A method for measuring the torque of superconducting wire

Abstract

The present invention belongs to the technical field of superconducting material detection, and particularly relates to a method for measuring the torque of superconducting wire. The present invention discloses a method for measuring the torque of superconducting wire. After annealing the superconducting wire to be tested in an annealing furnace, spray-painting treatment is carried out on the surface of the superconducting wire. Subsequently, the superconducting wire is rolled and the paint is removed, and the distance between the threads on the surface of the bare wire is measured. The torque of the superconducting wire is calculated according to the distance between the threads, the number of the outermost core wires of the wire, and the lengths of the wire before and after rolling. The present invention measures the torque of the wire according to the hardness difference between the superconductor and the matrix. This method is simple to operate, has a wide application range, and high measurement accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of superconducting material detection, and particularly relates to a method for measuring the torque of superconducting wire. Background Art

[0002] Magnetic field changes can induce coupling currents in multi-core composite superconductors. The coupling currents pass through the matrix between the core wires, forming a loop between the superconducting wires, resulting in coupling losses.

[0003] The twisting process optimizes the magnetic field and current distribution of multi-core superconducting wires, improves the performance of superconducting wires under the action of external magnetic fields and currents, and reduces energy losses caused by factors such as flux pinning, vortex motion, eddy current losses, and non-uniform current distribution. In this way, the superconductor can maintain higher superconductivity, conduct current better, and significantly improve the working efficiency and stability of the superconducting wire. Especially for high-precision superconducting applications, such as MRI scanners, particle accelerators, and high-magnetic-field applications, an accurate twisting process is of great significance. Therefore, it is necessary to accurately measure the torque of superconducting wire to reduce the coupling loss during the magnetic field change process of the superconducting wire and improve the stability and transmission efficiency of the superconducting current.

[0004] The existing conventional method for measuring the torque of superconducting wire is the "corrosion - untwisting method", that is, after the matrix is corroded by acid, the non-corrosive twisted core wires are left, and they are untwisted, and then the torque is measured. This method is only applicable to the case where "the matrix can be corroded / superconductor cannot be corroded". In the actual operation process, the manual untwisting operation has a great influence, the measurement accuracy is general, and it is necessary to study a more accurate method for measuring the torque of superconducting wire to adapt to high-precision superconducting applications. Summary of the Invention

[0005] To solve the above technical problems, the present invention proposes a more environmentally friendly and higher measurement accuracy method for measuring the torque of superconducting wire. This method uses annealing to adjust the hardness difference between the superconductor and the matrix, making the hardness difference more obvious, and then performing plane rolling on it. The cross-sectional shape and size of the wire are adjusted through plane rolling, and the actual torque of the wire is calculated using the rebound mechanism.

[0006] On the one hand, the present invention provides a method for measuring the torque of superconducting wire, which includes the following steps;

[0007] Step 1: Take the wire to be tested, and the number of the outermost core wires of the wire to be tested is denoted as n2;

[0008] Step 2: Put the wire to be tested into an annealing furnace for annealing to obtain an annealed wire;

[0009] Step 3: Spray paint the annealed wire obtained in Step 2, intercept a section of the spray-painted wire and measure its length, and mark the length as L1;

[0010] Step 4: Flat roll the wire after spray painting intercepted in Step 3, measure the length of the wire after rolling, and mark the length as L2;

[0011] Step 5: Remove the paint from the wire after rolling in Step 4, measure the pitch length between n1 threads on the surface of the bare wire after paint removal, and mark the pitch length as L3;

[0012] Step 6: Calculate the torque based on the measured data; the calculation formula for the torque is as follows:

[0013] 。

[0014] Further, in the method for measuring the torque of superconducting wire, the wire to be inspected in Step 1 is a multi-core superconducting wire obtained by twisting and stretching.

[0015] Further, in the method for measuring the torque of superconducting wire, the number of cores of the multi-core superconducting wire is not more than 100 cores.

[0016] Further, in the method for measuring the torque of superconducting wire, the annealing temperature in Step 2 is 200~450 °C, and the annealing time is 20~45 min.

[0017] Further, in the method for measuring the torque of superconducting wire, the paint used in the spray painting treatment in Step 3 is acetal paint, and the viscosity of the acetal paint is 2300~2700 maps.

[0018] Further, in the method for measuring the torque of superconducting wire, the film thickness of the spray painting treatment is 100~200 microns.

[0019] Further, in the method for measuring the torque of superconducting wire, the height of the flat rolling in Step 4 is 1 / 2~1 / 3 of the height of the wire after spray painting.

[0020] Further, in the method for measuring the torque of superconducting wire, the paint removal in Step 5 is carried out by soaking in oxalic acid.

[0021] On the other hand, the present invention also provides a computer device, which includes: a processor and a memory, and at least one program code is stored in the memory, and the at least one program code is loaded and executed by the processor to implement the operations performed in the above method for measuring the torque of superconducting wire.

[0022] On yet another aspect, the present invention also provides a computer-readable storage medium, in which at least one program code is stored, and the at least one program code is loaded and executed by a processor to implement the operations performed in the above method for measuring the torque of superconducting wire.

