Manual quantitative ultrasonic detection method and device for fillet weld defects of thin special structure

Abstract

The invention relates to a manual quantitative ultrasonic detection method and device for fillet weld defects of a thin special structure, and belongs to the field of nondestructive detection of welding quality. The detection device utilizes an industrial computer and a built-in ultrasonic pulse sound card to control pulse type transmitting and receiving of an ultrasonic probe, manual accurate stepping type positioning detection of the ultrasonic detection device is achieved based on a photoelectric sensor, echo signals are collected and processed, and the defect size is quantitatively evaluated. And due to the semi-automatic design, the structure is simplified, the size is greatly reduced, the applicability is good, the reliability is high, and maintenance is easy. According to the detection method, guided wave detection is adopted, so that the detection efficiency can be greatly improved, whether defects exist or not can be intuitively judged by establishing a B scanning graph through characteristic values of guided waves, the sizes of the defects can be quantitatively calibrated through an attenuation relation of defect edges, and the judgment of the defects is more accurate and efficient. According to the invention, rapid and accurate quantitative detection of defects of fillet welds of thin special structures with different plate thicknesses is realized.

Description

Technical Field

[0001] The present invention relates to the field of nondestructive testing of welding quality, and in particular to a manual quantitative ultrasonic testing method and device for thin special structure fillet weld defects, which is suitable for thin special structure fillet weld testing. The special structure described in the present invention refers to a fillet weld workpiece with a complex working condition structure and poor detection accessibility. Background Art

[0002] During ultrasonic testing, the propagation law of sound waves is related to the structure and thickness of the workpiece to be tested. When testing thin plates, fillet joints of different plate thicknesses have a complex effect on the propagation of sound waves, and the echo amplitude of the body wave is small, making it difficult to identify defects.

[0003] As for ultrasonic testing devices, fully automatic testing devices are large in size and difficult to use in special corner joints. They are also complex in structure and difficult to repair and maintain. They require programming and positioning of specific test workpieces. They are difficult to use and difficult to control for good contact with the workpiece surface, making it difficult to accurately and concisely test the workpiece to be tested. Summary of the invention

[0004] The purpose of the present invention is to provide a manual quantitative ultrasonic detection method and device for defects in thin corner welds with special structures, which solves the problems of existing fully automatic detection devices, such as large size, unsuitability for detection of special corner joints, complex structure, and difficult maintenance. The present invention adopts a guided wave detection method to extract characteristic values ​​of guided wave echoes, generate B-scan detection images, and perform quantitative analysis of defects. By establishing the attenuation relationship of sound waves in different plate thicknesses, defects in any plate thickness can be quantitatively calibrated. In order to adapt to the special structures of different workpieces, two corresponding detection devices are designed, and the manual detection device has a simple structure, reliable performance, easy use, and easy maintenance, and is worth wide promotion.

[0005] The above-mentioned object of the present invention is achieved by the following technical solutions: The manual quantitative ultrasonic detection method for defects in thin special structure corner welds adopts a manual quantitative ultrasonic detection device and a step-by-step positioning photoelectric sensor mechanism to realize quantitative identification of defects during manual positioning detection; the guided wave is used as the detection sound wave, and the guided wave echo is processed and the characteristic value is extracted, and the defect size is automatically calibrated; the spring is used to keep the probe in a stable coupling state during detection; the vertical structure is used to ensure the stable scanning of the device; the detection steps include: Step 1: According to different structures of the workpiece to be tested, select the same-side receiving and transmitting detection mode or the double-side receiving and transmitting detection mode of the manual quantitative ultrasonic testing device; Step 2: After cleaning the workpiece detection surface and applying coupling agent, install the detection device and adjust the position and posture. Adjust the initial probe position so that the echo amplitude is the maximum value to ensure the synchronous transmission and reception of the signal; Step 3: The manual quantitative ultrasonic testing device performs a Y-axis step-by-step scan on the workpiece to be tested, and collects and stores the ultrasonic guided wave echo signal; Step 4: Perform HHT (Hilbert-Huang Transform) data processing on the waveguide signal, take the instantaneous amplitude of IMF1 (first-order single frequency component) as the characteristic value and make a B-scan image; Step 5: Quantitatively identify defect sizes: Prepare fillet weld workpieces with different plate thicknesses, prefabricate fillet joints with plate thicknesses of T1, T2, T3…Ti, and measure the defect sizes of the calibration parts with metallographic tests as B1, B2, B3…Bi to obtain the internal defect array T of the calibration part. 训练 =[T1, T2, T3…Ti], B 训练 =[B1, B2, B3…Bi] Step 5.1: In the B scan image, according to the defect size B 训练 Establish each plate thickness T 训练 Attenuation relationship of medium sound wave at the defect edge: It is known that the acoustic wave intensity of the defect center on the B-scan image is C1, C2, C3...Ci, and the acoustic wave intensity of the defect edge is E1, E2, E3...Ei. The second-order polynomial model is used to describe the relationship between the acoustic wave intensity of the defect center and the acoustic wave intensity of the defect edge:

