An apparatus and method for ultrasonic testing of butt welds

Abstract

This invention relates to the field of ultrasonic non-destructive testing technology for butt welds in special equipment, and particularly to an ultrasonic testing device and method for butt welds. The invention proposes an ultrasonic testing device and method for butt welds, comprising selecting a dual-channel phased array detector, connecting phased array linear probes with multiple array elements symmetrically distributed on both sides of the weld, the phased array linear probes being mounted on a probe holder, and each phased array linear probe being connected to a transverse wave wedge. This invention can realize multiple testing modes, including TOFD non-parallel D-scan, TOFD offset non-parallel D-scan, TOFD parallel B-scan, and phased array sector scanning. It aims to solve the technical problems of low testing efficiency and the need for multiple replacements of testing devices in existing ultrasonic testing of butt welds.

Description

Technical Field

[0001] This invention relates to the technical field of ultrasonic non-destructive testing of butt welds in special equipment, and particularly to an ultrasonic testing device and method for butt welds. Background Technology

[0002] Ultrasonic nondestructive testing (NDT) is an essential technology for the NDT of butt welds in the field of special equipment, and the accuracy and reliability of its test results are directly related to the safe operation of the equipment. Currently, there are specific standards in China, such as the NB / T47013 series, which clearly stipulate that ultrasonic phased array testing and time-of-flight ultrasonic diffraction (TOFD) can be used as periodic inspection methods for pressure-bearing equipment. In practical applications, ultrasonic phased array shear wave fan-shaped scanning, due to its flexible beam deflection and focusing capabilities, can effectively cover the weld cross-section and is the most widely used method. Meanwhile, TOFD technology, with its high accuracy in measuring defect height and high sensitivity to area-type defects, has also become a routine method for butt weld inspection.

[0003] The conventional inspection process typically involves the operator first using a pair of TOFD probes for non-parallel TOFD scanning to determine the presence and location of defects along the weld. Then, a single phased array probe is used for independent scanning, acquiring a sector-shaped image of the weld to determine the defect type, orientation, and equivalent size. Finally, the inspector manually compares and cross-references the images obtained from the two methods for comprehensive defect analysis. The drawbacks of this approach are: low inspection efficiency (requiring two or more scans with different instruments and probes, a cumbersome and time-consuming process); difficulty in ensuring complete consistency of probe paths between the two scans, introducing errors into subsequent image comparison and defect localization; and potential differences in coupling states between the two scans, affecting image consistency and comparability.

[0004] To improve efficiency, some invention patents have proposed improved solutions, using the same scanning frame to simultaneously clamp phased array probes and TOFD probes or single crystal straight probes for one-time scanning, thereby simultaneously acquiring multiple detection results. Although this greatly improves detection efficiency, it also has inherent drawbacks. Because two different types of probes need to be installed at the same time, the scanning frame becomes bulky, has poor adaptability to complex structures, and the probe clamping and debugging process is cumbersome.

[0005] Therefore, it is necessary to propose an ultrasonic testing device and method for butt welds that integrates phased array sector scanning and TOFD detection modes. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an ultrasonic testing device and method for butt welds, which aims to solve the technical problem of needing to replace the testing device multiple times in the prior art.

[0007] To achieve the above objectives, in a first aspect, the present invention proposes an ultrasonic testing method for butt welds, comprising the following steps:

[0008] S1. Select a dual-channel phased array ultrasonic testing instrument and connect it to a phased array linear probe with multiple array elements symmetrically distributed on both sides of the weld. The phased array linear probe is set on the probe frame, and each phased array linear probe is connected to a transverse wave wedge.

[0009] S2, TOFD non-parallel D-scan; Configure TOFD non-parallel D-scan detection parameters, set the probes as transmitting and receiving probes respectively, determine the transmitting element sequence and receiving element sequence to be excited, and calculate the transmitting and receiving delays; Keep the probe holder perpendicular to the weld axis, and realize the TOFD non-parallel D-scan by manually controlling the probe holder to move forward;

[0010] S3, TOFD offset non-parallel D scan; Keeping the parameters of step S2 unchanged, rotate the probe holder to form a certain angle with the weld axis, and manually control the probe holder to move forward to achieve TOFD offset non-parallel D scan;

[0011] S4, TOFD parallel B-scan; Based on S2 and S3, locate the defect, preliminarily assess the defect depth and location, determine the sequence of transmitting and receiving elements to be excited, and calculate the transmission and reception delays. The TOFD parallel B-scan is achieved by manually controlling the probe frame to move forward.

[0012] S5. Phased array sector scan: Configure phased array sector scan detection parameters, control the left and right probes to work in self-transmitting and self-receiving mode respectively, and realize shear wave sector scan within the set angle range.

