Short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel

Abstract

A short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel belongs to the field of non-oriented electrical steel manufacturing, and comprises the following steps: smelting molten steel according to set chemical components in percentage by mass: 3.0-3.7% of Si, 0.5-1.0% of Al, 0.2-0.6% of Mn, less than or equal to 0.0025% of C, less than or equal to 0.0025% of S, less than or equal to 0.003% of N, less than or equal to 0.0006% of O, less than or equal to 0.10% of Sn or Sb or Sn + Sb, and the balance of Fe and inevitable impurities; molten steel is subjected to continuous casting, rough rolling, intermediate billet coiling, finish rolling, acid pickling, primary cold rolling, intermediate annealing, secondary cold rolling, final annealing and insulating layer coating, after finish rolling, the head and the tail of a hot rolled plate are 10-15 m long and are not subjected to laminar cooling, and non-oriented electrical steel finished plates with the nominal thicknesses of 0.10 mm, 0.15 mm and 0.20 mm are obtained.

Description

Technical Field

[0001] The invention belongs to the field of non-oriented electrical steel manufacturing, and in particular relates to a short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel. Background Art

[0002] Non-oriented electrical steel is mainly used as the core material of generators, motors and compressors working in a rotating magnetic field. With the rise of high-end industries such as drive motors for new energy vehicles, high-speed machine tool spindle motors and high-speed flywheel energy storage systems, motors are required to develop in the direction of miniaturization, high torque and high efficiency. With the increase of operating frequency, core loss, especially eddy current loss, will increase significantly, which will affect the output efficiency of the drive motor. Under high frequency conditions, the iron loss of non-oriented electrical steel is mainly eddy current loss, and eddy current loss is proportional to the square of the operating frequency or steel plate thickness. Therefore, reducing the thickness of non-oriented electrical steel is an important means to reduce iron loss; in addition, increasing the silicon content can also effectively reduce iron loss. At present, emerging industries such as new energy vehicles and unmanned robots have a great demand for thin-gauge high-silicon non-oriented electrical steel with a thickness of ≤0.2mm.

[0003] Patent CN114369761A discloses a thin gauge non-oriented silicon steel and its preparation method. The composition of the non-oriented electrical steel prepared in the document includes C≤0.005%, Si: 2.0-4.0%, Mn: 0.20-2.0%, P≤0.02%, S≤0.005%, Al: 0.3-1.4%, N≤0.005%, Ti≤0.005%, Nb≤0.005%, and (Si+1.3Al) / Mn≥2.1%, 3.0%≤Si+Mn≤4.4%, and the rest is iron and inevitable impurities. After continuous casting, it is rough rolled at 900-1150℃ and fine rolled at 800-950℃ to obtain a 2mm thick hot-rolled plate, normalized at 760-840℃, trimmed, and then cold-rolled to 0.2mm in one step using a twenty-roll mill, and finally annealed at 830-880℃ to obtain a finished product. This method prevents large edge cracks by controlling the first pass reduction rate of cold rolling to less than 18% and the final pass reduction rate to less than 20%. Due to the low normalizing temperature, the performance of the 0.2 mm thick non-oriented electrical steel prepared by this method is B 50 ≥1.60T, P 1.0 / 400 ≤12W / kg.

[0004] Patent CN116411152A discloses a normalizing method for non-oriented electrical steel. For non-oriented silicon steel with a composition range of: C≤0.004%, Si: 2.2-4.0%, Mn: 0.1-1.2%, Al: 0.1-1.2%, S≤0.01%, Ti≤0.005%, Nb≤0.005%, the specific normalizing process is: heating the hot-rolled plate to have a target temperature, heating the hot-rolled plate of non-oriented electrical steel with a set chemical composition to have a target temperature; under the conditions of the target temperature and a first set time, the heated hot-rolled plate is heated evenly; at a second set time, Under the above conditions, the hot-rolled plate after being heated is self-heated and then cooled to obtain a normalized substrate; wherein the normalization temperature and time are calculated according to the composition, specifically, the target temperature = 1133-66.67×[Si]+66.67×[Mn]-33.33×[Al], the first set time = -44.18+25.45×[Si]+15.00×[Mn]+11.36×[Al], and the second set time = 188.18-25.45×[Si]-15.00×[Mn]-11.36×[Al]. This method solves the problem that the grain size of non-oriented electrical steel hot-rolled plates is too large during the normalization process, and reduces the probability of cold rolling defects or strip breaks to a certain extent, but does not completely solve the edge cracking and strip breakage problems during the cold rolling process.

[0005] Patent CN110565022B discloses a method for manufacturing high-grade non-oriented electrical steel. The components of the non-oriented electrical steel prepared in this document, by weight percentage, include Si: 2.9-3.5%, Mn: 0.15-1.0%, Al: 0.5-1.5%, C≤0.0040%, S≤0.0060%, Ti≤0.0030%, N≤0.0040%, and the total content of the remaining impurities V, Nb, B, Ca, Mo, and Ni is controlled below 0.02%, and the rest is Fe and unavoidable impurities. The ingot is rolled into a hot-rolled plate with a thickness of 2.0 to 3.0 mm, and then normalized at 900 to 1050°C before rolling. During the rolling process, the edge cracks are cut off, and the edge of the strip is trimmed online by 2 to 10 mm. At this time, the temperature of the strip is above 100°C, and the trimming process ensures that the rolling process does not stop. This operation avoids the process of cutting the edge cracks in the offline preparation unit, reduces the shear stress of cold cutting, and the final finished product thickness is 0.5 mm. This method reduces the risk of strip breakage caused by cold rolling edge cracks through online trimming, but increases the difficulty of production and reduces the yield rate.

[0006] At present, thin-gauge high-silicon non-oriented electrical steel is mainly produced through two or three rolling processes, which is called two-step cold rolling process or three-step cold rolling process. The two-step cold rolling process or three-step cold rolling process can well solve the problem that high-silicon non-oriented silicon steel is difficult to roll into thin gauge due to its large deformation resistance.

[0007] Patent CN115522127A discloses an ultra-thin non-oriented electrical steel and a method for manufacturing the same. The components of the non-oriented electrical steel prepared in the document are calculated by weight percentage, including C: 0.001-0.005%, Si: 2.0-3.0%, Mn: 0.1-0.5%, Al: 0.02-1.00%, P≤0.02%, S≤0.005%, Sn: 0.03-0.1 0%, the balance is iron and unavoidable impurities, the hot rolled plate thickness is 1.0-1.5mm, the hot rolling finishing temperature is 750-950℃, then normalized and pickled at 850-930℃, a single stand 6-roller mill is used for one cold rolling to 0.2-0.4mm, 850-950℃ intermediate annealing and then secondary cold rolling to 0.120-0.140mm, and annealed plate is obtained by continuous annealing at 850-1000℃. However, the production process is long, and the high temperature normalization process will cause dense iron oxide scale on the surface of the hot rolled plate, which increases the burden of subsequent pickling, and on the other hand, it will also lead to increased manufacturing costs.

