An ultrasonic detection system and method for the counterbore of the tie rod bolt of a gas turbine turbine disk

Abstract

The present invention discloses an ultrasonic detection system and method for the counterbore of the tie bolt of a gas turbine turbine disk. The system includes an ultrasonic probe, a coded scanning tooling, a calibration block, and an ultrasonic signal transmitting and collecting device. The method includes the steps of: S501: Cooperating the ultrasonic probe with the coded scanning tooling and connecting it to the ultrasonic signal transmitting and collecting device; S502: Calibrating and setting the ultrasonic detection sensitivity through the calibration block; S503: Scanning by cooperating the encoder scanning tooling and the ultrasonic probe, and positioning and quantifying the detected defects. By adopting a conventional ultrasonic probe and a phased array ultrasonic probe, as well as a coded scanning tooling and a calibration block, the present invention realizes the effective simulation and comprehensive, efficient, and reliable detection of the crack defects in the counterbore of the tie bolt of the turbine disk; aiming at the detection characteristics of different parts of the counterbore of the tie bolt, the conventional ultrasonic detection and phased array ultrasonic detection technologies are respectively adopted to realize the comprehensive detection of defects with different positions and orientations.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic testing, and particularly relates to an ultrasonic testing system and method for the counterbore of the tie rod bolt of a gas turbine turbine disk. Background Art

[0002] The turbine disks of each stage of a gas turbine are generally fixed together by circumferential tie rod bolts, serving as the main body of the turbine rotor and transmitting the torque generated by the turbine blades. The tie rod bolts not only have to bear the tensile force and pre-tightening force generated by the gravity of the turbine rotor itself, but also have to bear the air flow impact force and vibration stress during operation, so that the tie rod bolts are always in a relatively high stress state. The stress of the tie rod bolts is mainly borne by the joint surface between the tie rod bolt nut and the counterbore part of the turbine disk, resulting in a highly concentrated stress at the counterbore part of the turbine disk. In particular, the stress state at the fillet position of the counterbore of the tie rod bolt is the worst, and it is easy to generate harmful defects such as cracks at the counterbore position of the turbine disk, which damage the structural integrity of the turbine disk. Summary of the Invention

[0003] The purpose of the present invention is to timely detect harmful defects such as cracks at the counterbore of the tie rod bolt of the turbine disk, and provides an ultrasonic testing system and method for the counterbore of the tie rod bolt of a gas turbine turbine disk. By combining a conventional ultrasonic probe and a phased array ultrasonic probe with a coded scanning tooling, a comprehensive and effective detection of harmful defects such as cracks at the counterbore of the tie rod bolt of the turbine disk is realized, and the reliability and detection efficiency of the detection are improved.

[0004] The present invention is realized by adopting the following technical solutions:

[0005] An ultrasonic testing system for the counterbore of the tie rod bolt of a gas turbine turbine disk includes an ultrasonic probe, a coded scanning tooling, a calibration block, and an ultrasonic signal transmitting and collecting device;

[0006] The ultrasonic probe includes a conventional ultrasonic probe and a phased array ultrasonic probe;

[0007] The conventional ultrasonic probe is used to detect the defects of the counterbore of the tie rod bolt from the end face of the turbine disk, and a longitudinal wave straight probe or a small-angle longitudinal wave straight probe is adopted;

[0008] The phased array ultrasonic probe is used to detect the defects of the counterbore of the tie rod bolt from the arc surface of the turbine disk, and a linear array or planar array transverse wave phased array ultrasonic probe is adopted;

[0009] The phased array ultrasonic probe is installed on the coded scanning tooling, and both the phased array ultrasonic probe and the coded scanning tooling are connected to the ultrasonic signal transmitting and collecting device;

[0010] The phased array ultrasonic probe is coupled to the surface of the detection part of the counterbore of the turbine disk tie rod bolt through the coded scanning tooling, emits ultrasonic waves under the excitation of the ultrasonic signal transmitting and collecting device, receives the ultrasonic waves returned from the detection part of the counterbore of the turbine disk tie rod bolt, and converts the ultrasonic waves into ultrasonic signals and sends them to the ultrasonic signal transmitting and collecting device;

[0011] The coded scanning tooling is used to clamp the phased array ultrasonic probe and record the position and scanning speed of the phased array ultrasonic probe;

[0012] The calibration test block is used to calibrate the resolution and positioning accuracy of the ultrasonic probe and calibrate the detection sensitivity of the ultrasonic probe;

[0013] The ultrasonic signal transmitting and collecting device is used to transmit, receive and process ultrasonic signals and display the ultrasonic signals in a graphical way.

[0014] A further improvement of the present invention is that the incident angle of the small-angle longitudinal wave straight probe is 5-8°;

[0015] The detection sensitivity of the longitudinal wave straight probe or the small-angle longitudinal wave straight probe is lower than that of the phased array ultrasonic probe.

