Processing technology of transformer iron core

Abstract

The invention provides a processing technology of a transformer iron core, which comprises the following steps: collecting strip-shaped waste generated by cutting an amorphous alloy strip, mixing and smelting the strip-shaped waste and an amorphous alloy base material according to a mass ratio of 1: (4-6), heating to 1300-1350 DEG C under the protection of argon, smelting for 30-40 minutes, and spraying and casting to form a regenerated amorphous alloy strip of 20-25 microns; the regenerated strip and the silicon steel strip are wound into a concentric double-ring structure, an inner ring is formed by winding regenerated amorphous alloy to the thickness of 50-60 mm, and an outer ring is formed by winding silicon steel to the thickness of 30-40 mm; and finally, a sealant formed by mixing an acidic silicone sealant and a curing agent according to the mass ratio of (10-15): 1 is filled in a double-ring interlayer gap, reinforcement forming is conducted, the using amount of the amorphous alloy is reduced through regional material layout, the waste utilization rate is increased in combination with a regeneration process, and meanwhile magnetic circuit distribution and insulation performance are optimized. The process is suitable for batch production of high-efficiency and energy-saving transformer iron cores, and the magnetic performance requirement is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformer core manufacturing, and more specifically, relates to a processing technology for transformer core. Background Art

[0002] In the manufacturing of transformer cores, amorphous alloy materials are widely used due to their high magnetic permeability and low iron loss properties. However, the high cost of raw materials has become a bottleneck restricting large-scale industrial production. The cutting process of amorphous alloy strips produces a large amount of strip waste. Traditional processes typically discard this strip as industrial waste or simply recycle it. However, direct disposal not only wastes resources but also increases the environmental burden. Simply recycling the recycled material can significantly degrade its magnetic properties due to imperfect melting processes (such as oxidation and impurity incorporation), making it difficult to meet the performance requirements of the core. This problem poses a technical challenge to the effective recycling of waste.

[0003] In addition, traditional transformer cores mostly use a single material structure, such as all-amorphous alloy or all-silicon steel design. Although all-amorphous alloy cores have excellent magnetic properties, the material cost is too high; while all-silicon steel cores are lower in cost, but have high magnetic losses, making it difficult to meet the needs of high efficiency and energy saving. In order to balance cost and performance, some studies have attempted to use amorphous alloys and silicon steel in combination, but the existing technology mostly adopts a uniform mixing or simple stacking method, resulting in the high amount of amorphous alloys. At the same time, the design of the composite structure needs to solve the problem of magnetic circuit matching at the interface of different materials. If the interlayer bonding is not tight or the gap is not properly controlled, it is easy to cause uneven magnetic resistance, reducing the overall efficiency of the core.

[0004] Therefore, the contradiction between the high cost of amorphous alloys and the inefficient utilization of waste, the contradiction between material usage and magnetic performance balance in composite structure design, and the contradiction between stability and strip performance requirements in the waste recycling process have become urgent problems that need to be solved in the processing of transformer amorphous alloy cores. Summary of the Invention

[0005] An object of the present invention is to address at least the above-mentioned drawbacks and to provide at least the advantages which will be described hereinafter.

[0006] The present invention provides a processing technology for a transformer core, which reduces the amount of amorphous alloy used through waste recycling and regional winding, thereby achieving the effects of efficient resource utilization and cost compression.

[0007] The present invention provides a processing technology for a transformer core, comprising the following steps: Collect strip waste generated by cutting amorphous alloy strips; Mixing and smelting the strip-shaped scrap and the amorphous alloy base material in a mass ratio of 1:4-6; Heat to 1300-1350℃ under argon protection, and control the melting time to 30-40 minutes; The molten alloy liquid is spray-casted into a recycled amorphous alloy strip with a thickness of 20-25 μm; The recycled amorphous alloy strip and the silicon steel strip are respectively and continuously wound into a concentric double ring structure, wherein the inner ring area is wound with the recycled amorphous alloy strip to a thickness of 50-60 mm, and the outer ring area is wound with the silicon steel strip to a thickness of 30-40 mm; The interlayer gap of the double-ring structure is filled with mixed sealant and reinforced into shape. The mixed sealant is obtained by mixing acidic silicone sealant and curing agent in a mass ratio of 10-15:1.