[0008] Patent CN108504926A discloses a non-oriented electrical steel for new energy vehicles and a production method thereof. The components of the non-oriented electrical steel prepared in the document include Si: 3.0-4.0%, Al: 1.0-2.0%, (Si+Al): ≥4.5%, Mn: 1.0-2.0%, S≤0.003%, O≤0.003%, C≤0.002%, N≤0.002%, (Sn or Sb or Sn+Sb): 0.01-0.1%, rare earth elements: 0.001-0. 1%, the balance is Fe and other impurity elements, continuous casting to obtain 200-300mm ingot, rough rolling to obtain intermediate billet with a thickness of 20-30mm, and fine rolling to obtain hot-rolled plate with a thickness of 0.8-1.0mm, wherein the final rolling temperature is 880-920℃, the hot-rolled plate is not regularized after coiling at 600-700℃, and after pickling, it is cold-rolled to 0.4-0.5mm for one time, and then cold-rolled to 0.20-0.25mm for two times after intermediate annealing at 800-900℃, and finally annealed in 100% hydrogen atmosphere at 950-1200℃ to obtain annealed plate. The reduction rate of the first and second cold rolling is controlled at 50-60%. The magnetic properties are B 50 =1.669~1.681T,P 1.0 / 400=13.15~14.02W / kg. Although the invention technology can save the normalization process and simplify the process flow, the thickness of the hot-rolled plate is only 0.8~1.0mm, which is much lower than the normal product thickness (2.0~3.0mm) of the existing hot rolling production line, and the plate shape and thickness accuracy control is difficult. In addition, a large amount of 1.0~2.0mm thick transition material must be pre-matched for hot rolling, and gradually transitioned to this thin specification to ensure the continuity and stability of hot rolling production, which increases the difficulty of production operation and reduces the flexibility of production.

[0009] Patent CN112538592A discloses a non-oriented silicon steel and production method for high-speed motors with a frequency of ≥10000Hz. The composition of the non-oriented electrical steel prepared in the document includes C≤0.003%, Si: 2.8-3.5%, Mn: 0.05-1.0%, P≤0.0015%, N≤0.0008%, Al: 0.75-1.5%, S≤0.0009%, Sb: 0.001-0.1%, Sn: 0.001-0.1%, and Sb+Sn is 0.001-0.1%, and the rest is Fe and unavoidable impurities. The ingot is hot rolled to 1.8-2.3mm, pickled and coiled after normalization, and then rolled to the target thickness by three-step cold rolling plus two intermediate annealings. Specifically, the steel is first cold rolled to 0.5-0.7 mm, annealed at 980-1050°C, then cold rolled to 0.2-0.25 mm, annealed at 760-850°C, and then cold rolled to the target thickness of 0.02-0.15 mm, and finally annealed. This method uses three-step cold rolling + two intermediate annealings, which has a lengthy process flow, low production efficiency, and high production costs.

[0010] It can be seen from the above patented technology that due to the high silicon content of high silicon non-oriented electrical steel, the deformation resistance during the cold rolling process is very large, and the hot rolled plate needs to be normalized before cold rolling. It is very difficult to achieve the target thickness of ≤0.2mm through one rolling process, and there are problems such as cold rolling edge cracks and even broken strips, and the resulting reduction in yield. Therefore, the use of one-step cold rolling method to manufacture thin-gauge high silicon non-oriented electrical steel requires strict control of the normalization process, edge trimming, and pass reduction rate distribution of the hot rolled plate, which is difficult to produce and does not completely solve the problem of edge cracking during the cold rolling process.

[0011] In addition, it can be seen from the above patent technology that when preparing thin-gauge high-silicon non-oriented electrical steel sheets by two-step cold rolling or three-step cold rolling, it is also necessary to perform normalizing treatment on the hot-rolled sheets before cold rolling, and then perform two-step cold rolling or three-step cold rolling with intermediate annealing. Normalizing treatment can increase the grain size before cold rolling, help weaken the difficult-to-magnetize {111} texture, and improve the magnetic properties of the product. However, normalizing treatment of hot-rolled sheets also has many disadvantages: (1) it increases the thickness of the oxide scale, which increases the difficulty and burden of the subsequent pickling process; (2) it increases the grain size, increases the ductile-brittle transition temperature, and aggravates the brittleness of the steel sheet, resulting in prominent problems such as strip breakage and severe edge cracking during the cold rolling process, which not only increases the production difficulty but also reduces the material yield; (3) normalizing treatment increases the production process, the production process is long and the production cost is high. It can be seen that eliminating the normalizing treatment process of hot-rolled sheets is of great significance for preparing thin-gauge high-silicon non-oriented electrical steel with a thickness of ≤0.2mm by two-step cold rolling. Therefore, it is necessary to develop a new two-step cold rolling process technology that can not only eliminate the normalizing treatment process, but also improve the yield rate and ensure excellent magnetic properties, so as to achieve low-cost, high-efficiency and short-process manufacturing of high-performance, thin-gauge, high-silicon non-oriented electrical steel.

[0012] However, the existing two-step cold rolling method that omits the normalizing process requires the hot-rolled plate thickness to be controlled at 0.8 to 1.0 mm, and the plate shape and thickness accuracy are difficult to control. Moreover, according to the production experience of enterprises, a large amount of 1.0 to 2.0 mm thick transition material must be pre-matched for hot rolling, and gradually transitioned to this thin specification to ensure the continuity and stability of hot rolling production, which increases the difficulty of production operation and reduces production flexibility.

[0013] In summary, the research and development of a two-step cold rolling process that eliminates normalizing treatment to produce thin-gauge high-silicon non-oriented electrical steel, which is used to replace the traditional two-step cold rolling process or three-step cold rolling process with normalizing treatment, has important practical values ​​of simplifying the process flow, saving energy and reducing consumption, reducing costs and increasing efficiency, and reducing the amount of acid solution. The key point of the research and development of a two-step cold rolling process that eliminates normalizing treatment is whether it can solve the problem of cold rolling edge cracking while eliminating normalizing treatment, whether it can ensure excellent magnetic properties, and whether it can adapt to the characteristics of the existing production line to facilitate production operations. Summary of the invention

[0014] In view of the problems and shortcomings of the existing production technology of thin-gauge high-silicon non-oriented electrical steel, the purpose of the present invention is to provide a short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel, which is obtained by smelting molten steel, continuous casting, and hot rolling to obtain hot-rolled plates, and then pickling the hot-rolled plates, and then undergoing a cold rolling, intermediate annealing, a secondary cold rolling, a final annealing, and an insulating layer coating to obtain a low iron loss, high magnetic induction, high silicon non-oriented electrical steel with a thickness of ≤0.20mm and no edge cracks.