[0016] A further improvement of the present invention is that the number of array elements of the phased array ultrasonic probe is not less than 16.

[0017] A further improvement of the present invention is that the coded scanning tooling includes a wheel encoder and a clamping device;

[0018] The wheel encoder is used to convert the position and scanning speed information of the ultrasonic probe into electrical signals and transmit the electrical signals to the ultrasonic signal acquisition device;

[0019] There is 1 wheel encoder, which is integrated on one of the sliding wheels of the coded scanning tooling. There are 4 sliding wheels, which are respectively located at the four corners of the coded scanning tooling;

[0020] The clamping device is used to fix the ultrasonic probe on the coded scanning tooling and ensure good coupling with the surface of the detection part during the scanning process.

[0021] A further improvement of the present invention is that the calibration test block includes a calibration test block base body and a groove;

[0022] The shape and external dimensions of the calibration test block base body are the same as those of the counterbore of the turbine disk tie rod bolt to be detected. The material, sound velocity and acoustic impedance of the calibration test block base body are the same as or similar to those of the counterbore of the turbine disk tie rod bolt to be detected;

[0023] The grooving process is carried out at the part to be detected of the counterbore of the tie rod bolt of the turbine disk, and is used to simulate the forms, sizes, positions and trend characteristics of defects that are likely to occur.

[0024] A further improvement of the present invention is that the grooving is processed by an electric discharge machining method, the trend of the grooving is perpendicular to or forms a set angle with the axial direction of the counterbore of the tie rod bolt, and when detecting the grooving defect with a set angle by conventional ultrasonic testing, a small-angle longitudinal wave probe is used for detection.

[0025] A further improvement of the present invention is that the ultrasonic signal transmitting and collecting device includes a transmitting module, a collecting module and a processing module;

[0026] The transmitting module is used to transmit pulsed electrical signals with a certain repetition frequency to excite the ultrasonic probe to generate ultrasonic waves;

[0027] The collecting module is used to receive the ultrasonic signals returned by the ultrasonic probe, convert them from analog signals into digital signals and store and record them;

[0028] The processing module is used to perform calibration, filtering, noise reduction and transformation operations on the digital signals, and display them in the form of waveforms or images.

[0029] An ultrasonic testing method for the counterbore of the tie rod bolt of a gas turbine turbine disk, which is based on the ultrasonic testing system for the counterbore of the tie rod bolt of a gas turbine turbine disk, includes the following steps:

[0030] Step 1: Fix the ultrasonic probe on the coded scanning tooling, and connect the ultrasonic probe, the coded scanning tooling and the ultrasonic signal transmitting and collecting device;

[0031] Step 2: Fix the coded scanning tooling on the surface of the part to be detected of the calibration test block, ensure good coupling of the ultrasonic probe, and use the ultrasonic signal transmitting and collecting device to excite the ultrasonic probe to generate ultrasonic waves and scan the grooving of the part to be detected to find the highest wave, and calibrate and set the sensitivity of the ultrasonic testing;

[0032] Step 3: Fix the coded scanning tooling and the ultrasonic probe on the surface of the part to be detected of the counterbore of the tie rod bolt of the turbine disk, push the coded scanning tooling to drive the ultrasonic probe to scan, and in the process of scanning, record the position and scanning distance of the ultrasonic probe in real time through the wheel encoder. If the reflected echo of the part to be detected exceeds the reference, determine the defect position through the propagation time and detection angle of the ultrasonic wave, and quantify the defect.

[0033] A further improvement of the present invention lies in that, in step two, when a longitudinal wave straight probe or a small-angle longitudinal wave straight probe is used as the ultrasonic probe, calibration and setting of the ultrasonic detection sensitivity are performed from the end face of the calibration test block for the counterbore of the tie rod bolt of the turbine disk to be detected, and a coded scanning tooling is not used; in step three, when a longitudinal wave straight probe or a small-angle longitudinal wave straight probe is used as the ultrasonic probe, scanning is performed from the end face of the counterbore of the tie rod bolt of the turbine disk to be detected, and a coded scanning tooling is not used.

[0034] The focusing mode of the phased array ultrasonic probe adopts the projection focusing mode, and the projection focusing position is set near the part to be detected.

[0035] The present invention has at least the following beneficial technical effects:

[0036] A gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system and method provided by the present invention, by using a conventional ultrasonic probe and a phased array ultrasonic probe, as well as a coded scanning tooling and a calibration test block, realizes effective simulation and comprehensive, efficient and reliable detection of crack defects in the counterbore of the tie rod bolt of the turbine disk; aiming at the detection characteristics of different parts of the tie rod bolt counterbore, conventional ultrasonic detection and phased array ultrasonic detection technologies are respectively adopted to realize comprehensive detection of defects at different positions and orientations. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system of the present invention;

[0038] Figure 2 is a schematic diagram of the ultrasonic probe in a gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system of the present invention;

[0039] Figure 3 is a schematic diagram of the coded scanning tooling in a gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system of the present invention;

[0040] Figure 4 is a schematic diagram of the calibration test block in a gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system of the present invention.

