Ultrasonic detection method for large nuclear power penetration assembly end socket and reference block for ultrasonic detection

Abstract

The invention relates to the field of ultrasonic detection, in particular to a reference block for ultrasonic detection of a large nuclear power penetration assembly end socket and a detection method.The reference block comprises a test block body, the test block body is of a fan-shaped structure, and the curvature radius of an inner arc and the curvature radius of an outer arc of the test block body are consistent with the curvature radius of the penetration assembly end socket to be detected; at least three transverse holes distributed in the radial direction from the inner arc to the outer arc are formed in one side of the fan-shaped surface of the test block body, and an inner surface groove and an outer surface groove distributed in the thickness direction of the test block body are formed in the inner arc surface and the outer arc surface of the other side of the fan-shaped surface of the test block body respectively. The invention further discloses an ultrasonic detection method, after the reference block is adopted for calibration, ultrasonic detection is conducted on a workpiece, and the ultrasonic detection method has the advantages of being easy to operate, high in detection efficiency and good in sensitivity and is particularly suitable for ultrasonic detection of the large nuclear power penetration assembly end socket.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic testing technology, specifically a method for ultrasonic testing of the end cap of a large nuclear power plant penetration component and a comparative test block for ultrasonic testing. Background Technology

[0002] Ultrasonic testing is a standard nondestructive testing (NDT) method that effectively detects internal discontinuities in products. Large nuclear power plant penetration heads are crucial components connecting the nuclear island and conventional islands. Due to the harsh conditions they must withstand—high temperature and high pressure—their reliability must be guaranteed. Ultrasonic testing is commonly used to inspect their internal quality. Taking the P01 penetration as an example, with an outer diameter of φ1911mm and an inner diameter of φ963mm, its large thickness-to-diameter ratio makes full-volume scanning with conventional shear wave beams difficult, and the long sound path leads to significant sound energy attenuation and low detection sensitivity. Furthermore, to ensure effective coupling, the probe needs to be surface-ground, and the change in the probe's refraction angle after grinding also needs to be measured.

[0003] Based on the above issues, it was considered to use a small-angle longitudinal wave angle probe to scan along the outer circumference at a half-span distance. However, using a transverse wave angle probe to scan along the inner circumference at a half-span distance requires the use of reflectors representing internal and surface defects during calibration. But the current comparison test block cannot measure the refraction angle of the probe after grinding, nor can it meet the calibration requirements for the half-span sensitivity of the inner and outer surfaces.

[0004] Application No. 202510220983.8 discloses an ultrasonic testing block and method for the nozzle of a voltage regulator. The testing block includes a TCG curve reference block, which comprises a body, a first weld overlay layer, and a simulated groove; and an inner rounded corner simulation block, which comprises a tube body, a second weld overlay layer, and a crescent-shaped groove. This invention, by processing the first weld overlay layer and the simulated groove on the outer surface of the TCG curve reference block, can effectively simulate the morphology of the outer surface of the inner rounded corner area of ​​the nozzle on the voltage regulator, test the coupling state of the ultrasonic probe, and make the ultrasonic inspection results more reliable. By processing the second weld overlay layer on the inner surface of the inner rounded corner simulation block, it can effectively simulate the morphology of the inner surface of the inner rounded corner area of ​​the nozzle on the voltage regulator, test the sound beam coverage effect of the ultrasonic probe, and make the ultrasonic inspection results more reliable. By processing the crescent-shaped groove inside the inner rounded corner simulation block, it can effectively perform ultrasonic time gain correction TCG curve and scan sensitivity calibration. This method is only applicable to ultrasonic testing of the nozzles on the end caps of voltage regulators, and not to internal quality testing of the end caps of large nuclear power plant penetration components. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems and provide a comparative test block for ultrasonic testing of large nuclear power plant penetration head, which is simple in structure, easy to operate, and simultaneously meets the requirements for measuring the refraction angle of the probe after grinding and calibrating the sensitivity of the half-span of the inner and outer surfaces.

[0006] Another objective of this invention is to provide an ultrasonic testing method for the end cap of a large nuclear power plant penetration component using the aforementioned comparative test block, which has the advantages of high testing efficiency and high sensitivity.

