Electromagnetic detection method and system for nuclear engineering equipment weld defect determination

Abstract

The application discloses an electromagnetic detection method and system for nuclear engineering equipment weld defect determination. The method comprises detecting a standard block and using a defect-free area of the standard block to obtain a reference Bx signal for signal base value zeroing, detecting a specified defect area of the standard block, determining a threshold line according to the Bx signal in the specified defect area, and determining that a first Bx signal that does not exceed the threshold line is qualified, or marking a position of the first Bx signal that exceeds the threshold line as a suspected defect position, and then re-detecting the suspected defect position area to distinguish false signals. The electromagnetic detection method for nuclear engineering equipment weld defect determination can more conveniently, quickly, accurately and efficiently obtain a detection result without thinning or damaging a base material, and can distinguish characteristic signals, thereby realizing accurate detection of nuclear engineering equipment weld defects, and ensuring safe and stable operation of the nuclear engineering equipment.

Description

Technical Field

[0001] This application relates to the field of nuclear engineering technology, and in particular to an electromagnetic detection method and system for determining weld defects in nuclear engineering equipment. Background Technology

[0002] With the continuous development of society, the demand for electrical energy is increasing. From the current application of nuclear engineering, nuclear energy, as a clean energy source, has demonstrated relatively ideal results in practical applications. The reliable, stable, and safe operation of nuclear fuel equipment has become a crucial factor affecting the efficient operation of nuclear engineering in practical applications. New / spent fuel transport containers, as important specialized equipment for transporting nuclear fuel assemblies, play a vital role in the nuclear industry's fuel cycle. According to transport container regulations, the lifting lugs and tethering lugs of new / spent fuel transport containers must undergo load testing periodically (e.g., every two years). Furthermore, during the welding process of lifting lugs and tethering lugs, weld defects such as porosity, slag inclusions, undercut, and lack of fusion are difficult to completely avoid, and the degree of impact of different degrees of weld defects on weld quality varies. Therefore, to meet the different weld quality requirements of different pressure-bearing components, non-destructive testing methods are needed before and after load testing to assess the degree of weld defects in the lifting lugs and tethering lugs, thereby evaluating the weld quality.

[0003] Currently, the commonly used non-destructive testing methods are liquid penetrant testing and magnetic particle testing. Magnetic particle testing uses magnetic powder as a display medium to observe defects. Patent CN102645485 discloses a magnetic particle testing method for small-sized fillet welds in boiler headers, which utilizes an open coil. The method involves first applying magnetic powder around the fillet weld between the tube seat and the boiler header, then detecting longitudinal defects and transverse defects. Bidirectional vertical magnetization is achieved through coil magnetization and electromagnetic induction, thus enabling the detection of defects in the fillet weld. Liquid penetrant testing involves using a highly penetrating liquid to penetrate surface defects in a component and then making those defects visible. Patent CN110530767 discloses a remote automatic penetrant testing device and method for a control rod drive mechanism. This device includes a penetrant application module, a monitoring camera, and a lighting module. The penetrant application module allows for the application of penetrant to the lower Ω-shaped weld of the control rod drive mechanism, enabling remote liquid penetrant non-destructive testing. However, all of the above methods require sanding to remove the surface paint, which may lead to thinning or damage to the base material. At the same time, it is not easy to clean and demagnetize the product after testing, which is time-consuming and labor-intensive, resulting in low testing efficiency and poor testing results. Summary of the Invention

[0004] The purpose of this application is to solve the aforementioned technical problems.

[0005] To achieve the above objectives, the first aspect of this application proposes an electromagnetic detection method for determining weld defects in nuclear engineering equipment, comprising:

[0006] Step S1: Detect the defect-free area of ​​the standard test block to obtain the reference Bx signal, and use the reference Bx signal to reset the signal base value to zero;

[0007] Step S2: Detect the specified defect area of ​​the standard test block and determine the threshold line based on the Bx signal in the specified defect area;

[0008] Step S3: Inspect the weld to be tested and obtain the first Bx signal. If the first Bx signal does not exceed the threshold line, the weld to be tested is judged to be qualified and the test ends. If the first Bx signal exceeds the threshold line, mark the position of the first Bx signal exceeding the threshold line on the weld to be tested as the suspected defect position and proceed to step S4.

[0009] Step S4: Re-inspect the weld to be tested with the suspected defect location as the midpoint and a width of 15-25mm before and after it to obtain the second Bx signal. If the obtained second Bx signal is a false signal, the weld to be tested is judged to be qualified and the test ends.

[0010] Furthermore, in step S4, a second Bz signal and a second butterfly pattern are also obtained. If the second Bx signal obtained in step S4 is not a spurious signal, then proceed to step S5.