[0008] Preferably, the curing agent is methyltriacetoxysilane; the interlayer gap is filled in a vacuum environment and the iron core is pressed at an injection pressure of 0.5-1 MPa; and the curing is completed by heating to 120-150° C. and keeping the temperature for 40-50 minutes.

[0009] Preferably, the coiling of the recycled amorphous alloy strip and the silicon steel strip comprises the following steps: Using a split winding tool, the recycled amorphous alloy strip is first continuously wound in the inner ring area to a thickness of 50-60mm; After the inner ring is wound, the winding fixture positioning reference is switched so that the starting end of the outer ring silicon steel strip overlaps the outer surface of the inner ring and is continuously wound along the circumferential direction to a thickness of 30-40 mm.

[0010] Preferably, the spray casting of the recycled amorphous alloy strip comprises the following steps: Adjust the spray casting speed to 30-35m / s; Control the molten alloy flow width to 50-60mm; A silicone oil cooling tank with a constant temperature of 80°C-100°C is set at the outlet of the spray-cast strip.

[0011] Preferably, the smelting process comprises the following steps: The vacuum degree in the furnace was reduced from normal pressure to 1×10 -1 -5×10 -1 Pa, and maintain for 5-10 minutes, while simultaneously purging the furnace chamber with an argon flow rate of 4-5 L / min; During the smelting process, the initial argon flow rate is 4-5 L / min, and it is adjusted to 2-3 L / min after the alloy liquid is completely melted; After smelting, let the molten alloy stand for 5-8 minutes and continue to introduce argon gas to maintain a flow rate of 1-1.5L / min; After the standing is completed, the melt is filtered through an alumina ceramic filter with a pore size of 0.5mm to 1.5mm.

[0012] Preferably, the continuous winding comprises the following steps: When winding, the inner ring strip tension is controlled at 10N / mm 2 -20N / mm 2 , the outer ring strip tension is 20N / mm 2 -30N / mm 2 , and monitor the interlayer gap in real time, the gap between amorphous layers is 3-5μm, and the gap between silicon steel layers is 10-12μm; Before filling the gap with the mixed sealant, place the iron core in a vacuum annealing furnace, heat it to 400°C to 450°C under argon protection, and keep it warm for 30 to 40 minutes.

[0013] Preferably, the contact surface between the recycled amorphous alloy strip and the silicon steel strip is treated by the following steps: Coat the circumferential contact surfaces of the inner and outer rings with a nickel-based brazing material layer having a thickness of 0.1 mm to 0.3 mm; The contact surfaces are welded under argon protection at a temperature of 800°C to 850°C, a pressure of 10 MPa to 15 MPa, and a time of 5 seconds to 8 seconds; Perform ultrasonic flaw detection on the contact surface after welding to ensure that the interface defect area is less than 1%; An epoxy resin-based insulating coating having a thickness of 10 μm to 20 μm is sprayed on the contact surface after welding, with a curing temperature of 120° C. to 130° C. and a curing time of 30 minutes to 40 minutes.

[0014] Preferably, the impurity control in the smelting process comprises the following steps: Before smelting, 0.01% to 0.03% of the mass of the melt is added to the furnace chamber as a rare earth element, lanthanum or cerium; After smelting, the melt is filtered using a two-stage filter screen. The aperture of the first-stage filter screen is 1mm to 1.5mm, and the aperture of the second-stage filter screen is 0.5mm to 0.8mm.

[0015] Preferably, the preparation and filling of the mixed sealant includes the following steps: The acidic silicone sealant and the methyltriacetoxysilane curing agent were mixed in a mass ratio of 10:1. During the mixing process, the temperature was controlled at 25°C to 30°C, the stirring speed was 300r / min to 500r / min, and the mixing time was 10min to 15min. During the mixing process, nano-silicon dioxide powder accounting for 5% to 8% of the total mass of the colloid is added to the mixed colloid, with a particle size of 20nm to 50nm and a specific surface area of ​​150m 2 / g to 200m 2 / g; The mixed colloid is degassed by a vacuum degassing machine with a degassing pressure of -0.08 MPa to -0.1 MPa and a degassing time of 5 min to 8 min.