[0007] The ultrasonic testing comparison block of the present invention includes a block body, which is a fan-shaped structure. The inner and outer arc radii of curvature are consistent with the curvature radius of the end cap of the penetrating component to be tested. At least three transverse holes are radially distributed from the inner arc to the outer arc on one side of the fan-shaped surface of the block body. Inner surface grooves and outer surface grooves distributed along the thickness direction of the block body are respectively opened on the inner and outer arc surfaces on the other side of the fan-shaped surface of the block body.

[0008] The inner and outer surface grooves are rectangular or V-shaped grooves. Preferably, the depth of the inner and outer surface grooves is 1-5% of the radial thickness of the fan-shaped surface of the test block body.

[0009] The horizontal hole is a blind hole.

[0010] Of the at least three transverse holes distributed radially, the transverse holes closest to the outer and inner arcs are 8-12 mm from the edge, and the remaining transverse holes are distributed at equal intervals radially.

[0011] The ultrasonic testing method for the end cap of a large nuclear power plant penetration component of the present invention uses the aforementioned comparative test block and proceeds with the following steps: A: By detecting the highest echo from any transverse hole on the comparison block, the corresponding probe refraction angles of the ground ultrasonic test probe during testing on the outer and inner arc surfaces of the comparison block were obtained. ; B: By measuring the wave height of each transverse hole, the detection curves of the transverse holes on the outer and inner surfaces of the test block by the ultrasonic test probe are obtained respectively. C: By measuring the highest amplitude of the reflections from the outer and inner surface grooves respectively, the detection curves of the outer and inner surface grooves of the ultrasonic test probe during the detection of the inner and outer circular arc surfaces of the comparison test block are obtained respectively.

[0012] In step A, the leading edge of the ultrasonic test probe after grinding is measured on the comparison test block. L0; Project the transverse holes on the comparison block radially onto the points on the outer and inner circular arc surfaces, respectively, and record them as the outer and inner marker points. Place the ultrasonic testing probe on the outer and inner circular arc surfaces of the comparison block, respectively, and move the ultrasonic testing probe back and forth circumferentially. When the highest echo is measured for any transverse hole, record the arc length from the position of the ultrasonic testing probe to the corresponding outer or inner marker point. or Then, substitute the values ​​into the following formulas to calculate the corresponding ultrasonic probe refraction angles for outer and inner circular arc surface testing, respectively. : = tan = = tan = In the above formula: and Arc length and The corresponding central angle; R is the radius of curvature of the outer arc; r is the radius of curvature of the inner arc; h is the radial distance of the measured transverse hole from the outer circular surface.

[0013] In step B, the ultrasonic test probe is placed on the outer and inner arc surfaces of the comparison test block, and the ultrasonic test probe is moved back and forth along the circumference to find the highest amplitude of the transverse hole closest to the outer and inner arc surfaces, respectively. The probe is then adjusted to the reference wave height, and the wave heights of the other transverse holes are found in turn. All wave height points are connected into a line to plot the transverse hole detection curves on the outer and inner surfaces, respectively.

[0014] In step C, the ultrasonic test probe is placed on the inner and outer arc surfaces of the comparison test block, and the ultrasonic test probe is moved back and forth along the circumference to measure the highest wave amplitude reflected by the outer and inner surface grooves, respectively. The probe is adjusted to the reference wave height and a horizontal line is drawn, which are recorded as the outer surface groove detection curve and the inner surface groove detection curve, respectively.

[0015] It also includes step D: The ultrasonic test probe is used to perform a half-span scan on the inner and outer surfaces of the end cap to be tested. If a defect is found during the scan on the corresponding inner or outer surface, the corresponding curve is selected based on the location of the defect and the location of the ultrasonic test probe, and compared with the highest reflected wave of the defect. If the highest wave amplitude of the defect exceeds the corresponding curve, it is judged as unqualified; otherwise, it is judged as qualified.