[0011] Step S5: If the second Bx signal, the second Bz signal, and the second butterfly pattern are all complete, the weld to be tested is judged as unqualified and the test ends; otherwise, proceed to step S6.

[0012] Step S6: If the second Bz signal or the second butterfly pattern is incomplete, and the second Bx signal does not exceed the threshold line, the weld to be tested is determined to be qualified and the test ends; otherwise, proceed to step S7.

[0013] Step S7: If the second Bx signal is an uncorrelated signal, record the type of the uncorrelated signal and end the detection; otherwise, proceed to step S8.

[0014] Step S8: If the second Bx signal is not an irrelevant signal, the weld to be tested is judged as unqualified and the test ends.

[0015] Furthermore, the standard test blocks are made using the same materials and welding methods as nuclear engineering equipment.

[0016] Furthermore, in step S1, in the defect-free area, 8-12 reference Bx signals are collected and averaged to reset the signal base value to zero.

[0017] Further, in step S2, the interface of the Bx signal is defined, and two threshold lines symmetrical to the zero value are set on the interface, such that the threshold corresponding to the two threshold lines is a, and the larger absolute value of the maximum or minimum value of the Bx signal in the defect area is b, and a and b satisfy the following relationship:

[0018] 80% ≤ a / b ≤ 100%;

[0019] The distance between threshold lines accounts for 30-40% of the interface height.

[0020] Furthermore, step S3 includes steps S3-1 and S3-2.

[0021] Step S3-1: The nuclear engineering equipment includes two or more welds to be tested. All welds to be tested are tested separately to obtain the pre-inspection Bx signal. If the pre-inspection Bx signal of one or more welds to be tested does not exceed the threshold line, the corresponding weld to be tested is judged to be qualified; if the pre-inspection Bx signal of one or more welds to be tested exceeds the threshold line, then proceed to step S3-2.

[0022] Step S3-2: Re-inspect one or more welds under test whose pre-inspection Bx signal exceeds the threshold line to obtain the first Bx signal. Mark the position of the first Bx signal that exceeds the threshold line on the weld under test as the suspected defect position, and proceed to step S4.

[0023] Furthermore, the weld seam of the nuclear engineering equipment is the weld seam of the lifting lug of the nuclear engineering container.

[0024] By applying the above-described technical solution of this application, at least the following technical effects are achieved:

[0025] 1. This electromagnetic detection method, by setting a threshold line, makes it easy to observe whether the height of the maximum distortion of the Bx signal on the side deviating from zero amplitude reaches the height of the threshold line, thereby enabling more convenient, faster, more accurate and more efficient acquisition of detection results.

[0026] 2. This electromagnetic detection method, by zeroing the signal baseline value, can comprehensively, conveniently, and accurately acquire the magnetic field signal generated by the base magnetic field, thereby achieving zeroing the signal baseline value and providing accurate data support for subsequent defect judgment.

[0027] 3. Based on segmented detection of suspected signals, this electromagnetic detection method adds a step of calibrating and re-checking the defect location where suspected signals reappear. This avoids judging weld defects as unqualified when they exceed the threshold line due to detection operation errors, and can distinguish between false signals and defect signals, thereby effectively reducing the probability of missed detections and false detections, making the detection results more reliable.

[0028] 4. Based on the verification of characteristic signals, this electromagnetic detection method adds a judgment process when individual signals in the characteristic signals are incomplete, which effectively reduces the probability of missed detection and false detection, making the detection results more reliable. It can also distinguish between spurious signals, irrelevant signals and defect signals, thereby realizing the accurate detection of defects such as porosity, slag inclusion and cracks on the surface of welds of nuclear engineering equipment.

[0029] 6. Compared with magnetic particle testing, this electromagnetic testing method eliminates the need for magnetizing the test piece and applying magnetic powder, making the testing operation simpler.

[0030] 7. Compared with conventional penetrant testing technology, this electromagnetic testing method can detect internal defects in carbon steel welds, thus achieving higher testing accuracy.

[0031] 8. Compared with X-ray detection technology, this electromagnetic detection method is radiation-free and does not require a dedicated time window, thus making the detection efficiency higher.

[0032] To achieve the above objectives, the second aspect of this application proposes an electromagnetic detection system for judging weld defects in nuclear engineering equipment, comprising a host computer and an electromagnetic detection probe. The electromagnetic detection probe is used to detect the weld to be tested, and the host computer is used to control the electromagnetic detection probe and display data.

