Preparation method of non-oriented electrical steel sheet with strong Goss texture

Abstract

The invention discloses a preparation method of a non-oriented electrical steel sheet with a strong Goss texture, and belongs to the technical field of ferrous metallurgy. The method comprises the following steps: S1, carrying out molten steel smelting by utilizing a vacuum induction furnace, and casting at 1450-1550 DEG C to form a cast ingot; s2, the cast ingot is subjected to heat preservation for 120 min to 180 min at the temperature of 1100 DEG C to 1200 DEG C, a two-roller reversible rolling mill is adopted for conducting rough rolling cogging or forging cogging on a casting blank, and an intermediate blank is obtained; s3, the intermediate billet is charged and heated at the room temperature, heat preservation is conducted for 30 min to 60 min at the temperature of 980 DEG C to 1080 DEG C, then hot rolling is conducted, rolling is conducted six times, heat preservation is conducted for 2 min to 10 min again in a furnace, and a 1.5 mm to 2.3 mm hot rolled plate is obtained through the single-pass rolling reduction rate of 30% to 40%; s4, after the hot-rolled plate is subjected to acid pickling, the hot-rolled plate is subjected to five-pass cold rolling at the rolling reduction rate of 50-75%, and a cold-rolled plate is obtained; and S5, the cold-rolled sheet is subjected to annealing treatment under the protective atmosphere, the annealing temperature ranges from 900 DEG C to 1050 DEG C, and the annealing heat preservation time ranges from 2 min to 8 min. According to the method, the content of favorable textures such as Goss textures and eta textures in the annealed sheet is increased, and the magnetic performance of the non-oriented electrical steel is improved.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of strong Goss texture non-oriented electrical steel sheet and belongs to the technical field of steel metallurgy. BACKGROUND

[0002] Electrical steel is an important soft magnetic material and is widely used in many fields such as electronics, electric power and military industry. The production process of non-oriented silicon steel mainly includes traditional thick slab rolling (such as including smelting, casting, hot rolling, cold rolling and the like), thin plate still continuous casting and rolling (such as including smelting, continuous casting and rolling, soaking finish rolling, cold rolling and the like), thin strip continuous casting (such as including smelting, thin strip continuous casting, hot rolling, cold rolling and the like). The texture evolution can be effectively controlled in each process by changing the process parameters, so that the recrystallization texture of the finished silicon steel is improved, and the performance of the non-oriented silicon steel thin plate is improved. Therefore, in the actual production of electrical steel, the control technology of multiple processes and multiple factors needs to be considered.

[0003] Chinese patent CN 116479307 B adopts a thin strip continuous casting method to obtain a cast strip with strong lambda texture. After subsequent hot rolling, cold rolling and annealing, a lambda texture mainly composed of cubic and rotated cubic is obtained, and the volume fraction is 20-31%, thereby improving the magnetic properties of the non-oriented electrical steel. The above method further verifies that the beneficial texture formed in the early stage of processing has a certain heredity.

[0004] Compared with the thin strip continuous casting process, the traditional casting-hot rolling process adopts thick slab heating-single stand reversible rough rolling-multi stand finish rolling process to prepare hot-rolled electrical steel. Hot rolling is the first processing procedure after ingot formation, which provides the basis for the subsequent processing procedures and significantly affects the evolution of the microstructure and texture of the material. However, in the hot rolling process, there is little awareness of obtaining beneficial texture and microstructure by controlling the hot rolling process, so the probability of obtaining non-oriented electrical steel hot-rolled plate with high content of beneficial texture is low, which ultimately leads to low content of beneficial texture in the cold-rolled and annealed sheet, thereby restricting the improvement of the magnetic properties of the non-oriented electrical steel sheet. SUMMARY

[0005] In view of the above technical status, the application improves the texture and grain size of the hot-rolled plate by precisely controlling the hot rolling process, and maintains this beneficial microstructure in the subsequent cold rolling and final annealing to further improve the magnetic properties of the non-oriented electrical steel sheet, and proposes a preparation method of strong Goss texture non-oriented electrical steel sheet.

