Ultrasonic detection integrated test block for curved surface longitudinal butt joint

Abstract

The ultrasonic detection integrated test block comprises a main body structure, and a convex curved surface detection surface and a concave curved surface detection surface are arranged at the two ends of the main body structure respectively. The main body structure is provided with a concentric reflection arc group, a K value reference hole group, a distance-amplitude curve hole group, a plane detection area and a sharp corner groove which respectively face the convex surface and the concave surface; and the curvatures of the convex curved surface detection surface and the concave curved surface detection surface are consistent with the curvatures of the outer surface and the inner surface of the detected workpiece respectively. Therefore, in cooperation with an upgraded ultrasonic detector, the problem of poor coupling of a planar test block can be eliminated, the positioning precision is improved to 1mm, the transverse wave sound velocity and the K value of a curved surface probe are directly measured, dependence on the nominal K value of the probe is avoided, the error problem of curved surface sound path distance calculation and defect positioning is solved, a single test block can cover the whole process of calibration, measurement, curve making and the like, test block replacement is reduced, and the test efficiency is improved. Therefore, the method is suitable for on-site rapid detection.

Description

Technical Field

[0001] The present application relates to the technical field of non-destructive testing, and in particular to an integrated test block for ultrasonic testing of curved longitudinal butt joints. Background Art

[0002] In the ultrasonic testing of curved longitudinal butt joints of pressure-bearing equipment (such as titanium alloy spherical shells and manned pressure-resistant cabins of deep-sea probes), the existing technology has the following key problems:

[0003] 1. Inadequate adaptability for curved surface testing: Traditional ultrasonic test blocks (such as CSK-IA and RB-L) are mostly flat, resulting in poor coupling with curved workpieces (such as the inner and outer surfaces of spherical shells). This makes it difficult to calibrate the probe's incident point and refraction angle, leading to low positioning accuracy. For example, the test blocks specified in Appendix J of NB / T47013.3-2015, "Ultrasonic Testing Method for Curved Longitudinal Butt Joints in Pressure Equipment," are only suitable for testing surfaces with a curvature radius of 50mm to 250mm. Workpieces with large curvatures are treated as flat plates. This results in insufficient error when high-precision testing is required.

[0004] 2. Lack of actual measurement of key parameters: The shear wave sound velocity of different titanium alloy materials varies significantly due to the thermal processing process. The existing standard does not provide a measurement method, and reliance on literature values ​​leads to errors in sound path calculation. The actual refraction angle (K value) of the curved probe is affected by the curvature of the surface. Traditional test blocks cannot measure it directly and need to be indirectly estimated by grinding the probe, which results in large errors (for example, the error of a flat test block in detecting a 60mm deep transverse through hole is as high as 3mm). This test block uses a full-thickness K value reference hole to directly measure the actual refraction angle at different depths, avoiding parameter deviations caused by insufficient hole depth in traditional test blocks.

[0005] 3. Functional dispersion and low efficiency: The existing test blocks have a single function and need to be replaced frequently to complete steps such as zero point calibration and distance-amplitude curve creation. It is impossible to realize the incident point calibration, sound velocity measurement, K value measurement and timely baseline adjustment of the curved probe in an integrated manner. The detection process is cumbersome and the accuracy is insufficient.

[0006] In response to the above problems, the present invention provides an integrated curved surface detection test block, which solves the technical bottlenecks such as poor coupling, difficult parameter measurement, and low efficiency in curved surface detection through curved surface detection surface design, multi-functional area layout and actual measurement method, and meets the detection needs of high-voltage and high-reliability equipment. Summary of the Invention

[0007] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0008] To this end, one of the purposes of this application is to provide an integrated test block for ultrasonic testing of curved longitudinal butt joints. Combined with an upgraded ultrasonic detector, it can eliminate the coupling difference problem of flat test blocks, improve the positioning accuracy to 1mm, directly measure the shear wave speed and the K value of the curved probe, avoid relying on the nominal K value of the probe, and solve the error problems of curved sound path calculation and defect positioning. A single test block can cover the entire process of calibration, measurement, curve making, etc., reduce the replacement of test blocks, improve detection efficiency, and is suitable for on-site rapid detection.

[0009] In order to achieve the above-mentioned purpose, the first embodiment of the present application proposes an integrated test block for ultrasonic detection of curved longitudinal butt joints, including a main body structure, wherein a convex curved surface detection surface and a concave curved surface detection surface are respectively provided on the upper and lower surfaces of the main body structure, and the curvatures of the two surfaces are respectively consistent with the curvatures of the outer surface and inner surface of the workpiece to be measured, the curvature is a cylindrical curvature, and the material is the same as that of the workpiece to be measured, and a concentric reflection arc group, a K value reference hole group, a distance-amplitude curve hole group, a plane detection area and a sharp angle groove are provided on the main structure; the concentric reflection arc group is located on the left side of the main structure, each comprising two groups of concentric arcs of different radii, distributed along the radial direction of the main structure, and used for zero point calibration of the curved probe, actual measurement of shear wave sound velocity and timely baseline adjustment; the K value reference hole group includes a concave K value reference hole located near the convex curved surface detection surface and a concave K value reference hole located near the concave The convex surface K value reference hole near the curved surface detection surface, the convex surface K value reference hole and the concave surface K value reference hole are both radially distributed Φ2 long horizontal holes, the hole depth is the full thickness of the workpiece to be measured, and are used to measure the refraction angle (K value) of the curved surface probe; the distance-amplitude curve hole group is distributed on both sides of the main structure, including 8 transverse through holes of different depths, and maintains a distance from the concentric reflection arc group to avoid signal interference, and is used to produce the distance-amplitude detection curve of the curved surface probe; the plane detection area is located on the right side of the main structure, which is a 30° oblique plane, used for sensitivity adjustment and timely baseline calibration of the plane straight probe; the pointed angle groove is located at the lower right edge of one side of the concave curved surface detection surface, which is a 60° pointed angle structure with a depth of 2mm, and the tip points to the edge of the main body. It is only used to calibrate the maximum sound range once during convex surface detection to avoid interference from multiple reflectors.

[0010] An integrated test block for ultrasonic testing of curved longitudinal butt joints in an embodiment of the present application, when used in conjunction with an upgraded ultrasonic detector, can eliminate the coupling difference problem of planar test blocks, improve the positioning accuracy to 1 mm, directly measure the shear wave velocity and the K value of the curved probe, avoid relying on the nominal K value of the probe, and solve the error problems in the calculation of the curved sound path and defect positioning. A single test block can cover the entire process of calibration, measurement, curve making, etc., reduce the replacement of test blocks, improve detection efficiency, and is suitable for on-site rapid detection.

[0011] In addition, the integrated ultrasonic testing block for curved longitudinal butt joints proposed in the present application may also have the following additional technical features:

[0012] In one embodiment of the present application, the main structure is a columnar body, and the convex curved surface detection surface and the concave curved surface detection surface are respectively arranged at two ends of the columnar body, and the centers of the two circles coincide with each other.