[0016] The present invention has at least the following beneficial effects: This invention achieves efficient waste recycling by mixing amorphous alloy cutting scrap with parent metal in a proportional manner, reducing raw material costs and lowering the environmental burden. Furthermore, the concentric double-ring structure of an inner ring of recycled amorphous alloy and an outer ring of silicon steel reduces the amount of amorphous alloy used while maintaining both magnetic and insulating properties.

[0017] The present invention eliminates contact surface gaps and blocks leakage current paths through interface brazing and insulation treatment.

[0018] The present invention adds the rare earth element lanthanum during the smelting process to refine the grain boundaries and adsorb impurities, and performs two-stage filter pressing to significantly improve the purity of the material, reduce the grain boundary resistance, and improve the AC magnetic permeability.

[0019] The present invention forms a dense insulating layer by adding nano-silicon dioxide powder and acidic silicone sealant, thereby improving the dielectric strength and meeting the insulation requirements of 35kV transformers.

[0020] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0022] It should be noted that the experimental methods described in the following embodiments, unless otherwise specified, are conventional methods. The reagents and materials described, unless otherwise specified, are commercially available. For example, the vacuum induction melting furnace can be the Jinzhou Hangxing / ZGL-100Z, and the single-roller quenching equipment can be the Edmund Bühler (Germany) / PA500. In the description of the present invention, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "disposed" should be understood broadly, meaning, for example, fixedly connected or disposed, detachably connected or disposed, or integrally connected or disposed. A person of ordinary skill in the art will understand the specific meanings of the above terms in the present invention in specific circumstances. Terms such as "transverse," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" to indicate orientations or positional relationships are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limitations on the present invention.

[0023] The processing technology of the transformer core provided by the present invention comprises the following steps: Collect strip waste generated by cutting amorphous alloy strips; Mixing and smelting the strip-shaped scrap and the amorphous alloy base material in a mass ratio of 1:4-6; Heat to 1300-1350°C under argon protection, and control the melting time to 30-40 minutes; The molten alloy liquid is spray-casted into a recycled amorphous alloy strip with a thickness of 20 μm-25 μm; The recycled amorphous alloy strip and the silicon steel strip are respectively and continuously wound into a concentric double ring structure, wherein the inner ring area is wound with the recycled amorphous alloy strip to a thickness of 50 mm to 60 mm, and the outer ring area is wound with the silicon steel strip to a thickness of 30 mm to 40 mm; The interlayer gap of the double-ring structure is filled with mixed sealant and reinforced into shape. The mixed sealant is obtained by mixing acidic silicone sealant and curing agent in a mass ratio of 10-15:1.

[0024] Example 1 A process for processing a transformer core comprises the following steps: S1. Collecting waste: Collecting strip-shaped waste generated by cutting amorphous alloy strips.

[0025] S2, mixed melting: the strip scrap is put into a vacuum induction melting furnace (vacuum degree is 1×10 -2 Pa), mixed with amorphous alloy base material at a mass ratio of 1:5.

[0026] S3. Melting process: Heat to 1350°C under argon protection for 35 minutes. After melting, let the molten alloy stand for 6 minutes while continuously introducing argon at a flow rate of 1.3 L / min.

[0027] S4. Spray-casting recycled strip: The molten alloy was spray-casted through a single-roll rapid quenching device into a recycled amorphous alloy strip with a thickness of 23 μm. During spray-casting, the copper roller speed was adjusted to 33 m / s, the molten alloy stream width was 55 mm, and a silicone oil cooling tank maintained at a constant temperature of 90°C was installed at the outlet of the spray-cast strip.

