CN110231398B - Simulation test block for detecting defects of lead-sealed eddy current test and manufacturing method and application thereof - Google Patents
Simulation test block for detecting defects of lead-sealed eddy current test and manufacturing method and application thereof Download PDFInfo
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- CN110231398B CN110231398B CN201910641103.9A CN201910641103A CN110231398B CN 110231398 B CN110231398 B CN 110231398B CN 201910641103 A CN201910641103 A CN 201910641103A CN 110231398 B CN110231398 B CN 110231398B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
- G01N27/9006—Details, e.g. in the structure or functioning of sensors
Abstract
The invention relates to the technical field of power cable lead sealing quality detection, in particular to a simulation test block for detecting defects of lead sealing eddy current and a manufacturing method and application thereof. The method comprises the following steps: the test block comprises a test block base material, an insulating material layer and a defect structure; the defect structure is arranged on the test block base material, and the insulating material layer covers the defect structure and the test block base material; the defect structure is eight grooves, namely a first groove to an eighth groove respectively, the first to fourth grooves are sequentially arranged in parallel to four sides of the square, the fifth to eighth grooves are sequentially arranged in a manner of being parallel to four sides of the square, the fifth to eighth grooves are all positioned on the inner sides of the first to fourth grooves, and the first to eighth grooves are not connected; the first, third, fifth and seventh grooves are parallel to each other, and the second, fourth, sixth and eighth grooves are parallel to each other. The simulation test block for detecting the defects of the lead seal eddy current can truly simulate the material, the surface state, the coverage insulation and the defect structure of the detected lead seal.
Description
Technical Field
The invention relates to the technical field of power cable lead sealing quality detection, in particular to a simulation test block for detecting defects of lead sealing eddy current and a manufacturing method and application thereof.
Background
This information disclosed in this background of the invention is only for the purpose of increasing an understanding of the general background of the invention and is not necessarily to be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
The quality defects of the body and the accessories of the crosslinked polyethylene insulated power cable are main reasons for causing the faults of the high-voltage cable, the lead sealing is used as one of the key processes of field installation, sealing and grounding of the accessories of the high-voltage cable, and the quality of the lead sealing formed after the lead sealing directly influences the safe and stable operation of the high-voltage cable. Once the lead seal has the defects of cracking, holes and the like due to the factors of unqualified installation quality or stress, vibration and the like in operation, the accessory is easily affected with moisture or poor in electrical connection, the insulation degree is reduced, and therefore fault tripping of a high-voltage cable line and even cable breakdown accidents are caused, and serious economic loss is caused. Particularly, in the construction of various joints of high-voltage cables, high-quality lead sealing is more required.
The lead seal of the cross-linked polyethylene insulated power cable is used as a cable accessory, and is a molding structure formed by sealing a gap between the end part of a tail pipe and a metal sleeve by using an alloy material such as lead and tin which are melted by heating, and the like, and the surface of the molding structure is covered with a layer of heat-shrinkable tube with the thickness of 3-5mm in a heat shrinkage mode, wherein the material is mainly plastic and comprises insulating materials such as PVC, ABS, EVA, PET and the like. The process of making the lead seal is called lead enameling or lead sealing, and the process of covering the thermal shrinkage insulating material is called thermal shrinkage sheath. In recent years, typical lead seal defects collected at accident sites are surface knife-mark scratches and radial cracking deformation. The surface knife mark-shaped scratch is mainly caused by that the execution of a lead seal processing technology is not in place, and radial cracking is caused by the reason and is influenced by factors such as stress, vibration and the like in operation, so that the defects such as lead seal cracking, deformation and the like are caused. Therefore, it is necessary to utilize an effective and reliable detection means to perform detection and evaluation on the quality of the lead seal of the cable, so as to ensure the sealing safety of various ends of the cable, thereby avoiding the breakdown accident caused by the lead seal defect of the cable. However, manual lead seal inspection needs to strip a lead seal thermal shrinkage sleeve and a waterproof wrapping tape, recovery is difficult, and efficiency is low, so that detection of surface defects of a lead seal of a cable accessory under the condition of not removing external insulation is very important.