[0013] Preferably, in step S2, the TOFD non-parallel D-scan detection parameters are configured based on the wall thickness and sound velocity of the material under test; the transmitting and receiving element sequences to be excited are determined, and the transmitting and receiving delays are calculated based on the set longitudinal wave incident angle and simulated TOFD probe parameters; the array elements of the transmitting and receiving probes adopt a symmetrical array element sequence to achieve the same symmetrical detection mode as TOFD detection. Preferably, in step S4, the array elements of the transmitting and receiving probes adopt an asymmetrical array element sequence. During the detection process, the probe position remains unchanged, the depth of the sound beam intersection point remains unchanged, and the lateral position shifts according to the change of the activated array element sequence to achieve the same parallel detection mode as the synchronous translation of the probe in TOFD parallel detection.

[0014] Preferably, in step S5, phased array sector scanning detection parameters are configured according to the wall thickness and sound velocity of the material being inspected; the angle range is set to 30°-70°; after shear wave sector scanning, left sector scan image and right sector scan image are obtained respectively, and comprehensive analysis is performed through data fusion algorithm, which is the superposition of amplitudes in repeated regions.

[0015] Preferably, in the TOFD non-parallel D-scan mode of S2, the transmitting and receiving probes use the same delay parameters. This is achieved by ensuring the longitudinal wave incident angle in the wedge is less than the first critical angle, exciting longitudinal waves in the material for TOFD detection, and utilizing the delay control function of the phased array probe to apply a beam deflection θ to the selected m array elements. p By sequentially increasing the fixed delay Δt of adjacent array elements, the synthesized wavefront within the wedge forms an angle θ with the normal. p A plane longitudinal wave at an angle, with a relative delay of Δt between adjacent array elements. ,

[0016] In the formula, Let be the longitudinal wave velocity of the wedge; for m excitation array elements, the absolute delay of the i-th element is t. i， .

[0017] As a preferred embodiment, the depth d of the defect diffraction point in S2 is... Where T is the arrival time of the diffracted wave emitted from the diffraction endpoint. Let be the longitudinal wave velocity in the material; based on the arrival time difference T2-T1 of the diffracted waves at the lower and upper ends of the defect, the height H of the defect itself is initially estimated as H=d2-d1, where d2 is the depth of the lower end of the defect and d1 is the depth of the upper end of the defect; for strip defects, parabolic cursor fitting is used, and the left end arc of the defect is fitted with the cursor to obtain the lateral coordinate y1, and the right end arc is fitted with the cursor to obtain the lateral coordinate y2. The length of the defect along the weld axis is y2-y1.

[0018] Preferably, the data fusion method for the left and right sector scan images is as follows: the two sector scan images are represented as amplitude functions I1(r,θ) and I2(r,θ) in polar coordinates, respectively, where r is the radial distance and θ is the angle. Linear pixel amplitude fusion is then performed on the two images in polar coordinates, and the amplitude of the fused image is I... f (r,θ) is

[0019] I f (r,θ)=αI1(r,θ)+(1-α)I2(r,θ), where α is the linear fusion weight, satisfying 0≤α≤1.

[0020] To achieve the above objectives, in a second aspect, the present invention proposes an ultrasonic testing device for butt welds, used in the ultrasonic testing method for butt welds of the first aspect. The device includes a dual-channel phased array ultrasonic testing instrument, a probe frame spanning above the butt weld of the material under test, a pair of phased array linear probes with identical parameters symmetrically clamped and mounted on the probe frame, the phased array linear probes being electrically connected to the ultrasonic testing instrument via probe cables, the phased array elements of the phased array linear probes enabling selective excitation and reception, the probes being fastened to a shear wave wedge by bolts, the lower plane of the shear wave wedge being tightly fitted to the upper surface of the material under test, and symmetrically arranged along the central axis of the butt weld.

[0021] Preferably, the transverse wave wedge is made of Rexolite polystyrene, and the transverse wave refraction angle of the wedge is 50°; the probe holder is rotatable.

[0022] To achieve the above objectives, in a third aspect, the present invention provides a storage medium comprising a stored program, wherein, when the program is executed, the device on which the storage medium is located executes the ultrasonic testing method for butt welds described in the first aspect.

[0023] To achieve the above objectives, in a fourth aspect, the present invention provides a processor for running a program, wherein the program executes the ultrasonic testing method for butt welds described in the first aspect.

[0024] Compared with the prior art, the beneficial effects of the ultrasonic testing device and method for butt welds provided by the present invention are as follows:

[0025] 1. This invention employs a dual-channel phased array ultrasonic testing instrument, two phased array linear array probes, and a matching probe holder to perform integrated testing of butt welds. The phased array linear array probes combine bidirectional sector scanning with TOFD (Transmission and Detection of Difference) transmission and reception functions. The dual-channel phased array ultrasonic testing instrument integrates both phased array sector scanning and TOFD testing functions, eliminating the need to replace probes and testing equipment when switching between the two testing methods. This effectively simplifies the testing process, shortens testing time, and avoids testing errors caused by probe or equipment replacement, thus improving the convenience and stability of the testing operation.