[0006] in, a ( T i ) is the coefficient of the quadratic term, b ( T i ) is the coefficient of the first-order term, c ( T i ) is the constant term coefficient; C is the acoustic wave intensity at the defect center; Step 5.2: Establish plate thickness T 训练 Relationship with the attenuation of sound waves at defects: The exponential fitting model is used to describe the relationship between different plate thicknesses T and binomial coefficients a, b, c:

[0007] in, a 0 and a 1 for a ( T ), b 0 and b 1 for b ( T ), c 0 and c 1 for c (T )’s exponential function coefficients; By integrating the above functional relationship, the relationship between the acoustic wave intensity C at the defect center and the acoustic wave intensity E at the defect edge under different plate thicknesses is obtained:

[0008] Step 5.3: According to the attenuation relationship of the training piece, find the attenuation relationship of the sound wave at the defect edge of a certain plate thickness. After entering the attenuation value, the defect size can be quantitatively calibrated in the B-scan image.

[0009] Another object of the present invention is to provide a manual quantitative ultrasonic detection device for defects of thin special structure fillet welds, comprising an industrial computer 1, an ultrasonic array transceiver mechanism 3, an ultrasonic pulse transceiver mechanism 4, a step-by-step positioning photoelectric sensor mechanism 6 and a motion control mechanism; the industrial computer 1 has a built-in ultrasonic control card, which is connected to the ultrasonic array transceiver mechanism 3, the ultrasonic pulse transceiver mechanism 4, and the step-by-step positioning photoelectric sensor mechanism 6 through a data line, and performs motion control, ultrasonic data acquisition, signal processing, data storage and graphical display on an ultrasonic excitation probe 4.1; The step-by-step positioning photoelectric sensor mechanism 6 is: the connecting shaft 6.2 is nested and connected with the bearing 6.3, and the sleeve 6.4 is nested in the bearing 6.3 and then connected to the encoder 6.1 and then nested with the rubber wheel 2 6.5. When performing Y-direction scanning, the motion control module is pushed to make the rubber wheel 2 6.5 contact and roll, and the encoder 6.1 is driven to rotate through the relative movement of the sleeve 6.4 and the bearing 6.3, so as to accurately control the scanning step length and complete the Y-direction scanning; the encoder 6.1 includes an optical coupling sensor 6.11 and a grating disc 6.12, the bearing 6.3 is connected to the grating disc 6.12, the rotation of the bearing 6.3 drives the grating disc 6.12 to rotate in the same direction, and the rotation distance of the grating disc 6.12 is read by the optical coupling sensor 6.11, so as to control the precise distance of the step.

[0010] The ultrasonic array transceiver mechanism 3 includes: a vacuum suction cup 3.1, an array probe fixing seat 3.2 and an ultrasonic array probe 3.3. The ultrasonic array probe 3.3 is in full contact with the surface of the workpiece 2 to be measured through the array probe fixing seat 3.2 and is fixed by a vacuum suction cup 3.1. The ultrasonic array probe 3.3 realizes the signal collection of the echo for the structure that cannot normally receive the echo signal.