[0016] In step D: if the defect found during scanning is located on the outer or inner surface of the end cap to be tested, the corresponding outer surface groove detection curve or inner surface groove detection curve is compared with the highest reflected wave of the defect; if the defect found during scanning is located inside the end cap to be tested, the corresponding inner surface transverse hole detection curve or outer surface transverse hole detection curve is used to compare with the highest reflected wave of the defect, depending on whether the ultrasonic test probe is scanning on the inner or outer surface when the defect is found.

[0017] Beneficial effects: To address the issue of large nuclear power plant penetration heads having a large thickness-to-diameter ratio, making it difficult for conventional shear wave beams to perform full-volume scanning when using ultrasonic testing, a small-angle longitudinal wave angle probe is introduced for half-span scanning along the outer circumference. Simultaneously, to solve the calibration problem of using a shear wave angle probe for half-span scanning along the inner circumference, a comparative test block is specifically designed. The test block is designed as a fan-shaped structure with inner and outer arc curvature radii consistent with the curvature radius of the penetration head, simulating the local shape of the penetration head. Furthermore, one side of the fan-shaped surface of the test block has at least three transverse holes (representing reflectors of internal defects) radially distributed from the inner to the outer arc, simulating defects of different depths. On the other side of the fan-shaped surface of the test block, inner and outer surface grooves (representing reflectors of surface defects) are respectively distributed along the thickness direction of the test block, simulating defects on the inner and outer surfaces of the workpiece. By arranging transverse holes and surface grooves on both sides of a test block body, the ultrasonic probe can scan the transverse holes and surface grooves on both sides in the middle section of the arc surface of the test block body, and quickly complete the calibration process. This can not only measure the refraction angle of the probe after grinding, but also calibrate the half-span sensitivity of the inner and outer surfaces.

[0018] Furthermore, by scanning the inner and outer arc surfaces with an ultrasonic testing probe, the corresponding transverse hole detection curves on the outer and inner surfaces, as well as the groove detection curves on the outer and inner surfaces, can be obtained. Then, a half-span scan is performed on the inner and outer surfaces of the workpiece (i.e., the through-hole end cap to be tested). By comparing the highest reflected wave of the detected defect with the corresponding curve, the qualification of the defect can be quickly determined, greatly improving the detection efficiency. The transverse hole is preferably a blind hole, and three or more can be set radially. The specific number can be reasonably designed according to the thickness of the workpiece, thereby improving the sensitivity and accuracy of the detection.

[0019] This invention uses a test block whose detection parameters are matched to the workpiece height, enabling accurate calibration of the probe's refraction angle after grinding, thus improving the accuracy and precision of positioning and quantification. It is applicable to the calibration of detection systems and the plotting of distance amplitude curves when performing half-span scanning from the outer and inner surfaces respectively. It eliminates the influence of coupling loss differences caused by inconsistent curvature in other test blocks. After calibration using the aforementioned test block, the method of this invention performs ultrasonic testing on the workpiece, offering advantages such as simple operation, high detection efficiency, and good sensitivity. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the comparative test block of the present invention. Figure 2 This is a top view of the comparative test block of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of the end cap of the penetrating component to be tested.

[0022] Figure 4 This is a diagram showing the state of the ultrasonic test probe during testing on a comparison block.

[0023] Figure 5 This is a curve diagram of the detection of transverse holes on the outer surface in an embodiment of the present invention.

[0024] Figure 6 This is a curve diagram of the detection of transverse holes on the inner surface in an embodiment of the present invention.

[0025] Figure 7 This is a graph showing the detection curve of the outer surface groove in an embodiment of the present invention.

[0026] Figure 8 This is a graph showing the detection curve of the inner surface groove in an embodiment of the present invention.