Aiming at detecting the lead seal of a high-voltage cable accessory under the condition of not removing an external insulation, the current detection methods mainly comprise a loop resistance test, an X-ray digital imaging detection and an eddy current detection. However, the inventors believe that: the problem that the lead seal cracking cannot be completely and effectively detected exists in both loop resistance testing and X-ray digital imaging detection, and the eddy current detection technology has the obvious application advantages of no influence of a detection position, no touch of a detected part in operation, high detection efficiency and the like. Therefore, there is a need for a related art research for eddy current testing of lead sealing of high voltage cable accessories.
Disclosure of Invention
Therefore, after the research of the invention, the reasons for the problems are mainly found as follows: at present, the lead sealing eddy current testing lacks a material which is close to an actually detected workpiece and a defect structure test block for detecting sensitivity verification and equivalent comparison of defects, and lacks a tool for testing the performance of a lead sealing detection instrument and verifying the effectiveness of a detection process. Therefore, the invention provides a simulation test block for detecting defects of lead sealing eddy current, and a manufacturing method and application thereof.
The first object of the present invention: a simulation test block for detecting defects of lead-sealed eddy current is provided.
The second object of the present invention: a method for manufacturing a simulation test block for detecting defects of lead-sealed eddy current is provided.
The third object of the present invention: the simulation test block for detecting the defects of the lead-sealed eddy current and the application of the manufacturing method thereof are provided.
In order to realize the purpose, the invention discloses the following technical scheme:
firstly, the invention discloses a simulation test block for detecting defects of lead sealing eddy current, which comprises the following components: the test block comprises a test block base material, an insulating material layer and a defect structure; the defect structure is arranged on the test block base material, and the insulating material layer covers the defect structure and the test block base material and is used for sealing the defect structure and the surface of the test block base material where the defect structure is arranged; the defect structure comprises eight grooves, namely a first groove, a second groove, a third groove, a fourth groove and a fourth groove, wherein the first groove, the second groove and the fourth groove are the same in length, the lengths of the fifth to eighth grooves are the same, and the lengths of the first to fourth grooves are greater than the lengths of the fifth to eighth grooves; the depths of the first groove, the second groove, the third groove, the fourth groove, the fifth groove, the eighth groove and the fourth groove are sequentially increased in an increasing mode, and the increasing mode and the increasing quantity of the first groove, the second groove and the eighth groove are the same; the first to fourth grooves are arranged in sequence in a mode of being parallel to four sides of the square, the fifth to eighth grooves are all located on the inner sides of the first to fourth grooves, and the first to eighth grooves are not connected; the first, third, fifth and seventh grooves are parallel to each other, and the second, fourth, sixth and eighth grooves are parallel to each other.
As a further technical scheme, the material of the test block base material is lead-tin alloy; preferably a lead-tin alloy having a combination of 60-65% lead and 35-40% tin by mass. The lead-sealing welding rod for cable lead-sealing is lead-tin alloy. The melting point of lead is 327 ℃ and the melting point of tin is 232 ℃. Lead-tin alloys formulated with 65% lead and 35% tin are in a semi-solid state, i.e. paste-like, at temperatures ranging from 180 to 250 ℃. The lead-tin alloy with the proportion has a wider operable temperature range and is more suitable for lead enameling operation. If the tin content is too low, the enamel is not easy to be formed by wiping when the lead is enamel; if the tin content is too much, the operable temperature range of the solder is small, which is not beneficial to lead enameling operation.
As a further technical solution, the thickness of the insulating material layer can be selected according to the thickness of the insulating material in the detected high-voltage cable, for example, when the thickness of the insulating layer of the actually detected workpiece is less than or equal to 3mm, and less than or equal to 3mm, the thickness of the insulating material layer is 3mm; when the thickness of the insulating layer of the workpiece to be actually detected is less than or equal to 5mm and is less than 3mm, the thickness of the insulating material layer is 5mm.