[0011] The ultrasonic pulse transceiver mechanism 4 is controlled by the Y-axis motion mechanism 5, which is suitable for a structure in which the internal space of the workpiece 2 to be measured is small and the receiving probe cannot be installed; the connecting rod 5.1 of the Y-axis motion mechanism 5 is threadedly connected with the crossbeam 5.2, the crossbeam 5.2 is bolted to the slider 5.4 and then installed on the slide rail 5.5, the slide rail 5.5 is bolted to the base 5.3, driving the ultrasonic excitation probe 4.1 to move in the same direction along the surface of the workpiece 2 to be measured; the base 5.3 is tightly fitted with the workpiece 2 to be measured through the vacuum suction cup 5.6 to ensure the stability of the data during scanning.

[0012] The ultrasonic pulse transceiver mechanism 4 is motion-controlled by a height position adjustment mechanism 7, and is suitable for structures with a larger internal space of the workpiece 2 to be measured; the Y-axis connecting rod 7.1 and the Z-axis connecting rod 7.3 of the height position adjustment mechanism 7 are nested in the converter 7.2, and the moving distance of the ultrasonic excitation probe 4.1 is adjusted through the through hole of the connecting rod, and the converter 7.2 is pushed to control the Y-axis movement of the ultrasonic pulse transceiver mechanism 4; the height position adjustment mechanism 7 is a vertical structure, and its Y-axis connecting rod 7.1 and the Z-axis connecting rod 7.3 form a vertical structure with each other after contacting the workpiece 2 to be measured, which can ensure the stability of the manual quantitative ultrasonic detection device during the detection process.

[0013] The ultrasonic pulse transceiver mechanism 4 includes an ultrasonic excitation probe 4.1, a rubber wheel 4.2, a spring 4.3 and an excitation probe fixing seat 4.4. After the excitation probe fixing seat 4.4 is installed with the rubber wheel 4.2 and the spring 4.3, the ultrasonic excitation probe 4.1 is installed to realize the up and down floating function of the ultrasonic excitation probe 4.1, so that the ultrasonic excitation probe 4.1 is tightly and flexibly coupled with the workpiece 2 to be measured for stable scanning.

[0014] The beneficial effects of the present invention are as follows: in response to the detection requirements of thin corner welds with special structures, the present invention provides a manual quantitative ultrasonic detection device for defects of thin corner welds with special structures, which can use different detection devices for different structures, and the semi-automatic design structure simplifies the structure, has high stability, greatly reduces the volume, has good applicability, high reliability and easy maintenance, and can automatically adapt to the surface shape and height. Rapid and accurate quantitative detection of defects in thin corner welds with special structures of different plate thicknesses is achieved. In response to the requirements for detecting the welding quality of special thin corner welds, the present invention provides a manual quantitative ultrasonic detection method for defects of thin corner welds with special structures. The use of guided wave detection can greatly improve the detection efficiency. The B-scan diagram established by the characteristic value of the guided wave can intuitively determine whether there are defects. The size of the defect can be quantitatively calibrated by the attenuation relationship of the defect edge, making the determination of defects more accurate and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The illustrative examples of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0016] Figure 1 It is a schematic diagram of the double-side receiving and transmitting detection mode and device structure of the present invention; Figure 2 It is a schematic diagram of the same-side receiving and transmitting detection mode and device structure of the present invention; Figure 3 It is a schematic diagram of the structure of the ultrasonic pulse transmitting probe in the double-side detection mode of the present invention; Figure 4 It is a schematic diagram of the structure of the Y-direction scanning motion guide rail of the present invention; Figure 5 It is a schematic diagram of the structure of the ultrasonic array receiving probe of the present invention; Figure 6 It is a schematic diagram of the structure of the step-by-step positioning photoelectric sensor of the present invention; Figure 7 It is a schematic diagram of the automatic height adaptation device of the ultrasonic probe of the present invention; Figure 8 It is a schematic diagram of the probe height position adjustment mechanism of the present invention; Fig. 9 This is a typical measured image of ultrasonic guided wave echo signals of the detection method of the present invention; Fig.10 It is the instantaneous amplitude diagram of each order IMF of the ultrasonic guided wave echo signal of the detection method of the present invention; Fig.11 This is a diagram of ultrasonic B-scan detection results based on the first-order IMF amplitude characteristics of the detection method of the present invention.