[0033] The electromagnetic detection probe includes a probe housing, a magnetic field sensor, a probe cover, and a connector. The probe housing includes a support leg and a through slot. The bottom of the support leg has an arc structure that is adapted to the curvature of the nuclear engineering container. The magnetic field sensor is located in the through slot. The probe cover is detachably connected to the top of the probe housing, and the connector is detachably connected to the top of the probe cover.

[0034] Furthermore, the top of the probe housing has connecting grooves on both sides perpendicular to the direction of travel of the electromagnetic detection probe, and the bottom of the probe cover has connecting protrusions. The connecting grooves and connecting protrusions cooperate to realize the detachable connection between the probe cover and the probe housing.

[0035] Furthermore, the electromagnetic detection probe also includes a magnetic core and an excitation coil. The probe housing has a long groove and four corner grooves inside. The corner grooves are arranged adjacent to the long groove and the through groove. The magnetic core is set in the long groove, and the excitation coil is wound on the magnetic core and located in the corner grooves.

[0036] Furthermore, the electromagnetic detection probe also includes a signal processing circuit, which is housed within the probe housing.

[0037] Furthermore, the electromagnetic detection probe also includes a nut and a washer, and the connector is detachably connected to the probe cover via the nut and washer.

[0038] By applying the above-described technical solution of this application, at least the following technical effects are achieved:

[0039] 1. Compared with magnetic particle testing, this electromagnetic testing system eliminates the need for magnetizing the test piece and applying magnetic powder, making the testing operation simpler.

[0040] 2. Compared with conventional penetrant testing technology, this electromagnetic testing system can detect internal defects in carbon steel welds, thus achieving higher testing accuracy.

[0041] 3. Compared with X-ray detection technology, this electromagnetic detection system is radiation-free and does not require a dedicated time window, thus making the detection efficiency higher.

[0042] 4. By adapting the arc structure of the electromagnetic detection probe to the curvature of the nuclear engineering container under test, this electromagnetic detection system can further fit the electromagnetic probe to the weld under test during the test, thereby achieving accurate detection of the weld under test.

[0043] 5. This electromagnetic detection system, by setting up an electromagnetic detection probe and using a combination of long groove structure and four corner groove structure, can stably fit the electromagnetic detection probe with the nuclear engineering equipment, thereby achieving accurate acquisition of the magnetic field signal of the weld to be tested.

[0044] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0045] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0046] Figure 1 A flowchart of an electromagnetic detection method for determining weld defects in nuclear engineering equipment according to an embodiment is presented;

[0047] Figure 2(a) shows a top view of a standard test block according to a specific embodiment;

[0048] Figure 2(b) shows a front view of a standard test block according to a specific embodiment;

[0049] Figure 2(c) shows a side view of a standard test block according to a specific embodiment;

[0050] Figure 3 A characteristic signal diagram of the Bx signal after its base value is reduced to zero is shown in an embodiment.

[0051] Figure 4 A flowchart for determining the first Bx signal of the weld under test is presented in one embodiment.

[0052] Figure 5 A characteristic signal diagram of a defect detection Bx signal interface according to an embodiment is presented;

[0053] Figure 6 A characteristic signal diagram generated by the extraction in one embodiment is shown;

[0054] Figure 7 A characteristic signal diagram generated by jitter in one embodiment is shown;

[0055] Figure 8 A characteristic signal diagram generated by edge effects in one embodiment is presented;

[0056] Figure 9 A diagram of characteristic signals generated when the chassis is not powered on is shown according to an embodiment;

[0057] Figure 10 A characteristic signal diagram of a chassis suddenly losing power is shown in an embodiment;

[0058] Figure 11 A flowchart of another embodiment of an electromagnetic detection method for determining weld defects in nuclear engineering equipment is presented;

[0059] Figure 12 A feature signal diagram of a defect location verification detection following an embodiment is presented;

[0060] Figure 13 A feature signal diagram showing the absence of the Bz signal in one embodiment is presented;

[0061] Figure 14 A feature signal diagram of missing butterfly pattern in one embodiment is presented;

[0062] Figure 15 A characteristic signal diagram generated by the surface undulations of a weld seam is shown in one embodiment;

[0063] Figure 16 A feature signal diagram generated by the bite edge in one embodiment is shown;

[0064] Figure 17 A characteristic signal diagram of weld beads generated by an embodiment is presented;

[0065] Figure 18 A flowchart of an electromagnetic detection method for determining weld defects in nuclear engineering equipment, according to a specific embodiment, is presented;

[0066] Figure 19 An exploded view of an electromagnetic field detection probe according to one embodiment is shown;

[0067] Figure 20 A structural diagram of the bottom of the electromagnetic detection probe housing according to an embodiment is shown;

[0068] Figure 21 A structural diagram of the top of the electromagnetic detection probe housing according to one embodiment is shown;

[0069] Figure 22 A structural diagram of an embodiment of an electromagnetic detection probe cover is shown;

[0070] Figure 23 A structural diagram of the interior of the electromagnetic detection probe housing according to an embodiment is shown.

