A small-bore pipe corner joint phased array ultrasonic detection system and method

Abstract

The application discloses a small-caliber nozzle corner joint phased array ultrasonic detection system and method, and relates to the field of nozzle corner joint nondestructive detection. In the system, a phased array detector determines a detection area according to sound beam coverage analysis of a three-dimensional structure model of a debugging test block, and different scanning modes are configured for nozzle corner joints of different thicknesses and different types; the phased array probe sends ultrasonic waves covering the detection area to the contrast test block, determines a compensation curve, thereby calibrating the sensitivity of the system, and obtains an evaluation line and a quantitative line; the phased array probe sends ultrasonic waves covering the detection area to the target workpiece; a scanning device performs scanning operation on the target workpiece according to a scanning mode matched with the target workpiece, and generates a scanning image according to echo signals of the target workpiece; the phased array detector performs defect detection according to the scanning image, the three-dimensional structure model of the target workpiece, the evaluation line and the quantitative line, and obtains a defect detection result. The application can accurately and efficiently realize detection of the nozzle corner joint.

Description

Technical Field

[0001] This application relates to the field of non-destructive testing of pipe corner joints, and in particular to a phased array ultrasonic testing system and method for small-diameter pipe corner joints. Background Technology

[0002] Small-diameter corner joints (i.e., joint thickness of 3mm~30mm and pipe diameter of DN20-DN50) are widely used in pressure vessels, pipelines, and other equipment, and their welding quality directly affects the operational safety of the equipment. Due to their special structure (large curvature, complex weld type) and limited dimensions (joint thickness of 3mm~30mm), carbon steel small-diameter corner joints have several shortcomings in related inspection methods: First, the sound beam coverage is difficult to control precisely, easily leading to blind spots and missed detection of harmful defects such as buried cracks, lack of fusion, and incomplete penetration; second, the detection sensitivity is unstable, greatly affected by the operator's experience, resulting in low quantitative accuracy of defects; third, there is a lack of a unified and efficient inspection process for small-diameter corner joints of different thicknesses and types (placement type, insertion type, etc.), resulting in low inspection efficiency. Therefore, how to accurately and efficiently inspect corner joints has become an urgent problem to be solved. Summary of the Invention

[0003] The purpose of this application is to provide a phased array ultrasonic testing system and method for small-diameter pipe corner joints, which can accurately and efficiently detect pipe corner joints.

[0004] To achieve the above objectives, this application provides the following solution.

[0005] In a first aspect, this application provides a phased array ultrasonic testing system for small-diameter pipe corner joints, including: a phased array tester, a phased array probe, a comparison test block, and a scanning device.

[0006] The phased array detector is used to: model the test block to obtain a three-dimensional structural model of the test block, and perform sound beam coverage analysis based on the three-dimensional structural model of the test block to determine the detection area; the test block is a series of pipe corner joints of different specifications used for system debugging; different scanning methods are configured for pipe corner joints of different thicknesses and types.

[0007] The phased array probe is used to: emit ultrasonic waves covering the detection area to the comparison test block, determine a compensation curve based on the echo signal of the comparison test block, perform sensitivity calibration of the system based on the compensation curve and the set sensitivity, and determine the evaluation line and the quantitative line; the compensation curve includes: a depth compensation curve and an angle compensation gain curve; emit ultrasonic waves covering the detection area to the target workpiece; the target workpiece is the pipe corner joint to be tested.

[0008] The scanning device is used to: scan the target workpiece along the scanning path according to the set scanning parameters and the scanning method matched with the target workpiece, receive the echo signal of the target workpiece, generate a scanning image based on the echo signal of the target workpiece, and send the scanning image to the phased array detector.

[0009] The phased array detector is also used for: modeling the target workpiece to obtain a three-dimensional structural model of the target workpiece; and performing defect detection on the target workpiece based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line to obtain defect detection results.

[0010] In one embodiment, in obtaining defect detection results by performing defect detection on the target workpiece based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line, the phased array detector is specifically used for: identifying defects in the scanned image based on the three-dimensional structural model of the target workpiece, and determining a defect-related display area; the defect-related display area includes: a weld area and an area on the weld contour line; based on the defect-related display area, performing defect quantification according to the evaluation line and the quantitative line to obtain a defect quantification result; the defect quantification result includes: the depth, amplitude, indication length, and height of different defects; merging defects according to the defect quantification result to obtain a defect merging result; and classifying the target workpiece according to the defect merging result, using the joint welding quality of the target workpiece as the defect detection result.

[0011] In one embodiment, the phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a position sensor; the position sensor is disposed on the scanning device; the scanning device is also used to perform scanning operations on the test block according to set scanning parameters and a scanning method matching the test block during system debugging; the position sensor is used to collect the actual displacement of the scanning device during system debugging; the phased array detector is also used to calibrate the position sensor based on the displayed displacement and the actual displacement during system debugging; the calibrated position sensor is used to collect the actual displacement of the scanning device during actual testing; the phased array detector is also used to determine whether the scanning device performs scanning operations on the target workpiece along the scanning path based on the actual displacement during real-time testing.

