Using method of reference block for X-ray three-dimensional scanning reconstruction imaging detection

Abstract

The invention discloses a use method of a reference block for X-ray three-dimensional scanning reconstruction imaging detection, and relates to the field of X-ray imaging detection, and the use method comprises the following steps: in a cone beam scanning mode of X-ray three-dimensional scanning imaging equipment, collecting multi-angle projection images of a hole defect reference block and a crack defect; generating a three-dimensional voxel model of the test block in combination with a three-dimensional reconstruction algorithm; calculating the aperture parameter of the hole type test block and the crack width parameter of the crack type test block; and calculating deviation values between the aperture parameter and the crack width parameter and the test block calibration value, when the deviation values meet a preset rule, judging that the performance of the imaging detection system is qualified, and taking the reconstructed image as a calibration reference for quantitative defect measurement. According to the method, quantitative performance evaluation of the X-ray three-dimensional imaging system, establishment of a defect measurement calibration reference and portable monitoring of system stability are realized through scanning reconstruction and parameter deviation judgment of a reference block.

Description

Technical Field

[0001] The present invention relates to the field of X-ray imaging detection, and more particularly to a method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection. Background Art

[0002] X-ray three-dimensional scanning and reconstruction imaging technology is widely used in non-destructive testing in high-end manufacturing industries such as aerospace and nuclear power equipment. In particular, its imaging accuracy directly affects the safety evaluation results of key components in the quantitative analysis of internal holes and cracks in titanium alloy components.

[0003] Currently, traditional X-ray 3D inspection relies on indirect sensitivity control using equipment parameters, making it impossible to directly quantify the system's ability to detect minute defects. For example, existing technologies only provide general-purpose inspection rigs, without designing standard defect test blocks. While related solutions involve optimizing imaging systems, they fail to establish rules for determining deviations between calibration values ​​for pore and crack defects and reconstructed images. This leads to subjective evaluation of system performance and makes it impossible to trace defect measurement results back to a quantifiable benchmark.

[0004] Furthermore, long-term imaging equipment is susceptible to accuracy degradation due to component aging, but existing methods lack portable monitoring tools. Conventional methods require frequent inspections by specialized institutions or equipment disassembly. Furthermore, there are no dedicated verification modules for typical defects such as holes and cracks (e.g., 0.01mm-level gradient widths), making rapid on-site verification difficult and impacting the long-term reliability of test results.

[0005] Common technical solutions often use single-size defects or non-gradient crack structures in test blocks, which cannot simulate the size gradient of defects (such as crack width variation) in real workpieces. In addition, the test block material, surface roughness, and scanning parameters are not standardized, resulting in the reconstructed image being unable to serve as a universal calibration benchmark, and the measurement results between different devices are difficult to compare.

[0006] Therefore, how to design a method for using comparison test blocks for X-ray three-dimensional scanning and reconstruction imaging detection, integrating standardized defect test blocks, quantitative performance evaluation and calibration benchmark generation to achieve imaging system stability monitoring and improve defect measurement accuracy is an urgent problem that technical personnel in this field need to solve. Summary of the Invention

[0007] In view of this, the present invention provides a method for using comparison test blocks for X-ray three-dimensional scanning, reconstruction and imaging detection. By designing hole and crack comparison test blocks with specific structures, combined with standardized scanning and reconstruction processes, key parameter deviations are calculated to determine whether the system is qualified, and a calibration reference image is generated to solve the problems of no standard reference for quantitative measurement of defects and the inability to conveniently monitor system stability.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for using a comparison test block for X-ray three-dimensional scanning reconstruction imaging detection includes the following steps:

[0010] S1. Under the cone beam scanning mode of the X-ray 3D scanning imaging device, collect multi-angle projection images of hole defect comparison blocks and crack defects;

[0011] S2. Generate a three-dimensional voxel model of the test block using the multi-angle projection images in combination with a three-dimensional reconstruction algorithm;

[0012] S3. Calculating the pore diameter parameters of the hole-type test block and the crack width parameters of the crack-type test block based on the three-dimensional voxel model;

[0013] S4. Calculate the deviation between the aperture parameters and crack width parameters and the test block calibration values. When the deviation meets the preset rules, the imaging detection system performance is determined to be qualified, and the reconstructed image is used as the calibration benchmark for quantitative defect measurement.