[0015] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0016] (1) Molten steel: Molten steel is smelted according to the set chemical composition;

[0017] The chemical composition includes, by mass percentage, Si: 3.0-3.7%, Al: 0.5-1.0%, Mn: 0.2-0.6%, C≤0.0025%, S≤0.0025%, N≤0.003%, O≤0.0006%, Sn or Sb or Sn+Sb≤0.10%, and the balance is Fe and unavoidable impurities;

[0018] (2) Continuous casting: Molten steel is cast into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The stirring frequency is 2 to 18 Hz. The pulling speed during the continuous casting process is controlled to be 0.8 to 2.0 m / min to obtain a continuous casting billet with a thickness of 100 to 240 mm.

[0019] (3) Rough rolling: The continuous casting billet is sent into a heating furnace and heated to 1160-1190°C. The billet is kept in the furnace for 150-210 min. After it is taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed to obtain an intermediate billet with a thickness of 15-25 mm.

[0020] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0021] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1020-1040°C and the final rolling temperature is 890-910°C. A hot-rolled plate with a thickness of 2.3-2.7 mm is obtained. The hot-rolled plate is then cooled to 700-750°C by laminar water and then coiled. The head and tail of the hot-rolled plate are each 10-15 m long and are not subjected to laminar water cooling.

[0022] (6) Pickling: Pickling is carried out on the continuous pickling mill production line to remove surface iron oxide scale;

[0023] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.25 to 0.66 mm;

[0024] (8) Intermediate annealing: The cold-rolled sheet obtained in step (7) is annealed in a continuous annealing furnace, wherein the atmosphere in the furnace is a mixed atmosphere of hydrogen and nitrogen, the temperature of the soaking section is 920 to 960° C., and the soaking time of the soaking section is 0.5 to 1.0 min;

[0025] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain cold rolled sheets with thicknesses of 0.10±0.005 mm, 0.15±0.005 mm, and 0.20±0.005 mm, respectively. The total reduction ratio of the secondary cold rolling is controlled to be 61-70%.

[0026] (10) Final annealing: The cold-rolled sheet obtained in step (9) is subjected to final annealing in a continuous annealing furnace, wherein the atmosphere in the furnace is a mixed atmosphere of hydrogen and nitrogen, the temperature of the soaking section is 920 to 980° C., and the soaking time of the soaking section is 0.5 to 1.0 min;

[0027] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain non-oriented electrical steel finished sheets with nominal thicknesses of 0.10 mm, 0.15 mm and 0.20 mm, respectively.

[0028] in:

[0029] In the step (3), the starting temperature of the rough rolling is 1120-1150°C.

[0030] In the step (6), the pickling solution is a hydrochloric acid solution with a mass concentration of 2 to 6%, and the pickling temperature is 65 to 80°C.

[0031] In the step (8), the heating rate in the heating section during the annealing process is ≥30°C / s, and the cooling rate in the cooling section is 20-40°C / s.

[0032] In the steps (8) and (10), the volume fraction of hydrogen gas is ≥5%, and the dew point of the mixed atmosphere is ≤-25°C.

[0033] In the step (10), the heating rate in the heating section is ≥30°C / s, and the cooling rate in the cooling section is 20-40°C / s.

[0034] In the step (11), the magnetic properties of the finished electrical steel plate with a nominal thickness of 0.10 mm: 50 1.71~1.72T, P 10 / 400 9.3~9.7W / kg, P 10 / 1000 28.8~29.5W / kg; Magnetic properties of finished electrical steel plate with nominal thickness of 0.15mm: B 50 1.71~1.72T, P 10 / 400 10.2~10.7W / kg, P 10 / 1000 39.0~39.7W / kg; Magnetic properties of finished electrical steel plate with nominal thickness of 0.20mm: B 50 1.71~1.72T, P 10 / 400 11.3~12.0W / kg, P 10 / 1000It is 48.0~48.6W / kg.

[0035] The control principle of the process parameters of each process in the present invention is as follows:

[0036] (1) The present invention adopts electromagnetic stirring in the continuous casting process, the stirring frequency is 2 to 18 Hz, and the pulling speed in the continuous casting process is controlled to be 0.8 to 2.0 m / min, so as to obtain a continuous casting billet with a thickness of 100 to 240 mm. Its function is to control the proportion of equiaxed crystals in the continuous casting billet to more than 50%, so as to avoid excessive columnar crystals leading to micro crack defects on the edge in the subsequent hot rolling process.

[0037] (2) The present invention controls the hot rolling heating temperature at 1160-1190°C. The higher heating temperature is to ensure a higher final rolling temperature. Holding for 150-210 minutes can make the temperature inside and outside the ingot uniform and minimize burning. The starting rolling temperature is 1120-1150°C and the intermediate billet thickness is controlled at 15-25 mm. The purpose is to ensure that the finishing rolling reduction is ≤92%, reduce work hardening and thus reduce the deformation structure in the hot-rolled plate, and increase the volume fraction of recrystallized grains in the hot-rolled plate.

[0038] (3) The purpose of the present invention of sending the intermediate billet into the hot coil box is to coil the steel plate into a coil, which can not only reduce the temperature drop of the steel plate but also improve the temperature uniformity of the head, middle and tail of the steel plate.

[0039] (4) In the present invention, the start rolling temperature of the finishing rolling is controlled at 1020-1040°C, and the final rolling temperature is controlled at 890-910°C. If the start rolling temperature is lower than 1020°C, it is difficult to ensure the final rolling temperature during the hot rolling process and the deformation resistance during rolling is large; if the start rolling temperature is higher than 1040°C, the iron oxide scale formed at high temperature is not easy to remove. The thickness of the hot-rolled plate cannot be too thin. The purpose of controlling it at 2.3-2.7mm is to facilitate the hot rolling operation. During the hot rolling process, the temperature of the head and tail of the steel plate is often lower than that of the middle part. In order to ensure that the head and tail also have a higher temperature, the head and tail of the hot-rolled plate are not cooled by laminar water for a length of 10-15m. In addition, a higher coiling temperature of 700-750°C is adopted. The three measures of higher final rolling temperature, no laminar water cooling at the head and tail, and higher coiling temperature can ensure that the head, tail, and middle of the steel plate all obtain a gradient structure composed of upper and lower surface recrystallized grains and internal deformation structure. The total volume fraction of recrystallized grains is ≥30% and the internal stress of the remaining deformed grains is low, which is conducive to reducing the deformation resistance of the subsequent cold rolling process and facilitating cold rolling; and the average size of the upper and lower surface recrystallized grains is ≤80μm, and the fine grains are conducive to reducing the brittleness of the steel plate and improving toughness and plasticity. The above measures can not only reduce the cold rolling deformation resistance but also avoid edge cracking or belt breakage in the subsequent cold rolling process.

[0040] (5) Since the high-temperature normalizing treatment process is omitted in the present invention, the iron oxide scale on the surface of the hot-rolled plate is thinner, so a hydrochloric acid aqueous solution with a mass concentration of 2 to 6% is used for pickling at a temperature of 65 to 80° C. The purpose is to remove the iron oxide scale on the surface of the strip after hot rolling and coiling and improve the surface quality of the strip.