[0027] Among them, 1-test block body, 2-outer arc surface, 3-inner arc surface, 4-outer surface groove, 5-inner surface groove, 6-horizontal hole, 7-outer surface detection point, 8-outer surface detection point, 9-inner surface detection point, 10-inner surface detection point, 11-ultrasonic test probe, 12-outer marking point, 13-inner marking point, 14-through part end cap, 14.1-inner surface, 14.2-outer surface. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] The comparative test block of this invention includes a test block body 1, which has a fan-shaped structure. The radii of curvature of its inner and outer arcs are consistent with the radii of curvature of the end cap 14 of the through-piece to be tested. At least three transverse holes 6 (blind holes) are radially distributed from the inner arc to the outer arc on one side of the fan-shaped surface of the test block body 1. Inner surface grooves 5 and outer surface grooves 4, respectively distributed along the thickness direction of the test block body 1, are formed on the inner and outer arc surfaces 3 and 4 on the other side of the fan-shaped surface. Preferably, the inner surface grooves 5 and outer surface grooves 4 are rectangular or V-shaped grooves, and the depth of the inner surface grooves 5 and outer surface grooves 4 is 1-5% of the radial thickness of the fan-shaped surface of the test block body 1. Preferably, among the at least three radially distributed transverse holes 6, the distance N1 from the edge of the transverse holes 6 closest to the outer and inner arcs is 8-12 mm, and the remaining transverse holes are evenly distributed radially. The number of transverse holes 6 can be reasonably selected according to the radial thickness of the fan-shaped surface of the test block body 1 to ensure calibration accuracy. The transverse holes 6 and the inner and outer surface grooves 5 and 4 are respectively set on both sides of the test block body 1, so that the appropriate detection point of the ultrasonic detection probe 11 can be freely selected on the arc surface between the two, and multiple tests can be performed efficiently and quickly.

[0031] The specific parameters of the inner diameter, outer diameter, and central angle of the sector-shaped surface of the test block body 1 are not particularly limited, and can be reasonably designed according to the size of the end cap 14 of the penetrating part to be tested and the relevant parameters of the ultrasonic testing probe 11.

[0032] The ultrasonic testing method for the end cap of a large nuclear power plant penetration component of the present invention uses the aforementioned comparative test block 1 and proceeds with the following steps: A: By detecting the highest echo from any transverse hole on the comparison block, the refraction angle of the ultrasonic test probe 11 after grinding is obtained when it is detected on the outer arc surface 2 and the inner arc surface 3 of the comparison block 1. Specifically: The leading edge of the ground ultrasonic test probe was measured on the comparison test block. L0; Project the multiple transverse holes 6 on the comparison test block radially onto the outer arc surface 2 and the inner arc surface 3, respectively, and mark them as outer mark point 12 and inner mark point 13. Place the ultrasonic test probe 11 on the outer arc surface 2 and the inner arc surface 3 of the comparison test block (such as at the corresponding outer surface detection point and inner surface detection point). Move the ultrasonic test probe 11 back and forth circumferentially. When the highest echo of any transverse hole is measured, record the arc length from the position of the ultrasonic test probe 11 to the corresponding outer mark point 12 and inner mark point 13. and Then, substitute the values ​​into the following formulas to calculate the corresponding ultrasonic probe refraction angles for outer and inner circular arc surface testing, respectively. : = tan = = tan = In the above formula: and Arc length and The corresponding central angle; R is the radius of curvature of the outer arc; r is the radius of curvature of the inner arc; h is the radial distance of the measured transverse hole from the outer circular surface.

[0033] B: By measuring the wave height of each transverse hole, the detection curves of the transverse holes on the outer and inner surfaces of the comparison test block using the ultrasonic test probe 11 were obtained, specifically: Place the ultrasonic test probe 11 on the outer arc surface 2 and the inner arc surface 3 of the comparison test block respectively. Move the ultrasonic test probe 11 back and forth along the circumference to find the highest wave amplitude of the transverse hole 6 closest to the outer arc surface and the inner arc surface respectively. Adjust it to the reference wave height, and then find the wave height of other transverse holes 6 in turn. Connect all the wave height points into a line and draw the transverse hole detection curve of the outer surface and the transverse hole detection curve of the inner surface respectively.

[0034] C: By measuring the highest amplitude of the reflections from the outer surface groove 4 and the inner surface groove 5 respectively, the detection curves of the outer surface groove and the inner surface groove of the ultrasonic test probe 11 during the detection of the inner and outer arc surfaces of the comparison test block are obtained, specifically: Place the ultrasonic test probe on the inner arc surface 3 and the outer arc surface 2 of the comparison test block respectively, move the ultrasonic test probe 11 back and forth along the circumference, measure the highest wave amplitude reflected by the outer surface groove 4 and the inner surface groove 5 respectively, adjust to the reference wave height, draw a horizontal line, and record it as the outer surface groove detection curve and the inner surface groove detection curve respectively.