[0026] 2. This invention employs phased array linear probes deployed on both sides of the weld to perform a fan-shaped scan. After acquiring the detection data from both scans, a data fusion algorithm is used to comprehensively analyze and cross-verify the two sets of data to determine the weld damage. Compared to single-sided fan-shaped scanning, this method has the following advantages: it effectively avoids the problem of missed damage due to weld structure obstruction and detection angle during single-sided scanning, improving the accuracy of damage localization; simultaneously, the mutual verification of the two sets of data reduces systematic errors in a single detection direction, improves the accuracy of damage quantification assessment, and ensures the reliability and comprehensiveness of the detection results.

[0027] 3. This invention simulates the transmission and reception functions of a single-crystal probe in traditional TOFD testing by exciting only a portion of the array elements of a phased array linear probe. Combined with a transverse wave wedge, and through precise adjustment of the excitation delay of the activated array elements, refracted longitudinal waves at different angles are designed and excited within the test block according to the testing requirements, achieving non-parallel TOFD scanning. Compared to traditional single-crystal probe TOFD non-parallel scanning, this method eliminates the need for probe replacement or removal. The angle of the refracted longitudinal wave can be flexibly adjusted by regulating the array element excitation delay, adapting to the testing needs of welds of different thicknesses and structures. It offers greater versatility, eliminates the need for frequent adjustments to the probe installation angle, and improves the consistency and repeatability of the testing operation.

[0028] 4. This invention employs asymmetric activation of two phased array linear probe elements, utilizing the linear scanning function of an ultrasonic testing instrument to perform horizontal scanning at specific depths in the weld, achieving parallel TOFD scanning and overcoming the limitation of weld reinforcement height. Compared to traditional single-crystal probe TOFD parallel detection, this method eliminates the need for physical movement of the probe assembly, offers higher scanning accuracy than manual methods, and allows for precise control of the scanning step distance and range, improving the accuracy of defect detection in specific depth areas of the weld.

[0029] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the detection device of the present invention.

[0031] Figure 2 This is a flowchart of the detection method of the present invention.

[0032] Figure 3 This is a schematic diagram of the sound field principle for the non-parallel scanning mode of TOFD.

[0033] Figure 4 The simulation setup diagram for TOFD non-parallel scan mode.

[0034] Figure 5 This is a D-scan imaging image from a TOFD non-parallel scanning mode.

[0035] Figure 6 Simulation setup diagram for TOFD bias non-parallel scan mode.

[0036] Figure 7 This is a D-scan imaging image of the TOFD bias non-parallel scanning mode.

[0037] Figure 8 This is a schematic diagram of the sound field principle in TOFD parallel scan mode.

[0038] Figure 9This diagram shows the simulation settings for the TOFD parallel scan mode.

[0039] Figure 10 This is a B-scan image from a TOFD parallel scan mode.

[0040] Figure 11 This is a schematic diagram of the dual-sided phased array sector scanning principle.

[0041] Figure 12 This diagram shows the setup for a dual-phased array sector scan simulation.

[0042] Figure 13 This is a data fusion diagram of the results from a dual-phased array sector scan.

[0043] In the diagram: 1. Dual-channel phased array ultrasonic testing instrument; 2. Probe mount; 3. Phased array linear probe; 4. Phased array element; 5. Shear wave wedge; 6. Material under inspection; 7. Butt weld; 8. Transmitting element; 9. Receiving element; 10. Transmission delay; 11. Receiving delay; 12. Plane longitudinal wave deflected in the wedge; 13. Longitudinal wave refracted in the material under inspection; 14. Shear wave refracted in the material under inspection; 15. Bottom crack; 16. Diffraction wave at the crack tip; 17. Transmitting element before parallel B-scan; 18. Transmission delay before parallel B-scan; 19. Parallel B-scan 20. Receiver array element before inspection; 21. Receiver delay before parallel B scan; 22. Refracted longitudinal wave in the inspected material before parallel B scan; 23. Transmitter array element excited after linear scan; 24. Transmitter array element delay excited after linear scan; 25. Receiver array element delay excited after linear scan; 26. Refracted longitudinal wave in the inspected material excited after linear scan; 27. Internal non-fusion defect; 28. Planar longitudinal wave in the wedge; 29. ​​Refracted transverse wave in the inspected material; 30. Direct beam of sector scan; 31. First reflection of sector scan. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0045] See Figure 1This invention provides an ultrasonic testing device for butt welds, comprising a dual-channel phased array ultrasonic testing instrument 1 with both phased array and TOFD testing functions, and a probe holder 2 spanning above the butt weld 7 of the material under inspection 6. A pair of identical phased array linear probes 3 are symmetrically clamped and mounted on the probe holder. The phased array linear probes 3 are electrically connected to the dual-channel phased array ultrasonic testing instrument 1 via probe cables. The phased array elements 4 of the phased array linear probes 3 can achieve selective excitation and reception. The probes are fastened to shear wave wedges 5 with bolts. The lower plane of the shear wave wedges 5 is tightly fitted to the upper surface of the material under inspection 6 and is symmetrically arranged along the central axis of the butt weld 7. The dual-channel phased array ultrasonic testing instrument 1 has a phased array sector scanning mode for self-transmission and self-reception of the two probes, and a TOFD working mode for one-to-one transmission and one-to-reception of the two probes. The probe holder 2 is an adjustable structure used to adjust the symmetrical position of the two probes relative to the weld. The angle of the transverse wave wedge is selected according to the required range of the angle of the refracted transverse wave in the material being inspected (30°-70°). Preferably, a 50° transverse wave wedge is selected, and the wedge material is Rexolite polystyrene.