[0041] (6) The present invention utilizes a cold rolling mill to perform the first cold rolling. Compared with a single-stand twenty-high rolling mill, the cold rolling mill has higher production efficiency. The thickness of the first cold-rolled plate is controlled at 0.25 to 0.66 mm, in order to ensure that the total reduction rate of the subsequent second cold rolling is 61% to 70%.

[0042] (7) After the primary cold rolling, the present invention performs annealing (also called intermediate annealing) in a continuous annealing furnace, the heating rate in the heating section is ≥30°C / s, the temperature in the soaking section is 920-960°C, the soaking time in the soaking section is 0.5-1.0 min, and the cooling rate in the cooling section is 20-40°C / s. The purpose of this is to ensure that a coarser grain size is obtained, to create conditions for the formation of shear bands in the subsequent secondary cold rolling structure and the development of a favorable {001}∥ND texture. The purpose of using a hydrogen-nitrogen mixed atmosphere (hydrogen gas volume fraction ≥5%, dew point ≤-25°C) is to prevent oxidation of the steel plate surface and to ensure that secondary cold rolling can be performed directly.

[0043] (8) The second cold rolling of the present invention uses a single-frame twenty-roller cold rolling mill. On the one hand, the working roll diameter of the twenty-roller cold rolling mill is small, the thinning ability is strong, and the rolling mill has high rigidity and high plate shape and thickness control accuracy; on the other hand, since the intermediate annealing plate does not require pickling, it is impossible to use the pickling mill for cold rolling. The purpose of controlling the total reduction rate of the second cold rolling to 61-70% is to match the coarser grains of the intermediate annealing, jointly promote the formation of shear bands during the cold rolling process, and then create conditions for the development of the favorable texture {001}∥ND of the final annealed plate. At the same time, within this total reduction rate range, the secondary cold rolling structure has moderate deformation energy storage, which is conducive to recrystallization nucleation and grain growth in the subsequent annealing process, and provides favorable conditions for obtaining coarser grains in the final annealed plate.

[0044] (9) The heating rate of the heating section of the final continuous annealing process of the present invention is ≥30℃ / s, the temperature of the soaking section is 920~980℃, the soaking time is 0.5~1.0min, and the cooling rate of the cooling section is 20~40℃. The purpose is: (1) to prevent the heating rate from being too low and the time to reach the soaking temperature is too long, resulting in a large consumption of cold deformation storage energy in the recovery stage and insufficient recrystallization driving force, thereby reducing the favorable texture of magnetic properties in the finished plate and uneven organization; (2) higher soaking temperature and soaking time ensure that coarser recrystallized grains are obtained; (3) moderate cooling rate can not only quickly reduce the temperature of the steel plate, but also ensure that no large internal stress is generated inside the steel plate to damage the magnetic properties. The purpose of using a hydrogen and nitrogen mixed atmosphere with a hydrogen gas volume fraction ≥5% and a dew point ≤-25℃ is to prevent oxidation of the steel plate surface.

[0045] (10) The final annealed sheet is sequentially subjected to insulating layer coating, drying, and sintering to form an insulating film on the surface of the steel sheet.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. The technology of the present invention ensures that the hot-rolled plate has more recrystallized grains and fine grain size through coordinated control of continuous casting, billet heating, rough rolling, intermediate billet coiling, finish rolling and post-rolling cooling, and coiling process parameters, thereby reducing the deformation resistance of the steel plate and improving the toughness and plasticity of the material. Furthermore, it can directly cold roll without the normalizing treatment process, avoid cold rolling edge crack defects, and improve the yield rate.

[0048] 2. The technology of the present invention ensures that the thin-gauge high-silicon non-oriented electrical steel still has a good recrystallization texture and a large grain size, and thus has excellent magnetic properties, under the condition of eliminating the normalizing treatment process, through the coordinated control of the total reduction of the first cold rolling, the intermediate annealing process, the total reduction of the second cold rolling, and the final annealing process.

[0049] 3. Compared with the traditional two-step cold rolling process or three-step cold rolling process with normalizing treatment, since the technology of the present invention cancels the normalizing treatment and adopts a two-step cold rolling process, it has many advantages such as obvious simplification of process flow, energy saving and consumption reduction, cost reduction and efficiency improvement, improvement of yield rate and reduction of acid consumption, and realizes the low-cost, high-efficiency and short-process manufacturing of high-performance thin-gauge high-silicon non-oriented electrical steel.

[0050] 4. Compared with the current two-step cold rolling process technology without normalization treatment, the thickness of the hot-rolled plate in the technology of the present invention is the conventional thickness of the current hot rolling production of steel mills, so there is no need to pre-match and produce a large number of transition thickness steel plates, which is easy to produce and operate with strong flexibility; and through the coordinated control of the total reduction of the first cold rolling, the intermediate annealing process, the total reduction of the second cold rolling, and the final annealing process, the product has better magnetic properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A short-process manufacturing process flow chart of a thin-gauge high-silicon non-oriented electrical steel of the present invention;

[0052] Figure 2 Optical microstructure of the hot rolled plate obtained after finish rolling in Example 1 of the present invention;

[0053] Figure 3 The edge effect diagram of the finished non-oriented electrical steel plate produced in Example 1 of the present invention;

[0054] Figure 4 The edge effect diagram of the finished non-oriented electrical steel plate produced in Example 7 of the present invention;

[0055] Figure 5 Optical microstructure and macro texture of the finished non-oriented electrical steel sheet produced in Example 9 of the present invention;

[0056] Figure 6 Optical microstructure of the hot rolled plate obtained after finish rolling in Comparative Example 1 of the present invention;

[0057] Figure 7 The edge effect diagram of the finished non-oriented electrical steel plate obtained in Comparative Example 1 of the present invention;

[0058] Figure 8 The edge effect diagram of the finished non-oriented electrical steel plate obtained in Comparative Example 5 of the present invention;

[0059] Fig. 9 Optical microstructure and macro texture of the non-oriented electrical steel finished plate obtained in Comparative Example 6 of the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. The following are preferred embodiments of the present invention.

[0061] The equipment model used for metallographic structure observation involved in the present invention is Leica DM2500 M upright metallographic microscope. The equipment model used for macro texture detection involved in the present invention is Bruker D8 Discover X-ray diffractometer. The equipment model used for magnetic property detection involved in the present invention is MATS-3110M silicon steel magnetic property measurement device and SST-100 permeameter. The sample size is 100mm×30mm, and the magnetic induction intensity B in the rolling direction and transverse direction is measured. 50 and iron loss P10 / 400 , P 10 / 1000 , and take the average value respectively. Among them, B 50 It represents the magnetic induction intensity under the magnetic field strength of 5000A / m, P 10 / 400 It represents the iron loss under the alternating magnetic field of 1.0T and 400Hz, P 10 / 1000 It indicates the iron loss under the alternating magnetic field with magnetic induction intensity of 1.0T and 1000Hz.