[0017] In the figure: 1. Industrial computer; 2. Workpiece to be measured; 3. Ultrasonic array transceiver mechanism; 3.1. Vacuum suction cup 1; 3.2. Array probe fixing seat; 3.3. Ultrasonic array probe; 4. Ultrasonic pulse transceiver mechanism; 4.1. Ultrasonic excitation probe; 4.2. Rubber wheel 1; 4.3. Spring; 4.4. Excitation probe fixing seat; 5. Y-axis motion mechanism; 5.1. Connecting rod; 5.2. Crossbeam; 5.3. Base; 5.4. Slider; 5.5. Slide rail; 5.6. Vacuum suction cup 2; 6. Stepping positioning photoelectric sensor mechanism; 6.1. Encoder; 6.11. Optical coupling sensor; 6.12 Grating disk; 6.2. Connecting shaft; 6.3. Bearing; 6.4. Sleeve; 6.5. Rubber wheel 2; 7. Height position adjustment mechanism. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0019] See also Figures 1 to 11 As shown, the present invention discloses a manual quantitative ultrasonic detection method and device for defects in thin corner welds with special structures. The device uses an industrial computer and a built-in ultrasonic pulse sound card to control the pulsed emission and reception of the ultrasonic probe, realizes manual precise step-by-step positioning detection of the ultrasonic detection device based on a photoelectric sensor, and collects and processes the echo signal as well as quantitatively evaluates the defect size. The present invention adopts a simplified structure of a manual quantitative ultrasonic detection device to enhance the applicability of detection in a narrow space; adopts a step-by-step positioning photoelectric sensor mechanism to realize quantitative identification of defects during manual positioning detection; adopts guided waves as detection sound waves to overcome the shortcomings of traditional body waves in that the echo is insensitive and there are a large number of clutter when detecting thin structures; performs data processing and feature value extraction on the guided wave echo, and makes it visualized and automatically calibrates the defect size; adopts a spring mechanism to keep the probe in a stable coupling state during detection; and adopts a vertical structure to ensure stable scanning of the device.

[0020] The detection steps include: Step 1: According to different structures of the workpiece to be tested, select the same-side receiving and transmitting detection mode or the double-side receiving and transmitting detection mode of the manual quantitative ultrasonic testing device; Step 2: After cleaning the workpiece detection surface and applying coupling agent, install the detection device and adjust the position and posture. Adjust the initial probe position so that the echo amplitude is the maximum value to ensure the synchronous transmission and reception of the signal; Step 3: The manual quantitative ultrasonic testing device performs a Y-axis step-by-step scan on the workpiece to be tested, and collects and stores the ultrasonic guided wave echo signal; Step 4: Perform HHT (Hilbert-Huang Transform) data processing on the waveguide signal, take the instantaneous amplitude of IMF1 (first-order single frequency component) as the characteristic value and make a B-scan image; Step 5: Quantitatively identify defect sizes: Prepare fillet weld workpieces with different plate thicknesses, prefabricate fillet joints with plate thicknesses of T1, T2, T3…Ti, and measure the defect sizes of the calibration parts with metallographic tests as B1, B2, B3…Bi to obtain the internal defect array T of the calibration part. 训练 =[T1 T2 T3…Ti], B 训练 =[B1 B2 B3…Bi] 5.1. In the B scan, according to the defect size B 训练 Establish each plate thickness T 训练 Attenuation relationship of medium sound wave at the defect edge: It is known that the acoustic wave intensity of the defect center on the B-scan image is C1, C2, C3...Ci, and the acoustic wave intensity of the defect edge is E1, E2, E3...Ei. The second-order polynomial model is used to describe the relationship between the acoustic wave intensity of the defect center and the acoustic wave intensity of the defect edge:

[0021] in, a ( T i ) is the coefficient of the quadratic term, b ( T i ) is the coefficient of the first-order term, c ( T i ) is the constant term coefficient; C is the acoustic wave intensity at the defect center.

