Nanocrystalline soft magnetic strip and constant tension heat treatment method thereof

Abstract

The invention relates to a nanocrystalline soft magnetic strip material and a constant tension heat treatment method thereof, belongs to the technical field of nanocrystalline soft magnetic strip material processing, and solves the problems that a heat treatment process in the prior art cannot accurately and effectively adjust the magnetostriction coefficient of the nanocrystalline soft magnetic strip material, the processing efficiency is low, and actual production cannot be realized. The method comprises the steps that a strip wound on a strip feeding wheel sequentially winds around a driving guide wheel and a tensiometer, then penetrates through a constant-temperature heat treatment furnace, then winds around a driven guide wheel and finally winds around a strip collecting wheel, and constant tension is applied to the strip by regulating and controlling the rotating speed of the strip feeding wheel and the rotating speed of the strip collecting wheel. According to the method, annealing heat treatment is carried out while constant tension is applied to the strip, then through the rapid cooling technology, adjustment of the magnetic domain structure of the nanocrystalline strip is achieved, the soft magnetic performance is improved, the nanocrystalline strip with the low magnetostriction coefficient is obtained, and vibration noise is reduced for an iron core manufactured subsequently.

Description

Technical Field

[0001] This invention relates to the field of nanocrystalline flexible magnetic tape processing technology, and in particular to a nanocrystalline flexible magnetic tape and its constant tension heat treatment method. Background Technology

[0002] In fields such as power electronics, equipment manufacturing, and rail transportation, the iron core, as a core component for energy conversion, directly determines the operational reliability of the equipment. With the rapid upgrading of equipment towards miniaturization and high frequency, traditional iron cores cannot meet the performance requirements of high power density and low loss. Nanocrystalline soft magnetic materials, due to their excellent comprehensive soft magnetic properties, can serve as the primary material choice for future high-performance iron cores. When iron cores are used in equipment such as transformers and inverters, they generally operate under alternating magnetic field conditions. A large magnetostriction coefficient λs can cause periodic mechanical vibrations in the iron core, leading to low-frequency noise in the equipment. Simultaneously, the repeated movement of magnetic domain walls during vibration generates additional losses, offsetting the advantage of low loss. Long-term vibration can also lead to loosening of the iron core laminations and wear of the insulation layer, causing overheating and equipment failure. Therefore, the magnetostriction coefficient λs is a key performance factor that needs to be considered during the processing of nanocrystalline ribbons used in iron cores.

[0003] Currently, traditional heat treatment processes for nanocrystalline ribbons include crystallization annealing, vacuum annealing, and magnetic field-assisted annealing. The first two annealing methods can only control the size and internal stress of the microcrystals, but cannot precisely control the direction of the magnetic anisotropy formed by spontaneous magnetization, nor can they adjust the magnetostriction coefficient. Although the existing publicly available magnetic field-assisted heat treatment process in a vacuum environment allows the magnetic domains to be properly aligned under the action of an external magnetic field, reducing the system's free energy, forming uniaxial anisotropy, and adjusting the shape of the hysteresis loop to make the magnetostriction coefficient approach zero, magnetic field-assisted annealing requires a high-precision magnetic field generator, requires complex process parameters to be controlled, has low processing efficiency, poor adjustment effect when batch processing ribbons, and uneven adjustment of the overall magnetostriction coefficient of the ribbon, making it unsuitable for actual production. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a nanocrystalline flexible magnetic tape and a constant tension heat treatment method thereof, in order to solve at least one of the problems in the prior art where the heat treatment process cannot accurately and effectively adjust the magnetostriction coefficient of the nanocrystalline flexible magnetic tape, the processing efficiency is low, and it is not feasible for actual production.

[0005] On one hand, embodiments of the present invention provide a constant tension heat treatment method for nanocrystalline soft magnetic tape. The method involves passing the tape wound on a feed roller sequentially around an active guide roller and a tension meter, passing it through a constant temperature heat treatment furnace, passing it around a driven guide roller, and finally winding it onto a take-up roller. A constant tension is applied to the tape by adjusting the rotational speeds of the feed roller and the take-up roller.

[0006] Furthermore, the nanocrystalline soft magnetic tape is an Fe-based nanocrystalline tape, and is at least one of the Fe-Si-B system, Fe-Si-B-Nb-Cu system, and Fe-Si-B-Cu system.