[0062] The following are examples and comparative examples of the present invention.

[0063] Example 1

[0064] A short process manufacturing method for thin gauge high silicon non-oriented electrical steel, the process flow chart is as follows Figure 1 As shown, the specific steps include:

[0065] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.10%, Al: 0.85%, Mn: 0.25%, C: 0.0020%, S: 0.0020%, N: 0.002%, O: 0.0005%, Sn: 0.05%, Sb: 0.05%, and the balance is Fe and unavoidable impurities.

[0066] (2) Continuous casting: The molten steel is made into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 0.8 m / min, and a continuous casting billet with a thickness of 120 mm is obtained;

[0067] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1160°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1120°C to obtain an intermediate billet with a thickness of 15 mm.

[0068] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0069] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1020°C and the final rolling temperature is 890°C. A 2.3 mm thick hot-rolled plate is obtained. The optical microstructure diagram is shown in the figure below. Figure 2 As shown, the recrystallized grains account for 34%, and then the hot rolled plate is coiled after being cooled to 700°C by laminar water flow; wherein, the head and tail of the hot rolled plate are each 10m long without laminar water cooling;

[0070] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 4% and the pickling temperature is 65°C.

[0071] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.26 mm;

[0072] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 960°C in the soaking section, a soaking time of 0.5 min in the soaking section, a cooling rate of 20°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 8% and a dew point of -28°C.

[0073] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.099 mm. The total reduction ratio of the secondary cold rolling is controlled to be 62%;

[0074] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 980°C in the soaking section, a soaking time of 0.5 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 8%, and a dew point of -28°C;

[0075] (11) Insulation coating: The final annealed sheet is subjected to insulation coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The edge effect of the obtained non-oriented electrical steel finished sheet is shown in the figure below: Figure 3 The magnetic properties are shown in Table 1.

[0076] Example 2

[0077] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0078] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.60%, Al: 0.98%, Mn: 0.55%, C: 0.0022%, S: 0.0023%, N: 0.002%, O: 0.0005%, Sn: 0.02%, Sb: 0.05%, and the balance is Fe and unavoidable impurities.

[0079] (2) Continuous casting: The molten steel is formed into continuous casting billets by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 2.0 m / min, and a continuous casting billet with a thickness of 240 mm is obtained;

[0080] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1190°C, and kept in the furnace for 210 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1150°C to obtain an intermediate billet with a thickness of 25 mm.

[0081] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0082] (5) Finish rolling: The intermediate billet is subjected to high-pressure water to remove the surface iron oxide scale and then to finish rolling. The starting rolling temperature is 1040°C and the final rolling temperature is 910°C to obtain a 2.7 mm thick hot-rolled plate, which is then cooled to 750°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 15 m, are not subjected to laminar water cooling.

[0083] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 8% and the pickling temperature is 80°C.

[0084] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.33 mm;

[0085] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 920°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 40°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 5% and a dew point of -25°C.

[0086] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.102 mm. The total reduction ratio of the secondary cold rolling is controlled to be 69%;

[0087] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 920°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 40°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -25°C;

[0088] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0089] Example 3

[0090] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0091] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.41%, Al: 0.82%, Mn: 0.51%, C: 0.0024%, S: 0.0024%, N: 0.003%, O: 0.0006%, Sn: 0.06%, and the balance is Fe and unavoidable impurities.

[0092] (2) Continuous casting: The molten steel is made into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.2 m / min, and a continuous casting billet with a thickness of 160 mm is obtained;

[0093] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1170°C, and kept in the furnace for 180 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1140°C to obtain an intermediate billet with a thickness of 20 mm.

[0094] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0095] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1030°C and the final rolling temperature is 900°C to obtain a 2.5 mm thick hot-rolled plate. The plate is then cooled to 730°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 12 m, are not subjected to laminar water cooling.

[0096] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 6% and the pickling temperature is 70°C.

[0097] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.28 mm;

[0098] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 950°C in the soaking section, a soaking time of 0.7 min in the soaking section, a cooling rate of 30°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 5% and a dew point of -26°C.

[0099] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.098 mm. The total reduction ratio of the secondary cold rolling is controlled to be 65%;

[0100] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 960°C in the soaking section, a soaking time of 0.7 min in the soaking section, a cooling rate of 30°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -26°C;

[0101] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0102] Example 4

[0103] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0104] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.23%, Al: 0.69%, Mn: 0.48%, C: 0.0024%, S: 0.0025%, N: 0.003%, O: 0.0006%, Sb: 0.05%, and the balance is Fe and unavoidable impurities.

[0105] (2) Continuous casting: The molten steel is formed into a continuous casting billet by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.0 m / min, and a continuous casting billet with a thickness of 120 mm is obtained;

[0106] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1160°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1130°C to obtain an intermediate billet with a thickness of 18 mm.

[0107] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0108] (5) Finish rolling: The intermediate billet is subjected to high-pressure water to remove the surface iron oxide scale and then to finish rolling. The starting rolling temperature is 1030°C and the final rolling temperature is 890°C to obtain a 2.3 mm thick hot-rolled plate, which is then cooled to 700°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 13 m, are not subjected to laminar water cooling.

[0109] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 4% and the pickling temperature is 65°C.

[0110] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.39 mm;

[0111] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 960°C in the soaking section, a soaking time of 0.5 min in the soaking section, a cooling rate of 20°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 7% and a dew point of -28°C.

[0112] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.152 mm. The total reduction ratio of the secondary cold rolling is controlled to be 61%;

[0113] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 980°C in the soaking section, a soaking time of 0.5 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 7%, and a dew point of -28°C;

[0114] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0115] Example 5

[0116] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0117] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.62%, Al: 0.93%, Mn: 0.60%, C: 0.0025%, S: 0.0023%, N: 0.003%, O: 0.0005%, Sn: 0.01%, Sb: 0.02%, and the balance is Fe and unavoidable impurities.

[0118] (2) Continuous casting: The molten steel is formed into continuous casting billets by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 2.0 m / min, and a continuous casting billet with a thickness of 220 mm is obtained;

[0119] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1190°C, and kept in the furnace for 200 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1150°C to obtain an intermediate billet with a thickness of 22 mm.

[0120] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0121] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1040°C and the final rolling temperature is 910°C to obtain a 2.55 mm thick hot-rolled plate. The plate is then cooled to 750°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 14 m, are not subjected to laminar water cooling.

[0122] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 8% and the pickling temperature is 80°C.

[0123] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.5 mm;

[0124] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 34°C / s in the heating section, a temperature of 960°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 40°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 5% and a dew point of -26°C.

[0125] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.150 mm. The total reduction ratio of the secondary cold rolling is controlled to be 70%;

[0126] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 920°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 40°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -26°C;

[0127] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0128] Example 6

[0129] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0130] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.53%, Al: 0.82%, Mn: 0.55%, C: 0.0022%, S: 0.0023%, N: 0.003%, O: 0.0006%, and the balance is Fe and unavoidable impurities.