[0014] Preferably, in said S1, the hole defect comparison test block is a cylinder with an outer diameter of Φ36mm×height 5mm, an end face roughness Ra≤1.6μm, and cylindrical holes of Φ0.1mm, Φ0.2mm, Φ0.3mm, Φ0.4mm and Φ0.5mm are processed at equal intervals on a circumference 2mm away from the edge; among which the Φ0.1mm hole is 1.6mm deep, and the rest are through holes.

[0015] Preferably, in S1, the crack-type defect comparison test block is divided into two semi-cylinders through the center of the circle in the height direction, and a blind hole of Φ5.6mm×3mm depth is processed at the center position of the dividing surface; by embedding a Φ6mm pin into the blind hole, a 0.4mm gap is formed between the two semi-cylinders at the pin embedding end, and the other end is tightly fitted, thereby forming a simulated crack with a linear gradient from 0mm to 0.4mm along the height direction.

[0016] Preferably, the two semi-cylinders are fixedly connected by a hard plastic fastening sleeve and screws, and the hard plastic fastening sleeve is wrapped around the outer circumference of the cylinder.

[0017] Preferably, in said S1, the scanning parameters of the hole defect comparison test block in the cone beam scanning mode are: ray source voltage 110 kV, current 960 μA, integration time 1100 ms, and number of projections 2520;

[0018] The scanning parameters of the crack defect comparison test block are: X-ray source voltage 280kV, current 1000μA, integration time 1200ms, and number of projections 2520.

[0019] Preferably, in S2, the 3D reconstruction algorithm adopts the FDK algorithm, including:

[0020] Perform flat panel detector geometric correction and dark field correction on the projected image;

[0021] Applying a ramp filter to the corrected projection data for filtering;

[0022] The filtered projection data are back-projected onto a 3D space grid along the cone-beam ray path to generate 3D voxel data.

[0023] Preferably, in S3, calculating the aperture parameters of the hole test block includes:

[0024] The central axis of each cylindrical hole is located in the 3D voxel model, the voxel coordinates of the hole wall edge are extracted, and the actual diameter of the cylindrical hole is fitted using the least squares method.

[0025] Preferably, in S3, calculating the crack width parameter of the cracked test block includes:

[0026] Cross sections were taken at intervals of 1 mm along the height direction of the cylinder;

[0027] Extract the crack edge contour in each cross-sectional image and calculate the shortest distance between the two edges as the crack width at that height position;

[0028] The linear variation curve of crack width with height is fitted according to the crack width values ​​at each height position.

[0029] Preferably, in S4, the preset rules include:

[0030] The absolute value of the Φ0.1mm aperture deviation of the hole defect comparison test block is ≤0.03mm, and the absolute value of the other aperture deviations is ≤0.01mm;

[0031] The absolute value of the crack width deviation of the crack defect comparison test block is ≤0.01mm.

[0032] Preferably, in S4, using the reconstructed image as a calibration reference for quantitative defect measurement includes:

[0033] The reconstructed image of the hole defect comparison block is used as the calibration reference base map for the quantitative measurement of circular defects; the reconstructed image of the crack defect comparison block is used as the calibration reference base map for the quantitative measurement of long strip defects.

[0034] It can be seen from the above technical solution that compared with the prior art, the technical solution of the present invention has the following advantages:

[0035] Beneficial effects:

[0036] 1. By calculating the deviation between the pore diameter and crack width parameters and the calibration values, and judging whether the system performance is qualified according to preset rules, the problem of traditional detection relying on indirect control is solved, and a quantifiable system stability evaluation standard is clarified to ensure the credibility of the imaging detection results.