[0046] For specific testing using an ultrasonic testing device for butt welds, please refer to [link / reference]. Figure 2 The specific detection method includes the following steps:

[0047] S1. Select a dual-channel phased array ultrasonic testing instrument and connect it to a phased array linear probe with multiple array elements symmetrically distributed on both sides of the weld. The phased array linear probe is set on the probe holder, and each phased array linear probe is connected to a transverse wave wedge.

[0048] Specifically, the ultrasonic testing device for butt welds is installed, connected, and debugged. Before testing, the device is installed according to the connection relationship of the aforementioned device, and all wires and plugs are connected. Coupling agent is applied to the butt weld 7 to be inspected to ensure good coupling between the probe and the workpiece surface. The dual-channel phased array ultrasonic testing instrument 1 is started to complete the system self-test and parameter initialization.

[0049] S2, TOFD non-parallel D-scan; Configure TOFD non-parallel D-scan detection parameters, set the probes as transmitting and receiving probes respectively, determine the transmitting and receiving array element sequences to be excited, and calculate the transmitting and receiving delays; Keep the probe holder perpendicular to the weld axis, and realize TOFD non-parallel D-scan by manually controlling the probe holder to move forward.

[0050] Specifically, the dual-channel phased array ultrasonic detector 1 is set to TOFD detection mode (e.g., Figure 3The detection range is defined, and the scanning coding function of the dual-channel phased array ultrasonic testing instrument 1 is calibrated. Based on the wall thickness and longitudinal wave velocity of the material under test 6, as well as the number, spacing, and width of the phased array elements 4 of the phased array linear probe, the longitudinal wave refraction angle is calculated; the activation sequence of the transmitting array element group (composed of several transmitting array elements 8) and the receiving array element group (composed of several receiving array elements 9) is determined according to the refraction angle, and the transmission delay 10 and reception delay 11 of each array element are calculated according to the incident angle and the spatial position of the array element group; the corresponding array element is activated using the delay parameters, and the probe frame is manually pushed along the weld extension direction by the scanning device installed on the probe frame 2 to perform TOFD non-parallel D scanning (such as...). Figure 4 ), collected by receiving array element 9 (e.g. D scan data) Figure 5 ). Figure 5 In the D-scan pattern, the following can be displayed: a) a straight wave, b) a diffracted wave at the upper end of the defect, c) a diffracted wave at the lower end of the defect, d) a longitudinal wave reflected from the bottom surface, and e) a transverse wave converted from the bottom surface mode. Based on the longitudinal coordinates of the defect diffracted waves in the D-scan pattern, the distribution location and length of the defect along the weld direction are determined; the preliminary depth and height of the defect are estimated based on the arrival time of the diffracted waves. Since the lateral offset of the defect relative to the weld centerline cannot be determined, the depth and height are preliminary estimates.

[0051] The material being tested was a carbon steel specimen with butt welds, 40 mm thick, with a longitudinal wave velocity of 5900 m / s and a transverse wave velocity of 3230 m / s. Six rectangular defects were pre-fabricated within the specimen. Figure 3 The detected defect is a bottom crack (15). The defect extends along the weld axis and is designed to be evenly distributed longitudinally. It includes two surface opening defects, two buried defects, and two bottom opening defects. The length and height of the defects are both 5 mm, and they are distributed sequentially in the depth direction. Among them, the third defect is 3 mm off to the right of the weld center axis.

[0052] According to Table 3 of Clause 5.2.5 of standard NB / T 47013.10-2015 "Non-destructive Testing of Pressure Equipment Part 10: Ultrasonic Testing by Time-of-Flight Diffraction Method", the TOFD testing parameters in this embodiment are set as follows: number of thickness zones 1, nominal frequency 5MHz, refraction angle 60°, and crystal diameter 6mm. The probe center distance PCS is set according to the principle that the sound beam intersection is located at 2 / 3 of the detection depth range, and the calculated PCS = 92.4mm. Figure 3 In this context, p represents the center-to-center distance of the probe (PCS).