[0028] S5, winding double ring structure: Inner ring winding: Using split winding tooling, the recycled amorphous alloy strip is continuously wound in the inner ring area to a thickness of 55mm, and the winding tension is controlled at 15N / mm 2 .

[0029] Outer ring winding: After switching the tooling positioning reference, the starting end of the outer ring silicon steel strip is overlapped on the outer surface of the inner ring, and the silicon steel strip is continuously wound along the circumferential direction to a thickness of 35mm. The winding tension is controlled at 25N / mm 2 The inner and outer rings are coated with a 0.1mm thick nickel-based brazing material layer on the full circumferential contact surface and then welded. The welding is carried out under argon protection at a temperature of 800°C, a pressure of 10 MPa, and a time of 5 seconds, and then left to solidify for 35 minutes. S6, gap filling and curing: The mixed sealant (acidic silicone sealant and methyl triacetoxysilane are mixed in a mass ratio of 10:1, the temperature is controlled at 28°C during the mixing process, the stirring speed is 400r / min, and the mixing time is 12 minutes) is injected into the gap between the layers using a vacuum injection machine. The injection pressure is 1MPa. -2 Pa) to 135 ° C and keep warm for 45 minutes to complete the curing.

[0030] Process Validation: The melt was filtered through an alumina ceramic filter (pore size 1.0 mm) and the impurity content was less than 0.03%.

[0031] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 1.89%, which basically met the design requirements.

[0032] Example 2 A processing technology for transformer core, which is basically the same as the steps in Example 1, except that the step S3 smelting process also includes reducing the vacuum degree in the furnace from normal pressure to 1×10 -1 Pa, and maintain it for 8 minutes, and simultaneously purge the furnace chamber with an argon flow rate of 4.5L / min; during the smelting process, the initial argon flow rate is 4.5L / min, and is adjusted to 2.5L / min after the alloy liquid is completely melted.

[0033] The winding process in step S5 also includes using an existing laser displacement sensor to monitor the interlayer gap in real time. The gap between the amorphous layer is controlled to be 4 μm ± 1 μm, and the gap between the silicon steel layer is controlled to be 11 μm ± 1 μm. Before the gap is filled with mixed sealant, the iron core is placed in a vacuum annealing furnace (vacuum degree is 1×10 -2 Pa), heated to 425°C under argon protection and kept at this temperature for 35 minutes.

[0034] Process Validation: The melt was filtered through an alumina ceramic filter (pore size 1.0 mm) and the impurity content was less than 0.03%.

[0035] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 1.87%, which basically met the design requirements.

[0036] Example 3 A processing technology for a transformer core, which is substantially the same as the steps in Example 2, except for the contact surface treatment: A nickel-based brazing material layer with a thickness of 0.2 mm is applied to the circumferential contact surfaces of the inner and outer rings; the contact surfaces are welded under argon protection at a welding temperature of 840°C, a pressure of 13 MPa, and a time of 7 seconds; the contact surfaces after welding are subjected to ultrasonic flaw detection to ensure that the interface defect area accounts for less than 1%; and an epoxy resin-based insulating coating with a thickness of 15 μm is sprayed on the surface of the contact surface after welding, with a curing temperature of 125°C and a time of 35 minutes.

[0037] Process Validation: The melt was filtered through an alumina ceramic filter (pore size 1.0 mm) and the impurity content was less than 0.03%.

[0038] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 0.82%, which met the design requirements.

[0039] Example 4 A processing technology for a transformer core, which is substantially the same as the steps in Example 3, except for the control of smelting impurities: Before smelting, lanthanum (La), a rare earth element accounting for 0.02% of the melt mass, was added to the furnace chamber. After smelting, the melt was filter-filtered using a two-stage filter screen, with the aperture of the first-stage filter screen being 1.2 mm and the aperture of the second-stage filter screen being 0.6 mm.

[0040] Process Validation: The melt is filtered using a two-stage alumina ceramic filter (primary pore size 1.2 mm, secondary pore size 0.6 mm), and the impurity content is less than 0.01%.

[0041] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 0.80%, which met the design requirements.