As a further technical solution, the material of the insulating material layer includes any one of PVC, ABS, EVA, PET, and the like.
As a further technical scheme, the test block base material is of a cubic structure, for example, the size of the test block base material can be 204-210mm in length, 204-210mm in width, 20-30mm in height or any other suitable size, for example, the test block base material is arc-shaped or hemispherical, and the test block base material is in a protection range as long as the test block base material is suitable for simulating defect test blocks related to lead sealing eddy current detection.
As a further technical scheme, the lengths of the first groove, the second groove, the third groove and the fourth groove are all 40mm, and the depths of the first groove, the second groove, the third groove and the fourth groove are 1mm, 2mm, 3mm and 4mm in sequence.
As a further technical scheme, the lengths of the fifth groove to the eighth groove are all 20mm, and the depths of the fifth groove to the eighth groove are 1mm, 2mm, 3mm and 4mm in sequence.
As a further technical scheme, the first groove, the second groove, the third groove and the fourth groove are all 40mm away from the edge of the test block base material 1.
As a further technical scheme, in the first, third, fifth and seventh grooves, the distance between adjacent grooves is 40mm; in the second, fourth, sixth and eighth grooves, the distance between adjacent grooves is 40mm.
As a further technical solution, the depth direction of the groove is perpendicular to the surface of the test block substrate 1 where the groove is located.
As a further technical scheme, the width of the groove is 1mm.
One of the characteristics of the simulation test block designed by the invention is as follows: the insulating material and the test block base material covered by the simulation test block are beneficial to truly simulating the structure of the lead seal to be detected, the defect structure on the simulation test block can effectively reflect the size of the defect of the eddy current detection lead seal and the equivalent size of an echo, the verification of detection sensitivity and the equivalent comparison of the defect are beneficial to ensuring the performance of a test lead seal detection instrument and the effectiveness of a verification detection process, and the effective detection of the surface defect of the lead seal is finally ensured.
The simulation test block designed by the invention has the following characteristics: (1) The reason for arranging the grooves in such a distribution is to simulate the actual defect layout of the surface of the lead seal to be detected, which may be transverse, longitudinal, or both, and the cracking direction of the lead seal is generally tensile stress, and the stress direction is generally transverse or longitudinal. (2) The defect structure is arranged in such a way that a defect-free position is required to carry out a checking and debugging area such as a shaking signal and a background noise signal before lead-sealed eddy current detection, and the arrangement of the positive center surrounded by the fifth groove, the eighth groove and the fifth groove meets the requirement. (3) The device has the advantages that the device can meet the requirements of checking and debugging shaking signals and background noise signals before lead-sealed eddy current detection, can also check the sensitivity of defects and compare and evaluate the sizes of the defects, combines the debugging before the detection with a defect simulation test block, greatly improves the detection efficiency, and simultaneously considers the beneficial effects of the invention.
Secondly, the invention discloses a preparation method of the simulation test block for detecting the defects of the lead sealing eddy current, which comprises the following steps:
(1) Selecting a base material raw material which is pore-free and uniform in material quality, and processing the base material raw material into a test block base material;
(2) And (2) processing a defect structure on the test block base material in the step (1) according to the arrangement, and then covering an insulating material layer on the outer surface of the test block base material to seal the defect structure and the surface of the test block base material on which the defect structure is positioned.
As a further technical solution, in the step (1), the preparation method of the test block base material comprises: mixing and heating lead-tin alloy at 185-250 ℃ to prepare a lead-tin alloy base material, then selecting the base material which is free of air holes and uniform in material quality through ultrasonic or digital ray detection, and cutting the base material into a cuboid to obtain the lead-tin alloy.
As a further technical scheme, in the step (1), the defect structure is manufactured by adopting a numerical control electric spark precision machining method.
Finally, the invention discloses the application of the simulation test block for detecting the defects of the lead seal eddy current and the manufacturing method thereof in the fields of nondestructive testing, power cable lead seal quality detection and the like.