[0006] In one aspect, the application provides a preparation method of strong Goss texture non-oriented electrical steel sheet, which comprises the following steps: S1, casting: smelting molten steel based on a set composition by using a vacuum induction furnace, and then casting into an ingot at 1450-1550 DEG C; S2, blooming: the ingot is kept at 1100-1200℃ for 120-180min, and the billet is roughed by a two-high reversing mill or is forged to obtain a 25-50mm intermediate billet; S3, hot rolling: the intermediate billet is heated at room temperature, kept at 980-1080℃ for 30-60min, and then is hot rolled by 6 passes, with a finish rolling temperature of 850-900℃, and then is kept for 2-10min, and then is rolled by a single pass with a reduction of 30-40%, with a finish rolling temperature above 900℃, to obtain a 1.5-2.3mm hot rolled plate; S4, pickling and cold rolling: the hot rolled plate is pickled, and then is cold rolled by 5 passes with a reduction of 50-75% to obtain a 0.4-0.7mm cold rolled plate; S5, heat treatment: the cold rolled plate is annealed in a protective atmosphere, with an annealing temperature of 900-1050℃ and an annealing time of 2-8min.

[0007] Optionally, in step S1, the mass percentage of each component in the ingot is: Si=2.8-4.8%, C≤0.008%, Mn=0.10%-0.50%, acid-soluble aluminum Als≤1.0%, S≤0.008%, P≤0.008%, N≤0.008%, Ti≤0.005%, and the balance is iron and unavoidable inclusions.

[0008] Optionally, in step S3, the reduction of the first pass is 40-50%, the reduction of the second pass is 38-48%, the reduction of the third pass is 35-45%, the reduction of the fourth pass is 30-40%, the reduction of the fifth pass is 25-35%, and the reduction of the sixth pass is 15-25%.

[0009] Optionally, in step S3, the temperature for the reheating and keeping is 950-1050℃.

[0010] Optionally, in step S3, the average grain diameter of the hot rolled plate is 100-600μm, the content of Goss texture is 12-25%, and the content of γ texture is not more than 10%.

[0011] Optionally, in step S5, the protective atmosphere is argon or a nitrogen-hydrogen mixed gas.

[0012] Optionally, the nitrogen-hydrogen mixed gas contains 10%-30% hydrogen and 90%-70% nitrogen by volume.

[0013] Optionally, in step S5, the annealing temperature is 900-1000℃.

[0014] In another aspect, the application also provides a strong Goss texture non-oriented electrical steel sheet, which is prepared by the above method, and the average grain diameter of the sheet is 50-300 μm, the Goss texture content is 10-22%, and the η texture content is 25-40%.

[0015] Optionally, the magnetic induction intensity B 50 of the sheet is 1.70-1.78 T, the iron loss P 15 / 50 is 2.0-3.0 w / kg.

[0016] Compared with the prior art, the application has the following advantages: 1. The application reduces the adverse texture in the hot-rolled sheet by controlling the hot-rolling temperature, hot-rolling pass, hot-rolling reduction, and finish-rolling temperature, so that the content of γ texture is not more than 10%.

[0017] 2. The application obtains larger grains by re-melting and heat preservation during the hot-rolling process, and under the action of single-pass deformation, strong Goss texture is obtained without dynamic recrystallization, which provides a good substrate for the subsequent preparation of cold-rolled sheet with excellent magnetic properties.

[0018] 3. The application improves the content of Goss texture, η texture and other beneficial textures in the annealed sheet by controlling the cold-rolling reduction and annealing process, and using the heredity of Goss texture, thereby improving the magnetic properties of the non-oriented electrical steel. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0020] Figure 1 is the microstructure and texture diagram of the non-oriented electrical steel hot-rolled sheet of Example 1 of the application; Figure 2 is the microstructure diagram of the non-oriented electrical steel sheet of Example 1 of the application; Figure 3 is the texture diagram of the non-oriented electrical steel sheet of Example 1 of the application; Figure 4 is the microstructure and texture diagram of the non-oriented electrical steel hot-rolled sheet of Comparative Example 1 of the application; Figure 5 is the microstructure diagram of the non-oriented electrical steel sheet of Comparative Example 1 of the application; Figure 6 is the texture diagram of the non-oriented electrical steel sheet of Comparative Example 1 of the application; DETAILED DESCRIPTION

[0021] In order to make the invention purposes, technical solutions and beneficial technical effects of the present application clearer, the present application will be described in detail below in combination with specific embodiments. It should be understood that the embodiments described in the present specification are only for the purpose of explaining the present application, and are not intended to limit the present application.