[0022] 5.2. Establish plate thickness T 训练 Relationship with the attenuation of sound waves at defects: The exponential fitting model is used to describe the relationship between different plate thicknesses T and binomial coefficients a, b, c:

[0023] in, a 0 and a 1 for a ( T ), b 0 and b 1 for b ( T ), c 0 and c 1 for c ( T )’s exponential function coefficients; By integrating the above functional relationship, the relationship between the acoustic wave intensity C at the defect center and the acoustic wave intensity E at the defect edge under different plate thicknesses is obtained:

[0024] 5.3. According to the attenuation relationship of the training piece, the attenuation relationship of the sound wave at the defect edge can be found for a specific plate thickness. After entering the attenuation value, the defect size can be quantitatively calibrated in the B-scan image.

[0025] See also Figures 1 to 11As shown, the manual quantitative ultrasonic detection device for defects of thin special structure fillet welds of the present invention comprises an industrial computer 1, an ultrasonic array transceiver mechanism 3, an ultrasonic pulse transceiver mechanism 4, a step-by-step positioning photoelectric sensor mechanism 6 and a motion control mechanism; the industrial computer 1 has a built-in ultrasonic control card, which is connected to the ultrasonic array transceiver mechanism 3, the ultrasonic pulse transceiver mechanism 4 and the step-by-step positioning photoelectric sensor mechanism 6 through a data line, and is used for motion control of an ultrasonic excitation probe 4.1 and ultrasonic data acquisition, signal processing, data storage and graphical display; See also Figure 6 As shown, the step-by-step positioning photoelectric sensor mechanism 6 includes: an encoder 6.1, a connecting shaft 6.2, the bearing 6.3, the sleeve 6.4 and the second rubber wheel 6.5, so that the connecting shaft 6.2 and the bearing 6.3 are nested, and the sleeve 6.4 is nested in the bearing 6.3 and then connected to the encoder 6.1 and then nested in the second rubber wheel 6.5. When performing Y-axis scanning, the motion control mechanism is pushed to make the second rubber wheel 6.5 contact and roll, and the encoder 6.1 is driven to rotate by the relative movement of the sleeve 6.4 and the bearing 6.3, so as to accurately control the scanning step length and complete the Y-axis scanning; the encoder 6.1 includes: an optical coupling sensor 6.11 and a grating disc 6.12. After the bearing 6.3 is connected to the grating disc 6.12, the bearing 6.3 rotates to drive the grating disc 6.12 to rotate in the same direction, and then the rotation distance of the grating disc 6.12 is read by the optical coupling sensor 6.11, so that the precise distance of the step can be controlled.

[0026] See also Figures 3 to 5 As shown, the ultrasonic array transceiver mechanism 3 includes: a vacuum suction cup 3.1, an array probe fixing seat 3.2 and an ultrasonic array probe 3.3. After the coupling agent is applied to the surface of the workpiece, the ultrasonic array probe 3.3 is completely in contact with the surface of the workpiece 2 to be measured through the array probe fixing seat 3.2, and then fixed by the vacuum suction cup 3.1. The ultrasonic array probe 3.3 can realize the signal collection of the echo for the structure that cannot normally receive the echo signal; The ultrasonic pulse transceiver mechanism 4 is controlled by the Y-direction motion mechanism 5, and is applicable to the structure where the internal space of the workpiece 2 to be measured is small and the receiving probe cannot be installed. The Y-direction motion mechanism 5 includes: a connecting rod 5.1, a crossbeam 5.2, a base 5.3, a slider 5.4, a slide rail 5.5 and a vacuum suction cup 2 5.6. The connecting rod 5.1 is threadedly connected with the crossbeam 5.2, the crossbeam 5.2 is bolted with the slider 5.4 and then installed on the slide rail 5.5, and the slide rail 5.5 is bolted with the base 5.3 to drive the ultrasonic excitation probe 4.1 to move in the same direction along the surface of the workpiece to be measured; the base 5.3 is tightly fitted with the workpiece 2 to be measured through the vacuum suction cup 2 5.6 to ensure the stability of the data during scanning, and can be applicable to a variety of materials such as ferromagnetic or non-ferromagnetic.