[0035] Step D: The ultrasonic test probe 11 is used to perform a half-span scan on the inner and outer surfaces of the end cap 14 to be tested. If a defect is found during the scan on the corresponding inner or outer surface, the corresponding curve is selected based on the location of the defect and the location of the ultrasonic test probe, and compared with the highest reflected wave of the defect. If the highest wave amplitude of the defect exceeds the corresponding curve, it is judged as unqualified; otherwise, it is judged as qualified. Specifically: If the defect found during scanning is located on the outer or inner surface of the end cap of the penetrating component to be tested, the corresponding outer surface groove detection curve or inner surface groove detection curve should be compared with the highest reflected wave of the defect. If the defect found during scanning is located inside the end cap of the penetrating component to be tested, the corresponding inner surface transverse hole detection curve or outer surface transverse hole detection curve should be used to compare with the highest reflected wave of the defect, depending on whether the ultrasonic test probe was scanning on the inner or outer surface when the defect was found. If the highest wave amplitude of the defect exceeds the corresponding curve, it is judged as unqualified; otherwise, it is judged as qualified.

[0036] The following example uses the workpiece P01 through-hole as an example. Its outer diameter is φ1911mm and its inner diameter is φ963mm, serving as the end cap 14 of the through-hole to be tested. The test block body 1 of the comparison test block is fan-shaped, with an inner diameter of φ963mm, an outer diameter of φ1911mm, and a central angle of 85°. Five transverse holes are distributed radially on one side. The distance N1 from the two transverse holes 6 closest to the outer arc and the inner arc to the nearest arc surface edge is 10mm. The other three transverse holes 6 are evenly distributed in the radial thickness. On the other side, the outer arc surface 2 and the inner arc surface 3 are respectively provided with outer surface grooves 4 and inner surface grooves 5, both of which are rectangular grooves with a groove depth of 6mm. In this embodiment, the outer arc surface 2 is provided with outer surface detection points 7 near the outer mark point 12 and outer surface detection points 8 near the outer surface groove 4, respectively. The inner arc surface 3 is provided with inner surface detection points 10 near the inner mark point 13 and inner surface detection points 9 near the inner surface groove 5, respectively.

[0037] Detection Example: A: The leading edge of the ground ultrasonic test probe 11 was measured on the comparison test block using the edge method. L 0; Place the ultrasonic test probe 11 at the detection point 7 on the outer surface of the outer arc surface 2 of the comparison test block and move the ultrasonic test probe 11 back and forth along the circumference. When the highest echo of any transverse hole is measured, record the arc length from the position of the ultrasonic test probe 11 to the corresponding outer mark point 12. The refraction angle β1 of the ultrasonic test probe on the outer arc surface can be calculated by the following formula; = tan = In the above formula: arc length The corresponding central angle; R is the radius of curvature of the outer arc; h is the radial distance between the measured transverse hole and the outer arc surface 2; β1 is the refraction angle of the measured probe.

[0038] In this embodiment, It is 53.6mm. With θ = 3.8°, R = 955.5 mm, and h = 120 mm, the refraction angle β1 of the probe is calculated to be 24°.

[0039] The same method was used to perform internal surface testing. The ultrasonic test probe 11 was placed at the internal surface testing point 10 of the inner arc surface 3 of the comparison test block and moved back and forth along the circumference. When the highest echo of any transverse hole was measured, the arc length from the position of the ultrasonic test probe 11 to the corresponding inner mark point 13 was recorded. The refraction angle β2 of the probe on the inner arc surface can be calculated by the following formula; = tan = In the above equation: arc length The corresponding central angle; R is the radius of curvature of the outer arc; r is the radius of curvature of the inner arc; h is the radial distance from the measured transverse hole to the outer circular surface; β2 is the refraction angle of the measured probe.