[0042] Example 5 A processing process for a transformer core is substantially the same as that of Example 3, except that a mixed sealant is prepared and filled: an acidic silicone sealant and a methyltriacetoxysilane curing agent are mixed in a mass ratio of 10:1, the temperature is controlled at 28° C., the stirring speed is 400 r / min, and the mixing time is 12 minutes; during the mixing process, nano-silicon dioxide powder accounting for 7% of the total mass of the colloid is added to the mixed colloid, the powder particle size is 35 nm, and the specific surface area is 180 m² / g; and the mixed colloid is degassed using a vacuum degassing machine at a degassing pressure of −0.09 MPa for 7 minutes.

[0043] Process Validation: The melt was filtered through an alumina ceramic filter (pore size 1.0 mm) and the impurity content was less than 0.03%.

[0044] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 0.81%, which met the design requirements.

[0045] Comparative Example 1 A processing process for a transformer core is basically the same as the steps of Example 5, except that the acidic silicone sealant is replaced by epoxy resin glue, and no nano-silica powder is added.

[0046] The melt was filtered through an alumina ceramic filter (pore size 1.0 mm) and the impurity content was less than 0.03%.

[0047] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 0.87%, which met the design requirements.

[0048] Comparative Example 2 A processing process for a transformer core is basically the same as the steps of Example 5, except that the acidic silicone sealant is replaced by epoxy resin sealant.

[0049] The melt was filtered through an alumina ceramic filter (pore size 1.0 mm) and the impurity content was less than 0.03%.

[0050] The welding interface was tested by ultrasonic flaw detection, and the defect area accounted for 0.81%, which met the design requirements.

[0051] Experiment 1 Sample preparation: Transformer core samples were prepared according to the process steps of Examples 1-5 and Comparative Examples 1-2. Five samples were prepared for each group and the average value was taken.

[0052] Test method: Dielectric Strength: Use a high-voltage breakdown tester (according to GB / T1408.1-2016 "Electrical Strength Test Method for Insulating Materials") to test the withstand voltage of the insulating coating between core layers. The test voltage is increased at a rate of 1 kV / s until breakdown occurs. The breakdown voltage is recorded and the dielectric strength (kV / mm) is calculated.

[0053] Air void ratio: The core cross section was observed using a metallographic microscope (1000×), and the ratio of the interlayer gap area to the total cross-sectional area was calculated using image analysis software (ImageJ). The measurement was repeated five times and the average value was taken.

[0054] No-load loss: Measure the core no-load loss (W / kg) at rated voltage (50Hz sinusoidal wave) using a no-load loss test system (power analyzer + standard transformer) based on the test method recommended in IEC60076-8:2018 "Power Transformers - Part 8: Application Guidelines" (see Appendix 1).

[0055] Magnetic Permeability: The Epstein Circle method (in accordance with GB / T3655-2008 "Method for measuring the magnetic properties of electrical steel sheets (strips) using the Epstein Circle") is used to test the AC permeability (μr) of the iron core in a 50Hz alternating magnetic field. The magnetic field strength range is 1A / m to 100A / m, and the test waveform is a sinusoidal wave.

[0056] The test results of dielectric strength, air void ratio, no-load loss and magnetic permeability of each group of samples are shown in Table 1.

[0057] Table 1: The test results in Table 1 show that Example 5 exhibits significantly better dielectric strength than Example 3 due to the uniform dispersion of nano-silica powder, forming a dense insulating layer that blocks leakage current paths. Furthermore, the reduction of air gaps and interface defects reduces no-load losses. Example 4 also exhibits significantly better dielectric strength than Example 3 due to the reduction of pores and improved insulation uniformity achieved through smelting impurity control (rare earth elements + two-stage filtration). Furthermore, smelting impurity control (0.02% La + two-stage filtration) significantly improves material purity, reduces grain boundary resistance, and increases AC permeability, effectively meeting the insulation requirements of 10kV-35kV transformers. In contrast, the epoxy resin adhesive in Comparative Example 1 exhibits weak insulation performance and lacks nano-powder reinforcement, resulting in high shrinkage and poor filling efficiency, which affects dielectric strength and air gap ratio. In Comparative Example 2, the epoxy resin adhesive exhibits poor dispersion and bonding with the nano-silica powder, which affects filling efficiency, leading to uneven magnetic resistance and increased air gaps, which compromises insulation performance and reduces dielectric strength.