[0023] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0024] The present invention applies an annealing process to adjust the hardness difference between the superconducting material and the substrate, making the hardness difference more obvious. Then, the superconducting wire is subjected to planar rolling to adjust the cross-sectional shape and size of the wire, and the actual torque of the wire is calculated using a rebound mechanism. This method for measuring the torque of superconducting wires is simple to operate, has high measurement accuracy, and a wide range of applications. It overcomes the measurement limitation of the prior art "corrosion-untwisting method" which is only applicable to the case where "the substrate can be corroded / the superconductor cannot be corroded", and also overcomes the limitations of the prior art such as cumbersome actual operation, large influence of manual untwisting operation, and low measurement accuracy. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the cross-section of the wire core in Example 1. Figure 1 In which 1 is copper; Figure 1 In which 2 is the wire core.

[0026] Figure 2 It is a schematic diagram for measuring the pitch between 6 threads on the surface of the wire after removing the paint in Example 1. Detailed Embodiments

[0027] Next, the technical solution of the present invention will be described in conjunction with embodiments. However, the present invention is not limited to the following embodiments.

[0028] To enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention will be further described below in conjunction with specific embodiments and drawings, but the embodiments cited are not intended to limit the present invention.

[0029] In the following embodiments, the experimental methods and detection methods are all conventional methods unless otherwise specified; the reagents and materials are all commercially available unless otherwise specified.

[0030] Example 1

[0031] This example provides an example for measuring the torque of a wire with a copper ratio of 7, 6 cores, and a finished wire specification of Φ1.856mm.

[0032] The theoretical torque of this wire is 35 mm. Using the torque measurement method for niobium-titanium (Nb-Ti) and niobium trisulfide (Nb3Sn) composite superconductors in the GB / T 40296-2021 standard, hereinafter referred to as the "corrosion-untwisting method", the measured torque is 37 mm. The measurement steps using the torque measurement method provided by the present invention are as follows:

[0033] Take a 5m sample of wire with a copper ratio of 7, 6 cores, and a finished wire specification of Φ1.856mm as the wire to be inspected. Record the number of core wires in the outermost layer of the wire to be inspected. The number of core wires in the outermost layer of this wire to be inspected is 6, and record n2 = 6. Place the wire to be inspected into an annealing furnace and anneal it at 200°C for 20 minutes. Subsequently, spray the wire with an acetal paint having a viscosity of 2300 - 2700 maps, with a spray thickness of 100 microns. After spraying, the wire specification is Φ1.956mm. Mark a 2m (L1) position in the middle of the sample, and perform flat rolling on the selected wire with a rolling height of H0.800mm. After rolling, measure the length between the marks as 2.10m (L2). Subsequently, use oxalic acid to remove the paint from the rolled wire until obvious threads exist on the surface of the bare wire, and measure the distance between 6 (n1) threads, which is the pitch. Record this pitch, and the pitch is 30mm (L3). The schematic cross-section diagram of the core wire of the wire is as shown in Figure 1 shown, and the number of core wires is 6. The pitch measurement between 6 threads on the surface of the wire after paint removal is as shown in Figure 2 shown, Figure 2 in which the 6 threads are respectively marked as 1, 2, 3, 4, 5, and 6. Measure the distance between the 6 threads, which is the pitch, and the pitch is 30mm. Calculate the torque of the wire according to the wire torque formula.

[0034]

[0035] In the formula: n2 - the number of core wires in the outermost layer of the wire; L1 - the length intercepted after the annealed wire is spray-treated; L2 - the length of the intercepted wire after flat rolling; L3: the pitch length between n1 threads on the surface of the bare wire after paint removal; n1 - the number of threads corresponding to the pitch length.

[0036] Calculate the torque of this wire as 34.3mm.

[0037] Using the torque measurement method provided by the present invention, the measured torque of the wire is 34.3mm. Compared with the torque of 37mm measured by the "corrosion - untwisting method", it is closer to the theoretical torque of 35mm of this wire, and the measurement accuracy is higher.

[0038] Example 2

[0039] The present invention provides an example of measuring the torque of a wire with a copper ratio of 3, 54 cores, and a finished wire specification of Φ0.895mm.

[0040] The theoretical torque of this wire is 85mm, and the torque measured by the "corrosion - untwisting method" is 88mm. The measurement steps using the torque measurement method provided by the present invention are as follows:

[0041] Take a 5m sample of wire with a copper ratio of 3, 54 cores, and a finished wire specification of Φ0.895mm as the wire to be inspected. Record the number of core wires in the outermost layer of the wire to be inspected. The number of core wires in the outermost layer of this wire to be inspected is 24, and record n2 = 24. Put the wire to be inspected into an annealing furnace and anneal it at 350°C for 40 minutes. Subsequently, spray the wire with acetal paint having a viscosity of 2300 - 2700 maps, with a spraying thickness of 200 microns. After spraying, the wire specification is Φ1.000mm. Mark a 2m (L1) position in the middle of the sample, and perform flat rolling on the wire with a rolling height of H0.400mm. After rolling, measure the length between the marks as 2.05m (L2). Subsequently, use oxalic acid to remove the paint from the wire until obvious threads appear on the surface of the bare wire, and measure the spacing between 7 (n1) threads, which is the pitch. Record this pitch. The pitch is 22mm (L3), and calculate the torque using the wire torque calculation formula in Example 1.