[0012] In one embodiment, regarding the determination of defects based on the evaluation line and the quantitative line in the defect correlation display area to obtain the defect quantitative result, the phased array detector is specifically used to: determine the depth and amplitude of defects whose echo amplitude exceeds the evaluation line in the defect correlation display area; for defects between the evaluation line and the quantitative line, determine the indication length of the defect using the evaluation line absolute sensitivity method; for defects exceeding the quantitative line, determine the indication length of the defect using the -6dB method; and for defects exceeding the evaluation line, determine the height of the defect using the -6dB half-wave height method or the endpoint diffraction method.

[0013] In one embodiment, in obtaining a defect merging result based on the defect quantification result, the phased array detector is specifically used to: in the defect quantification result, for adjacent non-circular defects, if the distance between the two defects in the indicated length direction is less than the smaller of the indicated lengths of the two defects, and the distance between the two defects in the depth direction is less than the smaller of the heights of the two defects, then the adjacent non-circular defects are merged. The depth of the merged defect is the smaller of the depths of the two defects, the indicated length of the merged defect is the distance between the endpoints of the two defects before and after merging, and the height of the merged defect is the larger of the heights of the two defects or the sum of the heights of the two defects. The defect merging result includes: the depth of the merged defect, the indicated length of the merged defect, and the height of the merged defect.

[0014] In one embodiment, the scanning method includes: for a placement-type pipe corner joint, a primary wave is used to detect the root, and a secondary wave is used to detect the surface and middle; for an insertion-type pipe corner joint, a primary wave or a secondary wave is used to detect the main pipe side, a primary wave is used to detect the root of the branch pipe side, and a secondary wave is used to detect the surface and middle of the branch pipe side; the scanning angle of the phased array probe is between 35° and 75°.

[0015] In one embodiment, the phased array probe is a shear wave phased array probe; the nominal frequency of the phased array probe is 5MHz~10MHz; the excitation aperture of the primary excitation element in the phased array probe is determined according to the thickness of the workpiece.

[0016] In one embodiment, the phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a wedge; the distance between the wedge and the target workpiece is less than a set distance value; the curvature of the wedge and the test surface of the target workpiece are matched; the ultrasonic waves emitted by the phased array probe reach the surface of the target workpiece through the wedge.

[0017] In one embodiment, the evaluation line is used to determine whether a defect has occurred; the quantitative line is used to determine whether the defect needs to be quantified; the sensitivity of the evaluation line and the quantitative line is determined based on the workpiece thickness.

[0018] Secondly, this application provides a phased array ultrasonic testing method for small-diameter pipe corner joints, which is used in the aforementioned phased array ultrasonic testing system for small-diameter pipe corner joints. The phased array ultrasonic testing method for small-diameter pipe corner joints includes the following steps.

[0019] After the system's sensitivity is calibrated, a scan image of the target workpiece is acquired, and the target workpiece is modeled to obtain a three-dimensional structural model of the target workpiece. The scan image is generated by the scanning device scanning the target workpiece along the scanning path according to the set scanning parameters and the scanning method matching the target workpiece, receiving the echo signal of the target workpiece, and generating the image based on the echo signal of the target workpiece.

[0020] Based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line, defect detection is performed on the target workpiece to obtain the defect detection results.

[0021] The system's sensitivity calibration process includes: a phased array detector modeling the test block to obtain a three-dimensional structural model of the test block, and performing acoustic beam coverage analysis based on the three-dimensional structural model of the test block to determine the detection area; the test block is a series of pipe corner joints of different specifications used for system debugging; the phased array detector is configured with different scanning modes for pipe corner joints of different thicknesses and types; the phased array probe emits ultrasonic waves covering the detection area to the comparison test block, and determines the compensation curve based on the echo signal of the comparison test block; the system's sensitivity is calibrated based on the compensation curve and the set sensitivity to determine the evaluation line and quantitative line; the compensation curve includes a depth compensation curve and an angle compensation gain curve.

[0022] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a phased array ultrasonic testing system and method for small-diameter pipe corner joints. The phased array tester performs sound beam coverage analysis based on the three-dimensional structural model of the test block to ensure that the sound beam covers the detection area, resulting in comprehensive and blind-spot-free detection coverage. The phased array tester is configured with different scanning modes for pipe corner joints of different thicknesses and types, enabling a unified and efficient testing process for pipe corner joints of different thicknesses and types, thus improving testing efficiency. The phased array probe emits ultrasonic waves covering the detection area to the comparison test block, determines the compensation curve, and thereby performs system sensitivity calibration to obtain the evaluation line and quantitative line, solving the problem of unstable detection sensitivity. This application can accurately and efficiently detect pipe corner joints. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a phased array ultrasonic testing system for a small-diameter pipe corner joint provided in an embodiment of this application.

[0025] Figure 2 The acoustic simulation diagrams of pore defects at different locations provided in the embodiments of this application are shown.

[0026] Figure 3 Verification diagram of the detection results of pore defects at different locations provided in the embodiments of this application.

[0027] Figure 4 The acoustic simulation diagrams of the non-fusion defects at different locations provided in the embodiments of this application are shown.

[0028] Figure 5 Verification diagram of the detection results of non-fusion defects at different locations provided in the embodiments of this application.

[0029] Figure 6 The acoustic simulation diagrams of crack defects at different locations provided in the embodiments of this application are shown.

[0030] Figure 7 This is a verification diagram showing the detection results of crack defects at different locations provided in the embodiments of this application. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The current testing methods for pipe corner joints have drawbacks such as numerous blind spots, unstable sensitivity, low quantitative accuracy of defects, and low testing efficiency. In addition, they have not been specifically optimized for the structural characteristics of pipes, making it impossible to effectively distinguish between structural signals and defect signals, and thus failing to meet the complex testing requirements of pipe corner joints.