[0027] See also Figure 7 and Figure 8 As shown, the ultrasonic pulse transceiver mechanism 4 is controlled by the height position adjustment mechanism 7, which is suitable for the structure with a large internal space of the workpiece 2 to be tested. The height position adjustment mechanism 7 includes: a Y-axis connecting rod 7.1, a converter 7.2, and a Z-axis connecting rod 7.3. The Y-axis connecting rod 7.1 and the Z-axis connecting rod 7.3 are nested in the converter 7.2. The moving distance of the ultrasonic excitation probe 4.1 can be adjusted through the through hole of the connecting rod, and the Y-axis movement of the device can be controlled by pushing the converter 7.2; the height position adjustment mechanism 7 is a vertical structure, and its Y-axis connecting rod 7.1 and the Z-axis connecting rod 7.3 form a vertical structure with each other after contacting with the workpiece 2 to be tested, which can ensure the stability of the manual quantitative ultrasonic detection device during the detection process.

[0028] See also Figure 3 As shown, the ultrasonic pulse transceiver mechanism 4 includes: an ultrasonic excitation probe 4.1, a rubber wheel 4.2, a spring 4.3 and an excitation probe fixing seat 4.4. After the excitation probe fixing seat 4.4 is installed with the rubber wheel 4.2 and the spring 4.3, the ultrasonic excitation probe 4.1 is installed, which can be used to realize the up and down floating function of the ultrasonic excitation probe 4.1, so that the ultrasonic excitation probe 4.1 can be tightly and flexibly coupled with the workpiece 2 to be measured for stable scanning. Example

[0029] The present invention performs ultrasonic detection of fillet welds of a front bumper beam assembly structure of a passenger car, wherein the material is 6061 aluminum alloy, the thickness combination is 2mm+2mm, and there are 38 assembled fillet welds. The center frequency of the waveguide excitation probe is 2.5MHz, and the excitation incident angle is 65°. Since the fillet weld structure of the front bumper beam assembly structure is complex and the internal space of the workpiece to be tested is small, a double-sided transceiver detection mode and device are used for effective detection. The detection method and device are used to detect the fillet welds of the aluminum alloy bumper beam assembly structure, and a training piece detection is formulated to find the 2mm+2mm combination sound wave attenuation relationship of the 6061 aluminum alloy. 38 welds are detected, and the waveguide echo is processed and visualized to form a B-scan diagram, and the defect size is calibrated in the B-scan diagram using the sound wave attenuation relationship. The size of the internal defect of the fillet weld of the aluminum alloy bumper beam assembly structure is measured by metallographic test and compared, and the results show that the maximum error between the detection result using the method and device and the actual defect measurement is no more than 0.01mm. Example

[0030] The present invention performs ultrasonic detection on the corner welds of a railway passenger car body, wherein the material of the corner welds is SUS301L austenitic stainless steel, the thickness combination is 2mm+2.5mm, the number of assembled corner welds is 17, the center frequency of the waveguide excitation probe is 2.5MHz, and the excitation incident angle is 60°; since the structure of the corner welds of the railway passenger car body is complex and the internal space of the workpiece to be tested is relatively large, a same-side receiving and transmitting detection mode and a device are adopted for effective detection; the detection method and the device are used to detect the corner welds of the stainless steel body, a training piece detection is formulated and a 2mm+2.5mm combination sound wave attenuation relationship of the SUS301L austenitic stainless steel is found; 17 welds are detected, and data processing and image visualization are performed on the waveguide echo to form a B-scan diagram, and the defect size is calibrated in the B-scan diagram using the sound wave attenuation relationship; the size of the internal defect of the stainless steel body corner weld is measured by metallographic test, and a comparison is made, and the result shows that the maximum error between the detection result using the method and the device and the measured actual defect is no more than 0.01mm.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made to the present invention shall be included in the protection scope of the present invention.