[0042] Calculate the torque of this wire to be 85.9mm.

[0043] Using the torque measurement method provided by the present invention, the measured torque of the wire is 85.9mm. Compared with the torque of 88mm measured by the "corrosion - torque removal method", it is closer to the theoretical torque of 85mm of this wire, and the measurement accuracy is higher.

[0044] Example 3

[0045] The present invention provides a measurement example of the torque of a wire with a copper ratio of 1.5, 85 cores, and a finished wire specification of Φ1.400mm.

[0046] The theoretical torque of this wire is 45mm, and the torque measured by the "corrosion - torque removal method" is 43.6mm. The measurement steps using the torque measurement method provided by the present invention are as follows:

[0047] Take a 5m sample of wire with a copper ratio of 1.5, 85 cores, and a finished wire specification of Φ1.400mm as the wire to be inspected. Record the number of core wires in the outermost layer of the wire to be inspected. The number of core wires in the outermost layer of this wire to be inspected is 6, and record n2 = 6. Put the wire to be inspected into an annealing furnace and anneal it at 450°C for 45 minutes. Subsequently, spray the wire with acetal paint having a viscosity of 2300 - 2700 maps, with a spraying thickness of 200 microns. After spraying, the wire specification is Φ1.600mm. Mark a 2m (L1) position in the middle of the sample, and perform flat rolling on the wire with a rolling height of H0.600mm. After rolling, measure the length between the marks as 2.3m (L2). Subsequently, use oxalic acid to remove the paint from the wire until obvious threads appear on the surface of the bare wire, and measure the spacing between 7 (n1) threads, which is the pitch. Record this pitch. The pitch is 52mm (L3). Calculate the torque using the wire torque calculation formula in Example 1.

[0048] The torque of this wire rod is calculated to be 45.2 mm.

[0049] Using the torque measurement method provided by the present invention, the measured torque of the wire rod is 45.2 mm. Compared with the torque of 43.6 mm measured by the "corrosion-untwisting method", it is closer to the theoretical torque of 45 mm of this wire rod, and the measurement accuracy is higher.

[0050] As described above, the basic principle, main features and advantages of the present invention are preferably described. The above embodiments and the description are only descriptions of the preferred embodiments of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the present invention.

Claims

1. A method for measuring the torque of a superconducting wire, characterized in that, Including the following steps; Step 1: Take the wire to be inspected, and the number of core wires in the outermost layer of the wire to be inspected is counted as n2; Step 2: Put the wire to be inspected into an annealing furnace for annealing to obtain an annealed wire; Step 3: Perform a painting treatment on the annealed wire obtained in Step 2, intercept a section of the painted wire and measure its length, and mark the length as L1; Step 4: Perform flat rolling on the painted wire intercepted in Step 3, measure the length of the wire after rolling, and mark the length as L2; Step 5: Remove the paint from the wire after rolling in Step 4, measure the pitch length between n1 threads on the surface of the bare wire after removing the paint, and mark the pitch length as L3; Step 6: Calculate the torque based on the measured data; the calculation formula for the torque is as follows: 。 2. The method for measuring the torque of a superconducting wire according to claim 1, wherein In Step 1, the wire to be inspected is a multi-core superconducting wire obtained by twisting and stretching.

3. The method for measuring the torque of a superconducting wire according to claim 2, wherein The number of cores of the multi-core superconducting wire is not higher than 100 cores.

4. The method for measuring the torque of a superconducting wire according to claim 1, wherein In Step 2, the annealing temperature is 200~450°C, and the annealing time is 20~45 min.

5. The method for measuring the torque of a superconducting wire according to claim 1, characterized in that, In Step 3, the paint used for the painting treatment is acetal resin paint, and the viscosity of the acetal resin paint is 2300~2700 maps.

6. The method for measuring the torque of a superconducting wire according to claim 5, wherein The film thickness of the painting treatment is 100~200 microns.

7. The method for measuring the torque of a superconducting wire according to claim 1, characterized in that, In Step 4, the height of the flat rolling is 1 / 2~1 / 3 of the height of the painted wire.

8. The method for measuring the torque of a superconducting wire according to claim 1, characterized in that In Step 5, the paint removal is carried out by soaking in oxalic acid.

9. A computer device, characterized in that, The computer device includes: a processor and a memory. At least one program code is stored in the memory, and the at least one program code is loaded and executed by the processor to implement the operations performed in the superconducting wire torque measurement method according to any one of claims 1~8.

10. A computer-readable storage medium, characterized in that, At least one program code is stored in the computer-readable storage medium, and the at least one program code is loaded and executed by the processor to implement the operations performed in the superconducting wire torque measurement method according to any one of claims 1~8.

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