[0022] Firstly, the present application provides a preparation method of strong Goss texture non-oriented electrical steel sheet, comprising the following steps: S1, casting: smelting molten steel based on the set composition by using a vacuum induction furnace, and then pouring into an ingot at 1450-1550℃, wherein the mass percentage of each component in the ingot is: Si=2.8-4.8%, C≤0.008%, Mn=0.10%-0.50%, acid-soluble aluminum Als≤1.0%, S≤0.008%, P≤0.008%, N≤0.008%, Ti≤0.005%, and the balance is iron and unavoidable inclusions; S2, breakdown: the ingot is kept at 1100-1200℃ for 120-180min, and then rough rolling breakdown or forging breakdown is performed on the cast blank by using a two-high reversing mill to obtain an intermediate blank with a thickness of 25-50mm; S3, hot rolling: the intermediate blank is heated at room temperature, kept at 980-1080℃ for 30-60min, and then hot rolled, and the final rolling temperature is 850-900℃, and then the blank is reheated and kept for 2-10min, and then single-pass rolling is performed at a reduction rate of 30-40%, and the final rolling temperature is above 900℃, and then a hot-rolled sheet with a thickness of 1.5-2.3mm is obtained; S4, pickling and cold rolling: after the hot-rolled sheet is pickled, it is cold-rolled by 5 passes at a rolling reduction rate of 50-75% to obtain a cold-rolled sheet with a thickness of 0.4-0.7mm; S5, heat treatment: the cold-rolled sheet is annealed in a protective atmosphere at an annealing temperature of 900-1050℃ for 2-8min.

[0023] It should be noted that in step S1, silicon (Si) is the core element of electrical steel, which has the effects of increasing resistivity, reducing hysteresis loss, stabilizing ferrite, reducing magnetostriction, and increasing hardness. Specifically, silicon dissolves in ferrite, which can significantly increase the resistivity of the steel, thereby effectively reducing the eddy current loss, which is the most important means to reduce iron loss; silicon can inhibit the existence of interstitial atoms such as carbon and nitrogen in the lattice, making the magnetic domain wall more easily move, thereby reducing the hysteresis loss; silicon is a strong ferrite-forming element, which makes the steel maintain a single ferrite structure at room temperature, avoiding the occurrence of austenite phase transformation, thereby simplifying the production process. However, too high silicon content will make the steel brittle, affecting the punching performance, therefore, the silicon content is limited to 2.8-4.8%, preferably 2.8-3.5%.

[0024] Manganese (Mn): solid solution strengthening, increase strength. Combined with sulfur to form MnS, prevent more harmful FeS formation, thereby improving hot working properties. But if the MnS formed too much or size is not appropriate, will damage the magnetic properties. Therefore the invention limits the manganese content of 0.10-0.50%.

[0025] Acid-soluble aluminum Als: acid-soluble aluminum as the effective form of aluminum in steel, can be dissolved in ferrite, increase the resistivity, reduce the eddy current loss. But excessive aluminum will affect the steel castability and surface quality, therefore the invention limits the acid-soluble aluminum Als≤1.0%.

[0026] Carbon (C): carbon will increase the hysteresis loss, is the culprit of magnetic aging. In the long-term operation or use of the motor, carbon will be in the form of cementite precipitated, so that the iron loss increases sharply. Therefore the invention limits C≤0.008%.

[0027] Sulfur (S) and nitrogen (N): they will form MnS, AlN and other small inclusions with manganese, aluminum and other, these inclusions will pin the magnetic domain wall, hinder its movement, significantly increase the hysteresis loss. Therefore the invention limits S≤0.008%, N≤0.008%.