[0013] In one embodiment of the present application, the concentric reflection arc group includes a first concentric arc and a second concentric arc, the centers of the first concentric arc and the second concentric arc are both on the convex curved surface detection surface or the concave curved surface detection surface, the radii of the two groups of arcs are R1 and R2 (R1≠R2), respectively, with a total of four arc surfaces, and the arc surfaces are respectively facing the inside and outside of the main structure, forming a reflection interface with the same vertex as the curved surface detection surface, which is used for zero point calibration of the curved probe, actual measurement of shear wave sound velocity and timely baseline adjustment.

[0014] In one embodiment of the present application, the convex surface K value reference hole and the concave surface K value reference hole are both perpendicular to the main structure, and are the long horizontal holes closest to the concave surface detection surface and the convex surface detection surface respectively.

[0015] In one embodiment of the present application, the diameter of the transverse through hole of the distance-amplitude curve hole group is Φ2mm, the hole depth is the full thickness of the workpiece being measured, and it is radially distributed along the detection surface, and the hole axis is perpendicular to the curvature radius direction of the detection surface.

[0016] In one embodiment of the present application, the 30° oblique angle plane of the planar detection area forms a 30° angle with the axis of the main structure, and the surface roughness of the plane is consistent with the planar detection surface of the workpiece being measured.

[0017] In one embodiment of the present application, the tip of the pointed groove points to the edge of the main structure, and the groove depth is 2 mm, which is used to form a reflection signal of a specific sound range during detection to calibrate the maximum sound range.

[0018] In one embodiment of the present application, a method for ultrasonically detecting a curved longitudinal butt joint includes the following steps:

[0019] (a) Couple the concave-convex surface probe to the convex or concave detection surface of the main structure, and select the probe with the corresponding curvature according to the surface type (convex / concave) of the workpiece to be measured;

[0020] (b) Using a concentric reflection arc set, calibrate the probe's incident point, adjust the time baseline, and measure the shear wave velocity;

[0021] (c) Using the K-value reference hole group, the probe's refraction angle (K value) is measured. A distance-amplitude curve is created using the distance-amplitude curve hole group. The actual K value is calculated using the instrument's built-in algorithm, combining the surface curvature radius R, the surface curvature radius r, the hole depth H, and the sound path s.

[0022] (d) Use the sharp-angle slot to calibrate the maximum sound path and eliminate interference clutter;

[0023] (e) Adjust the sensitivity of the straight probe in combination with the flat detection area.

[0024] In one embodiment of the present application, in step (c), the measurement of the refraction angle (K value) is achieved by the surface correction function of the ultrasonic instrument, and the actual K value is calculated based on the curvature radius of the main structure, the hole depth and the hole diameter of the K value reference hole group.

[0025] In one embodiment of the present application, the main structure is linked with the curved surface correction module of the ultrasonic testing instrument to automatically calculate the radial depth (H) and surface arc length of the defect.

[0026] The advantages of this application compared with the existing technology are:

[0027] (1) The convex / concave surface detection surface is consistent with the curvature of the workpiece, eliminating the coupling difference problem of the flat test block and improving the positioning accuracy to 1mm.

[0028] (2) Directly measure the shear wave velocity and the K value of the curved probe to avoid relying on nominal values ​​and solve the error problem of sound path calculation and defect location.

[0029] (3) A single test block covers the entire process of calibration, measurement, and curve making, which reduces the need for test block replacement, improves detection efficiency, and is suitable for rapid on-site detection.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0032] Figure 1 This is a top view of an integrated test block for ultrasonic testing of a curved longitudinal butt joint according to one embodiment of the present application;

[0033] Figure 2 This is a side perspective view of an integrated test block for ultrasonic testing of a curved longitudinal butt joint according to one embodiment of the present application;

[0034] Figure 3 This is a physical picture of an integrated test block for ultrasonic testing of curved longitudinal butt joints according to one embodiment of the present application;

[0035] Figure 4 This is a physical picture of an integrated test block for ultrasonic testing of curved longitudinal butt joints according to another embodiment of the present application;

[0036] Figure 5 This is a physical picture of an integrated test block for ultrasonic testing of curved longitudinal butt joints according to another embodiment of the present application;

[0037] Figure 6 This is a physical picture of an integrated test block for ultrasonic testing of curved longitudinal butt joints according to another embodiment of the present application;

[0038] Figure 7 An instrument interface for measuring the K value of a curved surface probe of an integrated test block for ultrasonic testing of a curved longitudinal butt joint according to one embodiment of the present application;

[0039] Figure 8 The present invention provides an instrument arrangement for measuring the K value of a curved surface probe of an integrated test block for ultrasonic testing of a curved longitudinal butt joint according to an embodiment of the present application.

[0040] Figure 9 Schematic diagram of a geometric model for measuring the convex surface K value of an integrated test block for ultrasonic testing of a curved longitudinal butt joint according to one embodiment of the present application; Figure 10 This is a geometric model and parameter annotation diagram for measuring the concave surface K value of an integrated test block for ultrasonic testing of a curved longitudinal butt joint according to an embodiment of the present application. As shown in the figure: 1. Main structure; 3. Concentric reflection arc group; 4. K-value reference hole group; 5. Distance-amplitude curve hole group; 6. Plane detection area; 7. Sharp-angle groove; 101. Convex curved surface detection surface; 102. Concave curved surface detection surface; 401. Convex K-value reference hole; 402. Concave K-value reference hole; 301. First concentric arc; 302. Second concentric arc. DETAILED DESCRIPTION

[0041] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application and are not to be construed as limiting the present application. On the contrary, the embodiments of the present application include all variations, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0042] The following describes an integrated test block for ultrasonic testing of curved longitudinal butt joints according to an embodiment of the present application with reference to the accompanying drawings.

[0043] like Figures 1-10As shown, an integrated test block for ultrasonic detection of curved longitudinal butt joints according to an embodiment of the present application may include a main structure 1, a convex curved surface detection surface 101 and a concave curved surface detection surface 102 are respectively provided at both ends of the main structure 1, and a concentric reflection arc group 3, a K value reference hole group 4, a distance-amplitude curve hole group 5, a plane detection area 6 and a sharp-angle groove 7 are provided on the main structure 1.

[0044] It is understandable that the main structure 1 is adapted to the detection surface

[0045] The main structure 1 is a cylinder, with the upper and lower bottom surfaces machined into convex and concave cylindrical test surfaces (concave) respectively. The radius of curvature matches the outer and inner surfaces of the workpiece being tested (such as a cylindrical container). The line connecting the sphere centers (i.e., the cylinder axis) coincides with the center of curvature of the test surface, and the materials are the same. During testing, the probe is tightly bonded to the test surface through the coupling agent, eliminating the problem of poor coupling between curved and flat surfaces and ensuring efficient transmission of sound waves.