[0034] To address the aforementioned deficiencies, this application provides a phased array ultrasonic testing system and method for small-diameter pipe corner joints that offers comprehensive detection coverage, high sensitivity, precise quantification, high detection efficiency, and strong adaptability.

[0035] In one exemplary embodiment, such as Figure 1 As shown, a phased array ultrasonic testing system for small-diameter pipe corner joints is provided, including: a phased array tester, a phased array probe, a comparison test block, and a scanning device.

[0036] The phased array detector is used to: model the test block to obtain a three-dimensional structural model of the test block, and perform sound beam coverage analysis based on the three-dimensional structural model of the test block to determine the detection area; the test block is a series of pipe corner joints of different specifications used for system debugging; different scanning methods are configured for pipe corner joints of different thicknesses and types.

[0037] The phased array probe is used to: emit ultrasonic waves covering the detection area to the comparison test block, determine a compensation curve based on the echo signal of the comparison test block, perform sensitivity calibration of the system based on the compensation curve and the set sensitivity, and determine the evaluation line and the quantitative line; the compensation curve includes: a depth compensation curve and an angle compensation gain curve; emit ultrasonic waves covering the detection area to the target workpiece; the target workpiece is the pipe corner joint to be tested.

[0038] The scanning device is used to: scan the target workpiece along the scanning path according to the set scanning parameters and the scanning method matched with the target workpiece, receive the echo signal of the target workpiece, generate a scanning image based on the echo signal of the target workpiece, and send the scanning image to the phased array detector.

[0039] The phased array detector is also used for: modeling the target workpiece to obtain a three-dimensional structural model of the target workpiece; and performing defect detection on the target workpiece based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line to obtain defect detection results.

[0040] In another exemplary embodiment of this application, in obtaining defect detection results by performing defect detection on the target workpiece based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line, the phased array detector is specifically used for: identifying defects in the scanned image based on the three-dimensional structural model of the target workpiece, and determining defect-related display areas and structurally irrelevant display areas; the defect-related display areas include: weld areas and areas on the weld contour line; the structurally irrelevant display areas are areas in the three-dimensional structural model of the target workpiece other than the defect-related display areas; based on the defect-related display areas, performing defect quantification according to the evaluation line and the quantitative line to obtain defect quantification results; the defect quantification results include: depth, amplitude, indication length, and height of different defects; merging defects according to the defect quantification results to obtain defect merging results; and classifying the target workpiece according to the defect merging results, using the joint welding quality of the target workpiece as the defect detection result.

[0041] In another exemplary embodiment of this application, the phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a position sensor; the position sensor is disposed on the scanning device; the scanning device is also used to perform scanning operations on the test block according to the set scanning parameters and the scanning method matching the test block during system debugging; the position sensor is used to collect the actual displacement of the scanning device during system debugging; the phased array detector is also used to calibrate the position sensor according to the displayed displacement and the actual displacement during system debugging; the calibrated position sensor is used to collect the actual displacement of the scanning device during actual testing; the phased array detector is also used to determine whether the scanning device performs scanning operations on the target workpiece along the scanning path according to the actual displacement during real-time testing.

[0042] In another exemplary embodiment of this application, in terms of obtaining a defect quantitative result by performing defect quantification based on the evaluation line and the quantitative line according to the defect correlation display area, the phased array detector is specifically used to: determine the depth and amplitude of defects whose echo amplitude exceeds the evaluation line in the defect correlation display area; for defects between the evaluation line and the quantitative line, determine the indication length of the defect using the evaluation line absolute sensitivity method; for defects exceeding the quantitative line, determine the indication length of the defect using the -6dB method; for defects exceeding the evaluation line, determine the height of the defect using the -6dB half-wave height method or the endpoint diffraction method.

[0043] In another exemplary embodiment of this application, in obtaining a defect merging result based on the defect quantification result, the phased array detector is specifically used to: in the defect quantification result, for adjacent non-circular defects, if the distance between the two defects in the indicated length direction is less than the smaller of the indicated lengths of the two defects, and the distance between the two defects in the depth direction is less than the smaller of the heights of the two defects, then the adjacent non-circular defects are merged. The depth of the merged defect is the smaller of the depths of the two defects, the indicated length of the merged defect is the distance between the endpoints of the two defects before and after merging, and the height of the merged defect is the larger of the heights of the two defects or the sum of the heights of the two defects. The defect merging result includes: the depth of the merged defect, the indicated length of the merged defect, and the height of the merged defect.

[0044] In another exemplary embodiment of this application, the scanning method includes: for a placement-type pipe corner joint, a primary wave is used to detect the root, and a secondary wave is used to detect the surface and middle; for an insertion-type pipe corner joint, a primary wave or a secondary wave is used to detect the main pipe side, a primary wave is used to detect the root of the branch pipe side, and a secondary wave is used to detect the surface and middle of the branch pipe side; the phased array probe adopts a transverse wave oblique beam fan scanning form, and the scanning angle of the phased array probe is between 35° and 75°.

[0045] In another exemplary embodiment of this application, the phased array detector may be an instrument with functions such as corner joint modeling, A / B / C / D / S type display, and defect location measurement and analysis, preferably an instrument with three-dimensional modeling function, such as M2MGEKKO.

