Method for detecting core breakage position and core breakage rate of superconducting wire

Abstract

The invention discloses a method for detecting the core breakage position and the core breakage rate of a superconducting wire, and relates to the technical field of superconducting wire detection, which comprises the following steps of: carrying out dieless stretching on a superconducting composite wire; carrying out fixed die stretching on the superconductive composite wire rod subjected to die-free stretching; carrying out on-line size monitoring and on-line resistance testing on the superconducting composite wire stretched by the fixed die; and obtaining a broken core position according to an on-line size monitoring result, and obtaining a broken core rate according to an on-line resistance test result. According to the method, the core breaking position and the core breaking rate are obtained by combining die-free stretching, fixed die stretching, online size monitoring and online resistance testing, the detection comprehensiveness, the detection efficiency and the detection accuracy of the core breaking position and the core breaking rate of the superconducting wire are improved, and nondestructive detection is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of superconducting wire detection, and in particular to a method for detecting a superconducting wire core breakage position and a superconducting wire core breakage rate. Background Art

[0002] Superconducting wires are widely used in high-energy physics, medical magnetic resonance imaging (MRI), power transmission and other fields, especially in high magnetic fields and low temperature environments. Superconducting wires are usually composed of porous non-superconducting baselines and several superconducting core wires. These core wires may break during the production process due to various factors (such as material defects, improper processing, etc.). Broken cores not only affect superconducting properties, but may also reduce the current carrying capacity of superconducting wires, thereby affecting their application performance. Therefore, accurately detecting the broken core position and broken core rate of superconducting wires is crucial to ensure product quality and safety.

[0003] The existing superconducting wire core breakage detection method is mainly a corrosion method, which performs corrosion treatment on the suspected core breakage area of ​​the superconducting composite wire to observe the actual core breakage situation in the area.

[0004] However, the corrosion method causes great damage to superconducting composite wires and cannot achieve 100% detection, so the comprehensiveness of the detection is poor. At the same time, the corrosion method has high operational complexity and low detection efficiency. In addition, the corrosion method cannot accurately locate the broken core position, so the detection accuracy is poor. Summary of the invention

[0005] The present application provides a method for detecting the position and rate of superconducting wire core breakage, so as to solve the problems of poor detection comprehensiveness, low detection efficiency and poor detection accuracy of existing superconducting wire core breakage detection technology.

[0006] On the one hand, the present application provides a method for detecting a superconducting wire core breakage position and a superconducting wire core breakage rate, comprising the following steps: Step 1: Performing dieless stretching on the superconducting composite wire.

[0007] Step 2: performing fixed die stretching on the superconducting composite wire after dieless stretching.

[0008] Step three, performing online size monitoring and online resistance testing on the superconducting composite wire after fixed die stretching.

[0009] Step 4: Obtain the broken core position according to the online size monitoring result, and obtain the broken core rate according to the online resistance test result.

[0010] In a possible implementation, in step one, the processing amount of the dieless stretching is 5%-40%.

[0011] In a possible implementation, in step 1, the heating temperature of the moldless stretching is 300-600° C., the cooling method is water cooling, and the stretching speed is 5-30 m / min.

[0012] In a possible implementation, in step 2, the single-pass processing rate of the fixed-die stretching is 30%.

[0013] In a possible implementation, in step 2, the deviation of the theoretical diameter fluctuation of the superconducting composite wire after fixed die stretching is set within ±0.001 mm.

[0014] In a possible implementation, in step three, the monitoring area of ​​the online dimension is 1 mm along the axial direction of the wire, and the monitoring area of ​​the online resistance test is 10 mm along the axial direction of the wire.

[0015] In a possible implementation, in step 4, obtaining the broken core position according to the online dimension monitoring result includes: The position where the necking phenomenon occurs in the online dimension monitoring results is regarded as the core breaking position.

[0016] In a possible implementation, the superconducting composite wire includes a porous non-superconducting element wire and a plurality of superconducting core wires.

[0017] In step 4, obtaining the core break rate according to the online resistance test result includes: By utilizing the resistivity difference between the porous non-superconducting wire and the superconducting core wire, the broken core rate is obtained according to the resistance of the area where the broken core position is located and the resistance of the non-broken core area.

[0018] A method for detecting the broken core position and broken core rate of a superconducting wire in the present application has the following advantages: By combining dieless stretching, fixed die stretching, online dimension monitoring and online resistance testing, the broken core position and broken core rate are obtained, which improves the comprehensiveness, efficiency and accuracy of the detection of the broken core position and broken core rate of superconducting wires.

[0019] By performing dieless stretching on superconducting composite wires, the defects of the superconducting wires themselves can be magnified, making it easier to detect broken cores.