[0007] Furthermore, the thickness of the strip is 14-28 μm.

[0008] Furthermore, the yield strength of the strip is 400-600 MPa.

[0009] Furthermore, the constant tension is 20-50 MPa.

[0010] Furthermore, the internal temperature of the constant-temperature heat treatment furnace is the crystallization temperature T of the strip. x1 ±10℃.

[0011] Furthermore, the residence time of the strip in the constant temperature heat treatment furnace is 1-3 minutes.

[0012] Furthermore, the strip material after being treated in the constant temperature heat treatment furnace is cooled.

[0013] Furthermore, the groove width of the active guide wheel, the tension gauge, and the driven guide wheel is 5-15% greater than the width of the strip.

[0014] Furthermore, the hardness of the active guide wheel, the tension meter, and the driven guide wheel is ≥HV200, and the surface roughness Ra≤0.8μm.

[0015] On the other hand, embodiments of the present invention provide a nanocrystalline flexible magnetic tape, wherein the tape is prepared by the above method, and the magnetostriction coefficient λs of the tape is ≤12×10 -6 The vibration noise under a 1kHz alternating magnetic field is ≤55dB.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] 1. Unlike existing crystallization, vacuum, or magnetic field-assisted annealing processes, this invention performs heat treatment on nanocrystalline ribbons while applying constant tension, by controlling the magnetostriction coefficient λs to 20 × 10⁻⁶. -6 ~30×10 -6 The magnetic domain structure of the nanocrystalline ribbon can significantly reduce the magnetostriction coefficient λs of the nanocrystalline ribbon, thereby reducing the noise caused by periodic vibrations in the iron core application caused by the alternating magnetic field working environment, reducing losses, improving mechanical stability and reliability, extending the service life of components and reducing the failure rate.

[0018] 2. The present invention adjusts the thickness of the nanocrystalline ribbon to ensure that it has low iron loss and high magnetic properties during application, while also ensuring a certain mechanical strength, reducing the sensitivity to constant tension fluctuations during heat treatment, and promoting the uniformity of winding density.

[0019] 3. The present invention controls the magnitude of the constant tension applied to the strip by the feed roller and the take-up roller, so that while the magnetic domain structure of the strip changes during the heat treatment process, the loss of mechanical properties caused by plastic deformation can be avoided, and even the breakage during the processing can be avoided.

[0020] 4. The present invention regulates the internal temperature of the constant temperature heat treatment furnace, which enables the nanocrystalline ribbon to partially crystallize during the heat treatment process and avoids excessive grain growth that would cause the magnetostriction coefficient to rebound.

[0021] 5. The present invention regulates the residence time of the strip inside the constant temperature heat treatment furnace, which can ensure uniform heating of the strip, enable the internal stress of the strip to be fully transferred, promote the uniformity of crystallization, and avoid abnormal growth of α-Fe grains and precipitation of hard magnetic phases such as Fe-B, which would increase the magnetostriction coefficient of the strip.

[0022] 6. The present invention regulates the cooling rate of the strip after heat treatment, which can ensure the stability of the crystallization structure, magnetic properties and subsequent processing performance of the strip after heat treatment, avoid the introduction of internal stress due to excessive cooling of the strip, and prevent excessive precipitation of amorphous phase from affecting magnetic properties.

[0023] 7. The magnetostriction coefficient λs of the nanocrystalline flexible magnetic tape prepared by the method of this invention is ≤12×10⁻⁶. -6 The vibration noise under a 1kHz alternating magnetic field is ≤55dB.

[0024] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0025] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0026] Figure 1 The magnetic domain structure direction of the nanocrystalline ribbon of the present invention and the direction of the constant tension it is subjected to during heat treatment;

[0027] Figure 2 This is a process flow diagram of the heat treatment method of the present invention;

[0028] Figure 3 A system structure diagram for implementing the heat treatment method of the present invention;

[0029] Figure label:

[0030] 1- Feeding roller; 2- Active guide roller; 3- Tension meter; 4- Constant temperature heat treatment furnace; 5- Cooling device; 6- Driven guide roller; 7- Take-up roller; 8- Nanocrystalline ribbon. Detailed Implementation