[0058] Experiment 2 Sample preparation: Example 1 Group: Five groups of iron core contact surface samples were prepared after welding according to the process of Example 1.

[0059] Example 5 Groups of core contact surface specimens were prepared according to the process of Example 5, totaling 5 groups.

[0060] Control group: No nickel-based brazing filler metal layer treatment, directly sprayed with epoxy resin coating (thickness 15 μm, curing conditions 125 ° C / 35 minutes), a total of 5 groups.

[0061] Test method: Cross-hatch adhesion test (according to ASTM D3359-17): Use a crosshatch tool (blade spacing 1mm) to draw a 10×10 grid on the coating surface, apply 3M tape and quickly peel it off, that is, peel the tape at a constant speed (e.g., within 1 second), and observe the coating falling off. Grade definition (0B-5B): 5B: The cut edge is completely smooth without any shedding.

[0062] 4B: Slight loss of intersection (≤5%).

[0063] 3B: Edge loss 5%-15%.

[0064] 2B: 15%-35% loss.

[0065] 1B: 35%-65% loss.

[0066] 0B: Shedding > 65%.

[0067] Pull-off adhesion test (according to ASTM D4541-17): Using an adhesion tester (DeFelsko PosiTest AT-A), adhere a 20 mm diameter aluminum ingot to the coating surface and pull vertically until the coating peels off. Record the maximum pull-off force (MPa).

[0068] The test results of each group of samples are shown in Table 2.

[0069] Table 2: Group Cross-cut grade (0B-5B) Tensile strength (MPa) Example 1 group 4B (≤5% shedding) 9.6±0.4 Example 3 group 5B (no shedding) 13.3±0.6 control group 1B (>35% shedding) 4.0±0.3 As shown in the test results in Table 2, Example 3 achieved 5B coating adhesion and 13.3 MPa pull-out strength, meeting high reliability requirements, thanks to a 0.2 mm brazing filler metal layer and optimized soldering parameters (840°C / 13 MPa / 7 seconds). While Example 1 exhibited slightly lower adhesion (4B) and strength (9.6 MPa) due to the thinner brazing filler metal layer and lower soldering pressure, these results were still significantly superior to the control group. The control group's results demonstrate that omitting brazing pretreatment can lead to interface failure.

[0070] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiment. They can be applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized.

Claims

1. The processing technology of transformer core is characterized by: The following steps are involved: Collect strip waste generated by cutting amorphous alloy strips; Mixing and smelting the strip-shaped scrap and the amorphous alloy base material in a mass ratio of 1:4-6; Heat to 1300-1350℃ under argon protection, and control the melting time to 30-40 minutes; The molten alloy liquid is spray-casted into a recycled amorphous alloy strip with a thickness of 20-25 μm; The recycled amorphous alloy strip and the silicon steel strip are respectively and continuously wound into a concentric double ring structure, wherein the inner ring area is wound with the recycled amorphous alloy strip to a thickness of 50-60 mm, and the outer ring area is wound with the silicon steel strip to a thickness of 30-40 mm; The interlayer gap of the double-ring structure is filled with mixed sealant and reinforced into shape. The mixed sealant is obtained by mixing acidic silicone sealant and curing agent in a mass ratio of 10-15:

1.

2. The processing technology of transformer core according to claim 1, characterized in that: The curing agent is methyltriacetoxysilane; the interlayer gap is filled in a vacuum environment with a glue injection pressure of 0.5-1 MPa and the iron core is pressed; the temperature is heated to 120-150° C. and kept warm for 40-50 minutes to complete the curing.