[0046] External surface inspection: Use a concave curved probe (the curvature of the wedge matches the convex curved inspection surface 101), with the convex surface of the test block facing upwards, and place the probe on the convex curved inspection surface 101 for scanning.

[0047] Internal surface inspection: Turn the test block over, use a convex curved probe (the curvature of the wedge matches the concave curved detection surface 102), and place the probe on the concave curved detection surface 102 for scanning.

[0048] Calibration function of concentric reflex arc group 3

[0049] The concentric reflective arc group 3 is located on the left side of the main structure 1 and includes two groups of concentric arcs with different radii, distributed along the radial direction of the main body, on the detection surface (101 / 102).

[0050] Zero point calibration: The probe emits sound waves and determines the probe's incident point position through the arc reflection signal to eliminate the leading edge error.

[0051] Shear wave velocity measurement: The acoustic path difference between arcs of different radii (such as R50 and R100 arcs) is used to calculate the actual shear wave velocity (such as the measured value of 3055m / s) to avoid relying on literature values.

[0052] Time baseline adjustment: According to the sound path of the arc reflection signal, calibrate the instrument time baseline to ensure that the sound path display is consistent with the actual detection.

[0053] Refraction Angle Measurement of K-Value Reference Hole Group 4

[0054] The K-value reference hole group 4 includes: convex K-value reference holes 401: located near the concave curved surface detection surface 102, distributed radially, with the hole axis perpendicular to the main structure 1, the hole diameter Φ2mm, and the hole depth is the full thickness of the workpiece.

[0055] Concave K-value reference hole 402: Located near the convex curved surface detection surface 101, the structure is symmetrical with the convex reference hole, and the hole depth is the full thickness of the workpiece, ensuring that the refraction angle measurement range exceeds the near field area when detecting the internal and external surfaces.

[0056] During testing, the probe emits sound waves to the reference hole, and the position of the reflected signal from the bottom of the hole is combined with the instrument's surface correction function (input hole depth, hole diameter, and workpiece curvature radius) to calculate the actual refraction angle (K value). For example, when testing the outer surface, the signal from the convex reference hole (401) at a depth of 60 mm is measured to be K = 0.92, thereby improving the defect location accuracy.

[0057] Distance-amplitude curve hole group 5 curve creation

[0058] The distance-amplitude curve hole group 5 is distributed on both sides of the main structure 1, and includes 8 full-thickness transverse through holes (Φ2×full thickness), which are evenly distributed along the radial direction of the detection surface, and the hole depth covers the full thickness range of the workpiece from the surface to the bottom (such as 10 to 80 mm).

[0059] Each hole maintains a distance (e.g., ≥10 mm) from the concentric reflection arc group (3) to avoid signal interference and ensure the independence of the echo signal within the entire thickness range.

[0060] Straight probe adaptation for plane detection zone 6

[0061] The plane detection area 6 is located on the right side of the main body and is a 30° oblique plane. The surface roughness is consistent with the plane detection surface of the workpiece being measured.

[0062] The flat straight probe is placed in this area, and by adjusting the sensitivity, the distance-amplitude curve is created and the baseline calibration is completed in time, taking into account the plane detection requirements (such as Class C detection standards).

[0063] Calibration of the maximum sound range of sharp-angle slot 7

[0064] The sharp-angle groove 7 is located at the lower right edge of one side of the concave curved detection surface 102, has a 60° sharp angle structure, a groove depth of 2 mm, and a tip pointing to the edge of the main body.

[0065] During external surface inspection, the direct wave emitted by the probe is reflected by the sharp-angle groove 7, and the maximum sound range is calibrated once to distinguish effective defect signals from clutter, thereby improving the defect recognition capability.

[0066] It should be noted that the sharp-angle groove 7 is only used for convex surface detection. When detecting the inner surface of the cylinder, the probe is coupled to the convex cylindrical detection surface. The direct wave is reflected by the sharp-angle groove, and the maximum sound range is calibrated once to avoid interference from external surface clutter.

[0067] Workflow Summary

[0068] 1. Coupling probe: Select a probe with the corresponding curvature according to the test surface (convex surface 101 / concave surface 102) and apply coupling agent to ensure a good fit.

[0069] 2. Calibration and measurement:

[0070] Calibrate the incident point, measure the sound velocity, and adjust the time base using the concentric reflection arc group 3;

[0071] The refraction angle (K value) is measured using the K value reference hole group 4, and the instrument surface correction module is used.

[0072] 3. Curve production: Use distance-amplitude curve hole group 5 to produce the test curve, covering the full thickness range.

[0073] 4. Auxiliary functions:

[0074] The plane straight probe adjusts the sensitivity in the plane detection area 6;

[0075] The sharp-angled groove 7 is used to calibrate the maximum sound range and eliminate interference signals.

[0076] Through the above steps, the integrated test block realizes the precise calibration of the curved probe, parameter measurement and test preparation, meeting the high-precision detection requirements of curved surface welds of high-voltage equipment.

[0077] In one embodiment of the present application, Figures 1-10 As shown, the main structure 1 is a columnar body, and the convex curved surface detection surface 101 and the concave curved surface detection surface 102 are respectively arranged at two ends of the columnar body, and the centers of the two circles coincide with each other.

[0078] As will be understood, the main structure 1 is a cylindrical object, constructed from the same material, heat treatment, and surface finish as the workpiece being tested, ensuring no attenuation or coupling errors caused by material differences during testing. Convex and concave detection surfaces 101 and 102 are located at either end, respectively. The line connecting their centers coincides with the axis of the cylinder, forming a geometrically symmetrical structure. This ensures uniform distribution of the ultrasonic beam along the axis and eliminates positioning errors caused by surface curvature.

[0079] Detection surface adaptation and probe selection

[0080] External surface inspection: Use a concave curved probe (the curvature of the wedge matches the convex curved inspection surface 101), couple the probe to the convex curved inspection surface 101, with the convex surface of the test block facing upward, and inject the sound beam along the axis of the cylinder, fitting the curvature of the workpiece's external surface.

[0081] Inner surface detection: Flip the test block and use a convex curved probe (the curvature of the wedge matches the concave curved detection surface 102), coupled to the concave curved detection surface 102, to adapt to the curvature of the inner surface of the workpiece and achieve symmetrical adaptation of the inner and outer detection.

[0082] In one embodiment of the present application, Figures 1-10 As shown, the concentric reflection arc group 3 includes a first concentric arc 301 and a second concentric arc 302. The centers of the first concentric arc 301 and the second concentric arc 302 are both on the convex curved detection surface 101 or the concave curved detection surface 102. The radii of the two groups of arcs are R1 and R2 (R1≠R2), respectively, with a total of four arc surfaces. The arc surfaces are respectively facing the inside and outside of the main structure 1, forming a reflection interface with the same vertex as the curved detection surface, which is used for zero point calibration of the curved probe, actual measurement of shear wave sound velocity and timely baseline adjustment.