[0131] (2) Continuous casting: The molten steel is made into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.6 m / min, and a continuous casting billet with a thickness of 180 mm is obtained;

[0132] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1180°C, and kept in the furnace for 170 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1130°C to obtain an intermediate billet with a thickness of 20 mm.

[0133] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0134] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1030°C and the final rolling temperature is 900°C to obtain a 2.45 mm thick hot-rolled plate. The plate is then cooled to 720°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 12 m, are not subjected to laminar water cooling.

[0135] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 6% and the pickling temperature is 70°C.

[0136] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.45 mm;

[0137] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 940°C in the soaking section, a soaking time of 0.8 min in the soaking section, a cooling rate of 30°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 6% and a dew point of -25°C.

[0138] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.149 mm. The total reduction ratio of the secondary cold rolling is controlled to be 67%;

[0139] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 950°C in the soaking section, a soaking time of 0.7 min in the soaking section, a cooling rate of 30°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 6%, and a dew point of -25°C;

[0140] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0141] Example 7

[0142] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0143] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.18%, Al: 0.95%, Mn: 0.26%, C: 0.0024%, S: 0.0022%, N: 0.002%, O: 0.0005%, Sn: 0.02%, Sb: 0.02%, and the balance is Fe and unavoidable impurities.

[0144] (2) Continuous casting: The molten steel is formed into a continuous casting billet by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 0.8 m / min, and a continuous casting billet with a thickness of 100 mm is obtained;

[0145] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1160°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1120°C to obtain an intermediate billet with a thickness of 15 mm.

[0146] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0147] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1020°C and the final rolling temperature is 890°C to obtain a 2.3 mm thick hot-rolled plate. The plate is then cooled to 700°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 11 m, are not subjected to laminar water cooling.

[0148] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 4% and the pickling temperature is 65°C.

[0149] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.52 mm;

[0150] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 920°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 7% and a dew point of -26°C.

[0151] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.203 mm. The total reduction ratio of the secondary cold rolling is controlled to be 61%;

[0152] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 920°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 7%, and a dew point of -26°C;

[0153] (11) Insulation coating: The final annealed sheet is subjected to insulation coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The edge effect of the obtained non-oriented electrical steel finished sheet is shown in the figure below: Figure 4 The magnetic properties are shown in Table 1.

[0154] Example 8

[0155] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0156] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.50%, Al: 0.96%, Mn: 0.57%, C: 0.0025%, S: 0.0022%, N: 0.003%, O: 0.0006%, Sn: 0.03%, Sb: 0.04%, and the balance is Fe and unavoidable impurities.

[0157] (2) Continuous casting: The molten steel is formed into continuous casting billets by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 2.0 m / min, and a continuous casting billet with a thickness of 220 mm is obtained;

[0158] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1190°C, and kept in the furnace for 210 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1150°C to obtain an intermediate billet with a thickness of 25 mm.

[0159] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0160] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1040°C and the final rolling temperature is 910°C to obtain a 2.6 mm thick hot-rolled plate. The plate is then cooled to 750°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 15 m, are not subjected to laminar water cooling.

[0161] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 8% and the pickling temperature is 80°C.

[0162] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.66 mm;

[0163] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 960°C in the soaking section, a soaking time of 0.5 min in the soaking section, a cooling rate of 40°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 10% and a dew point of -30°C.

[0164] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.198 mm. The total reduction ratio of the secondary cold rolling is controlled to be 70%;

[0165] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 980°C in the soaking section, a soaking time of 0.5 min in the soaking section, a cooling rate of 40°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 10%, and a dew point of -30°C;

[0166] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0167] Example 9

[0168] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0169] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.25%, Al: 0.75%, Mn: 0.56%, C: 0.0024%, S: 0.0025%, N: 0.003%, O: 0.0005%, Sn: 0.04%, Sb: 0.04%, and the balance is Fe and unavoidable impurities.

[0170] (2) Continuous casting: The molten steel is made into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.2 m / min, and a continuous casting billet with a thickness of 160 mm is obtained;

[0171] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1180°C, and kept in the furnace for 180 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1140°C to obtain an intermediate billet with a thickness of 20 mm.

[0172] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0173] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1030°C and the final rolling temperature is 900°C to obtain a 2.6 mm thick hot-rolled plate. The hot-rolled plate is then cooled to 730°C by laminar water and then coiled. The head and tail of the hot-rolled plate, each with a length of 13.5 m, are not subjected to laminar water cooling.

[0174] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 6% and the pickling temperature is 75°C.

[0175] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.6 mm;

[0176] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 940°C in the soaking section, a soaking time of 0.7 min in the soaking section, a cooling rate of 30°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 5% and a dew point of -25°C.

[0177] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.198 mm. The total reduction ratio of the secondary cold rolling is controlled to be 67%;

[0178] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 960°C in the soaking section, a soaking time of 0.7 min in the soaking section, a cooling rate of 30°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -25°C;

[0179] (11) Insulation coating: The final annealed sheet is subjected to insulation coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The optical microstructure and macro texture of the obtained non-oriented electrical steel finished sheet are as follows: Figure 5 The magnetic properties are shown in Table 1.

[0180] Comparative Example 1

[0181] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0182] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.18%, Al: 0.75%, Mn: 0.36%, C: 0.0025%, S: 0.0024%, N: 0.003%, O: 0.0006%, Sn: 0.02%, Sb: 0.05%, and the balance is Fe and unavoidable impurities.

[0183] (2) Continuous casting: The molten steel is formed into a continuous casting billet by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 0.8 m / min, and a continuous casting billet with a thickness of 100 mm is obtained;

[0184] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1150°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1100°C to obtain an intermediate billet with a thickness of 30 mm.

[0185] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0186] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1010°C and the final rolling temperature is 880°C. A 2.2 mm thick hot-rolled plate is obtained. The optical microstructure diagram is shown in the figure below. Figure 6 As shown, the recrystallized grains account for 26%, and then the hot rolled plate is coiled after being cooled to 650°C by laminar water flow; wherein, the head and tail of the hot rolled plate are 30m long each and are not subjected to laminar water flow cooling;

[0187] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 4% and the pickling temperature is 65°C.

[0188] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.8 mm;

[0189] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 900°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 5% and a dew point of -27°C.

[0190] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.104 mm. The total reduction ratio of the secondary cold rolling is controlled to be 87%;

[0191] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 900°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -27°C;

[0192] (11) Insulation coating: The final annealed sheet is subjected to insulation coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The edge effect of the obtained non-oriented electrical steel finished sheet is shown in the figure below: Figure 7 The magnetic properties are shown in Table 1.

[0193] Comparative Example 2

[0194] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0195] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.34%, Al: 0.92%, Mn: 0.47%, C: 0.0024%, S: 0.0024%, N: 0.003%, O: 0.0005%, Sn: 0.03%, Sb: 0.03%, and the balance is Fe and unavoidable impurities.