Claims

1. A manual quantitative ultrasonic detection method for defects in thin special structure fillet welds, characterized by: A manual quantitative ultrasonic testing device and a step-by-step positioning photoelectric sensor mechanism are used to achieve quantitative identification of defects during manual positioning testing. Guided waves are used as detection sound waves to process data and extract characteristic values ​​of guided wave echoes, and automatically calibrate the defect size. A spring is used to keep the probe in a stable coupling state during testing. A vertical structure is used to ensure stable scanning of the device. The testing steps include: Step 1: According to different structures of the workpiece to be tested, select the same-side receiving and transmitting detection mode or the double-side receiving and transmitting detection mode of the manual quantitative ultrasonic testing device; Step 2: After cleaning the workpiece detection surface and applying coupling agent, install the detection device and adjust the position and posture. Adjust the initial probe position so that the echo amplitude is the maximum value to ensure the synchronous transmission and reception of the signal; Step 3: The manual quantitative ultrasonic testing device performs a Y-axis step-by-step scan on the workpiece to be tested, and collects and stores the ultrasonic guided wave echo signal; Step 4: Perform HHT data processing on the waveguide signal, take the instantaneous amplitude of IMF1 as the characteristic value and make a B-scan image; Step 5: Quantitatively identify defect sizes: Prepare fillet weld workpieces with different plate thicknesses, prefabricate fillet joints with plate thicknesses of T1, T2, T3…Ti, and measure the defect sizes of the calibration parts with metallographic tests as B1, B2, B3…Bi to obtain the internal defect array T of the calibration part. 训练 =[T1, T2, T3…Ti], B 训练 =[B1, B2, B3…Bi].

2. The manual quantitative ultrasonic detection method for defects in thin special structure fillet welds according to claim 1 is characterized by: The quantitative identification of defect size described in step 5 is specifically: Step 5.1: In the B scan image, according to the defect size B 训练 Establish each plate thickness T 训练 Attenuation relationship of medium sound wave at the defect edge: It is known that the acoustic wave intensity of the defect center on the B-scan image is C1, C2, C3...Ci, and the acoustic wave intensity of the defect edge is E1, E2, E3...Ei. The second-order polynomial model is used to describe the relationship between the acoustic wave intensity of the defect center and the acoustic wave intensity of the defect edge: ； in, a ( T i ) is the coefficient of the quadratic term, b ( T i ) is the coefficient of the first-order term, c ( T i ) is the constant term coefficient, C is the acoustic wave intensity at the defect center; Step 5.2: Establish plate thickness T 训练 Relationship with the attenuation of sound waves at defects: The exponential fitting model is used to describe the relationship between different plate thicknesses T and binomial coefficients a, b, c: ； in, a 0 and a 1 for a ( T ), b 0 and b 1 for b ( T ), c 0 and c 1 for c ( T )’s exponential function coefficients; By integrating the above functional relationship, the relationship between the acoustic wave intensity C at the defect center and the acoustic wave intensity E at the defect edge under different plate thicknesses is obtained: ； Step 5.3: According to the attenuation relationship of the training piece, find the attenuation relationship of the sound wave at the defect edge of a certain plate thickness. After entering the attenuation value, the defect size can be quantitatively calibrated in the B-scan image.