[0083] It is understandable that

[0084] 1. Geometric structure and parameter design

[0085] 1. Center positioning:

[0086] Convex surface detection 101 scene:

[0087] The center O1 of the first concentric arc 301 is located on the convex curved detection surface 101, and the arc surface faces the outside of the main structure 1 (i.e., convex toward the edge of the main structure);

[0088] Concave surface detection surface 102 scene:

[0089] The center O2 of the second concentric arc 302 is located on the concave detection surface 102 , and the arc surface faces the interior of the main structure 1 (ie, is concave toward the main axis).

[0090] Radius Difference:

[0091] Assume that the radius of the first concentric arc 301 is R1 and R2, and the radius of the second concentric arc 302 is R1 and R2 (R1≠R2, such as R1=50mm, R2=100mm). The two are centered on the common vertex O and distributed radially along the main structure 1 to form reflection interfaces with different sound paths.

[0092] 2. Detailed Workflow

[0093] 1. Probe coupling and detection surface adaptation

[0094] External surface inspection (convex surface inspection surface 101):

[0095] Couple the concave curved probe (the wedge curvature matches the convex curved detection surface 101 ) to the convex curved detection surface 101 , aligning the probe incident point with the circle center O1 (surface vertex) to ensure that the sound beam is incident vertically along the normal direction of the arc 301 .

[0096] Inner surface detection (concave surface detection surface 102):

[0097] Flip the test block and couple the convex curved probe (the curvature of the wedge matches the concave curved detection surface 102 ) to the concave curved detection surface 102 . The probe incident point is aligned with the center O2 (surface vertex), and the sound beam is incident vertically along the normal direction of the arc 302 .

[0098] 2. Zero point calibration (incident point correction)

[0099] Signal reflection path:

[0100] The probe transmits an ultrasonic signal to the first concentric arc 301 (radius R1, radius R2). The signal is reflected by the arc surface and returns to the probe with a sound path of 2R1. Similarly, the sound path to the second concentric arc 302 (radius R2) is 2R2.

[0101] Find the highest position of the echo, use a ruler to measure the distance from the front edge of the probe to the vertex of the concentric arc R1, subtract the measured distance from R1 to obtain the distance from the incident point to the front edge (probe front edge).

[0102] 3. Shear wave speed measurement

[0103] Principle of double arc method:

[0104] Using the two arc sound path difference Δs=2(R2-R1) and the corresponding echo time difference Δt, the formula Calculate the actual shear wave speed of sound.

[0105] Example: If R1 = 50 mm, R2 = 100 mm, sound path difference Δs = 100 mm, time difference Δt = 33.3 μs, then the measured sound velocity is

[0106] 4. Time Baseline Adjustment

[0107] Reference sound range setting:

[0108] The theoretical sound path of the first concentric arc 301 (R1 and R2) or the second concentric arc 302 (R1 and R2) is used as a calibration reference.

[0109] Instrument adjustment:

[0110] The instrument function automatically matches the distance scale displayed on the screen with the actual sound range (R1 and R2), ensuring that the defect sound range displayed during subsequent inspections is consistent with the actual one, with a positioning accuracy of ≤1mm.

[0111] In one embodiment of the present application, Figures 1-10 As shown, the convex surface K value reference hole 401 and the concave surface K value reference hole 402 are both perpendicular to the main structure 1 and are the long horizontal holes closest to the concave curved surface detection surface 102 and the convex curved surface detection surface 101 respectively.

[0112] It can be understood that the convex surface K-value reference holes 401 are located near the concave surface detection surface 102, distributed along its radial direction, with the hole axis perpendicular to the main body; the concave surface K-value reference holes 402 are located near the convex surface detection surface 101, distributed along its radial direction, with the hole axis perpendicular to the main body. Both are Φ2mm long horizontal holes with a hole depth covering the thickness range of the workpiece being measured (e.g., 40mm, 60mm, 80mm), and are used to measure the actual refraction angle (K value) of the curved surface probe.

[0113] Detailed workflow

[0114] Step 1: Probe Selection and Coupling

[0115] External surface testing: Use a concave curved probe (the curvature of the wedge matches the convex curved testing surface 101), couple it to the convex curved testing surface 101, with the convex surface of the test block facing upwards, and ensure that the probe sound beam is incident vertically along the radial direction.

[0116] Inner surface detection: Turn the test block over, select a convex curved probe (the curvature of the wedge matches the concave curved detection surface 102), couple it to the concave curved detection surface 102, and let the sound beam be incident vertically along the radial direction.

[0117] Step 2: Signal emission and reflection collection

[0118] The probe transmits an ultrasonic signal to the convex surface K value reference hole 401 or the concave surface K value reference hole 402 , and the signal is reflected by the hole and then returns to the probe.

[0119] Since the hole axis is perpendicular to the main body, the reflection signal path is clear, avoiding the error in sound path calculation caused by hole tilt.

[0120] Step 3: Calculation of actual refraction angle (K value)

[0121] Use the ultrasonic instrument's surface K value measurement function to enter the following parameters:

[0122] Hole depth (h): such as 60 mm (radial depth from the detection surface);

[0123] Aperture (d): Φ2mm;

[0124] Inner and outer radius of the workpiece (R / r): For example, outer radius is 990mm, inner radius is 900mm (depending on the parameters of the workpiece being measured).

[0125] The instrument automatically calculates the actual refraction angle K (such as the measured K = 0.92) based on the sound path (s) and geometric relationship, and corrects the deviation of the probe's nominal K value.

[0126] Step 4: Internal and external surface detection and adaptation

[0127] When inspecting the outer surface, the convex surface K value reference hole 401 is used to measure the refraction angle under the convex surface;

[0128] When inspecting the inner surface, the refraction angle under the concave surface is measured through the concave surface K value reference hole 402 to ensure that the inspection accuracy under the two curvatures is consistent.

[0129] In one embodiment of the present application, Figures 1-10 As shown, the diameter of the transverse through hole of the distance-amplitude curve hole group 5 is Φ2mm, the hole depth is the full thickness of the workpiece being measured, and it is distributed radially along the detection surface. The hole axis is perpendicular to the curvature radius of the detection surface.

[0130] As can be understood, the distance-amplitude curve hole group 5 is distributed on both sides of the main structure 1 and includes eight long horizontal holes with a diameter of 2 mm. The depth increases from the surface of the measured workpiece to the inside, covering a detection range of 10 to the workpiece thickness (e.g., 80 mm). Each hole is spaced apart from the concentric reflection arc group 3 to avoid signal interference and ensure the independence and accuracy of the reflected signals.

[0131] Detailed workflow

[0132] Step 1: Probe Preparation and Coupling

[0133] A curved probe that matches the curvature of the detection surface (a concave probe for external surface detection, a convex probe for internal surface detection) is selected and tightly coupled to the convex detection surface 101 or the concave detection surface 102 through a coupling agent.