Compared with the prior art, the invention has the following beneficial effects:
(1) The simulation test block for detecting the defects of the lead seal eddy current can truly simulate the material, the surface state, the coverage insulation and the defect structure of the detected lead seal.
(2) The defect structure on the simulation test block designed by the invention can effectively reflect the size of the defect of the eddy current detection lead seal and the equivalent size of the echo, can be effectively used for detection sensitivity check and defect evaluation, and can be effectively used for testing the performance of a lead seal detection instrument and verifying the effectiveness of the detection process.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
FIG. 1 is a top view of a mock test block for a leaded sealed eddy current test defect in example 1 of the present invention.
Fig. 2 is a front view of a simulation test block for a lead sealed eddy current test of defects in embodiment 1 of the present invention.
FIG. 3 is a top view of a mock test block for a leaded sealed eddy current testing defect as per example 2 of the present invention.
FIG. 4 is a diagram showing the effect of the wobble signal in embodiment 5 of the present invention.
FIG. 5 is a graph showing the effect of small-sized defects in example 5 of the present invention.
FIG. 6 is a diagram showing the effect of large-size defects in example 5 of the present invention.
The reference numerals in the drawings denote: 1-a test block substrate, 2-an insulating material layer, 3-a first groove, 4-a second groove, 5-a third groove, 6-a fourth groove, 7-a fifth groove, 8-a sixth groove, 9-a seventh groove and 10-an eighth groove.
Detailed Description
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
As described in the background art, the current lead sealing eddy current inspection lacks a material and defect structure test block which is close to an actually detected workpiece for detection, sensitivity verification and defect equivalent comparison, and lacks a tool for testing the performance of a lead sealing detection instrument and verifying the effectiveness of a detection process. Therefore, the present invention provides a simulation test block for detecting defects by using lead-sealed eddy current and a method for manufacturing the same, and the present invention will be further described with reference to the accompanying drawings and the detailed description.
Example 1
Referring to fig. 1 and 2, a mock block for leaded eddy current testing defects, comprising: the test block comprises a test block base material (1), an insulating material layer (2) and a defect structure; the defect structure is arranged on the test block base material (1), and the insulating material layer (2) covers the defect structure and the test block base material (1) and is used for sealing the defect structure and the surface of the test block base material (1) where the defect structure is arranged; the defect structure comprises eight grooves, namely first to eighth grooves (3, 4, 5, 6, 7, 8, 9 and 10), wherein the lengths of the first to fourth grooves (3, 4, 5 and 6) are the same, the lengths of the fifth to eighth grooves (7, 8, 9 and 10) are the same, and the lengths of the first to fourth grooves (3, 4, 5 and 6) are greater than the lengths of the fifth to eighth grooves (7, 8, 9 and 10); the depths of the first to fourth grooves (3, 4, 5 and 6) are sequentially increased, the depths of the fifth to eighth grooves (7, 8, 9 and 10) are sequentially increased, and the increasing mode and the increasing increment of the first to fourth grooves are the same; the first to fourth grooves (3, 4, 5, 6) are sequentially arranged in a mode of being parallel to four sides of a square, the fifth to eighth grooves (7, 8, 9, 10) are sequentially arranged in a mode of being parallel to four sides of the square, the fifth to eighth grooves (7, 8, 9, 10) are all located on the inner sides of the first to fourth grooves (3, 4, 5, 6), and the first to eighth grooves are not connected; the first, third, fifth and seventh grooves (3, 5, 7 and 9) are parallel to each other, and the second, fourth, sixth and eighth grooves (4, 6, 8 and 10) are parallel to each other.