[0196] (2) Continuous casting: The molten steel is formed into continuous casting billets by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.2 m / min, and a continuous casting billet with a thickness of 150 mm is obtained;

[0197] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1100°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1050°C to obtain an intermediate billet with a thickness of 35 mm.

[0198] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0199] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1000°C and the final rolling temperature is 860°C to obtain a 2.1 mm thick hot-rolled plate. The plate is then cooled to 650°C by laminar water and then coiled. The head and tail of the hot-rolled plate are 35 m long and are not subjected to laminar water cooling.

[0200] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 6% and the pickling temperature is 75°C.

[0201] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.9 mm;

[0202] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 850°C in the soaking section, a soaking time of 1.5 min in the soaking section, a cooling rate of 20°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 6% and a dew point of -26°C.

[0203] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.099 mm. The total reduction ratio of the secondary cold rolling is controlled to be 89%;

[0204] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 880°C in the soaking section, a soaking time of 1.5 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -26°C;

[0205] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0206] Comparative Example 3

[0207] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0208] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.16%, Al: 0.83%, Mn: 0.25%, C: 0.0025%, S: 0.0025%, N: 0.002%, O: 0.0006%, Sn: 0.04%, Sb: 0.05%, and the balance is Fe and unavoidable impurities.

[0209] (2) Continuous casting: The molten steel is formed into a continuous casting billet by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 0.8 m / min, and a continuous casting billet with a thickness of 150 mm is obtained;

[0210] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1120°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1100°C to obtain an intermediate billet with a thickness of 35 mm.

[0211] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0212] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1000°C and the final rolling temperature is 870°C to obtain a 2.1 mm thick hot-rolled plate. The hot-rolled plate is then cooled to 680°C by laminar water and then coiled. The head and tail of the hot-rolled plate are 35 m long and are not subjected to laminar water cooling.

[0213] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 4% and the pickling temperature is 65°C.

[0214] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 1.3 mm;

[0215] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 880°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 9% and a dew point of -29°C.

[0216] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.150 mm. The total reduction ratio of the secondary cold rolling is controlled to be 88.5%;

[0217] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 850°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 9%, and a dew point of -29°C;

[0218] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0219] Comparative Example 4

[0220] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0221] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.51%, Al: 0.77%, Mn: 0.47%, C: 0.0024%, S: 0.0023%, N: 0.003%, O: 0.0006%, Sn: 0.03%, Sb: 0.05%, and the balance is Fe and unavoidable impurities.

[0222] (2) Continuous casting: The molten steel is made into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.5 m / min, and a continuous casting billet with a thickness of 180 mm is obtained;

[0223] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1100°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1080°C to obtain an intermediate billet with a thickness of 45 mm.

[0224] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0225] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1020°C and the final rolling temperature is 850°C to obtain a 3 mm thick hot-rolled plate. The hot-rolled plate is then cooled to 670°C by laminar water and then coiled. The head and tail of the hot-rolled plate are 45 m long and are not subjected to laminar water cooling.

[0226] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 4% and the pickling temperature is 70°C.

[0227] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 1.5 mm;

[0228] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 860°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 30°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 8% and a dew point of -26°C.

[0229] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.150 mm. The total reduction ratio of the secondary cold rolling is controlled to be 90%;

[0230] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 880°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 30°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 8%, and a dew point of -26°C;

[0231] (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0232] Comparative Example 5

[0233] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0234] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.60%, Al: 0.83%, Mn: 0.44%, C: 0.0025%, S: 0.0024%, N: 0.003%, O: 0.0006%, Sn: 0.04%, Sb: 0.03%, and the balance is Fe and unavoidable impurities.

[0235] (2) Continuous casting: The molten steel is formed into a continuous casting billet by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.0 m / min, and a continuous casting billet with a thickness of 170 mm is obtained;

[0236] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1120°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1100°C to obtain an intermediate billet with a thickness of 45 mm.

[0237] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0238] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1050°C and the final rolling temperature is 860°C to obtain a 2.9 mm thick hot-rolled plate. The hot-rolled plate is then cooled to 660°C by laminar water and then coiled. The head and tail of the hot-rolled plate are 40 m long and are not subjected to laminar water cooling.

[0239] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 6% and the pickling temperature is 70°C.

[0240] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 1.5 mm;

[0241] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 850°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 30°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 5% and a dew point of -25°C.

[0242] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.203 mm. The total reduction ratio of the secondary cold rolling is controlled to be 86.5%;

[0243] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 850°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 20°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 5%, and a dew point of -25°C;

[0244] (11) Insulation coating: The final annealed sheet is subjected to insulation coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The edge effect of the obtained non-oriented electrical steel finished sheet is shown in the figure below: Figure 8 The magnetic properties are shown in Table 1.

[0245] Comparative Example 6

[0246] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0247] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.42%, Al: 0.75%, Mn: 0.36%, C: 0.0024%, S: 0.0024%, N: 0.002%, O: 0.0006%, Sn: 0.04%, Sb: 0.06%, and the balance is Fe and unavoidable impurities.

[0248] (2) Continuous casting: The molten steel is made into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.2 m / min, and a continuous casting billet with a thickness of 180 mm is obtained;

[0249] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1100°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1060°C to obtain an intermediate billet with a thickness of 40 mm.

[0250] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0251] (5) Finish rolling: The intermediate billet is subjected to high-pressure water to remove the surface iron oxide scale and then to finish rolling. The starting rolling temperature is 1030°C and the final rolling temperature is 860°C to obtain a 2.1 mm thick hot-rolled plate, which is then cooled to 680°C by laminar water and then coiled. The head and tail of the hot-rolled plate are 35 m long and are not subjected to laminar water cooling.

[0252] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 6% and the pickling temperature is 75°C.

[0253] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.8 mm;

[0254] (8) Intermediate annealing: The primary cold-rolled sheet is annealed in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 900°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 40°C / s in the cooling section, and a hydrogen-nitrogen mixed atmosphere with a hydrogen volume fraction of 8% and a dew point of -27°C.

[0255] (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain a cold rolled sheet with a thickness of 0.20 mm. The total reduction ratio of the secondary cold rolling is controlled to be 75%;

[0256] (10) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 35°C / s in the heating section, a temperature of 880°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 30°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 8%, and a dew point of -27°C;

[0257] (11) Insulation coating: The final annealed sheet is subjected to insulation coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The optical microstructure and macro texture of the obtained non-oriented electrical steel finished sheet are as follows: Fig. 9 The magnetic properties are shown in Table 1.

[0258] Comparative Example 7

[0259] A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel specifically comprises the following steps:

[0260] (1) Molten steel: Molten steel is smelted according to the chemical composition, which includes, by mass percentage, Si: 3.55%, Al: 0.69%, Mn: 0.52%, C: 0.0025%, S: 0.0023%, N: 0.003%, O: 0.0006%, Sn: 0.04%, Sb: 0.04%, and the balance is Fe and unavoidable impurities.