[0134] Step 2: Layered scanning and signal acquisition

[0135] The probe scans the transverse through holes on both sides of the main structure 1 in sequence, and the depth of each transverse through hole corresponds to a different detection depth (such as 10mm, 20mm, 40mm, 60mm, 80mm, etc.).

[0136] The probe transmits ultrasonic signals, receives echoes reflected from the holes, and records the echo amplitude and corresponding sound path distance of holes at each depth.

[0137] Step 3: Distance-amplitude curve creation

[0138] The collected echo amplitude data is input into the ultrasonic instrument, and the instrument draws a distance-amplitude curve with the hole depth as the horizontal coordinate (10mm to the workpiece thickness) and the echo amplitude as the vertical coordinate.

[0139] The curve covers the full thickness inspection range and is used for quantitative evaluation of defect echoes in subsequent inspections to determine whether the defect size and location meet standards (such as NB / T47013.3-2015).

[0140] Step 4: Internal and external surface detection and adaptation

[0141] When inspecting the outer surface, a curve is drawn using the transverse through hole data on the convex curved surface inspection surface 101 side; when inspecting the inner surface, the test block is flipped over and a curve is drawn using the transverse through hole data on the concave curved surface inspection surface 102 side to ensure uniform inspection standards for both inside and outside.

[0142] In one embodiment of the present application, Figures 1-10 As shown, the 30° oblique plane of the plane detection area 6 forms a 30° angle with the axis of the main structure 1, and the surface roughness of the plane is consistent with the plane detection surface of the workpiece to be measured.

[0143] It is understood that the plane detection area 6 is located on the right side of the main structure 1 and is an oblique plane with a 30° angle with the main axis. Its surface roughness is consistent with the plane detection surface of the workpiece being measured (e.g., Ra ≤ 0.8μm). This design ensures that the coupling effect of the plane straight probe in this area is consistent with the actual plane portion of the workpiece, avoiding detection errors caused by surface condition differences.

[0144] Detailed workflow

[0145] Step 1: Probe Selection and Coupling

[0146] Use a flat straight probe (not a curved probe) and fit it tightly to the flat detection area 6 through a coupling agent to ensure that the sound beam is perpendicular to the incident plane and avoid reflection loss caused by angle deviation.

[0147] Step 2: Sensitivity Adjustment

[0148] The probe transmits ultrasonic signals, scans the 30° oblique plane of the plane detection area 6, and collects the reflected echo of the Φ2 long horizontal hole.

[0149] By adjusting the instrument gain, the echo amplitude of standard reflectors (such as Φ2 long horizontal holes) at different depths can meet the detection standard requirements (such as the evaluation line height specified in NB / T47013.3-2015), completing the sensitivity calibration.

[0150] Step 3: Time Baseline Adjustment

[0151] The geometric characteristics of the plane detection area 6 are utilized to calibrate the time base of the ultrasonic instrument with the plane in the thickness direction of the main body as a reference.

[0152] Step 4: Compatibility of plane and curved surface detection

[0153] When inspecting the planar area of ​​the workpiece (such as the planar portion of the butt weld between the tube seat and the spherical shell), the calibrated planar straight probe can be used directly without replacing the test block, thereby improving inspection efficiency.

[0154] When testing curved surfaces (such as the inner and outer surfaces of a spherical shell), the test block is turned over and the convex / concave curved surface (101 / 102) is used in conjunction with the curved probe, while the flat surface detection area 6 serves as an auxiliary calibration area to ensure uniform parameters under different detection modes.

[0155] In one embodiment of the present application, Figures 1-10 As shown, the tip of the pointed groove 7 points to the edge of the main structure 1, and the groove depth is 2 mm, which is used to form a reflection signal of a specific sound range during detection to calibrate the maximum sound range.

[0156] As you can see, the sharp-angled groove 7, located on the lower right side of the main structure 1, is a 60-degree sharp angle with a depth of 2mm, its tip pointing toward the edge of the main body. This structure is designed in conjunction with the convex curved detection surface 101 to ensure that when testing external surfaces, direct waves can form a clear reflection signal here, which is used to calibrate the maximum sound path.

[0157] Detailed workflow

[0158] Step 1: Probe coupling and signal launch

[0159] During the external surface inspection, the concave curved surface probe is coupled to the convex curved surface inspection surface 101 , with the convex surface of the test block facing upwards, and the probe emits direct ultrasonic waves that propagate radially along the main structure 1 .

[0160] Step 2: Reflection signal acquisition

[0161] When the ultrasonic signal reaches the sharp-angled groove 7, the 60-degree sharp-angled structure causes the sound wave to be reflected, forming an echo signal with a specific sound path.

[0162] The groove depth of 2mm ensures that the reflected signal is within the effective sound range of the detection area to avoid confusion with near-surface clutter.

[0163] Step 3: Maximum sound range calibration

[0164] The reflected echo of the sharp-angle groove 7 is identified by the instrument, and its sound path is determined to be the maximum propagation distance of the primary wave under the current detection conditions (that is, the sound path from the probe to the bottom of the groove).

[0165] This sound path is used as a benchmark to distinguish effective defect signals in the weld area from interference noise (such as bottom surface echoes or structural reflection waves) that are beyond the detection range.

[0166] Step 4: Clutter judgment and defect identification

[0167] During the detection process, if the echo signal sound range is greater than the maximum sound range calibrated by the sharp-angle slot 7, it is judged as invalid clutter; otherwise, the defect equivalent is evaluated in combination with the distance-amplitude curve (produced by the distance-amplitude curve hole group 5) to improve the defect recognition efficiency.

[0168] In one embodiment of the present application, Figures 1-10 As shown, a method for ultrasonic testing of curved longitudinal butt joints comprises the following steps:

[0169] (a) Coupling the concave-convex surface probe with the convex detection surface 101 or the concave detection surface 102 of the main structure 1, and selecting a probe with the corresponding curvature according to the type of the workpiece surface to be measured (convex / concave);

[0170] (b) calibrating the probe's incident point, adjusting the time baseline, and measuring the shear wave velocity using concentric reflection arc group 3;

[0171] (c) Use K-value reference hole group 4 to measure the probe's refraction angle (K value), and use distance-amplitude curve hole group 5 to create a distance-amplitude curve. Combined with the surface curvature radius R, the surface curvature radius r, the hole depth H, and the sound path s, the actual K value is calculated using the instrument's built-in algorithm.

[0172] (d) The maximum sound path is calibrated once through the sharp-angle groove 7 to eliminate interference clutter;

[0173] (e) Adjust the sensitivity of the straight probe in conjunction with the plane detection area 6.