[0040] In this embodiment, It is 30mm. It is 14.5mm. Given a radius of 5.3°, radius R of 955.5 mm, radius r of 481.5 mm, and radius h of 360 mm, the refraction angle of the probe is calculated. It is 25.3°.

[0041] B: Place the ultrasonic test probe 11 at the detection point 7 on the outer surface of the outer arc surface 2 of the comparison test block. Move the ultrasonic test probe 11 back and forth along the circumference. When the highest amplitude of the transverse hole 6 closest to the outer arc surface 2 is measured, adjust it to the reference wave height. Then find the wave heights of the other transverse holes in sequence, connect all the wave height points with a line, and draw the transverse hole detection curve on the outer surface (see...). Figure 5 ); Simultaneously, the ultrasonic test probe 11 is placed at the detection point 10 on the inner surface of the inner arc surface 3 of the comparison test block. The ultrasonic test probe 11 is moved back and forth along the circumference. When the highest amplitude of the transverse hole 6 closest to the inner arc surface 3 is measured, it is adjusted to the reference wave height. Then, the wave heights of other transverse holes are found in sequence, and all wave height points are connected into a line to draw the inner surface transverse hole detection curve (see...). Figure 6 ); C: Place the ultrasonic test probe 11 at the detection point 8 on the outer surface of the outer arc surface 2 of the comparison test block, and move the ultrasonic test probe 11 back and forth along the circumference to find the highest wave amplitude reflected by the inner surface groove 5. Adjust it to the reference wave height, draw a horizontal line, and record it as the inner surface groove detection curve (see...). Figure 7 Simultaneously, the ultrasonic test probe 11 is placed at the detection point 9 on the inner surface of the inner arc surface 3 of the comparison test block. The ultrasonic test probe 11 is moved back and forth along the circumference to find the highest amplitude of the wave reflected by the outer surface groove 4. It is adjusted to the reference wave height, and a horizontal line is drawn, which is recorded as the outer surface groove detection curve (see...). Figure 8 ).

[0042] D: The ultrasonic test probe 11 is first scanned half-span on the outer surface of the end cap 14 to be tested. If a defect is found and the defect is located on the inner surface, the highest reflected wave of the defect is found and compared with the inner surface groove detection curve. If the highest wave amplitude exceeds the curve, it is unqualified; otherwise, it is qualified. If the defect is located inside, the highest reflected wave of the defect is found and compared with the outer surface transverse hole detection curve. If the highest wave amplitude exceeds the curve, it is unqualified; otherwise, it is qualified. Similarly, the ultrasonic test probe 11 is used to perform a half-span scan on the inner surface of the through-hole end cap 14 to be tested. If a defect is found and the defect is located on the outer surface, the highest reflected wave of the defect is found and compared with the outer surface groove detection curve. If the highest wave amplitude exceeds the curve, it is unqualified; otherwise, it is qualified. If the defect is located inside, the highest reflected wave of the defect is found and compared with the inner surface transverse hole detection curve. If the highest wave amplitude exceeds the curve, it is unqualified; otherwise, it is qualified.

[0043] In this embodiment, the through-hole end cap 14 passed the inspection.

[0044] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A comparative test block for ultrasonic testing of the end cap of a large nuclear power plant penetration component, comprising a test block body, characterized in that, The test block body has a fan-shaped structure, and the inner and outer arc curvature radii are consistent with the curvature radius of the end cap of the through part to be tested. At least three transverse holes are radially distributed from the inner arc to the outer arc on one side of the fan-shaped surface of the test block body. The inner and outer arc surfaces on the other side of the fan-shaped surface of the test block body are respectively provided with inner surface grooves and outer surface grooves distributed along the thickness direction of the test block body.

2. The comparative test block for ultrasonic testing of the end cap of a large nuclear power plant penetration component as described in claim 1, characterized in that, The inner surface groove and the outer surface groove are rectangular grooves or V-shaped grooves.

3. The comparative test block for ultrasonic testing of the end cap of a large nuclear power plant penetration component as described in claim 1 or 2, characterized in that, The horizontal hole is a blind hole.

4. The comparative test block for ultrasonic testing of the end cap of a large nuclear power plant penetration component as described in claim 3, characterized in that, Of the at least three transverse holes distributed radially, the transverse holes closest to the outer and inner arcs are 8-12 mm from the edge, and the remaining transverse holes are distributed at equal intervals radially.