3. The processing technology of transformer core according to claim 1, characterized in that: The coiling of the recycled amorphous alloy strip and the silicon steel strip comprises the following steps: Using a split winding tool, the recycled amorphous alloy strip is first continuously wound in the inner ring area to a thickness of 50-60mm; After the inner ring is wound, the winding fixture positioning reference is switched so that the starting end of the outer ring silicon steel strip overlaps the outer surface of the inner ring and is continuously wound along the circumferential direction to a thickness of 30-40 mm.

4. The processing technology for transformer core according to claim 1, characterized in that: The spray casting of the recycled amorphous alloy strip comprises the following steps: Adjust the spray casting speed to 30-35m / s; Control the molten alloy flow width to 50-60mm; A silicone oil cooling tank with a constant temperature of 80°C-100°C is set at the outlet of the spray-cast strip.

5. The processing technology of transformer core according to claim 1, characterized in that: The smelting process comprises the following steps: The vacuum degree in the furnace was reduced from normal pressure to 1×10 -1 Pa~5×10 -1 Pa, and maintain for 5-10 minutes, while simultaneously purging the furnace chamber with an argon flow rate of 4-5 L / min; During the smelting process, the initial argon flow rate is 4-5 L / min, and it is adjusted to 2-3 L / min after the alloy liquid is completely melted; After smelting, let the molten alloy stand for 5-8 minutes and continue to introduce argon gas to maintain a flow rate of 1-1.5L / min; After the standing is completed, the melt is filtered through an alumina ceramic filter with a pore size of 0.5 mm to 1.5 mm.

6. The processing technology for transformer core according to claim 1, characterized in that: The continuous winding comprises the following steps: When winding, the inner ring strip tension is controlled at 10N / mm 2 -20N / mm 2 The outer ring strip tension is 20N / mm²-30N / mm², and the interlayer gap is monitored in real time. The gap between the amorphous layer is 3-5μm, and the gap between the silicon steel layer is 10-12μm. Before filling the gap with the mixed sealant, place the iron core in a vacuum annealing furnace, heat it to 400°C to 450°C under argon protection, and keep it warm for 30 to 40 minutes.

7. The processing technology for transformer core according to claim 1, characterized in that: The contact surface between the recycled amorphous alloy strip and the silicon steel strip is processed by the following steps: Coat the circumferential contact surfaces of the inner and outer rings with a nickel-based brazing filler metal layer having a thickness of 0.1 mm to 0.3 mm; The contact surfaces are welded under argon protection at a temperature of 800°C to 850°C, a pressure of 10 MPa to 15 MPa, and a time of 5 seconds to 8 seconds; Perform ultrasonic flaw detection on the contact surface after welding to ensure that the interface defect area is less than 1%; An epoxy resin-based insulating coating having a thickness of 10 μm to 20 μm is sprayed on the contact surface after welding, with a curing temperature of 120° C. to 130° C. and a curing time of 30 minutes to 40 minutes.

8. The processing technology for transformer core according to claim 5, characterized in that: Impurity control in the smelting process includes the following steps: Before smelting, 0.01% to 0.03% of the mass of the melt is added to the furnace chamber as a rare earth element, lanthanum or cerium; After smelting, the melt is filtered using a two-stage filter screen. The aperture of the first-stage filter screen is 1mm to 1.5mm, and the aperture of the second-stage filter screen is 0.5mm to 0.8mm.

9. The processing technology for transformer core according to any one of claims 1 to 8, characterized in that: The preparation and filling of the mixed sealant comprises the following steps: The acidic silicone sealant and the methyltriacetoxysilane curing agent were mixed in a mass ratio of 10:

1. During the mixing process, the temperature was controlled at 25°C to 30°C, the stirring speed was 300r / min to 500r / min, and the mixing time was 10min to 15min. During the mixing process, nano-silicon dioxide powder accounting for 5% to 8% of the total mass of the colloid is added to the mixed colloid, with a particle size of 20nm to 50nm and a specific surface area of ​​150m 2 / g to 200m 2 / g; The mixed colloid is degassed by a vacuum degassing machine with a degassing pressure of -0.08 MPa to -0.1 MPa and a degassing time of 5 min to 8 min.

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