[0037] 2. The reconstructed images of hole-type and crack-type test blocks are used as calibration reference base maps for circular and long strip defects, respectively, providing a unified reference for the quantitative measurement of actual workpiece defects (such as size and morphological analysis). This overcomes the deficiency of existing technologies in lacking effective comparison tools and significantly improves the accuracy and consistency of defect measurement.

[0038] 3. Through standardized test block structure design and fixed scanning parameters, the detection process can be executed regularly and quickly, realizing convenient monitoring of the performance degradation of imaging equipment during long-term use, and ensuring the continuous and reliable operation of the detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0040] Figure 1 A flowchart of a method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection provided by an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the structure of a hole defect comparison test block provided by an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of the structure of a comparative test block for crack defects provided by an embodiment of the present invention;

[0043] In the figure, 1-cylinder, 2-hard plastic fastening sleeve, 3-screw, 4-pin. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] like Figure 1 As shown, this embodiment provides a method for using a comparison test block for X-ray three-dimensional scanning reconstruction imaging detection, including the following steps:

[0046] S1. Under the cone beam scanning mode of the X-ray 3D scanning imaging device, collect multi-angle projection images of hole defect comparison blocks and crack defects;

[0047] S2. Generate a three-dimensional voxel model of the test block using the multi-angle projection images in combination with a three-dimensional reconstruction algorithm;

[0048] S3. Calculating the pore diameter parameters of the hole-type test block and the crack width parameters of the crack-type test block based on the three-dimensional voxel model;

[0049] S4. Calculate the deviation between the aperture parameters and crack width parameters and the test block calibration values. When the deviation meets the preset rules, the imaging detection system performance is determined to be qualified, and the reconstructed image is used as the calibration benchmark for quantitative defect measurement.

[0050] This method achieves quantitative performance evaluation of the X-ray three-dimensional imaging system through scanning, reconstruction and parameter deviation analysis of standardized hole / crack comparison test blocks. At the same time, it uses the reconstructed images to establish a calibration benchmark for defect measurement and supports regular portable system stability monitoring, solving the problem of traditional detection lacking quantitative evaluation tools and calibration benchmarks.

[0051] The following is a further detailed description of each of the above steps and related features;

[0052] In this embodiment, S1, in the cone beam scanning mode of the X-ray three-dimensional scanning imaging device, multi-angle projection images of the hole defect comparison test block and the crack defect comparison test block are collected; wherein the material of the hole defect comparison test block and the crack defect comparison test block is TA15 titanium alloy;

[0053] like Figure 2 As shown, the hole defect comparison test block is a cylinder with an outer diameter of Φ36mm and a height of 5mm, with an end surface roughness of Ra≤1.6μm, and cylindrical holes of Φ0.1mm, Φ0.2mm, Φ0.3mm, Φ0.4mm and Φ0.5mm are processed at equal intervals on the circumference 2mm away from the edge; the Φ0.1mm hole is 1.6mm deep, and the rest are through holes. The design indicators of the hole comparison test block are shown in Table 1 below:

[0054] Table 1

[0055] Nominal size Geometric tolerances Test results Φ0.1×H1.6 Φ±0.02×H±0.10 Φ0.11×H1.57 Φ0.2 through hole ±0.02 Φ0.21 Φ0.3 through hole ±0.02 Φ0.31 Φ0.4 through hole ±0.02 Φ0.41 Φ0.5 through hole ±0.02 Φ0.51

[0056] The hole defect comparison test block simulates real pore defects through a stepped pore size distribution with strict shape and position tolerances, providing a high reliability benchmark for the verification of the aperture measurement accuracy of the reconstructed image.