[0020] By subjecting the superconducting composite wire after die-less stretching to fixed-die stretching, the core breakage problem can be effectively exposed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic flow chart of a method for detecting a superconducting wire core breakage position and a superconducting wire core breakage rate provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] like Figure 1 As shown, the embodiment of the present application provides a method for detecting the broken core position and broken core rate of a superconducting wire, comprising the following steps: Step 1: Performing dieless stretching on the superconducting composite wire.

[0025] Step 2: performing fixed die stretching on the superconducting composite wire after dieless stretching.

[0026] Step three, performing online size monitoring and online resistance testing on the superconducting composite wire after fixed die stretching.

[0027] Step 4: Obtain the broken core position according to the online size monitoring result, and obtain the broken core rate according to the online resistance test result.

[0028] Exemplarily, in step one, the processing amount of the dieless stretching is 5%-40%.

[0029] Exemplarily, in step one, the heating temperature of the moldless stretching is 300-600° C., the cooling method is water cooling, and the stretching speed is 5-30 m / min.

[0030] Exemplarily, in step 2, the single-pass processing rate of the fixed die stretching is 30%.

[0031] Exemplarily, in step 2, the deviation of the theoretical diameter fluctuation of the superconducting composite wire after fixed die stretching is set within ±0.001 mm.

[0032] Exemplarily, in step three, the monitoring area of ​​the online dimension is 1 mm along the axial direction of the wire, and the monitoring area of ​​the online resistance test is 10 mm along the axial direction of the wire.

[0033] Exemplarily, in step 4, obtaining the broken core position according to the online dimension monitoring result includes: The position where the necking phenomenon occurs in the online dimension monitoring results is regarded as the core breaking position.

[0034] Exemplarily, the superconducting composite wire comprises a porous non-superconducting element wire and a plurality of superconducting core wires.

[0035] In step 4, obtaining the core break rate according to the online resistance test result includes: By utilizing the resistivity difference between the porous non-superconducting wire and the superconducting core wire, the broken core rate is obtained according to the resistance of the area where the broken core position is located and the resistance of the non-broken core area.

[0036] Specifically, the superconducting composite wires in Examples 1 to 3 all adopt niobium-titanium-copper composite wires, including a porous copper base wire and a plurality of NbTi core wires.

[0037] Embodiment 1: This embodiment provides an implementation process for detecting the broken core position and broken core rate of a superconducting wire with a copper ratio of 1, 60 cores, and a finished wire diameter of 0.819 mm: Step 1: Perform dieless stretching on a superconducting composite wire with a diameter of 1.200 mm, with a dieless stretching processing amount of 5%, stretching to a diameter of 1.170 mm, a heating temperature of 300° C., a cooling method of water cooling, and a stretching speed of 5 m / min.

[0038] Step 2: The superconducting composite wire after dieless stretching is subjected to two fixed die stretchings, the single pass processing rate of the fixed die stretching is 30%, the theoretical diameter after fixed die stretching fluctuates between 0.818-0.820 mm, and the theoretical resistance fluctuates between 599.0-599.2 μΩ.

[0039] Step three, performing online size monitoring and online resistance testing on the superconducting composite wire after fixed die stretching.

[0040] Step 4: According to the online size monitoring results, the wire diameter at 13546m is 0.806mm, and there is an obvious necking phenomenon, so this position is determined as the broken core position. The resistance of the area where the broken core position is located is 582.2μΩ, which is less than the theoretical resistance fluctuation. The resistivity difference between the porous copper base wire and the NbTi core wire is used to obtain the broken core rate and calculate the number of broken cores to be 2, and the number of complete core wires is 58.

[0041] The test results of Example 1 were verified using a corrosion method and were found to be correct.

[0042] Embodiment 2: This embodiment provides an implementation process for detecting the broken core position and broken core rate of a superconducting wire with a copper ratio of 7, a core number of 15, and a finished wire diameter of 2.016 mm: Step 1: Perform dieless stretching on a superconducting composite wire with a diameter of 4.599 mm, with a dieless stretching processing amount of 20%, stretching to a diameter of 4.113 mm, a heating temperature of 450° C., a cooling method of water cooling, and a stretching speed of 15 m / min.

[0043] Step 2: The superconducting composite wire after dieless stretching is subjected to fixed die stretching for 4 times, and the single pass processing rate of the fixed die stretching is 30%. The theoretical diameter after fixed die stretching fluctuates between 2.015-2.017 mm, and the theoretical resistance fluctuates between 59.5-59.7 μΩ.

[0044] Step three, performing online size monitoring and online resistance testing on the superconducting composite wire after fixed die stretching.