[0046] In another exemplary embodiment of this application, the phased array probe can be a shear wave phased array probe; the nominal frequency of the phased array probe is 5MHz~10MHz; the excitation aperture of the primary excitation element in the phased array probe is determined according to the thickness of the workpiece. In practical applications, the number of primary excitation elements is not less than 16. When matching the excitation aperture according to the thickness of the workpiece, a thickness of 3mm-15mm corresponds to an excitation aperture of 6mm-10mm, and a thickness greater than 15mm-30mm corresponds to an excitation aperture of 7mm-15mm.

[0047] In another exemplary embodiment of this application, the phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a wedge; the distance between the wedge and the target workpiece is less than a set distance value (e.g., 0.5 mm) to ensure coupling requirements; the curvature of the wedge and the detection surface of the target workpiece are matched; the ultrasonic waves emitted by the phased array probe reach the surface of the target workpiece through the wedge.

[0048] In another exemplary embodiment of this application, the phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a standard test block, which is used to perform basic calibration of the system, including: sound velocity calibration, etc.

[0049] In another exemplary embodiment of this application, the evaluation line is used to determine whether a defect has occurred; the quantitative line is used to determine whether the defect needs to be quantified; the setting sensitivity of the evaluation line and the quantitative line is determined based on the workpiece thickness.

[0050] Specifically, the depth compensation curve and angle compensation gain curve are used as benchmarks for system sensitivity calibration: This is compared to the test block. Using the curves of a 2mm diameter transverse hole at different depths and angles as a benchmark, the sensitivity is set according to the workpiece thickness. If the workpiece thickness is 3mm-6mm, the sensitivity is adjusted for the comparison test block. 2 (2mm in diameter) transverse holes, the sensitivity setting for the evaluation line / quantitative line is -14dB (i.e. 2-14dB), the set sensitivity of the rejection line is -8dB (i.e. 2-8dB); if the workpiece thickness is ≥6-30mm, for the comparison test block 2 (2mm in diameter) transverse holes, the sensitivity setting of the evaluation line is -16dB (i.e. 2-16dB), the set sensitivity of the quantitative line is -10dB (i.e. 2-10dB), the set sensitivity of the rejection line is -4dB (i.e. 2-4dB).

[0051] The following section uses a small-diameter carbon steel pipe (hereinafter referred to as a small pipe) corner joint as an example to introduce a more specific implementation process of the phased array ultrasonic testing system for the small-diameter pipe corner joint in the above embodiment.

[0052] While phased array ultrasonic testing technology has been applied in routine weld inspection, specific testing methods for carbon steel small pipe corner joints are still underdeveloped, particularly in areas such as probe parameter matching, beam coverage optimization, and accurate defect identification and quantification. These areas remain technologically challenging and cannot meet the requirements for efficient and accurate testing of small pipe corner joints. Therefore, this embodiment specifically addresses phased array ultrasonic non-destructive testing of carbon steel small pipe corner joints, resolving issues such as numerous blind spots, low sensitivity, poor quantitative accuracy, and low testing efficiency.

[0053] This embodiment achieves accurate testing of carbon steel small pipe corner joints by optimizing the selection of testing equipment, clarifying testing process parameters, and standardizing the testing process. Specifically, it includes the following steps.

[0054] 1. Preparation for testing.

[0055] (1) Determining the inspection area: The inspection area is defined as the weld itself of the small pipe and the area 5mm on both sides of the weld fusion line (or the actual heat-affected zone); if it is a re-inspection or inspection of key parts, it can be narrowed down to the corresponding parts.

[0056] (2) Surface preparation: Remove welding spatter, iron filings, oil stains and other impurities from the inspection area, and polish until the metal luster is exposed. The polishing width is determined according to the preset inspection process.

[0057] (3) Inspection marking: Mark the scanning start point and scanning direction on the scanning surface, set a reference line, and ensure that the probe position deviates from the reference line by no more than 5% during scanning.

[0058] 2. Equipment selection and debugging of the detection system.

[0059] (1) Equipment selection: Select a phased array detector with functions such as corner joint modeling, A / B / C / D / S type display, and defect location measurement and analysis. It is preferred to select an instrument with three-dimensional modeling function. Select a transverse wave phased array probe with a nominal frequency of 5MHz~10MHz and a minimum of 16 array elements for one excitation. Match the excitation aperture according to the workpiece thickness. Select a wedge block that matches the curvature of the detection surface. The gap between the wedge block and the workpiece contact surface should not be greater than 0.5mm to ensure coupling requirements. Select a scanning device with a probe clamping mechanism and a position sensor. The accuracy of the position sensor should meet the process requirements.

[0060] (2) Selection of test blocks: CSK-IA test blocks and A / B type phased array test blocks are selected as standard test blocks; PGS series test blocks and PRB series test blocks with the same or similar curvature as the scanning surface are selected as comparison test blocks (also known as simulation test blocks). The comparison test blocks must include harmful defects such as buried cracks, lack of fusion, and incomplete penetration.