Example 2
A simulation test block for detecting defects of lead-sealed eddy current is different from that of embodiment 1 in that: referring to fig. 3, the test block substrate (1) has a cubic structure with dimensions of 204mm in length, 204mm in width and 20mm in height. The lengths of the first to fourth grooves (3, 4, 5 and 6) are all 40mm, and the depths of the first to fourth grooves are 1mm, 2mm, 3mm and 4mm in sequence. The lengths of the fifth to eighth grooves (7, 8, 9 and 10) are all 20mm, and the depths of the grooves are 1mm, 2mm, 3mm and 4mm in sequence. The first to fourth grooves (3, 4, 5, 6) are all 40mm away from the edge of the test block base material (1). In the first, third, fifth and seventh grooves (3, 5, 7 and 9), the distance between adjacent grooves is 40mm; in the second, fourth, sixth and eighth grooves (4, 6, 8 and 10), the distance between adjacent grooves is 40mm; the width of the groove is 1mm, and the depth direction of the groove is vertical to the surface of the test block base material (1) where the groove is located.
Example 3
A preparation method of a simulation test block for detecting defects of lead sealing eddy current comprises the following steps:
(1) Mixing 65 mass percent of lead and 35 mass percent of tin, and heating at the temperature of 185-250 ℃ to prepare a lead-tin alloy base material which is internally provided with no air holes and is uniform, wherein the base material is a cuboid with the height of 22mm, the length of 206mm and the width of 206 mm;
(2) Testing the block base material obtained in the step (1) by using a digital ray detection method, selecting a uniform base material without pores, and processing the base material into a cube structure with a test size of 20mm high, 204mm long and 204mm wide by using a high-precision cutting and polishing tool to obtain a test block base material;
(3) Precisely machining a first groove, a second groove, a third groove and a fourth groove, namely a defect structure, on one surface of the test block base material (1) in the step (2), wherein the surface is 204mm long and 204mm wide by using numerical control electric sparks;
(4) And (4) covering an insulating material layer with the same area on the defect structure in the step (3), wherein the insulating material layer is made of PVC (polyvinyl chloride), and thus obtaining the simulation test block.
Example 4
A preparation method of a simulation test block for detecting defects of lead-sealed eddy current comprises the following steps:
(1) Mixing 60 mass percent of lead and 40 mass percent of tin, and heating at the temperature of 185-250 ℃ to prepare a lead-tin alloy base material which is internally provided with no air holes and is uniform, wherein the base material is a cuboid with the height of 33mm, the length of 218mm and the width of 216 mm;
(2) Testing the block base material obtained in the step (1) by using a digital ray, selecting a uniform base material without pores, and processing the base material into a cube structure with a test size of 30mm high, 210mm long and 210mm wide by using a high-precision cutting and polishing tool to obtain a test block base material;
(3) Precisely machining first to eighth grooves, namely defect structures, on one surface of the test block base material (1) in the step (2) with the length of 210mm and the width of 210mm by using numerical control electric sparks;
(4) And (4) covering an insulating material layer with the same area on the defect structure in the step (3), wherein the insulating material layer is made of PET (polyethylene terephthalate), and thus obtaining the simulation test block.