[0028] Phosphorus (P): easy to cause cold brittleness phenomenon, reduce the manufacturability of cold rolling process. Therefore the invention limits P≤0.008%.

[0029] Titanium (Ti): Ti is easy to combine with C, N, so that the precipitates greatly increase, strongly hinder the grain growth, worsen the magnetic properties of steel. Therefore the invention limits Ti≤0.005%.

[0030] As an embodiment of the invention, in the step S3, the rolling reduction of the first pass is 40-50%, the rolling reduction of the second pass is 38-48%, the rolling reduction of the third pass is 35-45%, the rolling reduction of the fourth pass is 30-40%, the rolling reduction of the fifth pass is 25-35%, the rolling reduction of the sixth pass is 15-25%; As an embodiment of the invention, in the step S3, the slab after 6 passes of rolling is kept at 950-1050℃ for 2-10min, then a 1.5-2.3mm thick hot-rolled plate is obtained by a rolling reduction of 30-40%; the average grain diameter of the hot-rolled plate is 100-600μm, the content of Goss texture is 12-25%, and the content of γ texture is not more than 10%.

[0031] As an embodiment of the invention, in the step S4, the cold rolling reduction is 50-75%, and the rolling pass is 5 passes.

[0032] As an embodiment of the present application, in the step S5, the protective atmosphere is argon or a nitrogen-hydrogen mixed gas containing 10%-30% hydrogen and 90%-70% nitrogen by volume, the annealing temperature is 900-1000 DEG C, and the annealing holding time is 2-8 min. Secondly, the present application provides a strong Goss texture non-oriented electrical steel sheet prepared by the above method, wherein the average grain diameter of the obtained electrical steel sheet is 50-300 μm, the Goss texture content is 10-22%, and the η texture ({hk0}<001>, <001> / rolling direction) content is 25-40%. As an embodiment of the present application, the magnetic induction intensity B 50 of the electrical steel sheet is 1.70-1.78 T, and the iron loss P 15 / 50 is 2.0-3.0 W / kg.

[0033] The present application provides a strong Goss texture non-oriented electrical steel sheet hot-rolled plate by controlling the hot-rolling pass, the hot-rolling reduction and the finish rolling temperature, which provides a good substrate for the subsequent preparation of a cold-rolled sheet with excellent magnetic properties.

[0034] Compared with the prior preparation technology, the design idea of the present application is to reduce the adverse texture in the hot-rolled plate by controlling the hot-rolling temperature, the hot-rolling pass, the hot-rolling reduction and the finish rolling temperature, to obtain larger grains by re-melting and holding, to obtain stronger Goss texture without dynamic recrystallization under the action of single pass deformation, and to improve the content of Goss texture, η texture and other beneficial textures in the annealed sheet by controlling the cold-rolling reduction and the annealing process, thereby improving the magnetic properties of the non-oriented electrical steel.

[0035] Embodiment 1

[0036] A strong Goss texture non-oriented electrical steel sheet preparation method, the specific steps are as follows: S1, casting: melting by a vacuum induction melting furnace and then casting into an ingot at 1550 DEG C. The chemical composition (mass percentage) of the ingot is: Si: 3.04%, C: 0.004%, S: 0.007%, Mn: 0.28%, Ti: 0.004%, acid-soluble aluminum Als: 0.9%, P: 0.008%, N: 0.006%, and the balance is iron and unavoidable inclusions; S2, breakdown: the ingot is kept at 1200 DEG C for 120 min, and then is subjected to breakdown by a two-high reversing mill, and after multi-pass rolling, a 30 mm intermediate billet is obtained. S3, hot rolling: the intermediate blank is heated in the furnace, and after holding at 1050℃ for 40 min, hot rolling is performed, the rolling reduction of the first pass is 45%, the rolling reduction of the second pass is 40%, the rolling reduction of the third pass is 38%, the rolling reduction of the fourth pass is 35%, the rolling reduction of the fifth pass is 28%, and the rolling reduction of the sixth pass is 21%, and the finish rolling temperature is 880℃, obtaining a plate strip of 2.3mm; the plate strip is held at 1050℃ for 3min, and then single-pass rolling with a rolling reduction of 31% is performed, and the finish rolling temperature is 950℃, obtaining a hot-rolled plate of 1.6mm thick; The hot-rolled plate is subjected to metallographic and texture detection, Figure 1 Fig. 2 is a microstructure diagram of the hot-rolled plate of the non-oriented electrical steel of the embodiment, and Fig. 3 is an ODF cross-sectional diagram of the texture of the hot-rolled plate of the non-oriented electrical steel of the embodiment, which is obtained by EBSD detection, 2=0° and Figure 1 It can be seen from Fig. 3 that the average grain diameter of the plate is 176μm, the strongest texture is Goss texture, the strongest point is 14.6, the content of Goss texture is 20.6%, and the content of γ texture is 8%.