[0031] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0032] Traditional heat treatment processes for nanocrystalline ribbons include crystallization annealing, vacuum annealing, and magnetic field-assisted annealing. The first two annealing methods can only control the size and internal stress of the microcrystals, but cannot precisely control the direction of the magnetic anisotropy formed by spontaneous magnetization, nor can they adjust the magnetostriction coefficient. Although the existing publicly available magnetic field-assisted heat treatment process in a vacuum environment allows the magnetic domains to align appropriately under the action of an external magnetic field, reducing the system's free energy, forming uniaxial anisotropy, and adjusting the shape of the hysteresis loop to make the magnetostriction coefficient approach zero, magnetic field-assisted annealing requires a high-precision magnetic field generator, requires complex process parameters to be controlled, has low processing efficiency, poor adjustment effect when batch processing ribbons, and uneven adjustment of the overall magnetostriction coefficient of the ribbon, making it unsuitable for actual production.

[0033] Therefore, the present invention provides a constant tension heat treatment method for nanocrystalline soft magnetic tape. The method involves passing the tape wound on the feed roller sequentially around the active guide roller and the tension meter, passing it through a constant temperature heat treatment furnace, passing it around the driven guide roller, and finally winding it onto the take-up roller. A constant tension is applied to the tape by adjusting the rotation speed of the feed roller and the take-up roller.

[0034] Compared with existing technologies, this invention, based on the formation laws of spontaneous magnetization and magnetoelastic energy in nanocrystalline ribbons, reveals that when nanocrystalline ribbons are subjected to external stress, in addition to the various anisotropic magnetocrystalline energies formed by spontaneous deformation, there are also magnetoelastic energies related to stress within the crystal, thereby adjusting the magnetic domain structure of the nanocrystalline ribbon. For nanocrystalline ribbons with λs > 0, applying constant tension during heat treatment can adjust its magnetic domain structure to 180° along the tension direction, significantly reducing the magnetostriction coefficient and thus reducing noise generated during core applications.

[0035] Unlike existing crystallization, vacuum, or magnetic field-assisted annealing processes, this invention performs heat treatment on nanocrystalline ribbons while applying constant tension. By controlling the magnetic domain structure of nanocrystalline ribbons with a magnetostriction coefficient λs > 0, the magnetostriction coefficient λs of the nanocrystalline ribbons can be significantly reduced. This reduces the noise generated by periodic vibrations caused by alternating magnetic field working environments in iron core applications, reduces losses, improves mechanical stability and reliability, extends the service life of components, and reduces the failure rate.

[0036] It should be noted that the nanocrystalline flexible magnetic tape described in this invention is an Fe-based nanocrystalline tape, which can be Fe-Si-B, Fe-Si-B-Nb-Cu, or Fe-Si-B-Cu nanocrystalline tape.

[0037] It should be noted that, in order to give the heat-treated strip a certain mechanical strength, reduce its sensitivity to constant tension fluctuations during the heat treatment process, and promote the uniformity of winding density, the present invention needs to limit the thickness of the nanocrystalline strip.

[0038] Specifically, the thickness of the strip is 14-28μm, which can be 14μm, 17μm, 20μm, 23μm, 26μm, or 28μm. If the thickness is too small, it may cause tensile fracture during the constant tension treatment. In subsequent applications, it may break due to poor mechanical stability, affecting the continuity of the magnetic circuit. If the thickness is too large, it will lead to uneven heat transfer inside the strip and incomplete amorphization transformation of the structure after cooling.

[0039] It should be noted that, in order to reduce the sensitivity of the strip to the actual fluctuation of constant tension during the heat treatment process and to ensure the continuity of processing, the present invention needs to limit the yield strength of the nanocrystalline soft magnetic tape.

[0040] Specifically, the yield strength of the strip is 400-600MPa, which can be 400MPa, 450MPa, 500MPa, 550MPa, or 600MPa.

[0041] It should be noted that, in order to eliminate the internal stress remaining in the strip during the previous processing, to ensure that the magnetic domains inside the strip can be oriented along the tension direction, and at the same time, to ensure that the constant tension is adapted to the safe range of plastic deformation of the nanocrystalline strip, so as to avoid the strip from breaking.

[0042] Specifically, the constant tension is 20-50 MPa, preferably 30-40 MPa, but can be 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, or 50 MPa. This allows for sufficient adjustment of the magnetic domain structure to reduce the magnetostriction coefficient, while ensuring that the tension does not exceed the yield strength of the nanocrystalline ribbon, thus avoiding plastic deformation and loss of mechanical properties. When the tension exceeds 50 MPa, the ribbon is prone to breakage during processing; when the tension is below 20 MPa, the change in the magnetic domain structure of the ribbon is not significant.