Example 5
The test block described in embodiment 2 is used as an object, when the eddy current testing technology is used for conducting lead seal testing, the thickness of the insulating material layer (2) is selected according to the requirement of the actually tested workpiece, when the thickness of the insulating layer of the actually tested workpiece is less than or equal to 3mm, the thickness of the insulating material layer (2) is 3mm, and when the thickness of the insulating layer of the actually tested workpiece is less than or equal to 5mm, the thickness of the insulating material layer (2) is 5mm. After selecting a proper insulating material layer (2), carrying out eddy current shaking signal calibration (refer to fig. 4) in a positive center surface surrounded by fifth to eighth grooves (7, 8, 9 and 10) by using a placed coil probe, testing and identifying a shaking signal by using the probe attached to the insulating material layer (2), adjusting amplitude equivalent and angle of the shaking signal and a background signal so as to facilitate later-stage defect identification, for example, adjusting the angle of the shaking signal to be in a 0-degree or 180-degree horizontal state and adjusting the amplitude equivalent to be in two proportional circles. And then, horizontally attaching the adjusted eddy current detection probe to an insulating material layer (2), and respectively detecting defect structures under the insulating material, namely first to eighth grooves (3, 4, 5, 6, 7, 8, 9 and 10), wherein the left and right moving directions of the probe are perpendicular to the length direction of the cutting grooves, and when the eddy current amplitude equivalent and the angle of the defect groove are obviously different from those of a previously calibrated shaking signal, the defect that the size of the defect can be effectively detected by a detection instrument system is proved, so that the purposes of calibrating the detection sensitivity and evaluating the size of the defect are achieved, and the verification of the performance of a lead sealing detection instrument and the effectiveness of the detection process is also realized. Referring to fig. 5, it is a waveform diagram of eddy current signals generated by small-sized defects of the fifth groove (7), the amplitude equivalent of the eddy current signals is slightly larger than the wobble signal, and the vertical, left and right layouts of the signals are obviously pulled apart, and the angle is obviously changed, so as to form 8-shaped defect signals which are easy to identify; referring to fig. 6, the waveform of the eddy current signal generated by the large-size defect of the fourth groove (6) is shown, the amplitude equivalent of the eddy current signal is obviously greater than that of the wobble signal, the vertical and horizontal layouts of the signal are obviously pulled apart, the angle is obviously changed, and an 8-shaped defect signal which is easier to identify is formed. The small-size defects and the large-size defects can be easily detected, and the amplitude equivalent weight and the angle of the small-size defects and the large-size defects are obviously compared. The test of the detection capability of the detection instrument before the eddy current detection of the lead seal and the doubtful detection capability of the detection instrument in the detection process can be verified on the test block.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (17)
1. A mock block for leaded sealed eddy current testing defects, comprising: the test block comprises a test block base material, an insulating material layer and a defect structure; the defect structure is arranged on the test block base material, and the insulating material layer covers the defect structure and the test block base material and is used for sealing the defect structure and the surface of the test block base material where the defect structure is arranged; the defect structure comprises eight grooves, namely a first groove, a second groove, a third groove, a fourth groove and a fourth groove, wherein the first groove, the second groove and the fourth groove are the same in length, the lengths of the fifth to eighth grooves are the same, and the lengths of the first to fourth grooves are greater than the lengths of the fifth to eighth grooves; the depths of the first groove, the second groove, the third groove, the fourth groove, the fifth groove, the eighth groove and the fourth groove are sequentially increased in an increasing mode, and the increasing mode and the increasing quantity of the first groove, the second groove and the eighth groove are the same; the first to fourth grooves are sequentially arranged in a manner of being parallel to four sides of the square, the fifth to eighth grooves are all positioned on the inner sides of the first to fourth grooves, and the first to eighth grooves are not connected; the first, third, fifth and seventh grooves are parallel to each other, and the second, fourth, sixth and eighth grooves are parallel to each other;
the simulation test block for detecting the defects of the lead seal eddy current test specifically comprises the following steps when the lead seal detection is implemented by using the eddy current detection technology:
(1) Selecting the thickness of the insulating material layer according to the actually detected thickness of the insulating material in the high-voltage cable workpiece;
(2) After selecting a proper insulating material layer, using a placement type coil probe to detect the defect structure:
calibrating eddy current shaking signals in a right center surface defined by the fifth to eighth grooves; after the probe is attached to the insulating material layer to test and identify the shaking signal, adjusting the amplitude equivalent weight and the angle of the shaking signal and the background signal, adjusting the angle of the shaking signal to be in a 0-degree or 180-degree horizontal state, and adjusting the amplitude equivalent weight to be in two proportional rings;
(3) The adjusted eddy current inspection probe is horizontally attached to an insulating material layer, and the defect structures below the insulating material are respectively measured:
the left and right moving directions of the probe are vertical to the length direction of the cutting groove.
2. The mock test block for leaded eddy current testing defects as defined in claim 1 wherein the material of said test block substrate is a lead-tin alloy.