[0053] The parameters of the selected phased array linear array probe are as follows: number of array elements n=32 (even number), array element width e=0.55mm, array element gap g=0.05mm, array element length w=6mm, array element center spacing d=e+g=0.6mm, and total aperture length 19.15mm.

[0054] Rexolite polystyrene shear wave wedges are used, with a shear wave refraction angle of 50° in carbon steel, a longitudinal wave velocity of 2360 m / s, and a shear wave velocity of 1160 m / s.

[0055] The excitation signal is a Hanning window modulated sine wave with a center frequency of 5MHz, a -6dB relative bandwidth of 50%, and a sampling frequency of 160MHz.

[0056] The middle m array elements of the transmitting and receiving probes are selected as the transmitting array element group and the receiving array element group, respectively, so that the total length L of the active array elements is approximately equal to the crystal diameter D of the simulated TOFD probe.

[0057] L≈me+(m-1)g

[0058] At this point, the range of excitation array element numbers is determined by the following formula.

[0059] [n / 2-m / 2+1, n / 2+m / 2]

[0060] Substituting n=32 and D=L=6mm, we get m=10. Therefore, the final activation of the transmitting and receiving probes consists of 10 elements, numbered 12-21, with both probes symmetrically activated. The initial sequence is numbered starting from the thinner end of the wedge.

[0061] Without applying a time delay, the plane wave emitted by the array element is refracted at the wedge / material interface and then excites a 50° transverse wave in the material under test (corresponding to...). Figure 3 (14) The transverse wave refracted in the material under test. According to Snell's law, at this time, the incident angle in the wedge is between the first critical angle and the second critical angle, and a wave mode conversion occurs. The refracted longitudinal wave is totally reflected, and only the refracted transverse wave enters the material under test.

[0062] To generate a 60° longitudinal wave in the material for TOFD detection, the incident angle of the longitudinal wave in the wedge must be less than the first critical angle. Using the delay control function of the phased array probe, a beam deflection θ is applied to the selected m array elements. p By sequentially increasing the fixed delay Δt of adjacent array elements, the synthesized wavefront within the wedge forms an angle θ with the normal. p Plane longitudinal waves at an angle (corresponding to) Figure 3 The plane longitudinal wave deflected in the wedge (12). The relative delay Δt between adjacent array elements is calculated by the following formula.

[0063]

[0064] In the formula, Let be the longitudinal wave velocity of the wedge. For m excitation array elements, the absolute delay t of the i-th element is... i for

[0065] The aforementioned delay causes the longitudinal waves emitted by the m array elements to coherently superimpose within the wedge, forming a set angle θ. p The deflected synthetic sound beam, after refraction at the interface, generates longitudinal waves at a specific angle in the material under test (corresponding to...). Figure 3 The longitudinal wave refracted in the tested material (13). In this embodiment, to obtain a 60° refracted longitudinal wave, the deflection angle θ inside the wedge is calculated. p The corresponding delay gradient Δt = 0.061 μs. The absolute delays of elements 12-21 of the transmitting probe are: 0.545 μs, 0.484 μs, 0.424 μs, 0.363 μs, 0.303 μs, 0.242 μs, 0.182 μs, 0.121 μs, 0.061 μs, and 0 μs, respectively. The receiving probe uses the same delay parameters as the transmitting probe.

[0066] The formula for calculating the depth d of the defect diffraction point is as follows: .

[0067] In the formula, T is the diffracted wave emitted from the diffraction endpoint (corresponding to...). Figure 3 The arrival time of the diffracted wave 16 at the tip of the crack. The longitudinal wave velocity is denoted as .

[0068] Based on the arrival time difference T2-T1 of the diffracted waves at the lower and upper ends of the defect, the defect height H is initially estimated as follows:

[0069] H=d2-d1

[0070] In the formula, d2 is the depth of the lower end of the defect, and d1 is the depth of the upper end of the defect. For strip defects, parabolic cursor fitting is used. The left end arc of the defect is fitted with the cursor to obtain the horizontal coordinate y1, and the right end arc is fitted with the cursor to obtain the horizontal coordinate y2. The length of the defect along the weld axis is y2-y1.

[0071] The test results show (e.g.) Figure 5 The longitudinal positions of the six defects are 10.3 mm, 29.8 mm, 49.6 mm, 70.3 mm, 90.4 mm, and 109.5 mm from the scanning zero point, respectively; the depths of their upper endpoints are 0 mm, 6.8 mm, 15.2 mm, 21.3 mm, 27.6 mm, and 36.5 mm, respectively; the average height measurement is 4.8 mm; and the average length measurement is 5.3 mm. Due to lateral offset, the third defect has errors in its depth and height measurements, requiring further TOFD parallel B-scanning for precise positioning.

[0072] S3, TOFD Offset Non-Parallel D Scan (rotate around the probe holder's central axis in the plane of the upper surface of the specimen, keeping the distances from the two probes to the weld equal after rotation); keep the parameters of step S2 unchanged, rotate the probe holder to form a certain angle with the weld axis, and manually control the probe holder to move forward to achieve TOFD offset non-parallel D scan.