[0061] (3) System debugging: ① Workpiece modeling: Establish a structural model of the small pipe corner joint, use simulation software to simulate the sound field, perform sound beam coverage analysis, adjust the probe leading edge and sound beam angle to ensure that the sound beam covers the detection area, and simulate the sound rays of the pore defects at different locations as shown in the figure. Figure 2 As shown, the acoustic simulation diagrams of the incomplete fusion defect at different locations are as follows: Figure 4 As shown in the figure, the acoustic simulation diagrams of the crack defect at different locations are as follows: Figure 6As shown; ② Scanning method settings: For placement-type pipe corner joints, primary wave (detecting the root) and secondary wave (detecting the surface and middle) are used for detection. For joints with a thickness of 3mm-7mm, tertiary wave + secondary wave fan scanning can be used (process verification required); For insertion-type pipe corner joints, the main pipe side (i.e., the cylinder) is detected using primary wave or secondary wave, and the branch pipe side is scanned in the same way as the placement type; The transverse wave oblique beam fan scanning angle of the phased array probe is controlled between 35° and 75°; ③ Delay rule settings: The initial focusing depth is set at the maximum detection sound path, and can be focused to the target area for precise quantification; ④ Sensitivity calibration: A depth compensation (Time Corrected Gain, TCG) curve and an angle compensation (Angle Corrected Gain) curve are generated on the comparison test block. Gain (ACG) curve, the sensitivity setting is determined according to the workpiece thickness. If the coupling loss and material attenuation of the test block and the comparison test block are different, sensitivity compensation is required and the result is included in the compensation curve; ⑤ Position sensor calibration: Move the scanning device around the fillet weld for a full circle, and the error between the instrument's displayed displacement and the actual displacement should be less than 1%; ⑥ Process verification: Verification is performed using a comparison test block to ensure that all reference reflectors (i.e., defects) can be clearly displayed, and the dimensional deviation is within the allowable range. The verification results of the detection results of porosity defects at different locations are shown in the figure below. Figure 3 As shown in the figure, the verification results of the detection results of the non-fusion defect at different locations are as follows. Figure 5 As shown in the figure, the verification results of the crack defect at different locations are as follows. Figure 7 As shown.

[0062] 3. Testing Implementation.

[0063] (1) Scanning parameter setting: A mechanical scanning method with a position sensor is adopted. The scanning step value is no more than 1 mm and the maximum angle step value is 1°. The maximum scanning speed is calculated according to the formula vmax=PRF / (N×M×△X), where the pulse repetition frequency PRF<c / 2s, c is the speed of sound, s is the maximum detection sound path, N is the average number of signal, M is the number of electronic scanning steps, and △X is the scanning step value. The actual scanning speed does not exceed the maximum scanning speed, and the coupling effect and data acquisition quality are guaranteed.

[0064] (2) Scanning operation: Scan the target workpiece at a constant speed along the scanning path to ensure that the deviation between the actual scanning path and the planned scanning path does not exceed 5% of the distance from the front end of the probe; each scan completely covers the entire weld seam, and the stopping position exceeds the starting position by 10%-20%; maintain stable coupling during the scanning process, monitor coupling if necessary, and re-scan if the coupling is poor; collect scanning images (including S / A / B / C / D type display), and the images must include the workpiece model outline.

[0065] 4. Verification of the detection system.

[0066] System verification shall be performed in the following situations: replacement of phased array detector, phased array probe, cable, or coupling agent (which needs to be applied to the detection surface of the workpiece and the front end of the phased array probe during detection); doubts about the results by the testing personnel; or continuous operation for 4 hours or more. The test shall be terminated in such cases. Verify the deviation of sensitivity, position sensor, and depth display. If the displacement deviation is >5%, sensitivity deviation is >3dB, depth deviation is >2mm, or wall thickness is 3% (take the larger value), the corresponding detection parts shall be reset and re-inspected.

[0067] 5. Defect identification and quantitative assessment.

[0068] (1) Data validity evaluation: assess the validity of the collected data, ensure that the data covers the weld length, and ensure that the continuous loss of A scan signal does not exceed 2mm. Otherwise, it is unqualified and needs to be scanned again.

[0069] (2) Defect identification: Combining the scanned images (A / S / B / C / D type display) and the characteristics of the workpiece structure and material, the defect-related display area and the structure-irrelevant display area are distinguished. The area outside the weld area in the three-dimensional model is the irrelevant display area, while the area on the weld area and weld outline is identified as the defect-related display area.

[0070] (3) Defect quantification: For defects whose echo amplitude reaches or exceeds the evaluation line, the depth, amplitude, indication length, and height are measured. Specifically, the indication length is determined using the -6dB method (single high point) or the endpoint -6dB method (multiple high points). For defects between the evaluation line and the quantitative line, the indication length is determined using the evaluation line absolute sensitivity method. The defect height is determined using the -6dB half-wave height method or the endpoint diffraction method to determine the maximum value.

[0071] (4) Defect merging: When the distance between adjacent non-circular defects in the indicated length direction (i.e., the X-axis) is less than the indicated length of the smaller defect, and the distance in the depth direction (i.e., the Z-axis) is less than the height of the smaller defect, they are merged. Among them, the depth after merging is the smaller value, the indicated length after merging is the distance between the front and rear endpoints of the projection, and the height after merging is the larger value (when the heights do not overlap) or the sum of the two (when the heights overlap).

[0072] (5) Quality grading: Defects are graded according to relevant standards to determine the welding quality of the joint.

[0073] 6. Special Case Handling: When inspecting austenitic stainless steel small pipe corner joints with a diameter of 4mm to 10mm (excluding 10mm), the above steps should be followed, but the influence of changes in acoustic properties such as material sound velocity and grain size on the inspection should be considered.