[0261] (2) Continuous casting: The molten steel is formed into a continuous casting billet by a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The pulling speed during the continuous casting process is controlled to be 1.5 m / min, and a continuous casting billet with a thickness of 190 mm is obtained;

[0262] (3) Rough rolling: The continuous casting billet is hot-charged and sent into the furnace, heated to 1100°C, and kept in the furnace for 150 min. After being taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed. The starting rolling temperature is 1050°C to obtain an intermediate billet with a thickness of 45 mm.

[0263] (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill;

[0264] (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1030°C and the final rolling temperature is 860°C to obtain a 2.5 mm thick hot-rolled plate. The hot-rolled plate is then cooled to 650°C by laminar water and then coiled. The head and tail of the hot-rolled plate are 40 m long and are not subjected to laminar water cooling.

[0265] (6) Pickling: Pickling is carried out on the pickling continuous unit production line to remove surface iron oxide scale. The pickling liquid is a hydrochloric acid aqueous solution with a mass concentration of 5% and the pickling temperature is 75°C.

[0266] (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.20 mm, and the total cold rolling reduction is controlled to be 92%;

[0267] (8) Final annealing: carried out in a continuous annealing furnace, with a heating rate of 30°C / s in the heating section, a temperature of 860°C in the soaking section, a soaking time of 1.0 min in the soaking section, a cooling rate of 30°C / s in the cooling section, a hydrogen-nitrogen mixed atmosphere in the furnace, a hydrogen volume fraction of 7%, and a dew point of -25°C;

[0268] (9) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain a non-oriented electrical steel finished sheet. The magnetic properties are shown in Table 1.

[0269] Table 1 Magnetic properties of the non-oriented electrical steel finished sheets obtained in Examples 1-9 of the present invention and Comparative Examples 1-7

[0270]

[0271] It can be seen from comparative examples 1-7 that when the preparation process is not within the design scope of the present invention, the magnetic properties of the product are significantly deteriorated and the edges of the finished plates are obviously cracked. The magnetic properties and edge effects in the embodiments of the present invention are significantly better than those in the comparative examples.

Claims

1. A short-process manufacturing method for thin-gauge high-silicon non-oriented electrical steel, characterized in that: The specific steps include: (1) Molten steel: Molten steel is smelted according to the set chemical composition; The chemical composition includes, by mass percentage, Si: 3.0-3.7%, Al: 0.5-1.0%, Mn: 0.2-0.6%, C≤0.0025%, S≤0.0025%, N≤0.003%, O≤0.0006%, Sn or Sb or Sn+Sb≤0.10%, and the balance is Fe and unavoidable impurities; (2) Continuous casting: Molten steel is cast into continuous casting billets through a continuous casting machine. Electromagnetic stirring is used during the continuous casting process. The stirring frequency is 2 to 18 Hz. The pulling speed during the continuous casting process is controlled to be 0.8 to 2.0 m / min to obtain a continuous casting billet with a thickness of 100 to 240 mm. (3) Rough rolling: The continuous casting billet is sent into a heating furnace and heated to 1160-1190°C. The billet is kept in the furnace for 150-210 min. After it is taken out of the furnace, the surface oxide scale is removed by high-pressure water and then rough rolling is performed to obtain an intermediate billet with a thickness of 15-25 mm. (4) Intermediate billet coiling: The intermediate billet is coiled in a hot coil box and then uncoiled and sent to the finishing mill; (5) Finish rolling: The intermediate billet is subjected to finish rolling after the surface oxide scale is removed by high-pressure water. The starting rolling temperature is 1020-1040°C and the final rolling temperature is 890-910°C. A hot-rolled plate with a thickness of 2.3-2.7 mm is obtained. The hot-rolled plate is then cooled to 700-750°C by laminar water and then coiled. The head and tail of the hot-rolled plate are each 10-15 m long and are not subjected to laminar water cooling. (6) Pickling: Pickling is carried out on the continuous pickling mill production line to remove surface iron oxide scale; (7) Primary cold rolling: The pickled sheet is cold rolled on a continuous pickling unit production line to obtain a primary cold rolled sheet with a thickness of 0.25 to 0.66 mm; (8) Intermediate annealing: The cold-rolled sheet obtained in step (7) is annealed in a continuous annealing furnace, wherein the atmosphere in the furnace is a mixed atmosphere of hydrogen and nitrogen, the temperature of the soaking section is 920 to 960° C., and the soaking time of the soaking section is 0.5 to 1.0 min; (9) Secondary cold rolling: The intermediate annealed sheet is cold rolled on a single-stand twenty-roller cold rolling mill to obtain cold rolled sheets with thicknesses of 0.10±0.005 mm, 0.15±0.005 mm, and 0.20±0.005 mm, respectively. The total reduction ratio of the secondary cold rolling is controlled to be 61-70%. (10) Final annealing: The cold-rolled sheet obtained in step (9) is subjected to final annealing in a continuous annealing furnace, wherein the atmosphere in the furnace is a mixed atmosphere of hydrogen and nitrogen, the temperature of the soaking section is 920 to 980° C., and the soaking time of the soaking section is 0.5 to 1.0 min; (11) Insulation layer coating: The final annealed sheet is subjected to insulation layer coating, drying and sintering in sequence to obtain non-oriented electrical steel finished sheets with nominal thicknesses of 0.10 mm, 0.15 mm and 0.20 mm, respectively.

2. The short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel according to claim 1, characterized in that: In the step (3), the starting temperature of the rough rolling is 1120-1150°C.

3. The short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel according to claim 1, characterized in that: In the step (6), the pickling solution is a hydrochloric acid solution with a mass concentration of 2 to 6%, and the pickling temperature is 65 to 80°C.

4. The short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel according to claim 1, characterized in that: In the step (8), the heating rate in the heating section during the annealing process is ≥30°C / s, and the cooling rate in the cooling section is 20-40°C / s.

5. The short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel according to claim 1, characterized in that: In the steps (8) and (10), the volume fraction of hydrogen gas is ≥5%, and the dew point of the mixed atmosphere is ≤-25°C.

6. The short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel according to claim 1, characterized in that: In the step (10), the heating rate in the heating section is ≥30°C / s, and the cooling rate in the cooling section is 20-40°C / s.

7. The short-process manufacturing method of thin-gauge high-silicon non-oriented electrical steel according to claim 1, characterized in that: In the step (11), the magnetic properties of the finished electrical steel plate with a nominal thickness of 0.10 mm: 50 1.71~1.72T, P 10 / 400 9.3~9.7W / kg, P 10 / 1000 28.8~29.5W / kg; Magnetic properties of finished electrical steel plate with nominal thickness of 0.15mm: B 50 1.71~1.72T, P 10 / 400 10.2~10.7W / kg, P 10 / 1000 39.0~39.7W / kg; Magnetic properties of finished electrical steel plate with nominal thickness of 0.20mm: B 50 1.71~1.72T, P 10 / 400 11.3~12.0W / kg, P 10 / 1000 It is 48.0~48.6W / kg.

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