[0174] It is understandable that the specific steps are as follows:

[0175] (a) Probe coupling and detection surface adaptation

[0176] Operation: Select a probe with the corresponding curvature according to the test surface. When testing the external surface, use a curved probe with a wedge processed into a concave surface, coupled to the convex curved test surface 101, with the convex surface of the test block facing upward. When testing the internal surface, turn the test block over and use a convex curved probe to couple to the concave curved test surface 102, ensuring that the probe curvature fully matches the test surface. Use a coupling agent to eliminate interface coupling errors.

[0177] Purpose: To achieve efficient coupling between the curved probe and the inner and outer surfaces of the workpiece, avoid the acoustic energy loss caused by the flat test block, and ensure the stability of the detection signal.

[0178] (b) Calibration and sound velocity measurement of concentric reflection arc group 3

[0179] Incident point calibration: The probe transmits an ultrasonic signal, which is reflected by the maximum arc of the concentric reflection arc group 3 (such as the first concentric arc 301 and the second concentric arc 302). After finding the highest reflection time, the distance between the front edge of the probe and the arc vertex is measured to obtain the probe incident point position.

[0180] Time base adjustment: Based on the arc theoretical sound range (such as the 2R sound range corresponding to R50 and R100) as the benchmark, adjust the instrument time base so that the sound range displayed on the screen is consistent with the actual detected sound range.

[0181] Shear wave velocity measurement: Using the difference in radius between the two arcs (ΔR) and the difference in echo time (Δt), the formula Calculate the actual shear wave speed (such as the measured value of 3055m / s) to avoid errors caused by relying on literature data.

[0182] (c) K value measurement and distance-amplitude curve production

[0183] K-value reference hole group 4 measurement: When inspecting the outer surface, the signal is transmitted through the convex K-value reference hole 401 (radially distributed, Φ2mm long through hole, such as 40mm depth). The instrument calculates the actual refraction angle K (such as K = 0.92) based on the hole depth and the workpiece curvature radius.

[0184] When inspecting the inner surface, the concave K-value reference hole 402 is used, and the process is consistent to ensure the measurement accuracy of the refraction angle of the inner and outer surfaces.

[0185] Distance-amplitude curve preparation: Scan 5 hole groups (8 Φ2mm transverse holes with different depths, ranging from 10 to 80mm) along both sides of the main body, collect the echo amplitude of each hole, draw a curve, and cover the entire thickness detection range to provide a benchmark for defect quantification.

[0186] (d) Sharp angle slot 7 calibrates the maximum sound path

[0187] Structural function: The sharp-angle groove 7 is a 60° sharp angle with a depth of 2mm on the lower right side, with the tip pointing to the edge of the main body. When detecting the outer surface, the direct wave forms the only reflected signal here, and the sound path is the straight line from the probe to the bottom of the groove.

[0188] In one embodiment of the present application, Figures 1-10 As shown, in step c, the measurement of the refraction angle (K value) is achieved through the surface correction function of the ultrasonic instrument, and the actual K value is calculated in combination with the curvature radius of the main structure 1, the hole depth and hole diameter of the K value reference hole group 4.

[0189] It is understandable that step c refraction angle (K value) measurement and distance-amplitude curve production

[0190] Core components: K-value reference hole group 4, ultrasonic instrument surface correction function, main structure 1.

[0191] 1. Probe coupling and parameter input

[0192] External surface inspection: couple the concave curved probe to the convex curved inspection surface 101, with the convex surface of the test block facing upwards;

[0193] Inner surface detection: the test block is turned over and the convex curved surface probe is coupled to the concave curved detection surface 102 .

[0194] Instrument parameter setting: input the inner and outer radius of the workpiece (such as outer radius 990mm, inner radius 900mm), the hole diameter of K value reference hole group 4 (Φ2mm) and the target hole depth (such as 40mm, 60mm, etc., covering the workpiece thickness range).

[0195] 2. Signal emission and reflection collection

[0196] The probe transmits an ultrasonic signal to the convex K-value reference hole 401 or the concave K-value reference hole 402. The signal enters the hole axis in a radial direction perpendicular to the axis of the hole (perpendicular to the line connecting the sphere centers), and returns to the probe after being reflected at the bottom of the hole.

[0197] The instrument captures the sound path (s) and echo position of the reflected echo, and combines it with the preset hole depth (h) and workpiece curvature radius (R / r) to enable the surface correction function.

[0198] 3. Calculation principle of actual K value

[0199] Geometric relationship: According to the law of refraction, the refraction angle K value (tanθ) is the ratio of the horizontal sound path to the hole depth, that is,

[0200] Surface correction: The instrument automatically compensates for the effect of surface curvature on the sound beam path through a built-in algorithm. The formula is: External inspection: K = tanθ,

[0201] Internal inspection: K=tanθ, θ=180°-α,

[0202] Where s is the measured sound path, H is the hole depth, and the final output is the actual refraction angle K (for example, K = 0.92 during external inspection).

[0203] 4. Multi-depth hole measurement and verification

[0204] Repeat the above steps for through holes of different depths (such as 40 mm, 60 mm, and 80 mm) in the K-value reference hole group 4 to verify the consistency of the refraction angle and ensure the measurement accuracy within the full thickness detection range (error ≤ 1%).

[0205] Application example: Using a 60mm deep convex K-value reference hole 401 and a workpiece outer radius of 990mm, the instrument calculates the actual refraction angle K = 0.92, correcting the deviation from the probe's nominal K value to provide precise parameters for defect location.

[0206] 5. Distance-amplitude curve production

[0207] Using the distance-amplitude curve, eight transverse holes of different depths (Φ2×40mm, depth 10-80mm) in hole group 5 were scanned hole by hole with the probe to collect the echo amplitude.

[0208] With hole depth as the horizontal coordinate and echo amplitude as the vertical coordinate, a distance-amplitude curve is drawn, covering the full thickness detection range of the workpiece, which is used for subsequent quantitative defect evaluation.

[0209] In one embodiment of the present application, Figures 1-10 As shown, the main structure 1 and the ultrasonic detector

[0210] The surface correction module of the detector is linked to automatically calculate the radial depth (H) and surface arc length of the defect

[0211] It can be understood that the main structure 1 and the surface correction module are linked to calculate the defect location:

[0212] 1. Parameter initialization before detection

[0213] Curvature radius input: The outer radius R (such as 990 mm) of the convex curved surface detection surface 101 and the inner radius r (such as 900 mm) of the concave curved surface detection surface 102 of the main structure 1 are input into the ultrasonic instrument as a geometric reference for surface correction.

[0214] Probe calibration: Measure the shear wave velocity (e.g., 3055 m / s) through the concentric reflection arc group 3, and use the K value reference hole group 4 to obtain the actual refraction angle K (e.g., 0.92) to ensure that the instrument parameters fully match the test block curvature.

[0215] 2. Defect signal acquisition and processing

[0216] Signal incidence: During testing, the concave and convex surface probe is coupled to the corresponding test surface (101 / 102), and the ultrasonic signal is transmitted to the weld area of ​​the workpiece. The defect reflection signal returns to the instrument, and the sound path s and echo amplitude are recorded.