[0043] It should be noted that, in order to ensure that the nanocrystalline ribbon material achieves partial crystallization during the heat treatment process and to avoid excessive grain growth leading to a rebound in the magnetostriction coefficient, the present invention needs to limit the internal temperature of the constant temperature heat treatment furnace.

[0044] Specifically, the internal temperature of the constant temperature heat treatment furnace is the crystallization temperature T of the strip. x1 ±10℃, can be used for T x1 -10℃, T x1 -7℃, T x1 -5℃, T x1 -3℃, T x1 T x1 +2℃, T x1 +5℃, T x1 +8℃, T x1 +10℃. This invention requires precise temperature control near the crystallization temperature to achieve partial crystallization and form nanocrystals. The final strip is mostly an amorphous substrate with a small portion of nanocrystal second phase. If the heating temperature is too high, it will lead to excessive grain growth, and if the heating temperature is too low, it will lead to incomplete partial crystallization.

[0045] It should be noted that the present invention can control the moving speed of the strip by adjusting the speed difference between the feed roller and the take-up roller. Combined with the length of the constant temperature heat treatment furnace, the strip can stay in the constant temperature heat treatment furnace for a period of time to ensure that the internal stress of the strip is fully transferred and the crystallization process is uniform. The time the strip stays in the constant temperature heat treatment furnace is the heat treatment holding time of the strip.

[0046] Specifically, the residence time of the strip in the constant temperature heat treatment furnace is 1-3 minutes, which can be 1 minute, 1.5 minutes, 2 minutes, 2.5 minutes, or 3 minutes. If the residence time is too short, the heat transfer of the strip will be insufficient, the magnetic domain structure transformation will be insufficient, and the magnetostriction coefficient cannot be effectively controlled. If the residence time is too long, the nanocrystals will grow abnormally, and hard magnetic second phases such as Fe-B will easily precipitate, resulting in an increase in the magnetostriction coefficient.

[0047] It should be noted that, in order to ensure the stability of the crystallization structure, magnetic properties and subsequent processing performance of the strip after heat treatment, to avoid the introduction of internal stress due to excessive cooling of the strip, and to prevent excessive precipitation of amorphous phase from affecting magnetic properties, this invention needs to limit the cooling rate of the strip after heat treatment.

[0048] Specifically, the strip material treated in the constant temperature heat treatment furnace is cooled at a rate of 50-200℃ / min, which can be 50℃ / min, 75℃ / min, 100℃ / min, 120℃ / min, 150℃ / min, 180℃ / min, or 200℃ / min. If the cooling rate is too fast, it can easily lead to rapid shrinkage after being held at high temperature, generating internal stress and deteriorating the soft magnetic properties. If the cooling rate is too slow, it can easily lead to abnormal growth of α-Fe nanocrystals and precipitation of the hard magnetic phase (Fe-B), resulting in an increase in the magnetostriction coefficient.

[0049] This invention employs an air-cooling method to cool the strip material conveyed from the constant temperature heat treatment furnace. The specific conditions are as follows: inert gas (high-purity nitrogen or argon) is used for air cooling, with the nozzle at an angle of 30-45° to the strip material to form a strong convection air curtain, ensuring that the strip surface temperature uniformity is <±5℃. The inert gas flow rate is adjusted so that the surface temperature of the strip material after cooling should be <50℃ and the core temperature should be <100℃.

[0050] It should be noted that the present invention controls the conveying direction of the heat-treated strip by using active guide wheels and driven guide wheels, ensuring that the strip can be conveyed smoothly and that the uniformity of the constant tension applied is guaranteed.

[0051] It should be noted that, in order to maintain the running direction of the strip while accurately measuring and controlling the constant tension on the strip, the tension gauge of the present invention includes three wheels.

[0052] It should be noted that, in order to ensure that the strip does not deviate during the traction process and to ensure the uniformity of the constant tension application, the present invention requires that the groove widths of the upstream active guide wheel, tension gauge and downstream driven guide wheel be adapted to the width of the nanocrystalline strip.