[0073] Specifically, keeping the parameters and configuration of step S2 unchanged, rotate the probe holder to form a certain angle with the weld axis, and manually control the probe holder to advance to achieve offset non-parallel D-scanning of TOFD (e.g., Figure 6 Offset non-parallel D-scan images, such as Figure 7 As shown, this mode can improve the detection rate of transverse defects and lateral non-fusion, and solve the shortcoming of conventional D-scan in missing transverse defects.

[0074] By rotating the defect to a position perpendicular to the weld axis (e.g.) Figure 6 This simulates common transverse planar defects in actual structures and uses an offset non-parallel scanning method to obtain the corresponding 3D scan images. Figure 7 The results show that the 25° offset non-parallel scanning can effectively detect transverse planar defects perpendicular to the weld axis, with clear defect echo characteristics and intuitive imaging; while the conventional non-parallel scanning method has obvious missed detection of this type of orientation defect.

[0075] S4, TOFD parallel B-scan; based on S2 and S3, locate the defect, preliminarily assess the defect depth and location, and determine the sequence of emitter array elements to be excited (corresponding to...). Figure 8 The sequence of transmitting array element 17 and receiving array element group (corresponding to the parallel B scan before scanning) Figure 8 The receiving array element 19 before the parallel B scan in the middle), and calculate the transmission delay (corresponding to Figure 8 The transmit delay (18) and receive delay (corresponding to) before the parallel B scan in the middle. Figure 8 The parallel B-scan of TOFD is achieved by manually controlling the probe mount to move forward (with a reception delay of 20 seconds before parallel B-scanning).

[0076] Specifically, based on the preliminary calculation of the defect depth and location using S2, the longitudinal wave refraction angle and probe center distance are determined. This allows for the determination of the refracted longitudinal wave 21 in the inspected material before parallel B-scan. The activation sequence and delay parameters of the transmitting and receiving array elements are then recalculated to obtain the transmitting array element 22 excited after linear scanning, the transmitting array element delay 23 excited after linear scanning, the receiving array element delay 24 excited after linear scanning, the receiving array element delay 25 excited after linear scanning, and the refracted longitudinal wave 26 in the inspected material excited after linear scanning, ensuring that the beam intersection depth always covers the defect depth. Through the linear scanning array element switching function of the ultrasonic testing instrument, the activated array elements (such as...) are sequentially shifted. Figure 8 , Figure 9 This allows for linear scanning of the sound beam without physically moving the probe, i.e., TOFD parallel B-scan (e.g.) Figure 10 According to the shortest arrival time T of the diffracted wave at the upper end of the internal unfused defect 27. min Determine the lateral coordinates of the defect in the B-scan map. Calculate the defect relative to the weld centerline. Lateral offset The direction and distance of the defect from the weld center axis are determined; at the same time, the depth and height of the defect are accurately calculated based on the propagation time of the diffraction wave.

[0077] Based on the preliminary measurement of the upper end point depth d1 of the third defect, in order to accurately obtain the defect depth, height and lateral position, the detection parameters were reconfigured: the PCS was adjusted so that the depth of the sound beam intersection point was 15mm, and the lateral translation of the sound beam was achieved by linear scanning.

[0078] The activation sequence for the linear scan array elements is as follows: the activation sequence for the transmitting array elements is 1-10, corresponding to the activation sequence for the receiving array elements is 25-32; the transmitting activation sequence is 2-9, corresponding to the receiving activation sequence is 24-31, and so on, until the transmitting activation sequence is 25-32, corresponding to the receiving activation sequence is 1-8. The longitudinal wave refraction angle is maintained at 60°, the beam intersection depth is fixed at 15mm, and the corresponding PCS is adjusted to 50mm.

[0079] The test results show (e.g.) Figure 10 ): Shortest arrival time T of the diffracted wave at the upper end of the defect min The corresponding depth is 14.3 mm, which is less than the 15.2 mm in Example 1; the calculated defect height based on the time difference of the diffraction waves at the upper and lower endpoints is 5.1 mm; the shortest arrival time T min The corresponding horizontal coordinate x1 is offset from the weld center axis x0 by 3.2mm, and the orientation is determined to be the right side of the weld.

[0080] S5. Phased array sector scan: Configure phased array sector scan detection parameters, control the left and right probes to work in self-transmitting and self-receiving mode respectively, and realize shear wave sector scan within the set angle range.

[0081] Specifically, the dual-channel phased array ultrasonic testing instrument 1 is set to phased array sector scanning, with both the left and right probes operating in self-generating and self-receiving mode. At this time, the wedge generates refracted transverse waves (such as...) in the material being tested. Figure 11The planar longitudinal wave 28 in the wedge enters the inspected material and generates a refracted transverse wave 29 in the inspected material. Based on the defect distribution area determined in steps S2 and S3, the cross section perpendicular to the weld is used as the inspection object. The sector sweep angle range and focusing parameters are configured, and a double-sided transverse wave sector sweep is performed to obtain the left and right sector sweep images respectively. A data fusion algorithm is used to comprehensively analyze the double-sided sector sweep images to obtain the precise location, equivalent size, and nature information of the defects.