[0217] Surface correction trigger: The instrument recognizes that the signal comes from the surface detection scene, starts the surface correction module, and calls the curvature radius R / r and the measured refraction angle K of the main structure 1.

[0218] 3. Calculation principle of radial depth (H)

[0219] Geometric model: Based on the surface geometry, the radial depth H of the defect is the difference between the distance from the center of the detection surface to the defect and the thickness of the spherical shell.

[0220] When inspecting the outer surface: Where θ = arctan(K) and s is the measured sound path.

[0221] When inspecting the inner surface: α=180°-θ,θ=arctanK, ensuring the uniformity of calculation logic for inner and outer surfaces.

[0222] Module linkage: The instrument's built-in algorithm automatically substitutes R / r, s, and K, and outputs the radial depth H of the defect from the inspection surface (accuracy ±1mm).

[0223] 4. Surface arc length Calculation principle

[0224] Arc length geometry: The surface arc length is the length of the arc projected by the defect on the inspection surface:

[0225] External inspection:

[0226] Internal inspection:

[0227] Built-in algorithm, automatically input R, r, s, K, output surface arc length

[0228] 5. Practical Application Examples

[0229] according to Figure 7 and Figure 8 As shown, the outer surface detection: R = 990mm, K = 0.92, θ = 42.61°, detecting a long horizontal hole 60mm away from the outer wall, H = 60mm, the instrument H reading is 59.7mm, the sound path S reading is 83.3mm, Reading 47mm.

[0230] Specifically, taking the outer surface inspection of a thick titanium alloy spherical shell as an example, the specific workflow of this integrated test block is explained:

[0231] 1. Preparation before testing

[0232] Probe selection and coupling:

[0233] A curved probe with a wedge block processed into a concave surface (the curvature matches the convex curved detection surface 101) is selected and tightly fitted to the convex curved detection surface 101 through a coupling agent, with the convex surface of the test block facing upward to ensure that the probe sound beam is incident vertically along the radial direction of the spherical shell.

[0234] Instrument parameter initialization:

[0235] Input the workpiece outer radius R = 990mm and inner radius r = 900mm, call the test block material parameters (consistent with the workpiece), and turn on the surface correction function of the ultrasonic instrument.

[0236] 2. Calibration of concentric reflection arc group 3

[0237] Entrance point calibration:

[0238] The probe transmits an ultrasonic signal, which is reflected by the first concentric arc (301, R50 / R100) of the concentric reflection arc group 3. The instrument calculates the probe incident point deviation through the echo time difference and corrects the front distance to an error of ≤0.5mm.

[0239] Shear wave speed measurement:

[0240] The speed of sound is calculated using the difference in the two arc sound paths Δs = 2 × (100-50) = 100 mm and the echo time difference Δt = 33.3 μs. As the instrument sound velocity benchmark.

[0241] Time base adjustment:

[0242] Using R=50 and R=100 as benchmarks, calibrate the instrument's time baseline so that the sound path displayed on the screen is consistent with the actual detection.

[0243] 3. Measured refraction angle of K value reference hole group 4

[0244] Signal acquisition:

[0245] The probe transmits a signal to the convex K-value reference hole 401 (depth 60 mm, Φ2 mm long through hole), and the reflected echo from the bottom of the hole is received. The measured sound path s=83.3 mm.

[0246] Surface correction calculation:

[0247] The instrument uses the formula to obtain the actual refraction angle K = 0.92, θ = 42.61° to correct the deviation of the probe's nominal K value.

[0248] 4. Distance-amplitude curve production

[0249] Layered scanning:

[0250] The probe scans hole by hole in hole group 5 (8 Φ2mm transverse holes with depths of 10, 20, 40, 60, and 80mm) along the distance-amplitude curve, and collects the echo amplitude of each hole.

[0251] Curve drawing:

[0252] With the hole depth as the horizontal coordinate and the echo amplitude as the vertical coordinate, a curve is drawn, covering the detection range from 10 to the workpiece thickness (80mm), as the defect quantification benchmark.

[0253] 5. Auxiliary functions of plane detection area 6 and sharp corner groove 7

[0254] Calibration of flat straight probes:

[0255] Replace the flat straight probe to flat detection area 6 (30° oblique plane), adjust the gain so that the echo of the Φ2 long through hole reaches the height of the evaluation line, and complete the sensitivity calibration and timely baseline adjustment.

[0256] Maximum sound range calibration:

[0257] During external surface inspection, the probe transmits a direct wave to the sharp-angle groove 7 (2 mm deep, 60° sharp angle), and the reflected sound path is calibrated as the maximum sound path to filter out long-distance clutter.

[0258] 6. Defect detection and location

[0259] Signal acquisition:

[0260] The probe scanned the spherical shell weld and found that the defect echo sound path s = 96.8mm and the amplitude reached the quantitative line of the curve.

[0261] Linked calculation:

[0262] The instrument automatically calls the test block curvature radius R = 990mm and the measured K = 0.92, calculates the radial depth H = 69mm, and the surface arc length Display defect location in real time.

[0263] 7. Inner surface detection switch

[0264] Turn the test block over, use the convex curved probe to couple to the concave curved detection surface 102, repeat the above steps, and calibrate the inner surface detection parameters through the concave K value reference hole 402 and the corresponding curved hole group to ensure consistent internal and external detection accuracy.

[0265] In summary, the integrated test block for ultrasonic testing of curved longitudinal butt joints in an embodiment of the present application, in conjunction with an upgraded ultrasonic detector, can eliminate the coupling difference problem of the flat test block, improve the positioning accuracy to 1 mm, directly measure the shear wave speed and the K value of the curved probe, avoid relying on the nominal K value of the probe, and solve the error problems in the calculation of the curved sound path and defect positioning. A single test block can cover the entire process of calibration, measurement, curve making, etc., reduce the replacement of test blocks, improve detection efficiency, and is suitable for on-site rapid detection.

[0266] It is necessary to add that:

[0267] Probe: The angle probe uses a Doppler 2.5MHz, K1, 13×13 narrow pulse probe.

[0268] Surface defect location:

[0269] When inspecting curved surfaces, after measuring the actual sound velocity of the workpiece, the sound path (s) is the correct measurement value that can be read by the ultrasonic instrument; after measuring the actual refraction angle K (θ) of the curved probe on the curved surface, combined with the inner and outer radii (R, r) of the workpiece, the radial depth (H) and surface arc length of the defect can be obtained.

[0270] The HS611 e ultrasonic equipment has been upgraded twice. The first time, the shear wave outer wall / inner wall circumferential detection was added. The direct method was used to read the radial depth (H) and surface arc length of the defect based on the sound path (s) and refraction angle K (θ) and inner and outer radius (R, r). Convenient for surface defect location calculation;

[0271]

[0272] Convex surface K value measurement:

[0273] The second function upgrade added the curved surface K value measurement function of the curved surface probe. The actual refraction angle K (θ) of the probe in the workpiece after grinding is measured based on the sound path (s), the radial depth (H) of the K value test hole, the diameter (d) of the K value test hole, and the inner and outer radii (R, r), thereby improving the accuracy of defect location.