[0053] Specifically, the groove width of the active guide wheel, the tension gauge, and the driven guide wheel is 5-15% greater than the width of the strip, which can be 5%, 7%, 9%, 11%, 13%, or 15%. If the groove width of the guide wheel or tension gauge is too large, it will cause the strip to deviate during traction and transmission, resulting in uneven distribution of constant tension during processing and ultimately poor magnetostrictive consistency of the entire strip. If the groove width is too small, it will increase the contact pressure between the strip and the guide wheel, increase friction during transmission, and increase the tension fluctuation amplitude, which may easily lead to breakage of the nanocrystalline strip.

[0054] It should be noted that, in order to ensure the transmission effect of constant tension, avoid strip buckling caused by friction between the guide wheel and the tension gauge surface, and reduce the adhesion of impurities to the strip due to wheel wear during traction, thereby reducing the risk of strip surface scratches, the present invention needs to limit the composition and performance of the tension gauge of the guide wheel.

[0055] Specifically, the guide wheel and tension gauge described in this invention are made of 304 stainless steel or alumina ceramic, preferably alumina ceramic.

[0056] More specifically, the upstream active guide wheel, tension meter, and downstream driven guide wheel have a hardness ≥ HV200 and a surface roughness Ra ≤ 0.8μm. If the surface hardness of the guide wheel is too low, the wheel surface will wear during long-term contact with the strip, resulting in reduced guide wheel accuracy and increased tension fluctuation during strip transmission. If the surface roughness is too high, the friction between the wheel surface and the strip will increase, leading to scratches or even breakage on the strip surface.

[0057] More specifically, alumina ceramics can achieve a hardness of HV1000 or higher, resulting in a longer service life compared to 304 stainless steel. It also boasts an optimal surface roughness of Ra≤0.2μm and a low coefficient of thermal expansion, ensuring that it will not experience a decrease in precision due to thermal expansion and contraction when in contact with heat-treated strips at relatively high temperatures.

[0058] According to some preferred embodiments of the present invention, a constant tension heat treatment method for nanocrystalline soft magnetic tape is provided by the present invention, specifically comprising:

[0059] S1: The nanocrystalline ribbon to be heat-treated is wound onto a feed roller. The nanocrystalline ribbon is Fe-Si-B, Fe-Si-B-Nb-Cu, or Fe-Si-B-Cu based ribbon, with a thickness of 14-28 μm and a width of 20-100 mm; its yield strength is 400-600 MPa, and its magnetostriction coefficient λs is 20 × 10⁻⁶. -6 ~30×10 -6 ;

[0060] S2: After the strip is successively passed around the upstream active guide wheel and tension gauge made of 304 stainless steel or alumina ceramic, it passes through an internal temperature of T, which is the crystallization temperature of the strip. x1A constant-temperature heat treatment furnace with a temperature range of ±10℃ and a furnace length of 1.5m is used. The strip passing through the furnace is cooled by air at a rate of 50-200℃ / min. The strip then passes over downstream driven guide wheels made of 304 stainless steel or alumina ceramic and is finally fixed on a take-up reel for traction and winding, resulting in heat-treated nanocrystalline soft magnetic tape. A constant tension of 20-50MPa is applied to the strip by adjusting the rotation speed of the feed and take-up reels, resulting in a strip speed of 0.5-1.5m / min. The groove width of the guide wheel and tension gauge is 5-15% greater than the strip width (e.g., 42-46mm when the strip width is 40mm), the hardness is ≥HV200, and the surface roughness Ra≤0.8μm.

[0061] This invention also provides a nanocrystalline flexible magnetic tape, which is prepared by the above method. In this invention, the nanocrystalline flexible magnetic tape is subjected to heat treatment while simultaneously undergoing constant tension treatment to obtain a nanocrystalline tape with a low magnetostriction coefficient, wherein the magnetostriction coefficient of the tape is 0 < λs ≤ 12 × 10⁻⁶. -6 After the adjusted nanocrystalline ribbon is rolled into an iron core, the vibration noise under a 1kHz alternating magnetic field is ≤55dB, which meets the requirements of low-noise iron core with small vibration amplitude and low noise.

[0062] The present invention will be further explained and illustrated below through examples and comparative examples.

[0063] The tape used in the examples and comparative examples was a Fe-Si-B-Nb-Cu nanocrystalline flexible magnetic tape. Its chemical composition, calculated by weight percentage, included: 73.5% Fe, 15.5% Si, 7% B, 3% Nb, and 1% Cu; the tape had a width of 30 mm, a yield strength of 500 MPa, a crystallization temperature of 540 °C, and a magnetostriction coefficient λs of 25 × 10⁻⁶. -6 .