[0057] like Figure 3The crack type defect comparison test block is divided into two half cylinders 1 along the height direction through the center of the cylinder with an outer diameter of 36 mm and a height of 40 mm, and a blind hole with a diameter of 5.6 mm and a depth of 3 mm is processed at the center of the split surface;

[0058] Further, by embedding the Φ6 mm pin 4 into the blind hole, the two half cylinders 1 form a 0.4 mm gap at the pin embedding end, and the other end is tightly fitted, thereby forming a simulated crack that linearly changes from 0 mm to 0.4 mm along the height direction;

[0059] Further, the two half cylinders are fixedly connected by a hard plastic fastening sleeve 2 and a screw 3, and the hard plastic fastening sleeve 2 is wrapped around the outer periphery of the cylinder; it not only ensures the tight fit of the split surface at the non-pin end, but also ensures the stability of the gap at the pin end. The hard plastic material avoids metal interference with X-ray imaging, and the screw fastening design facilitates test block disassembly, maintenance, and improves practicality and service life;

[0060] The design indicators of the crack type defect comparison test block are shown in Table 2 below:

[0061] Table 2

[0062]

[0063]

[0064] The crack type defect comparison test block realizes crack gradient through mechanical structure: a Φ36 mm x 40 mm cylinder is cut into two half cylinders along the height direction, a Φ5.6 mm x 3 mm blind hole is processed at the center of the split surface; a Φ6 mm pin (interference fit) is inserted to form a 0.4 mm gap at one end and a tight fit at the other end. This structure makes the crack width change linearly and continuously from 0 to 0.4 mm along the height direction, which can better simulate the gradual change characteristics of the real crack morphology and overcome the defect that the traditional test block cannot realize continuous width change.

[0065] Further, the scanning parameters of the hole type defect comparison test block in the cone beam scanning mode are: the ray source voltage is 110 kV, the current is 960 μA, the integral time is 1100 ms, and the projection number is 2520; the scanning parameters of the crack type defect comparison test block are: the ray source voltage is 280 kV, the current is 1000 μA, the integral time is 1200 ms, and the projection number is 2520; the X-ray three-dimensional scanning reconstruction imaging detection parameters of the hole type defect comparison test block and the crack type defect comparison test block are shown in Tables 3 and 4:

[0066] Table 3

[0067] Device Model X-ray machine Detector model Scan Mode FF85 FXE300.48 4343HE Cone-beam scanning Voltage / kv Current / μA Integration time / ms Number of projections 110 960 1100 2520

[0068] Table 4

[0069] Device Model X-ray machine Detector model Scan Mode FF85 FXE300.48 4343HE Cone-beam scanning Voltage / kv Current / μA Integration time / ms Number of projections 280 1000 1200 2520

[0070] The above scanning parameters are set differently according to the characteristics of two types of defects: the hole-type specimens use the low-energy parameters of 110kV and 960μA (small holes require high resolution), and the crack-type specimens use the high-energy parameters of 280kV and 1000μA (penetrating thicker materials); the integration time exceeds 1000ms and the number of projections reaches 2520, ensuring the signal-to-noise ratio and tomographic accuracy of the reconstructed image.

[0071] In this embodiment, S2, using the multi-angle projection images in combination with a three-dimensional reconstruction algorithm to generate a three-dimensional voxel model of the test block;

[0072] Among them, the 3D reconstruction algorithm adopts the FDK algorithm, including: performing flat-panel detector geometric correction and dark field correction on the projection image; applying a ramp filter to the corrected projection data for filtering; and reversely projecting the filtered projection data along the cone beam ray path to the 3D space grid to generate 3D voxel data.

[0073] The algorithm first performs geometric correction on the projected image to eliminate detector distortion and dark field correction to remove noise. It then applies a ramp filter to enhance edge features. Finally, it backprojects along the cone-beam rays to generate 3D voxel data. This algorithm efficiently processes cone-beam scan data, providing high-fidelity 3D models for subsequent quantitative measurements.

[0074] In this embodiment, S3, based on the three-dimensional voxel model, calculating the pore diameter parameters of the hole test block and the crack width parameters of the crack test block;

[0075] Calculating the aperture parameters of hole-type test blocks involves locating the central axis of each cylindrical hole in a 3D voxel model, extracting the voxel coordinates of the hole wall edge, and fitting the actual diameter of the cylindrical hole using the least squares method. This method avoids two-dimensional measurement errors and is particularly suitable for submillimeter precision verification of Φ0.1mm microholes.