[0045] Step 4: According to the online dimension monitoring results, the wire diameter at 9842m is 2.000mm, and there is an obvious necking phenomenon, so this position is determined as the broken core position. The resistance of the area where the broken core position is located is 59.1μΩ, which is less than the theoretical resistance fluctuation. The resistivity difference between the porous copper base wire and the NbTi core wire is used to obtain the broken core rate and calculate the number of broken cores to be 1, and the number of complete core wires is 14.

[0046] The test results of Example 2 were verified using a corrosion method and were found to be correct.

[0047] Embodiment 3: This embodiment provides an implementation process for detecting the broken core position and broken core rate of a superconducting wire with a copper ratio of 2, a core number of 85, and a finished wire diameter of 0.873 mm: Step 1: Perform dieless stretching on a superconducting composite wire with a diameter of 2.300 mm, with a dieless stretching processing amount of 40%, stretching to a diameter of 1.782 mm, a heating temperature of 600° C., a cooling method of water cooling, and a stretching speed of 30 m / min.

[0048] Step 2: The superconducting composite wire after dieless stretching is subjected to 4 passes of fixed die stretching, and the single pass processing rate of the fixed die stretching is 30%. The theoretical diameter after fixed die stretching fluctuates between 0.872-0.874 mm, and the theoretical resistance fluctuates between 407.2-407.4 μΩ.

[0049] Step three, performing online size monitoring and online resistance testing on the superconducting composite wire after fixed die stretching.

[0050] Step 4: According to the online size monitoring results, the wire diameter at 9842m is 0.865mm, and there is an obvious necking phenomenon, so this position is determined as the broken core position. The resistance of the area where the broken core position is located is 396.8μΩ, which is less than the theoretical resistance fluctuation. The resistivity difference between the porous copper base wire and the NbTi core wire is used to obtain the broken core rate and calculate the number of broken cores to be 5, and the number of complete core wires to be 80.

[0051] The test results of Example 3 were verified by the corrosion method and the test results were correct.

[0052] The embodiments of the present application combine dieless stretching, fixed die stretching, online dimension monitoring and online resistance testing to obtain the broken core position and broken core rate, thereby improving the comprehensiveness, efficiency and accuracy of detection of the broken core position and broken core rate of superconducting wires.

[0053] By performing dieless stretching on superconducting composite wires, the defects of the superconducting wires themselves can be magnified, making it easier to detect broken cores.

[0054] By subjecting the superconducting composite wire after die-less stretching to fixed-die stretching, the core breakage problem can be effectively exposed.

[0055] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0056] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for detecting the position and rate of superconducting wire core breakage, characterized in that: The following steps are involved: Step 1, performing dieless stretching on the superconducting composite wire; Step 2, performing fixed die stretching on the superconducting composite wire after dieless stretching; Step 3, performing online size monitoring and online resistance testing on the superconducting composite wire after being stretched by a fixed die; Step 4: Obtain the broken core position according to the online size monitoring result, and obtain the broken core rate according to the online resistance test result.

2. A method for detecting the broken core position and broken core rate of a superconducting wire according to claim 1, characterized in that: In step 1, the processing amount of the dieless stretching is 5%-40%.

3. A method for detecting the broken core position and broken core rate of a superconducting wire according to claim 1, characterized in that: In step 1, the heating temperature of the moldless stretching is 300-600° C., the cooling method is water cooling, and the stretching speed is 5-30 m / min.

4. A method for detecting the position and rate of superconducting wire core breakage according to claim 1, characterized in that: In step 2, the single-pass processing rate of the fixed die stretching is 30%.

5. The method for detecting the broken core position and broken core rate of a superconducting wire according to claim 1, characterized in that: In step 2, the deviation of the theoretical diameter fluctuation of the superconducting composite wire after the fixed die stretching is set within ±0.001 mm.

6. A method for detecting the broken core position and broken core rate of a superconducting wire according to claim 1, characterized in that: In step three, the monitoring area of ​​the online dimension is 1 mm along the axial direction of the wire, and the monitoring area of ​​the online resistance test is 10 mm along the axial direction of the wire.

7. A method for detecting the broken core position and broken core rate of a superconducting wire according to claim 1, characterized in that: In step 4, obtaining the broken core position according to the online dimension monitoring result includes: The position where the necking phenomenon occurs in the online dimension monitoring results is regarded as the core breaking position.

8. A method for detecting the broken core position and broken core rate of a superconducting wire according to claim 1, characterized in that: The superconducting composite wire comprises a porous non-superconducting base wire and a plurality of superconducting core wires; In step 4, obtaining the core break rate according to the online resistance test result includes: By utilizing the resistivity difference between the porous non-superconducting wire and the superconducting core wire, the broken core rate is obtained according to the resistance of the area where the broken core position is located and the resistance of the non-broken core area.

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