, and the balance is Fe and unavoidable impurities.

3. The cold rolling method according to claim 1, characterized in that, Ageing rolling is carried out during the second to fifth passes.

4. The cold rolling method according to claim 3, characterized in that, The ageing rolling starts when the rolling temperature reaches 200 °C, the temperature of the ageing rolling is 200 - 350 °C, and the time is 5 - 8 min.

5. The cold rolling method according to claim 3, characterized in that, The number of ageing rolling times between the second and fifth passes satisfies the following relational formula II: n = 7 - ln([Als] - 27[N] / 14) (II) In the formula: n is the number of ageing rolling times between the second and fifth passes, rounded to an integer, and the number of ageing times is not less than 1; [Als] is the content of Als in the steel, ppm; [N] is the content of N in the steel, ppm.

6. The cold rolling method according to claim 1, characterized in that In step S3, during the sixth-pass rolling, control the steel plate temperature ≤ 80 °C.

7. The cold rolling method according to claim 1, characterized in that In step (2), the difference between the maximum rolling speed and the minimum rolling speed in the first to sixth passes does not exceed 350 m / min.

8. The cold rolling method according to claim 1, characterized in that, The thickness of the high-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel is 0.15 - 0.2 mm.

9. High-silicon thin-gauge low-temperature high-magnetic-induction grain-oriented silicon steel prepared by the cold rolling method according to any one of claims 1 - 8.

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