[0037] S4, pickling and cold rolling: after the hot-rolled plate is pickled, a 0.5mm thin plate is obtained by cold rolling with a rolling reduction of 69% in 5 passes; S5, heat treatment: the cold-rolled plate is annealed at 1000℃ in an argon atmosphere, and the holding time is 5min.

[0038] A strong Goss texture non-oriented electrical steel thin plate is prepared by the above method, and microstructure and texture detection are performed on the thin plate. Figure 2 Fig. 6 is a microstructure diagram of the thin plate of the non-oriented electrical steel of the embodiment, and Fig. 7 is an ODF cross-sectional diagram of the texture of the thin plate of the non-oriented electrical steel of the embodiment, which is obtained by EBSD detection, Figure 2 Fig. 6 is a microstructure diagram of the thin plate of the non-oriented electrical steel of the embodiment, and Fig. 7 is an ODF cross-sectional diagram of the texture of the thin plate of the non-oriented electrical steel of the embodiment, which is obtained by EBSD detection, Figure 3 Fig. 6 is a microstructure diagram of the thin plate of the non-oriented electrical steel of the embodiment, and Fig. 7 is an ODF cross-sectional diagram of the texture of the thin plate of the non-oriented electrical steel of the embodiment, which is obtained by EBSD detection, 2=0° and 2=45°, from Figure 3 It can be seen from Fig. 7 that the thin plate contains η texture and Goss texture, the strongest point of the Goss texture is 11.2, the content of the Goss texture in the thin plate is 19.7%, and the content of the η texture is 37.2%. The magnetic induction intensity B 50 of the thin plate is 1.76T, and the iron loss P 15 / 50 is 2.2W / kg.

[0039] Example 2

[0040] A strong Goss texture non-oriented electrical steel thin plate preparation method, the specific steps are as follows: S1, casting: after smelting by a vacuum induction melting furnace, cast into ingot at 1500℃; the chemical composition of the ingot (mass percent) is: Si: 4.52%, C: 0.004%, S: 0.006%, Mn: 0.20%, Ti: 0.004%, acid-soluble aluminum Als: 0.009%, P: 0.007%, N: 0.005%, the balance is iron and inevitable inclusions; S2, blooming: the ingot is kept at 1150℃ for 150 min, and is bloomed by a two-high reversing mill, after multi-pass rolling, a 50mm intermediate billet is obtained; S3, hot rolling: the above intermediate billet is loaded into the furnace and heated with the furnace, after keeping at 1000℃ for 50 min, hot rolling is carried out, the rolling reduction of the first pass is 48%, the rolling reduction of the second pass is 43%, the rolling reduction of the third pass is 35%, the rolling reduction of the fourth pass is 32%, the rolling reduction of the fifth pass is 29%, the rolling reduction of the sixth pass is 20%, and the finish rolling temperature is 860℃, a 3.7mm plate strip is obtained; the above plate strip is kept at 1000℃ for 6 min, and then rolled by a single pass with a rolling reduction of 38%, and the finish rolling temperature is 930℃, a 2.3mm thick hot-rolled plate is obtained; The microstructure and texture of the hot-rolled plate are detected, the average grain diameter is 325μm, the content of Goss texture is 13.8%, and the content of γ texture is 5.2%.