[0082] Two 1mm diameter point defects were placed inside the weld area and in the heat-affected zone, respectively. Probes were symmetrically arranged on both sides of the weld, and a self-generating and self-receiving shear wave fan-shaped scan was performed. With no deflection, the shear wave refraction angle was 50°, and the fan-scan angle range was set to 30°-70°, with angle increments of 1° (e.g., ...). Figure 11 , Figure 12 Obtain the left and right sector scan images respectively (e.g.) Figure 13 The results show that this configuration can achieve direct reflection (such as...). Figure 11 The fan-shaped scan direct beam (30) and the bottom surface primary reflection (such as...) Figure 11 The presence of a defect was detected by a single reflection of the fan-shaped scan (31).

[0083] Two sector scan images are fused. The two sector scan images are represented by amplitude functions I1(r,θ) and I2(r,θ) in polar coordinates, respectively, where r is the radial distance and θ is the angle. Linear pixel amplitude fusion is performed on the two images in polar coordinates, and the amplitude of the fused image is I... f (r,θ) is

[0084] I f (r,θ)=αI1(r,θ)+(1-α)I2(r,θ)

[0085] In the formula, α is the linear fusion weight, satisfying 0 ≤ α ≤ 1. In this case, α is chosen to be 0.5.

[0086] The fused image clearly shows the intersection of the defect endpoints (e.g. Figure 13 The measured defect locations were (-14.8, -19.5) and (4.6, -24.7), with a maximum error of 0.8 mm between these locations and the actual defect locations (-14, -20) and (4, -25).

[0087] A pair of phased array linear probes are used to scan the weld seams of special equipment, integrating multiple imaging algorithms to improve defect detection rate and accuracy. Single-sided shear wave fan-shaped scanning utilizes beam deflection and focusing to achieve internal imaging of the weld seam, while double-sided ultrasonic phased array fan-shaped scanning overcomes the limitations of defect orientation. By superimposing and fusing the pixel amplitudes of overlapping areas, the imaging results from both sides are enhanced, improving defect assessment and obtaining information such as defect type, location, and equivalent size. Furthermore, by selectively exciting a portion of the linear array probe elements, the element delay is calculated based on parameters such as the target longitudinal wave refraction angle, diffusion angle, and the wall thickness of the inspected material, combined with the small size and large diffusion angle characteristics of the TOFD single-crystal transducer. The phased array linear probes simulate a TOFD transmit-receive mode, enabling non-parallel TOFD scanning without probe replacement, obtaining longitudinal position, depth, and height information of defects. Simultaneously, by asymmetrically exciting a portion of the array elements and calculating the delay based on the focusing depth, different array elements are switched using linear scanning mode to maintain consistent focusing depth, achieving parallel TOFD scanning without physical probe movement, obtaining the lateral position of defects. Multiple detection modes complement each other to achieve comprehensive and accurate characterization of defects.

[0088] Furthermore, this application embodiment also provides a storage medium for storing a computer program, wherein the computer program, when running, controls the device where the storage medium is located to execute the above-described ultrasonic testing method for butt welds.

[0089] Furthermore, this application embodiment also provides a processor for running a program, wherein the program executes the above-described ultrasonic testing method for butt welds during operation.

[0090] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0091] It is understood that the relevant features in the above methods and systems can be referenced interchangeably. Furthermore, the terms "first," "second," etc., in the above embodiments are used to distinguish between embodiments and do not represent the superiority or inferiority of any particular embodiment.

[0092] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0093] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, this application is not directed to any particular programming language. It should be understood that the content of this application described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of this application.

[0094] In addition, the memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0095] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0096] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0097] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0099] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0100] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0101] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0102] It should also be noted that 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 process, method, article, or apparatus. Unless otherwise specified, 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 that element.

[0103] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for ultrasonic testing of butt welds, characterized in that, Includes the following steps: S1. Select a dual-channel phased array ultrasonic testing instrument and connect it to a phased array linear probe with multiple array elements symmetrically distributed on both sides of the weld. The phased array linear probe is set on the probe frame, and each phased array linear probe is connected to a transverse wave wedge. S2, TOFD non-parallel D-scan; Configure TOFD non-parallel D-scan detection parameters, set the probes as transmitting and receiving probes respectively, determine the transmitting element sequence and receiving element sequence to be excited, and calculate the transmitting and receiving delays; Keep the probe holder perpendicular to the weld axis, and realize the TOFD non-parallel D-scan by manually controlling the probe holder to move forward; S3, TOFD offset non-parallel D scan; Keeping the parameters of step S2 unchanged, rotate the probe holder to form a certain angle with the weld axis, and manually control the probe holder to move forward to achieve TOFD offset non-parallel D scan; S4, TOFD parallel B-scan; Based on S2 and S3, locate the defect, preliminarily assess the defect depth and location, determine the sequence of transmitting and receiving elements to be excited, and calculate the transmission and reception delays. The TOFD parallel B-scan is achieved by manually controlling the probe frame to move forward. S5, Phased array sector scanning; Configure phased array sector scanning detection parameters, control the left and right probes to work in self-transmitting and self-receiving mode respectively, and realize shear wave sector scanning within the set angle range.