[0076] Furthermore, the crack width parameters of the cracked specimens are calculated by: cutting cross sections at intervals of 1 mm along the height direction of the cylinder; extracting the crack edge contour in each cross-sectional image, and calculating the shortest distance between the two edges as the crack width at that height position; fitting a linear curve of crack width versus height based on the crack width values ​​at each height position;

[0077] By fitting the height-width linear curve, the system's ability to detect crack width and gradual morphology can be simultaneously verified.

[0078] In this embodiment, S4 calculates the deviation between the aperture parameter and the crack width parameter and the calibration value of the test block. When the deviation meets the preset rules, the imaging detection system performance is determined to be qualified, and the reconstructed image is used as a calibration reference for quantitative defect measurement.

[0079] The preset rules include:

[0080] The absolute value of the Φ0.1mm aperture deviation of the hole defect comparison test block is ≤0.03mm, and the absolute value of the other aperture deviations is ≤0.01mm; the absolute value of the crack width deviation of the crack defect comparison test block is ≤0.01mm;

[0081] This rule takes into account both technical feasibility and application rigor. Qualified deviations indicate that the detection stability of volumetric and area defects meets the standards and can be used as a periodic calibration standard for equipment.

[0082] Furthermore, using the reconstructed image as a calibration benchmark for quantitative defect measurement includes:

[0083] The reconstructed image of the hole defect comparison block is used as the calibration reference base map for the quantitative measurement of circular defects; the reconstructed image of the crack defect comparison block is used as the calibration reference base map for the quantitative measurement of long strip defects.

[0084] In the actual inspection process, the reconstructed image of the hole test block generates a three-dimensional digital model with a stepped aperture of Φ0.1-0.5mm, while the crack test block generates a holographic image of a continuous, gradual crack of 0-0.4mm. After these images pass the deviation verification, they are stored as a standard reference base map library. When inspecting workpieces such as aircraft engine blades, the digital calibration software first loads the reference base map corresponding to the defect type (e.g., pores use the hole base map, fatigue cracks use the crack base map). Then, using a spatial feature matching algorithm, the known defect sizes in the reference map are mapped and calibrated with the spatial resolution and grayscale response curve of the current inspection system.

[0085] During continuous inspections on the production line, operators prioritize scanning two types of test blocks after starting the machine daily. Aperture deviation analysis and crack linearity verification are automatically performed. After verification, real-time calibration mode is activated. When inspecting a workpiece, a reconstruction algorithm overlays and compares the voxel data of the workpiece defect with a reference base map in three dimensions. For turbine disc mortise and tenon crack detection, for example, the software extracts voxel clusters in the crack area and automatically associates them with the edge sharpness parameters of segments of the same width in the crack-related reference base map. The measured values ​​are corrected using a convolutional neural network, ultimately outputting quantitative results with confidence intervals. This process ensures that inspection data from different batches of equipment have a unified measurement standard, significantly reducing missed detection rates and meeting airworthiness certification requirements.

[0086] Based on the above implementation process, the present invention has constructed a complete set of X-ray three-dimensional imaging detection performance evaluation and calibration system through the use of precisely designed hole and crack comparison test blocks, combined with standardized three-dimensional reconstruction algorithms. It uses hole test blocks with a stepped aperture distribution and crack test blocks with a gradual crack structure, combined with least squares fitting and crack width linear analysis technology, to achieve quantitative verification of volumetric and area defect detection capabilities; at the same time, it uses reconstructed images to establish a dynamic calibration benchmark, and transfers the measurement accuracy to the actual workpiece defect analysis through digital calibration to ensure that the detection results are traceable. This method realizes portable monitoring of system stability through optimized mechanical fixing structure and differentiated scanning strategy, fundamentally solving the industry problems of lack of quantitative evaluation tools and insufficient calibration benchmarks in traditional X-ray detection, and provides reliable quality assurance for high-precision industrial non-destructive testing.