[0274]

[0275] K=tanθ

[0276] Considering the influence of the aperture d of the test hole, S is replaced by S+d / 2 when calculating with the ultrasonic instrument.

[0277] Concave surface detection:

[0278] K value measurement:

[0279] Given r, s, and H, find θ (K = tanθ).

[0280] 1. Apply the law of cosines: (r+H) 2 =r 2 +s 2 -2rscosα

[0281] 2. Solve for α:

[0282] 3. Calculate θ: θ = 180° - α

[0283] 4. Determine the K value: K = tanθ

[0284] Defect location

[0285] Given the parameters: s, K(θ), R, r, find H,

[0286] 1. Calculate α: α = 180° - θ

[0287] 2. Solve for H:

[0288] 3. Calculate β:

[0289] First find tanβ:

[0290] Then find β:

[0291] 4. Calculation

Claims

1. An integrated test block for ultrasonic testing of curved longitudinal butt joints, characterized in that: The invention comprises a main structure (1), wherein the upper and lower surfaces of the main structure (1) are respectively provided with a convex curved detection surface (101) and a concave curved detection surface (102), the curvatures of which are respectively consistent with the curvatures of the outer surface and the inner surface of the workpiece to be measured, the curvatures are cylindrical curvatures, and the material is the same as that of the workpiece to be measured, and the main structure (1) is provided with a concentric reflection arc group (3), a K value reference hole group (4), a distance-amplitude curve hole group (5), a plane detection area (6) and a sharp angle groove (7); The concentric reflection arc group (3) is located on the left side of the main structure (1), and includes two groups of concentric arcs with different radii, which are distributed along the radial direction of the main structure (1) and are used for zero point calibration of the curved probe, actual measurement of shear wave sound velocity and timely baseline adjustment; The K value reference hole group (4) comprises a concave surface K value reference hole (402) located near the convex surface detection surface (101) and a convex surface K value reference hole (401) located near the concave surface detection surface (102), wherein the convex surface K value reference hole (401) and the concave surface K value reference hole (402) are both radially distributed Φ2 long transverse holes, the hole depth being the full thickness of the workpiece being measured, and are used for measuring the refraction angle (K value) of the curved surface probe; The distance-amplitude curve hole group (5) is distributed on both sides of the main structure (1), includes 8 transverse through holes of different depths, and maintains a spacing with the concentric reflection arc group (3) to avoid signal interference, and is used to produce a distance-amplitude detection curve of the curved surface probe; The plane detection area (6) is located on the right side of the main structure (1) and is a 30° oblique plane, used for sensitivity adjustment and baseline calibration of the plane straight probe; The pointed groove (7) is located at the lower right edge of one side of the concave curved detection surface (102), is a 60° pointed structure with a depth of 2 mm, and the tip points to the edge of the main body, and is only used to calibrate the maximum sound range once during convex surface detection to avoid interference from multiple reflectors.

2. The integrated ultrasonic testing block for curved longitudinal butt joints according to claim 1, characterized in that: The main structure (1) is a columnar body, and the convex curved surface detection surface (101) and the concave curved surface detection surface (102) are respectively arranged at two ends of the columnar body, and the centers of the two circles coincide with each other.

3. The integrated ultrasonic testing block for curved longitudinal butt joints according to claim 1, characterized in that: The concentric reflection arc group (3) comprises a first concentric arc (301) and a second concentric arc (302), the centers of the first concentric arc (301) and the second concentric arc (302) are both on the convex curved surface detection surface (101) or the concave curved surface detection surface (102), the radii of the two groups of arcs are R1 and R2 (R1≠R2), respectively, and there are four arc surfaces in total, and the arc surfaces are respectively oriented toward the inside and outside of the main structure (1), forming a reflection interface with a common vertex with the curved surface detection surface, and used for zero point calibration of the curved surface probe, actual measurement of shear wave sound velocity, and timely baseline adjustment.

4. The integrated ultrasonic testing block for curved longitudinal butt joints according to claim 1, characterized in that: The convex surface K value reference hole (401) and the concave surface K value reference hole (402) are both perpendicular to the main structure (1) and are respectively the long transverse holes closest to the concave curved surface detection surface (102) and the convex curved surface detection surface (101).

5. The integrated ultrasonic testing block for curved longitudinal butt joints according to claim 1, characterized in that: The diameter of the transverse through hole of the distance-amplitude curve hole group (5) is Φ2mm, the hole depth is the full thickness of the workpiece to be measured, and the hole is distributed radially along the detection surface, and the hole axis is perpendicular to the curvature radius direction of the detection surface.

6. The integrated ultrasonic testing block for curved longitudinal butt joints according to claim 1, characterized in that: The 30° oblique angle plane of the plane detection area (6) forms a 30° included angle with the axis of the main structure (1), and the surface roughness of the plane is consistent with the plane detection surface of the workpiece to be measured.

7. The integrated ultrasonic testing block for curved longitudinal butt joints according to claim 1, characterized in that: The tip of the pointed groove (7) points to the edge of the main structure (1), and the groove depth is 2 mm, and is used to form a reflection signal of a specific sound range during detection to calibrate a maximum sound range.

8. A method for ultrasonic testing of curved longitudinal butt joints, using the ultrasonic testing integrated test block according to any one of claims 1 to 7, characterized in that: The following steps are involved: (a) coupling a concave-convex curved surface probe with a convex curved surface detection surface (101) or a concave curved surface detection surface (102) of a main structure (1), and selecting a probe with a corresponding curvature according to the type of the curved surface (convex / concave) of the workpiece to be measured; (b) calibrating the incident point of the probe, adjusting the time base and measuring the shear wave speed through the concentric reflection arc group (3); (c) Using the K-value reference hole group (4) to measure the refraction angle (K value) of the probe, and using the distance-amplitude curve hole group (5) to create a distance-amplitude curve, the actual K value is calculated using the instrument's built-in algorithm in combination with the surface curvature radius R, the surface curvature radius r, the hole depth H, and the sound path s; (d) calibrating the maximum sound path once through the sharp angle slot (7) to eliminate interference clutter; (e) Adjust the sensitivity of the straight probe in conjunction with the plane detection area (6).

9. The ultrasonic detection method according to claim 8, characterized in that: In step (c), the refraction angle (K value) is measured by the curved surface correction function of the ultrasonic instrument, and the actual K value is calculated in combination with the curvature radius of the main structure (1), the hole depth and the hole diameter of the K value reference hole group (4).

10. The ultrasonic detection method according to claim 8, wherein: The main structure (1) is linked with the curved surface correction module of the ultrasonic testing instrument to automatically calculate the radial depth (H) and surface arc length of the defect.

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