3. The mock test block for the leaded sealed eddy current testing of defects as defined in claim 2 wherein the material of the test block substrate is a lead-tin alloy having a combination of 60-65% lead and 35-40% tin by mass.
4. The simulation test block for the lead sealing eddy current inspection defect of claim 1, wherein when the thickness of the insulating layer of the actually inspected workpiece is less than or equal to 3mm, the thickness of the insulating material layer is 3mm; when the thickness of the insulating layer of the workpiece to be actually detected is less than or equal to 5mm and is less than 3mm, the thickness of the insulating material layer is 5mm.
5. The proof mass for leaded sealed eddy current testing defects of claim 1 wherein the material of the insulating material layer comprises any one of PVC, ABS, EVA, PET, etc.
6. The mock test block for leaded sealed eddy current testing defects as defined in claim 1 wherein the test block substrate is of a cube configuration, an arc configuration or a hemispherical configuration.
7. The mock test block for the lead sealed eddy current testing of defects according to claim 6, wherein the test block substrate is a cube structure having dimensions of 204mm in length, 204mm in width and 20mm in height.
8. The simulation test block for lead sealing eddy current testing of defects as claimed in claim 1, wherein the first to fourth grooves each have a length of 40mm and a depth of 1mm, 2mm, 3mm, 4mm in this order.
9. The simulation test block for the lead sealing eddy current testing of defects as claimed in claim 1, wherein the lengths of the fifth to eighth grooves are 20mm, and the depths thereof are 1mm, 2mm, 3mm and 4mm in sequence.
10. The mock test block for lead sealed eddy current testing of defects according to claim 1 wherein said first through fourth grooves are each 40mm from the edge of the test block substrate 1.
11. The simulation test block for the lead sealing eddy current testing of defects as claimed in claim 1, wherein the first, third, fifth and seventh grooves have a spacing of 40mm between adjacent grooves; and in the second, fourth, sixth and eighth grooves, the distance between adjacent grooves is 40mm.
12. The test block for lead sealing eddy current testing of defects as set forth in claim 1, wherein the depth direction of the groove is perpendicular to the surface of the test block substrate 1 on which the groove is located.
13. The mock test block for leaded eddy current testing defects according to claim 1 wherein the width of the groove is 1mm.
14. The method for preparing a mock test block for the leaded sealed eddy current testing of defects as defined in any of the claims 1 to 13, comprising the following steps:
(1) Selecting a pore-free substrate raw material with uniform material quality, and processing the raw material into a test block substrate;
(2) And (2) processing a defect structure on the test block substrate in the step (1), and then covering an insulating material layer on the outer surface of the test block substrate so as to seal the defect structure and the surface of the test block substrate on which the defect structure is positioned.
15. The method according to claim 14, wherein in the step (1), the test piece base material is prepared by: mixing and heating lead-tin alloy at 185-250 ℃ to prepare a lead-tin alloy base material, then selecting the base material which is free of air holes and uniform in material quality through ultrasonic or digital ray detection, and cutting the base material into a cuboid to obtain the lead-tin alloy.
16. The method according to claim 15, wherein in the step (1), the defect structure is formed by a numerical control electric discharge precision machining method.
17. Use of a test block according to any one of claims 1 to 13 for eddy current testing of lead sealing defects and/or a test block prepared according to the method of any one of claims 14 to 16 in the field of non-destructive testing, quality testing of lead sealing of power cables.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910641103.9A CN110231398B (en) | 2019-07-16 | 2019-07-16 | Simulation test block for detecting defects of lead-sealed eddy current test and manufacturing method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910641103.9A CN110231398B (en) | 2019-07-16 | 2019-07-16 | Simulation test block for detecting defects of lead-sealed eddy current test and manufacturing method and application thereof |
Publications (2)
| Publication Number | Publication Date |
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| CN113049331A (en) * | 2021-03-12 | 2021-06-29 | 北京中实国金国际实验室能力验证研究有限公司 | Preparation method of nondestructive testing simulation test block and simulation test block |
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