[0071] Figure descriptions: 10. Probe housing; 101. Support leg; 102. Through groove; 103. Four-corner groove; 104. Long groove; 105. Connecting groove; 20. Magnetic field sensor; 30. Magnetic core; 40. Excitation coil; 50. Signal processing circuit; 60. Probe cover; 601. Connecting protrusion; 602. Connector hole; 70. Nut; 80. Washer; 90. Connector. Detailed Implementation

[0072] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0073] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0074] The following describes, with reference to the accompanying drawings, a flowchart of an electromagnetic detection method and system for determining weld defects in nuclear engineering equipment, according to embodiments of this application.

[0075] Figure 1 This is a flowchart of an electromagnetic detection method for determining weld defects in nuclear engineering equipment according to an embodiment of this application, as follows: Figure 1 As shown, the method includes the following steps:

[0076] Step S1: Detect the defect-free area of ​​the standard test block to obtain the reference Bx signal, and use the reference Bx signal to reset the signal base value to zero.

[0077] Among them, standard test blocks refer to test blocks that have the same material type, specifications, welding method, and automation level as the equipment under test, such as... Figures 2(a)-2(c) The image shows a standard test block in a specific embodiment.

[0078] Specifically, in the defect-free area of ​​the standard test block, 8-12 reference Bx signals are collected and averaged to reset the signal base value to zero.

[0079] In one embodiment, the characteristic signals of the alternating electromagnetic field include a Bx signal, a Bz signal, and a butterfly diagram. Generally, the direction parallel to the scanning direction is defined as the X direction, the direction perpendicular to the scanning direction and parallel to the surface of the device under test (DUT) is defined as the Y direction, and the direction perpendicular to the surface of the DUT is defined as the Z direction. Further, the Bx signal is defined as the magnetic field component in the X direction, which is proportional to the current density in the Y direction on the surface of the DUT; the Bz signal is defined as the magnetic field component in the Z direction, which is positively proportional to the current deflection curvature of the XY plane; the butterfly diagram is defined as the XY plane diagram of the Bx and Bz signals, where the X-axis represents the Bz signal and the Y-axis represents the Bx signal.

[0080] Among them, the Bz signal has high sensitivity only for cracks and large circular holes, while the Bx signal has high detection sensitivity for both circular holes and cracks. Therefore, choosing the Bx signal can provide more comprehensive and accurate data support for subsequent electromagnetic signal processing and defect judgment.

[0081] Furthermore, for AC electromagnetic field detection technology, the magnetic field signal acquired by the Bx signal consists of both the base magnetic field and the perturbation magnetic field caused by defects. For example... Figure 3 As shown, by collecting the first 10 magnetic field signals in the defect-free area of ​​the standard test block weld and subtracting the average of the first 10 data from the data collected later, the Bx signal generated by the base magnetic field can be eliminated, the Bx signal can be reduced to zero, and the Bx signal generated by the perturbed magnetic field can be obtained. At the same time, taking the average value can further reduce the error.

[0082] Through the above process, the magnetic field signal generated by the base magnetic field can be obtained comprehensively, conveniently and accurately, thereby realizing the signal base value to zero and providing accurate data support for subsequent defect judgment.

[0083] Step S2: Detect the specified defect area of ​​the standard test block and determine the threshold line based on the Bx signal in the specified defect area.

[0084] Specifically, the interface of the Bx signal is defined, and two threshold lines symmetrical to the zero value are set on the interface, such that the threshold corresponding to the two threshold lines is 'a', and the larger absolute value of the maximum or minimum value of the Bx signal in the defect area is 'b'. 'a' and 'b' should satisfy the following relationship: 80% ≤ a / b ≤ 100%. Meanwhile, the distance between the threshold lines is 30-40% of the interface height.

[0085] In one embodiment, the threshold range can be set by setting a / b = 100%, thereby enabling the matching of the larger absolute value of the maximum or minimum value of the Bx signal in the defect area of ​​the standard test block.

[0086] In one specific embodiment, firstly, the distortion of the Bx signal for a specified defect in the standard test block is obtained. The specified defect refers to the defect type and size, pre-defined based on past data and personnel experience. Then, the Bx signal interface is defined within a certain range, ensuring that the height of the maximum distortion on the side of the Bx signal deviating from zero amplitude is not less than 15% of the height of the Bx signal interface. Two threshold lines are symmetrically set above and below the zero amplitude, and the height of the area enclosed by these two threshold lines accounts for 30% of the height of the Bx signal interface.