[0074] Two specific examples are given below to illustrate the detection process.

[0075] Example 1: Inspection of a placement-type carbon steel small pipe corner joint (pipe thickness 8mm, pipe diameter DN50).

[0076] 1. Inspection preparation: Determine the inspection area as the weld and the 5mm area on both sides of the fusion line; grind the inspection area until the metal luster is exposed, with a grinding width of 20mm; mark the scanning starting point (top of the pipe) and the clockwise scanning direction, and set a reference line parallel to the weld.

[0077] 2. Equipment Selection and Debugging in the System: A phased array ultrasonic phased array testing instrument with 3D modeling capabilities was selected; a 5MHz shear wave phased array probe with an excitation aperture of 8mm and 16 array elements for a single excitation was selected; a wedge block matching the curvature of the DN50 pipe was selected with a contact surface gap of 0.3mm; a mechanical scanning device with a position sensor was selected. The standard test block was the CSK-IA test block, and the comparison test block was the PGS-3 test block.

[0078] System debugging: A placement-type corner connector model was established, and beam coverage analysis confirmed the absence of blind spots; the scanning mode was set to primary wave + secondary wave fan scanning, with an angle range of 35°~75°; the focusing depth was set at the maximum detection path of 12mm; a TCG curve was generated, and the sensitivity was set to the evaluation line. 2-16dB, quantitative line 2-10dB, rejection line 2-4dB; after calibrating the position sensor and moving the entire weld seam, the error is 0.8%; the comparison test block is used for verification, which can clearly show defects such as incomplete fusion and incomplete penetration, with a dimensional deviation of ±0.2mm.

[0079] 3. Inspection Implementation: The scanning step value is set to 0.8mm, the angle step value to 0.8°, the average number of signal scans is 4, the number of electronic scanning steps is 8, PRF=500Hz, the sound velocity c=3230m / s, the maximum detection sound path s=12mm, the maximum scanning speed vmax=500 / (4×8×0.8)=19.5mm / s is calculated, and the actual scanning speed is 15mm / s; the entire weld seam is scanned clockwise, and the stopping position is 15mm beyond the starting position; the coupling is stable during the scanning process, and S / A / B / C / D type images are acquired.

[0080] 4. System verification: After 3 hours of continuous operation, the system was verified. The sensitivity deviation was 1dB, the displacement deviation was 2%, and the depth deviation was 1mm, all of which met the requirements.

[0081] 5. Defect Assessment: The acquired data is valid, and there is no continuous loss of A-scan signal; one incomplete fusion defect was identified, with an amplitude of [missing information]. 2-8dB, depth 6mm, indication length 3mm (-6dB method), height 1.2mm; the defect did not reach the rejection line, and the quality classification is qualified.

[0082] Example 2: Inspection of insert-type carbon steel small pipe corner joint (pipe thickness 20mm, pipe diameter DN100).

[0083] 1. Inspection preparation: The inspection area is the weld and the 5mm area on both sides of the fusion line; grind the inspection area until the metal luster is exposed, with a grinding width of 30mm; mark the scanning starting point (top of the cylinder side) and the counterclockwise scanning direction, and set the reference line.

[0084] 2. System Equipment Selection and Debugging: A phased array ultrasonic phased array detector (with corner joint modeling function) is selected; a 6MHz shear wave phased array probe with an excitation aperture of 12mm and 32 array elements for a single excitation is selected; wedges matching the curvature of the cylinder are selected with a contact surface gap of 0.4mm; the scanning device is equipped with a position sensor. A-type phased array test blocks are used as standard test blocks, and dedicated comparison test blocks are used as comparison test blocks.

[0085] System debugging: An insert-type corner connector model was established, and the sound beam coverage analysis was satisfactory; the scanning mode was set to secondary wave scanning, with an angle range of 40°~70°; the focusing depth was set at the maximum detection sound path of 25mm; a TCG curve was generated, and the sensitivity was set to the evaluation line. 2-16dB, quantitative line 2-10dB, rejection line 2-4dB; after calibrating the position sensor and moving the entire weld seam, the error is 0.6%; using comparative test blocks for verification, cracks and slag inclusions can be clearly displayed, with a dimensional deviation of ±0.3mm.

[0086] 3. Inspection Implementation: The scanning step value is set to 1mm, the angle step value to 1°, the average number of signal scans to 6, the number of electronic scanning steps to 10, PRF=600Hz, the sound velocity c=3230m / s, the maximum detection sound path s=25mm, the maximum scanning speed vmax=600 / (6×10×1)=10mm / s is calculated, and the actual scanning speed is 8mm / s; the entire weld seam is scanned counterclockwise, and the stopping position is 18mm beyond the starting position; multiple types of scanning images are acquired, and the coupling is stable.

[0087] 4. System verification: After the test is completed, the system is verified, and no parameters exceed the standard deviation.

[0088] 5. Defect Assessment: Data valid; one porosity defect identified; amplitude... 2-12dB, depth 12mm, indicated length 2mm, height 0.8mm; defect acceptable, joint quality graded as acceptable.

[0089] Furthermore, when using traditional manual ultrasonic testing methods to inspect the placement-type small pipe corner joint in Example 1, two blind spots in the acoustic beam coverage were found during the inspection, failing to identify the incomplete fusion defect discovered in Example 1; for manually set... 2. Pore defects, quantitative deviation reaches ±0.8mm, detection efficiency is 40% lower than that of this application.