[0041] S4, pickling and cold rolling: after pickling the hot-rolled plate, a 0.65mm thin plate is obtained by cold rolling with a rolling reduction of 72% in 5 passes; S5, heat treatment: the above cold-rolled plate is annealed at 950℃ in a nitrogen-hydrogen mixed gas atmosphere containing 20% hydrogen and 80% nitrogen by volume, and the holding time is 6 min.

[0042] A strong Goss texture non-oriented electrical steel thin plate is prepared by the above method, the microstructure and texture of the thin plate are detected, the average grain diameter is 257μm, the content of Goss texture in the thin plate is 11.5%, and the content of η texture is 28.6%. The magnetic induction intensity B 50 of the annealed thin plate is 1.72T, and the iron loss P 15 / 50 is 2.5W / kg.

[0043] Comparative Example 1

[0044] The steps S1, S2, S4, S5 of the present comparative example are completely same as those of Example 1, the difference is that the step S3 of the present comparative example is as follows: S3. Hot rolling: After the above intermediate billet is loaded into the furnace, the furnace temperature is raised and held at 1050℃ for 40 min before hot rolling. The rolling reduction rate of the first pass is 53%, the rolling reduction rate of the second pass is 43%, the rolling reduction rate of the third pass is 38%, the rolling reduction rate of the fourth pass is 30%, the rolling reduction rate of the fifth pass is 29%, the rolling reduction rate of the sixth pass is 24%, and the rolling reduction rate of the seventh pass is 16%. The final rolling temperature is 850℃, and a 1.6mm hot-rolled plate is obtained. The obtained hot-rolled plate was subjected to microstructure and texture analysis. Figure 4 This is a microstructure and texture diagram of the hot-rolled non-oriented electrical steel sheet used in this comparative example. The texture diagram is an ODF cross-sectional image obtained from EBSD detection. 2 = 45°, from Figure 4 The hot-rolled plate shows fine equiaxed crystals on the surface and elongated grains in the core. The strongest point of the Goss texture is 2.9, the Goss texture content is 5.8%, and the γ texture content is 11.2%.

[0045] A non-oriented electrical steel sheet was prepared using the above method. The microstructure and texture of the sheet were then examined. Figure 5 This is a microstructure diagram of the non-oriented electrical steel sheet used in this comparative example. Figure 5 The average grain diameter is 45 μm. Figure 6 The texture diagram of the non-oriented electrical steel sheet in this comparative example is the ODF cross-sectional diagram obtained by EBSD detection. 2=0° and 2 = 45°, from Figure 6 The thin plate shows that η-texture and Goss texture are particularly rare, with Goss texture accounting for 0.6% and η-texture accounting for 2.4%. Magnetic induction intensity B 50 The iron loss is 1.62T, and the iron loss is P. 15 / 50 It is 3.1 W / kg.

[0046] Comparative Example 2

[0047] Steps S1, S2, S4, and S5 in this comparative example are exactly the same as in Example 2, except for step S3, which is as follows: S3. Hot rolling: After the above intermediate billet is loaded into the furnace, the furnace temperature is raised and held at 1000℃ for 50 min before hot rolling. The rolling reduction rate of the first pass is 55%, the rolling reduction rate of the second pass is 43%, the rolling reduction rate of the third pass is 38%, the rolling reduction rate of the fourth pass is 36%, and the rolling reduction rate of the fifth pass is 27%. The final rolling temperature is 860℃, resulting in a 3.7mm thick strip. The strip is then held at 850℃ for 5 min and then rolled with a single pass of 38% reduction rate. The final rolling temperature is 930℃, resulting in a 2.3mm thick hot-rolled plate. The microstructure and texture of the hot-rolled plate are detected, the average grain diameter is 76 μm, the texture orientation is random, there is no significant strong point texture, the Goss texture content is 6.7%, and the content of γ texture is 18.1%; A non-oriented electrical steel sheet is prepared by the above method, the microstructure and texture of the sheet are detected, the average grain diameter in the sheet is 58 μm, the content of Goss texture is 1.2%, and the content of η texture is 4.5%. The magnetic induction intensity B 50 is 1.66 T, the iron loss P 15 / 50 is 3.3 W / kg.