[0087] In the above process, after the Bx signal generated by the base magnetic field is zeroed in step S1, the distortion of the Bx signal caused by the defect can be displayed more intuitively by defining the interface and setting the threshold line. This allows the staff to identify the defect more clearly, quickly, conveniently and accurately. In addition, setting the distance between the threshold lines to the height of the interface to be no less than 30% can effectively ensure that no defect is missed.

[0088] Step S3: Inspect the weld to be tested to obtain the first Bx signal. If the first Bx signal does not exceed the threshold line, the weld to be tested is judged to be qualified and the test ends. If the first Bx signal exceeds the threshold line, mark the position of the first Bx signal exceeding the threshold line on the weld to be tested as the suspected defect position and proceed to step S4.

[0089] In one embodiment, such as Figure 4 As shown, step S3 specifically includes the following steps:

[0090] Step S3-1: If the nuclear engineering equipment includes two or more welds to be tested, all welds to be tested are tested separately to obtain pre-inspection Bx signals sequentially. If the pre-inspection Bx signal of one or more welds to be tested does not exceed the threshold line, the corresponding weld to be tested is deemed qualified. If the pre-inspection Bx signal of one or more welds to be tested exceeds the threshold line, proceed to step S3-2.

[0091] Step S3-2: Re-inspect one or more welds under test whose pre-inspection Bx signal exceeds the threshold line to obtain the first Bx signal. Mark the position of the first Bx signal that exceeds the threshold line on the weld under test as the suspected defect position, and proceed to step S4.

[0092] In one embodiment, after the standard test block is calibrated, each segment of the intermittent weld of the nuclear engineering equipment is tested sequentially, and the test data and results for each segment are saved. If the Bx signal distortion of the entire segment does not exceed the threshold line, the weld is deemed qualified. When the Bx signal distortion exceeds the threshold line, the following occurs: Figure 5The characteristic signal map shown is scanned at a constant speed until the segmented detection is completed. Then, the next step of judgment is performed, including: keeping the AC electromagnetic field detection parameters unchanged, and precisely scanning the segment where the suspected signal (i.e., the first Bx signal) appears at the same speed and in the same scanning direction. When the suspected defect signal (i.e., the second Bx signal) appears again, the probe scanning is stopped and the suspected defect location is marked.

[0093] Since manually determining the defect location when an abnormal signal occurs can introduce errors, the above process involves inspecting the weld to be tested and performing a detailed scan on any suspected signals to calibrate the defect locations where suspected signals reappear for subsequent verification testing. This avoids directly deeming the weld to be unqualified due to operational errors or other issues that cause the weld to exceed the threshold line. Furthermore, adding a certain distance before and after the scan helps prevent missed detections, effectively reducing the probability of false positives and making the test results more reliable. This also helps in further determining the defect location, condition, and type, providing data analysis support for solving welding operation problems and improving welding technology.

[0094] Step S4: Re-inspect the weld to be tested with the suspected defect location as the midpoint and a width of 15-25mm before and after it to obtain the second Bx signal. If the obtained second Bx signal is a false signal, the weld to be tested is judged to be qualified and the test ends.

[0095] In one embodiment, the weld area is scanned with the suspected defect as the center line, extending 20mm before and after it to verify the defect's location. If the signal is a false signal during verification, the weld area is deemed acceptable.

[0096] Among them, such as Figures 6-10 As shown, the spurious signals include characteristic signals where the distortion of the Bx signal exceeds the threshold line due to non-tested weld quality issues such as lift-off, jitter, and edge effects, as well as abnormal characteristic signals caused by the chassis not being powered on or the chassis suddenly losing power.

[0097] The above process, by verifying the defect location, can distinguish between spurious signals and defect signals, effectively reducing the probability of missed or false detections and making the detection results more reliable.

[0098] In another embodiment, such as Figure 11 As shown, if the second Bx signal obtained in step S4 is not a spurious signal, the following steps are also included:

[0099] Step S5: If the second Bx signal, the second Bz signal, and the second butterfly pattern are all complete, the weld to be tested is determined to be unqualified and the test ends; otherwise, proceed to step S6.

[0100] In one embodiment, if the weld area is scanned by 20mm before and after step S4, the result is as follows: Figure 12 If the second Bx signal, the second Bz signal, and the second butterfly pattern are all complete in the characteristic signal diagram shown, then the weld to be tested is judged as unqualified and the test ends.

[0101] Step S6: If the second Bz signal or the second butterfly pattern is incomplete, and the second Bx signal does not exceed the threshold line, the weld to be tested is determined to be qualified and the test ends; otherwise, proceed to step S7.