[0090] It should be noted that the phased array detector and comparison test block in this embodiment can be existing products that meet the standard requirements, without the need for special customization; the coupling agent used in the testing process can be a material with good sound transmission and that does not damage the surface of the workpiece, such as chemical paste or water; the testing personnel must have phased array ultrasonic testing qualifications, master the knowledge of small pipe materials, structure, manufacturing and welding processes, sound field modeling, etc., and have undergone special training; the timing of the testing should comply with the provisions of relevant laws, regulations, product standards and technical documents.

[0091] Based on the same inventive concept, this application also provides a phased array ultrasonic testing method for small-diameter pipe corner joints. The phased array ultrasonic testing method for small-diameter pipe corner joints is implemented using the phased array ultrasonic testing system for small-diameter pipe corner joints described in the above embodiment. The phased array ultrasonic testing method for small-diameter pipe corner joints includes the following steps.

[0092] (1) After the system sensitivity is calibrated, the scanning image of the target workpiece is acquired, and the target workpiece is modeled to obtain the three-dimensional structural model of the target workpiece; the scanning image is generated by the scanning device scanning the target workpiece along the scanning path according to the set scanning parameters and the scanning method matching the target workpiece, receiving the echo signal of the target workpiece, and generating the image based on the echo signal of the target workpiece.

[0093] (2) Based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line and the quantitative line, the target workpiece is subjected to defect detection to obtain the defect detection result.

[0094] The system's sensitivity calibration process includes: a phased array detector modeling the test block to obtain a three-dimensional structural model of the test block, and performing acoustic beam coverage analysis based on the three-dimensional structural model of the test block to determine the detection area; the test block is a series of pipe corner joints of different specifications used for system debugging; the phased array detector is configured with different scanning modes for pipe corner joints of different thicknesses and types; the phased array probe emits ultrasonic waves covering the detection area to the comparison test block, and determines the compensation curve based on the echo signal of the comparison test block; the system's sensitivity is calibrated based on the compensation curve and the set sensitivity to determine the evaluation line and quantitative line; the compensation curve includes a depth compensation curve and an angle compensation gain curve.

[0095] The phased array ultrasonic testing system and method for small-diameter pipe corner joints of this application have the following advantages.

[0096] 1. Comprehensive inspection coverage with no blind spots: Through targeted workpiece modeling and acoustic beam coverage analysis, combined with optimized scanning methods (first wave + second wave / third wave), it achieves full coverage of the root, surface, middle and heat-affected zone of the weld seam of the small pipe corner joint, effectively avoiding missed defects.

[0097] 2. High detection sensitivity and accurate quantification: By accurately matching probe parameters, optimizing sensitivity calibration and compensation schemes, and combining comprehensive analysis of multiple types of scanning images, the defect identification capability is significantly improved, the defect size measurement deviation is controlled within the allowable range, and the quantitative accuracy is better than traditional detection methods.

[0098] 3. Strong adaptability and versatility: Specialized testing procedures have been developed for carbon steel small pipe corner joints of different thicknesses (4mm~30mm) and different types (placement type, insertion type). At the same time, it can also be adapted to the testing of 4mm~10mm austenitic stainless steel small pipe corner joints, with a wide range of applications.

[0099] 4. High detection efficiency and good stability: The mechanical scanning method with position sensor is adopted, the detection process and parameter settings are standardized, human operation error is reduced, and detection efficiency is improved; the system verification mechanism ensures the stability of the detection process and the reliability of the detection results.

[0100] 5. Standardized operation and easy to promote: It clarifies the operation requirements and parameter standards for the entire process from preparation, debugging, implementation to evaluation, reduces the reliance on the experience of testing personnel, and facilitates its promotion and application within the industry.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A phased array ultrasonic testing system for small-diameter pipe corner joints, characterized in that, The phased array ultrasonic testing system for small-diameter pipe corner joints includes: a phased array tester, a phased array probe, a comparison test block, and a scanning device; The phased array detector is used for: Workpiece modeling is performed on the debugging test block to obtain a three-dimensional structural model of the debugging test block. Based on the three-dimensional structural model of the debugging test block, sound beam coverage analysis is performed to determine the detection area. The debugging test block is a series of pipe corner joints for system debugging. Different scanning methods are configured for pipe corner joints of different thicknesses and types; The phased array probe is used for: Ultrasonic waves covering the detection area are emitted to the comparison test block, and a compensation curve is determined based on the echo signal of the comparison test block. The system sensitivity is calibrated based on the compensation curve and the set sensitivity, and the evaluation line and quantitative line are determined. The compensation curve includes a depth compensation curve and an angle compensation gain curve. An ultrasonic wave covering the detection area is emitted towards the target workpiece; the target workpiece is a pipe corner joint to be tested. The scanning device is used for: According to the set scanning parameters and the scanning method matching the target workpiece, the scanning operation is performed on the target workpiece along the scanning path, the echo signal of the target workpiece is received, a scanning image is generated based on the echo signal of the target workpiece, and the scanning image is sent to the phased array detector. The phased array detector is also used for: The target workpiece is modeled to obtain a three-dimensional structural model of the target workpiece; Based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line, defect detection is performed on the target workpiece to obtain the defect detection result.

2. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 1, characterized in that, In terms of performing defect detection on the target workpiece based on the scanned image, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line to obtain defect detection results, the phased array detector is specifically used for: Based on the three-dimensional structural model of the target workpiece, defect identification is performed on the scanned image to determine the defect-related display area; The defect-related display area includes: the weld area and the area on the weld outline; Based on the defect-related display area, defect quantification is performed according to the evaluation line and the quantitative line to obtain the defect quantification result; the defect quantification result includes: the depth, amplitude, indication length and height of different defects; Based on the quantitative results of the defects, defects are merged to obtain the defect merging results; The target workpiece is graded according to the defect merging results, and the joint welding quality of the target workpiece is used as the defect detection result.

3. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 1, characterized in that, The phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a position sensor; the position sensor is mounted on the scanning device. The scanning device is also used to scan the test block according to the set scanning parameters and the scanning method matching the test block during system debugging; the position sensor is used to collect the actual displacement of the scanning device during system debugging; the phased array detector is also used to calibrate the position sensor according to the displayed displacement and the actual displacement during system debugging; the calibrated position sensor is used to collect the actual displacement of the scanning device during actual detection; the phased array detector is also used to determine whether the scanning device scans the target workpiece along the scanning path according to the actual displacement during real-time detection.

4. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 2, characterized in that, In terms of performing defect quantification based on the evaluation line and the quantitative line in the defect-related display area to obtain the defect quantification result, the phased array detector is specifically used for: The depth and amplitude of defects whose echo amplitude exceeds the assessment line are determined in the defect-related display area; For defects between the evaluation line and the quantitative line, the indication length of the defect is determined using the absolute sensitivity method of the evaluation line; for defects exceeding the quantitative line, the indication length of the defect is determined using the -6dB method. For defects exceeding the evaluation line, the height of the defect is determined using the -6dB half-wave height method or the endpoint diffraction method.

5. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 2, characterized in that, In terms of merging defects based on the quantitative defect results to obtain a defect merging result, the phased array detector is specifically used for: In the defect quantification results, for adjacent non-circular defects, if the distance between the two defects in the indicated length direction is less than the smaller of the indicated lengths of the two defects, and the distance between the two defects in the depth direction is less than the smaller of the heights of the two defects, then the adjacent non-circular defects are merged. The depth of the merged defect is the smaller of the depths of the two defects, the indicated length of the merged defect is the distance between the endpoints of the two defects before and after merging, and the height of the merged defect is the larger of the heights of the two defects or the sum of the heights of the two defects. The defect merging result includes: the depth of the merged defect, the indicated length of the merged defect, and the height of the merged defect.

6. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 1, characterized in that, The scanning method includes: for placement-type pipe corner joints, a primary wave is used to detect the root, and a secondary wave is used to detect the surface and middle; for insertion-type pipe corner joints, a primary or secondary wave is used to detect the main pipe side, a primary wave is used to detect the root of the branch pipe side, and a secondary wave is used to detect the surface and middle of the branch pipe side; the scanning angle of the phased array probe is between 35° and 75°.

7. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 1, characterized in that, The phased array probe is a shear wave phased array probe; the nominal frequency of the phased array probe is 5MHz~10MHz; the excitation aperture of the primary excitation element in the phased array probe is determined according to the thickness of the workpiece.

8. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 1, characterized in that, The phased array ultrasonic testing system for small-diameter pipe corner joints further includes: a wedge; the distance between the wedge and the target workpiece is less than a set distance value; the curvature of the wedge and the test surface of the target workpiece are matched; the ultrasonic waves emitted by the phased array probe reach the surface of the target workpiece through the wedge.

9. The phased array ultrasonic testing system for small-diameter pipe corner joints according to claim 1, characterized in that, The evaluation line is used to determine whether a defect has occurred; the quantitative line is used to determine whether the defect needs to be quantified; the sensitivity of the evaluation line and the quantitative line is determined based on the workpiece thickness.

10. A phased array ultrasonic testing method for small-diameter pipe corner joints, characterized in that, The phased array ultrasonic testing method for small-diameter pipe corner joints is used in the phased array ultrasonic testing system for small-diameter pipe corner joints according to any one of claims 1-9. The phased array ultrasonic testing method for small-diameter pipe corner joints includes: After the system's sensitivity is calibrated, a scan image of the target workpiece is acquired, and the target workpiece is modeled to obtain a three-dimensional structural model of the target workpiece. The scan image is generated by the scanning device scanning the target workpiece along the scanning path according to the set scanning parameters and the scanning method matching the target workpiece, receiving the echo signal of the target workpiece, and generating the image based on the echo signal of the target workpiece. Based on the scanned images, the three-dimensional structural model of the target workpiece, the evaluation line, and the quantitative line, defect detection is performed on the target workpiece to obtain the defect detection results; The system's sensitivity calibration process includes: The phased array detector models the test block to obtain a three-dimensional structural model of the test block, and performs sound beam coverage analysis based on the three-dimensional structural model of the test block to determine the detection area; the test block is a series of pipe corner joints for system debugging. The phased array detector is configured with different scanning methods for pipe corner joints of different thicknesses and types; The phased array probe emits ultrasonic waves covering the detection area to the comparison test block, and determines the compensation curve based on the echo signal of the comparison test block. The system sensitivity is calibrated based on the compensation curve and the set sensitivity to determine the evaluation line and the quantitative line. The compensation curve includes a depth compensation curve and an angle compensation gain curve.

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