[0048] From the comparison of Example 1 and Comparative Example 1, and the comparison of Example 2 and Comparative Example 2, it can be seen that by controlling the hot rolling process parameters such as hot rolling reduction and hot rolling temperature, a non-oriented electrical steel hot-rolled plate with strong Goss texture is obtained, and by subsequently controlling the cold rolling reduction and annealing temperature, a non-oriented electrical steel sheet with excellent magnetic properties is obtained.

[0049] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

1. A method of producing a strong Goss texture non-oriented electrical steel sheet, characterized by, The method comprises the following steps: S1, casting: smelting molten steel based on a set composition by using a vacuum induction furnace, and then casting into an ingot at 1450-1550 DEG C; S2, blooming: keeping the ingot at 1100-1200 DEG C for 120-180 min, and then rough rolling and blooming the ingot by using a two-high reversing mill or performing forging blooming to obtain an intermediate blank with a thickness of 25-50 mm; S3, hot rolling: heating the intermediate blank at room temperature, keeping it at 980-1080 DEG C for 30-60 min, and then performing hot rolling through 6 passes, with a finish rolling temperature of 850-900 DEG C, and then returning to the furnace for 2-10 min, and then performing single-pass rolling with a rolling reduction rate of 30-40%, with a finish rolling temperature above 900 DEG C, to obtain a hot-rolled sheet with a thickness of 1.5-2.3 mm; S4, pickling and cold rolling: pickling the hot-rolled sheet, and then performing cold rolling through 5 passes with a rolling reduction rate of 50-75% to obtain a cold-rolled sheet with a thickness of 0.4-0.7 mm; S5, heat treatment: annealing the cold-rolled sheet in a protective atmosphere, with an annealing temperature of 900-1050 DEG C and an annealing holding time of 2-8 min.

2. The method of claim 1, wherein, In the step S1, the mass percentage of each component in the ingot is as follows: Si=2.8-4.8%, C≤0.008%, Mn=0.10%-0.50%, acid-soluble aluminum Als≤1.0%, S≤0.008%, P≤0.008%, N≤0.008%, Ti≤0.005%, and the balance is iron and unavoidable inclusions.

3. The method of claim 1, wherein, In the step S3, the rolling reduction rate of the first pass is 40-50%, the rolling reduction rate of the second pass is 38-48%, the rolling reduction rate of the third pass is 35-45%, the rolling reduction rate of the fourth pass is 30-40%, the rolling reduction rate of the fifth pass is 25-35%, and the rolling reduction rate of the sixth pass is 15-25%.

4. The method of claim 1, wherein, In the step S3, the temperature of the returning to the furnace for holding is 950-1050 DEG C.

5. The method of claim 1, wherein, In the step S3, the average grain diameter of the hot-rolled sheet is 100-600 μm, the content of Goss texture is 12-25%, and the content of γ texture is not more than 10%.

6. The method of claim 1, wherein, In the step S5, the protective atmosphere is argon or a nitrogen-hydrogen mixed gas.

7. The method of claim 6, wherein, The nitrogen-hydrogen mixed gas contains hydrogen with a volume ratio of 10%-30% and nitrogen with a volume ratio of 90%-70%.

8. The method of claim 1, wherein, In the step S5, the annealing temperature is 900-1000 DEG C.

9. A strong Goss texture non-oriented electrical steel sheet characterized in that, The thin sheet is prepared by the method of any one of claims 1-8, the average grain diameter of the thin sheet is 50-300 μm, the content of Goss texture is 10-22%, and the content of η texture is 25-40%.

10. The sheet of claim 9, wherein The magnetic induction intensity B of the thin plate 50 The iron loss P is 1.70-1.78T. 15 / 50 It is 2.0-3.0w / kg.

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