[0102] In one specific embodiment, such as Figure 13 The image shows a feature signal diagram of the missing Bz signal, as shown below. Figure 14 The image shown is a feature signal diagram of the missing part of the butterfly diagram.

[0103] Step S7: If the second Bx signal is an uncorrelated signal, record the type of the uncorrelated signal and end the detection; otherwise, proceed to step S8.

[0104] In one embodiment, such as Figures 15-17 As shown, the uncorrelated signal refers to the characteristic signal where the distortion of the Bx signal exceeds the threshold line due to problems such as surface undulations, undercut, and weld beads in the inspected weld.

[0105] Step S8: If the second Bx signal is not an irrelevant signal, the weld to be tested is judged as unqualified and the test ends.

[0106] The above process, based on the verification of characteristic signals, adds a judgment process when individual signals in the characteristic signals are incomplete, which effectively reduces the probability of missed detection and false detection, making the detection results more reliable. It also realizes the differentiation of spurious signals, irrelevant signals and defect signals, and provides data analysis support for solving welding operation problems and improving welding technology.

[0107] It is worth noting that the welds of nuclear engineering equipment can be the welds of the lifting lugs of nuclear engineering containers.

[0108] By applying the above-described technical solution of this application, at least the following technical effects are achieved:

[0109] 1. This electromagnetic detection method, by setting a threshold line, makes it easy to observe whether the height of the maximum distortion of the Bx signal on the side deviating from zero amplitude reaches the height of the threshold line, thereby enabling more convenient, faster, more accurate and more efficient acquisition of detection results.

[0110] 2. This electromagnetic detection method, by zeroing the signal baseline value, can comprehensively, conveniently, and accurately acquire the magnetic field signal generated by the base magnetic field, thereby achieving zeroing the signal baseline value and providing accurate data support for subsequent defect judgment.

[0111] 3. Based on segmented detection of suspected signals, this electromagnetic detection method adds a step of calibrating and re-checking the defect location where suspected signals reappear. This avoids judging weld defects as unqualified when they exceed the threshold line due to detection operation errors, and can distinguish between false signals and defect signals, thereby effectively reducing the probability of missed detections and false detections, making the detection results more reliable.

[0112] 4. Based on the verification of characteristic signals, this electromagnetic detection method adds a judgment process when individual signals in the characteristic signals are incomplete, which effectively reduces the probability of missed detection and false detection, making the detection results more reliable. It can also distinguish between spurious signals, irrelevant signals and defect signals, thereby realizing the accurate detection of defects such as porosity, slag inclusion and cracks on the surface of welds of nuclear engineering equipment.

[0113] 6. Compared with magnetic particle testing, this electromagnetic testing method eliminates the need for magnetizing the test piece and applying magnetic powder, making the testing operation simpler.

[0114] 7. Compared with conventional penetrant testing technology, this electromagnetic testing method can detect internal defects in carbon steel welds, thus achieving higher testing accuracy.

[0115] 8. Compared with X-ray detection technology, this electromagnetic detection method is radiation-free and does not require a dedicated time window, thus making the detection efficiency higher.

[0116] In one specific embodiment, such as Figures 2(a)-2(c) As shown, a standard test block containing 2mm and 1mm diameter circular hole defects in the weld is used as an example, and the minimum defect alarm size is set to 1mm diameter circular hole defects.

[0117] like Figure 18 As shown, the specific steps include:

[0118] Step S101: Calibrate the standard test block.

[0119] Specifically, the standard test block is first calibrated. The AC electromagnetic field detection probe is placed in the defect-free area of ​​the weld of the standard test block, and the first ten data points are collected. The average of the first ten data points is then subtracted from each subsequent data point to achieve zeroing of the Bx signal base value. The characteristic signal is as follows: Figure 3 As shown.

[0120] Step S102: Set the threshold line.

[0121] Specifically, the alternating current electromagnetic field detection probe is scanned uniformly along the weld of the standard test block to obtain the distortion amount of the Bx signal of the 1-mm diameter circular hole defect in the standard test block. By framing the Bx signal interface within the range of -50 to +50, the height of the maximum distortion amount of the Bx signal on one side deviating from the zero amplitude is not less than 15% of the height of the Bx signal interface, and two threshold lines are symmetrically set above and below the zero amplitude, and the height of the area sandwiched by these two threshold lines accounts for 30% of the height of the Bx signal interface.

[0122] Step S103, segmented detection.