[0064] Examples 1-7

[0065] S1: The Fe-Si-B-Nb-Cu nanocrystalline ribbon to be heat-treated is wound on the feed roller with a thickness of 14–28 μm;

[0066] S2: The strip is sequentially passed around the upstream active guide wheel and tension gauge made of alumina ceramic material, and then through a constant temperature heat treatment furnace with an internal temperature of 540±10℃ and a furnace length of 1.5m. The strip is cooled by air cooling at a rate of 50-200℃ / min. It is then passed around the downstream driven guide wheel made of alumina ceramic material, and finally fixed on the take-up pulley for traction and winding, to obtain the heat-treated nanocrystalline soft magnetic tape. The constant tension applied to the strip by adjusting the rotation speed of the feed pulley and the take-up pulley is 20-50MPa, so that the moving speed of the strip is 0.5-1.5m / min. The groove width of the guide wheel and the tension gauge is 31.5-45mm, the hardness is ≥HV200, and the surface roughness Ra≤0.8μm.

[0067] The process parameters for heat treatment of nanocrystalline ribbons in Examples 1-7 and Comparative Examples 1-7 are shown in Table 1:

[0068]

[0069]

[0070] As shown in Table 1, this invention matches the dimensions (thickness and width) of the nanocrystalline ribbon to be heat-treated with the structure of the heat treatment system (groove width, hardness, and surface roughness of the guide wheel and tension gauge). By adjusting the speed difference between the feeding wheel and the take-up wheel in transporting the ribbon, the nanocrystalline ribbon is subjected to a constant tension during the heat treatment process, thereby effectively reducing the magnetostriction coefficient λs of the nanocrystalline ribbon. The magnetostriction coefficient λs of the nanocrystalline ribbon heat-treated by the method of this invention is reduced to ≤12×10⁻⁶. -6 The vibration noise under a 1kHz alternating magnetic field is ≤55dB. Furthermore, unlike existing magnetic field-assisted heat treatment processes, this invention adjusts the speed difference between the feed and take-up rollers to subject the strip to tension simultaneously during heat treatment. This eliminates the need for high-precision devices, simplifies operation, facilitates online control in actual production, and results in high processing efficiency, making it ideal for mass production of nanocrystalline strips.

[0071] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A constant tension heat treatment method for nanocrystalline soft magnetic tape, characterized in that, The method involves passing the strip wound on the feed roller sequentially around the active guide roller and the tension meter, then through a constant temperature heat treatment furnace, then around the driven guide roller, and finally wound onto the take-up roller. A constant tension is applied to the strip by adjusting the rotational speeds of the feed roller and the take-up roller.

2. The method according to claim 1, characterized in that, The nanocrystalline soft magnetic tape is an Fe-based nanocrystalline tape, and is at least one of the Fe-Si-B system, Fe-Si-B-Nb-Cu system, and Fe-Si-B-Cu system.

3. The method according to claim 1 or 2, characterized in that, The thickness of the strip is 14-28 μm. And / or, the yield strength of the strip is 400-600 MPa.

4. The method according to claim 1, characterized in that, The constant tension is 20-50 MPa.

5. The method according to claim 1, characterized in that, The internal temperature of the constant temperature heat treatment furnace is the crystallization temperature T of the strip. x1 ±10℃.

6. The method according to claim 1, characterized in that, The residence time of the strip in the constant temperature heat treatment furnace is 1-3 minutes.

7. The method according to claim 1, characterized in that, The strip material is cooled after being treated in the constant temperature heat treatment furnace.

8. The method according to claim 1, characterized in that, The groove width of the active guide wheel, the tension meter, and the driven guide wheel is 5-15% greater than the width of the strip.

9. The method according to claim 1, characterized in that, The hardness of the active guide wheel, the tension meter, and the driven guide wheel is ≥HV200, and the surface roughness Ra≤0.8μm.

10. A nanocrystalline flexible magnetic tape, characterized in that, The strip is prepared by the method according to any one of claims 1-9, wherein the magnetostriction coefficient λs of the strip is ≤12×10 -6 The vibration noise under a 1kHz alternating magnetic field is ≤55dB.

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