5. A method for ultrasonic testing of the end cap of a large nuclear power plant penetration component, characterized in that, Using the comparative test block according to any one of claims 1-4, the following steps are performed for testing: A: By detecting the highest echo from any transverse hole on the comparison block, the corresponding probe refraction angles of the ground ultrasonic test probe during testing on the outer and inner arc surfaces of the comparison block were obtained. ; B: By measuring the wave height of each transverse hole, the detection curves of the transverse holes on the outer and inner surfaces of the test block by the ultrasonic test probe are obtained respectively. C: By measuring the highest amplitude of the reflections from the outer and inner surface grooves respectively, the detection curves of the outer and inner surface grooves of the ultrasonic test probe during the detection of the inner and outer circular arc surfaces of the comparison test block are obtained respectively.

6. The ultrasonic testing method for the end cap of a large nuclear power plant penetration component as described in claim 5, characterized in that, In step A, the leading edge of the ultrasonic test probe after grinding is measured on the comparison test block. L 0; Project the transverse holes on the comparison block radially onto the points on the outer and inner circular arc surfaces, respectively, and record them as the outer and inner marker points. Place the ultrasonic testing probe on the outer and inner circular arc surfaces of the comparison block, respectively, and move the ultrasonic testing probe back and forth circumferentially. When the highest echo is measured for any transverse hole, record the arc length from the position of the ultrasonic testing probe to the corresponding outer and inner marker points. and Then, substitute the values ​​into the following formulas to calculate the corresponding ultrasonic probe refraction angles for outer and inner arc surface detection, respectively. : = tan = = tan = In the above formula: and Arc length and The corresponding central angle; R is the radius of curvature of the outer arc; r is the radius of curvature of the inner arc; h is the radial distance of the measured transverse hole from the outer circular surface.

7. The ultrasonic testing method for the end cap of a large nuclear power plant penetration component as described in claim 5, characterized in that, In step B, the ultrasonic test probe is placed on the outer and inner arc surfaces of the comparison test block, and the ultrasonic test probe is moved back and forth along the circumference to find the highest amplitude of the transverse hole closest to the outer and inner arc surfaces, respectively. The probe is then adjusted to the reference wave height, and the wave heights of the other transverse holes are found in turn. All wave height points are connected into a line to plot the transverse hole detection curves on the outer and inner surfaces, respectively.

8. The ultrasonic testing method for the end cap of a large nuclear power plant penetration component as described in claim 5, characterized in that, In step C, the ultrasonic test probe is placed on the inner and outer arc surfaces of the comparison test block, and the ultrasonic test probe is moved back and forth along the circumference to measure the highest wave amplitude reflected by the outer and inner surface grooves, respectively. The probe is adjusted to the reference wave height and a horizontal line is drawn, which are recorded as the outer surface groove detection curve and the inner surface groove detection curve, respectively.

9. The ultrasonic testing method for the end cap of a large nuclear power plant penetration component as described in any one of claims 5-8, characterized in that, It also includes step D: The ultrasonic test probe is used to perform a half-span scan on the inner and outer surfaces of the end cap to be tested. If a defect is found during the scan on the corresponding inner or outer surface, the corresponding curve is selected based on the location of the defect and the location of the ultrasonic test probe, and compared with the highest reflected wave of the defect. If the highest wave amplitude of the defect exceeds the corresponding curve, it is judged as unqualified; otherwise, it is judged as qualified.

10. The ultrasonic testing method for the end cap of a large nuclear power plant penetration component as described in claim 9, characterized in that, In step D: if the defect found during scanning is located on the outer or inner surface of the end cap to be tested, the corresponding outer surface groove detection curve or inner surface groove detection curve is compared with the highest reflected wave of the defect; if the defect found during scanning is located inside the end cap to be tested, the corresponding inner surface transverse hole detection curve or outer surface transverse hole detection curve is used to compare with the highest reflected wave of the defect, depending on whether the ultrasonic test probe is scanning on the inner or outer surface when the defect is found.

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