[0123] Specifically, after the calibration of the standard test block is completed, the detection of each segment is sequentially completed according to the intermittent weld of the lifting lug. If the distortion amount of the Bx signal in the entire segmented detection does not exceed the threshold line, the weld is determined to be qualified. When the distortion amount of the Bx signal exceeds the threshold line, continue the uniform scan until the detection of the segment is completed, as Figure 5 shown, and then proceed to the next determination.

[0124] Step S104, precise scan.

[0125] Specifically, while keeping the alternating current electromagnetic field detection parameters unchanged, precisely scan the segment with suspected signals at the same speed and in the same scanning direction. When a suspected defect signal appears again, stop the scan of the probe and mark the position of the suspected defect.

[0126] Step S105, recheck detection.

[0127] Specifically, with the suspected defect as the midline, scan the weld area 20 mm forward and backward respectively to recheck the position of the defect. If the signal during recheck is a false signal, as Figures 6-10 shown, then the weld area is determined to be qualified. If a complete Bx signal, Bz signal, and butterfly diagram appear during the recheck process and the positions are the same, as Figure 12 shown, then the weld area is determined to be unqualified.

[0128] Step S106, determine non-related signals.

[0129] Specifically, if the situation of the absence of the Bz signal or butterfly diagram appears in the recheck detection signal, as Figure 13 and Figure 14 shown, first observe whether the distortion amount of the Bx signal exceeds the threshold line. If it does not exceed, then the weld area is determined to be qualified. If it exceeds, check whether it is a non-related signal. If it is not a non-related signal, then the weld area is determined to be unqualified. If it is a non-related signal, as Figures 15-17 shown, then record the type of the non-related signal.

[0130] Through the above specific embodiments, detection results can be obtained more conveniently, quickly, accurately, and efficiently. Furthermore, it is possible to distinguish between spurious signals, irrelevant signals, and defect signals, thereby achieving accurate detection of defects such as porosity, slag inclusions, and cracks on the surface of welds in nuclear engineering equipment. This provides data analysis support for solving welding operation problems and improving welding technology, thus ensuring the safe and stable operation of nuclear engineering equipment.

[0131] To implement the above embodiments, this application also proposes an electromagnetic detection system for judging weld defects in nuclear engineering equipment, including a host computer and an electromagnetic detection probe. The electromagnetic detection probe is used to detect the weld to be tested, and the host computer is used to control the electromagnetic detection probe and display data.

[0132] In this embodiment, as Figure 19 and Figure 20 As shown, the electromagnetic detection probe includes a probe housing 10, a magnetic field sensor 20, a probe cover 60, and a connector 90. The probe housing 10 includes a support leg 101 and a through slot 102. The bottom of the support leg 101 has an arc-shaped structure that matches the curvature of the nuclear engineering vessel, allowing the electromagnetic probe to be fitted to the weld to be tested during inspection, thus achieving accurate detection of the weld. Furthermore, the magnetic field sensor 20 is located in the through slot 102 and is used to quickly acquire and transmit the magnetic field signal at the weld to be tested. Additionally, the probe cover 60 is detachably connected to the top of the probe housing 10, and the connector 90 is detachably connected to the top of the probe cover 60, thereby enabling flexible installation and removal of the components.

[0133] Furthermore, in this embodiment, as Figure 21 and Figure 22 As shown, the top of the probe housing 10 has connecting grooves 105 on both sides perpendicular to the direction of travel of the electromagnetic detection probe, and the bottom of the probe cover 60 has connecting protrusions 601. The connecting grooves 105 and the connecting protrusions 601 cooperate to realize the detachable connection between the probe cover 60 and the probe housing 10.

[0134] Furthermore, in this embodiment, as Figure 23 As shown, the electromagnetic detection probe also includes a magnetic core 30 and an excitation coil 40. Furthermore, the probe housing 10 has an elongated groove 104 and four corner grooves 103 inside, with the corner grooves 103 adjacent to both the elongated groove 104 and the through groove 102. The magnetic core 30 is disposed in the elongated groove 104, and the excitation coil 40 is wound around the magnetic core 30 and located in the corner grooves 103. This allows the electromagnetic detection probe to be securely attached to nuclear engineering equipment, thereby achieving accurate acquisition of the magnetic field signal of the weld to be tested.

[0135] Furthermore, such as Figure 19As shown, the electromagnetic detection probe also includes a signal processing circuit 50, which is disposed in the probe housing 10.

[0136] Furthermore, such as Figure 19 As shown, the electromagnetic detection probe also includes a nut 70 and a washer 80, and the connector 90 is detachably connected to the probe cover 60 via the nut 70 and the washer 80. Wherein, as Figure 22 As shown, the probe cover 60 is also provided with a connector hole 602 in the middle, and the connector hole 602 is fixed on the probe cover 60. Thus, the connector 90 can be connected to the probe cover 60 through the nut 70, washer 80, and connector hole 602.