2. The ultrasonic testing method for butt welds as described in claim 1, characterized in that, In step S2, the TOFD non-parallel D-scan detection parameters are configured according to the wall thickness and sound velocity of the material being inspected; the transmitting and receiving array element sequences to be excited are determined, and the transmitting and receiving delays are calculated based on the set longitudinal wave incident angle and the simulated TOFD probe parameters; the array element groups of the transmitting and receiving probes adopt symmetrical array element sequences to achieve the same symmetrical detection mode as TOFD detection.

3. The ultrasonic testing method for butt welds as described in claim 1, characterized in that, In S4, the array elements of the transmitting and receiving probes adopt an asymmetric array element sequence. During the detection process, the probe position remains unchanged, the depth of the sound beam intersection point remains unchanged, and the lateral position shifts according to the change of the activated array element sequence, so as to achieve the same parallel detection mode as the synchronous translation of the probe in TOFD parallel detection.

4. The ultrasonic testing method for butt welds as described in claim 1, characterized in that, In step S5, phased array sector scanning detection parameters are configured according to the wall thickness and sound velocity of the material being inspected; the angle range is set to 30°-70°; after shear wave sector scanning, left sector scan image and right sector scan image are obtained respectively, and comprehensive analysis is performed through data fusion algorithm, which is the superposition of amplitudes in repeated regions.

5. The ultrasonic testing method for butt welds as described in claim 2, characterized in that, In the TOFD non-parallel D-scan mode, the transmitting and receiving probes use the same delay parameters. This is achieved by ensuring the longitudinal wave incident angle in the wedge is less than the first critical angle, thus exciting a longitudinal wave in the material for TOFD detection. The delay control function of the phased array probe is used to apply a beam deflection θ to the selected m array elements. p By sequentially increasing the fixed delay Δt of adjacent array elements, the synthesized wavefront within the wedge forms an angle θ with the normal. p A plane longitudinal wave at an angle, with a relative delay of Δt between adjacent array elements. , In the formula, Let be the longitudinal wave velocity of the wedge; for m excitation array elements, the absolute delay of the i-th element is t. i， .

6. The ultrasonic testing method for butt welds as described in claim 5, characterized in that, The depth of the defect diffraction point in S2 is d. Where T is the arrival time of the diffracted wave emitted from the diffraction endpoint. Let be the longitudinal wave velocity in the material; based on the arrival time difference T2-T1 of the diffracted waves at the lower and upper ends of the defect, the height H of the defect itself is initially estimated as H=d2-d1, where d2 is the depth of the lower end of the defect and d1 is the depth of the upper end of the defect; for strip defects, parabolic cursor fitting is used, and the left end arc of the defect is fitted with the cursor to obtain the lateral coordinate y1, and the right end arc is fitted with the cursor to obtain the lateral coordinate y2. The length of the defect along the weld axis is y2-y1.

7. The ultrasonic testing method for butt welds as described in claim 4, characterized in that, The data fusion method for the left and right sector scan images is as follows: The two sector scan images are represented as amplitude functions I1(r,θ) and I2(r,θ) in polar coordinates, respectively, where r is the radial distance and θ is the angle. Linear pixel amplitude fusion is performed on the two images in polar coordinates, and the amplitude of the fused image is I... f (r,θ) is I f (r,θ)=αI1(r,θ)+(1-α)I2(r,θ), where α is the linear fusion weight, satisfying 0≤α≤1.

8. An ultrasonic testing device for butt welds, characterized in that, The ultrasonic testing method for butt welds according to any one of claims 1-7 includes a dual-channel phased array ultrasonic testing instrument, a probe frame spanning above the butt weld of the material under test, a pair of phased array linear probes with identical parameters symmetrically clamped and installed on the probe frame, the phased array linear probes being electrically connected to the ultrasonic testing instrument via probe cables, the phased array elements of the phased array linear probes being capable of selective excitation and reception, the probes being fastened to shear wave wedges by bolts, the lower plane of the shear wave wedges being tightly fitted to the upper surface of the material under test, and being symmetrically arranged along the central axis of the butt weld.

9. The ultrasonic testing device for butt welds as described in claim 8, characterized in that, The transverse wave wedge is made of Rexolite polystyrene, and the transverse wave refraction angle of the wedge is 50°; the probe holder is rotatable.

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