[0087] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. References to the same or similar parts between the various embodiments are sufficient. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For relevant parts, refer to the method description.

[0088] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection, characterized in that: The following steps are involved: S1. Under the cone beam scanning mode of the X-ray 3D scanning imaging device, collect multi-angle projection images of hole defect comparison blocks and crack defects; S2. Generate a three-dimensional voxel model of the test block using the multi-angle projection images in combination with a three-dimensional reconstruction algorithm; S3. Calculating the pore diameter parameters of the hole-type test block and the crack width parameters of the crack-type test block based on the three-dimensional voxel model; S4. Calculate the deviation between the aperture parameters and crack width parameters and the test block calibration values. When the deviation meets the preset rules, the imaging detection system performance is determined to be qualified, and the reconstructed image is used as the calibration benchmark for quantitative defect measurement.

2. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S1, the hole defect comparison test block is a cylinder with an outer diameter of Φ36 mm and a height of 5 mm, an end surface roughness Ra ≤ 1.6 μm, and cylindrical holes of Φ0.1 mm, Φ0.2 mm, Φ0.3 mm, Φ0.4 mm, and Φ0.5 mm are processed at equal intervals on a circumference 2 mm from the edge; The Φ0.1mm hole has a depth of 1.6mm, and the rest are through holes.

3. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S1, the crack defect comparison test block is divided into two semi-cylinders along the height direction through the center of the circle with an outer diameter of Φ36mm and a height of 40mm, and a blind hole of Φ5.6mm and a depth of 3mm is processed at the center position of the dividing surface; by embedding a Φ6mm pin into the blind hole, a 0.4mm gap is formed between the two semi-cylinders at the pin embedding end, and the other ends are tightly fitted, thereby forming a simulated crack with a linear gradient from 0mm to 0.4mm along the height direction.

4. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 3, characterized in that: The two semi-cylinders are fixedly connected by a hard plastic fastening sleeve and screws, and the hard plastic fastening sleeve is covered on the outer circumference of the cylinder.

5. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S1, the scanning parameters of the hole defect comparison test block in the cone beam scanning mode are: radiation source voltage 110kV, current 960μA, integration time 1100ms, and number of projections 2520; The scanning parameters of the crack defect comparison test block are: X-ray source voltage 280kV, current 1000μA, integration time 1200ms, and number of projections 2520.

6. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S2, the 3D reconstruction algorithm adopts the FDK algorithm, including: Perform flat panel detector geometric correction and dark field correction on the projected image; Applying a ramp filter to the corrected projection data for filtering; The filtered projection data are back-projected onto a 3D space grid along the cone-beam ray path to generate 3D voxel data.

7. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S3, calculating the aperture parameters of the hole test block includes: The central axis of each cylindrical hole is located in the 3D voxel model, the voxel coordinates of the hole wall edge are extracted, and the actual diameter of the cylindrical hole is fitted using the least squares method.

8. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S3, the calculation of the crack width parameter of the cracked test block includes: Cross sections were taken at intervals of 1 mm along the height direction of the cylinder; Extract the crack edge contour in each cross-sectional image and calculate the shortest distance between the two edges as the crack width at that height position; The linear variation curve of crack width with height is fitted according to the crack width values ​​at each height position.

9. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S4, the preset rules include: The absolute value of the Φ0.1mm aperture deviation of the hole defect comparison test block is ≤0.03mm, and the absolute value of the other aperture deviations is ≤0.01mm; The absolute value of the crack width deviation of the crack defect comparison test block is ≤0.01mm.

10. The method for using a comparison test block for X-ray three-dimensional scanning and reconstruction imaging detection according to claim 1, characterized in that: In S4, using the reconstructed image as a calibration reference for quantitative defect measurement includes: The reconstructed image of the hole defect comparison block is used as the calibration reference base map for the quantitative measurement of circular defects; the reconstructed image of the crack defect comparison block is used as the calibration reference base map for the quantitative measurement of long strip defects.

Images