3. A manual quantitative ultrasonic detection device for thin special structure fillet weld defects that implements the manual quantitative ultrasonic detection method for thin special structure fillet weld defects according to claim 1 or 2, characterized in that: The invention comprises an industrial computer (1), an ultrasonic array transceiver mechanism (3), an ultrasonic pulse transceiver mechanism (4), a step-by-step positioning photoelectric sensor mechanism (6) and a motion control mechanism; the industrial computer (1) has a built-in ultrasonic control card, which is connected to the ultrasonic array transceiver mechanism (3), the ultrasonic pulse transceiver mechanism (4) and the step-by-step positioning photoelectric sensor mechanism (6) via a data line, and performs motion control, ultrasonic data acquisition, signal processing, data storage and graphical display on an ultrasonic excitation probe (4.1); The step-by-step positioning photoelectric sensor mechanism (6) comprises: a connecting shaft (6.2) and a bearing (6.3) are nested and connected, and a sleeve (6.4) is nested in the bearing (6.3) and then connected to an encoder (6.1) and then nested with a second rubber wheel (6.5); when performing Y-direction scanning, the motion control mechanism is pushed to cause the second rubber wheel (6.5) to contact and roll, and the encoder (6.1) is driven to rotate by the relative movement of the sleeve (6.4) and the bearing (6.3), thereby accurately controlling the scanning step length and completing the Y-direction scanning; the encoder (6.1) comprises an optical coupling sensor (6.11) and a grating disc (6.12); the bearing (6.3) is connected to the grating disc (6.12); the rotation of the bearing (6.3) drives the grating disc (6.12) to rotate in the same direction; the rotation distance of the grating disc (6.12) is read by the optical coupling sensor (6.11), thereby controlling the precise distance of the step.

4. The manual quantitative ultrasonic detection device for defects of thin special structure fillet welds according to claim 3 is characterized in that: The ultrasonic array transceiver mechanism (3) comprises: a vacuum suction cup (3.1), an array probe fixing seat (3.2) and an ultrasonic array probe (3.3); the ultrasonic array probe (3.3) is in full contact with the surface of the workpiece (2) to be measured via the array probe fixing seat (3.2) and is fixed by the vacuum suction cup (3.1); the ultrasonic array probe (3.3) realizes the signal collection of the echo of a structure that cannot normally receive the echo signal.

5. The manual quantitative ultrasonic detection device for defects of thin special structure fillet welds according to claim 4 is characterized in that: The ultrasonic pulse transceiver mechanism (4) is controlled to move via a Y-axis motion mechanism (5), and is suitable for a structure in which the internal space of a workpiece (2) to be measured is small and a receiving probe cannot be installed; the connecting rod (5.1) of the Y-axis motion mechanism (5) is threadedly connected to a crossbeam (5.2), the crossbeam (5.2) is bolted to a slider (5.4) and then installed on a slide rail (5.5), the slide rail (5.5) is bolted to a base (5.3), and drives the ultrasonic excitation probe (4.1) to move in the same direction along the surface of the workpiece (2) to be measured; the base (5.3) and the workpiece (2) to be measured are tightly fitted via a second vacuum suction cup (5.6), thereby ensuring the stability of data during scanning.

6. The manual quantitative ultrasonic detection device for defects of thin special structure fillet welds according to claim 4 is characterized in that: The ultrasonic pulse transceiver mechanism (4) is controlled in motion by a height position adjustment mechanism (7), and is suitable for a structure with a large internal space of a workpiece (2) to be measured; the Y-axis connecting rod (7.1) and the Z-axis connecting rod (7.3) of the height position adjustment mechanism (7) are nested in a converter (7.2), and the moving distance of the ultrasonic excitation probe (4.1) is adjusted through the through hole of the connecting rod, so as to push the converter (7.2) to control the Y-axis movement of the ultrasonic pulse transceiver mechanism (4); the height position adjustment mechanism (7) is a vertical structure, and the Y-axis connecting rod (7.1) and the Z-axis connecting rod (7.3) thereof form a vertical structure with the workpiece (2) to be measured after contacting each other, thereby ensuring the stability of the manual quantitative ultrasonic detection device during the detection process.

7. The manual quantitative ultrasonic detection device for defects of thin special structure fillet welds according to claim 3 is characterized by: The ultrasonic pulse transceiver mechanism (4) comprises an ultrasonic excitation probe (4.1), a rubber wheel (4.2), a spring (4.3) and an excitation probe fixing seat (4.4); after the rubber wheel (4.2) and the spring (4.3) are installed on the excitation probe fixing seat (4.4), the ultrasonic excitation probe (4.1) is installed to realize the up and down floating function of the ultrasonic excitation probe (4.1), so that the ultrasonic excitation probe (4.1) and the workpiece (2) to be measured are tightly and flexibly coupled to facilitate stable scanning.

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