[0137] By applying the above-described technical solution of this application, at least the following technical effects are achieved:

[0138] 1. Compared with magnetic particle testing, this electromagnetic testing system eliminates the need for magnetizing the test piece and applying magnetic powder, making the testing operation simpler.

[0139] 2. Compared with conventional penetrant testing technology, this electromagnetic testing system can detect internal defects in carbon steel welds, thus achieving higher testing accuracy.

[0140] 3. Compared with X-ray detection technology, this electromagnetic detection system is radiation-free and does not require a dedicated time window, thus making the detection efficiency higher.

[0141] 4. By adapting the arc structure of the electromagnetic detection probe to the curvature of the nuclear engineering container under test, this electromagnetic detection system can further fit the electromagnetic probe to the weld under test during the test, thereby achieving accurate detection of the weld under test.

[0142] 5. This electromagnetic detection system, by setting up an electromagnetic detection probe and using a combination of long groove structure and four corner groove structure, can stably fit the electromagnetic detection probe with the nuclear engineering equipment, thereby achieving accurate acquisition of the magnetic field signal of the weld to be tested.

[0143] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0144] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. An electromagnetic detection method for judging weld defects in nuclear engineering equipment, characterized in that, include: Step S1: Detect the defect-free area of ​​the standard test block to obtain the reference Bx signal, and use the reference Bx signal to reset the signal base value to zero; Step S2: Detect the designated defect area of ​​the standard test block and determine the threshold line based on the Bx signal in the designated defect area; Step S3: Inspect the weld to be tested to obtain the first Bx signal. If the first Bx signal does not exceed the threshold line, the weld to be tested is judged to be qualified and the test ends. If the first Bx signal exceeds the threshold line, mark the position of the first Bx signal exceeding the threshold line on the weld to be tested as the suspected defect position and proceed to step S4. Step S4: Re-inspect the weld to be tested with the suspected defect location as the midpoint and a width of 15-25mm before and after it to obtain the second Bx signal. If the obtained second Bx signal is a false signal, the weld to be tested is judged to be qualified and the test ends. In step S4, a second Bz signal and a second butterfly pattern are also obtained. If the second Bx signal obtained in step S4 is not a pseudo signal, then proceed to step S5. Step S5: If the second Bx signal, the second Bz signal, and the second butterfly pattern are all complete, the weld to be tested is determined to be unqualified and the test ends; otherwise, proceed to step S6. Step S6: If the second Bz signal or the second butterfly pattern is incomplete, and the second Bx signal does not exceed the threshold line, the weld to be tested is determined to be qualified and the test ends; otherwise, proceed to step S7. Step S7: If the second Bx signal is an uncorrelated signal, record the type of the uncorrelated signal and end the detection; otherwise, proceed to step S8. Step S8: If the second Bx signal is not an irrelevant signal, the weld to be tested is determined to be unqualified and the test ends.

2. The method according to claim 1, characterized in that, The standard test block is made using the same materials and welding methods as the nuclear engineering equipment.

3. The method according to claim 2, characterized in that, In step S1, In the defect-free area, 8-12 reference Bx signals are collected and averaged to reset the signal base value to zero.

4. The method according to claim 3, characterized in that, In step S2, Define the interface for the Bx signal, and set two threshold lines symmetrical to the zero value on the interface, such that the threshold corresponding to the two threshold lines is 'a', and the larger absolute value of the maximum or minimum value of the Bx signal in the defect area is 'b', wherein 'a' and 'b' satisfy the following relationship: 80%≤a / b≤100%; The distance between the threshold lines is 30-40% of the interface height.

5. The method according to claim 3, characterized in that, Step S3 includes steps S3-1 and S3-2. Step S3-1: The nuclear engineering equipment includes two or more welds to be tested. All welds to be tested are tested separately to obtain a pre-inspection Bx signal. If the pre-inspection Bx signal of one or more welds to be tested does not exceed the threshold line, the corresponding weld to be tested is determined to be qualified; if the pre-inspection Bx signal of one or more welds to be tested exceeds the threshold line, then proceed to step S3-2. Step S3-2: Re-inspect one or more of the welds to be tested whose pre-inspection Bx signals exceed the threshold line to obtain a first Bx signal. Mark the position of the first Bx signal that exceeds the threshold line on the weld to be tested as a suspected defect position, and proceed to step S4.

6. The method according to any one of claims 1-4, characterized in that, The welds of the nuclear engineering equipment are the welds of the lifting lugs of the nuclear engineering container.

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