[0041] Figure 5 is a schematic diagram of the ultrasonic signal transmitting and collecting device in a gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system of the present invention;

[0042] Figure 6 is a flowchart of a gas turbine turbine disk tie rod bolt counterbore ultrasonic detection method of the present invention.

[0043] DESCRIPTION OF THE REFERENCE NUMERALS:

[0044] 10 - Ultrasonic probe, 101 - Conventional ultrasonic probe, 102 - Phased array ultrasonic probe, 20 - Encoded scanning tooling, 201 - Wheel encoder, 202 - Clamping device, 30 - Calibration test block, 301 - Calibration test block substrate, 302 - Groove, 40 - Ultrasonic signal transmitting and collecting device, 401 - Transmitting module, 402 - Collecting module, 403 - Processing module.

[0045] Detailed implementation manners

[0046] The present invention will be further described below with reference to the accompanying drawings.

[0047] Refer to Figure 1-6 A gas turbine turbine disk tie rod bolt counterbore ultrasonic detection system provided by the present invention is characterized in that it includes an ultrasonic probe 10, an encoded scanning tooling 20, a calibration test block 30, and an ultrasonic signal transmitting and collecting device 40; wherein the ultrasonic probe 10 is installed on the encoded scanning tooling 20, and both the ultrasonic probe 10 and the encoded scanning tooling 20 are connected to the ultrasonic signal transmitting and collecting device 40. Among them, the ultrasonic probe 10 is connected to the ultrasonic signal transmitting and collecting device 40 through a shielded cable, and the encoded scanning tooling 20 records its scanning distance through a wheel encoder 201 fixed on one of its four sliding wheels, and the wheel encoder 201 is connected to the ultrasonic signal transmitting and collecting device 40 through a signal line.

[0048] In the detailed implementation manner, the ultrasonic probe 10 is coupled to the surface of the part to be detected of the turbine disk tie rod bolt counterbore through the encoded scanning tooling 20, emits ultrasonic waves under the excitation of the ultrasonic signal transmitting and collecting device 40, and receives the ultrasonic waves returned by the part to be detected of the turbine disk tie rod bolt counterbore, and converts the ultrasonic waves into ultrasonic signals and sends them to the ultrasonic signal transmitting and collecting device 40. It should be noted that at this time, the ultrasonic probe used is a phased array ultrasonic probe 102. The conventional ultrasonic probe 101 generally does not use tooling clamping for scanning, but uses a manual method to couple on the end face of the turbine disk tie rod bolt counterbore and scan along the circumference of the counterbore diameter. The conventional ultrasonic probe 101 is used for the detection of positions inaccessible to phased array ultrasonic waves. For positions accessible to phased array ultrasonic waves, the phased array ultrasonic probe 102 should be preferentially selected for detection. The phased array ultrasonic probe 102 covers part of the part to be detected of the tie rod bolt counterbore, while the conventional ultrasonic probe can cover all parts to be detected of the tie rod bolt.

[0049] The encoded scanning tooling 20 is fixed on the surface of the part to be detected by magnetic adsorption. The encoded scanning tooling 20 is used to clamp the ultrasonic probe 10, record the position, scanning speed, etc. of the ultrasonic probe 10, and using the encoded scanning tooling 20 is also beneficial to improve the detection efficiency. Taking the 9F type gas turbine of GE Company as an example, its first-stage and third-stage turbine disks are tightened into a whole by 24 and 18 tie bolts respectively, and there are 24 and 18 corresponding tie bolt counterbores on the first-stage and third-stage turbine disks respectively. Fix the encoded scanning tooling 20 on the arc surface of the first-stage turbine disk and adjust the axial position of the phased array ultrasonic probe 102 so that the emitted ultrasonic beam can scan the part to be detected of the counterbore. Starting from the first counterbore, push the encoded scanning tooling 20 to drive the phased array ultrasonic probe 102 to scan clockwise or counterclockwise along the arc surface. Since the encoded scanning tooling 20 is magnetically adsorbed on the first-stage turbine disk through four sliding wheels, the axial position of the phased array ultrasonic probe 102 can be well maintained during the detection process, so that the scanning process can be carried out quickly and efficiently without adjusting the axial position of the phased array ultrasonic probe 102 at each counterbore. After scanning the 24 tie bolt counterbores of the first-stage turbine disk, scan the 18 tie bolt counterbores of the third-stage turbine disk in the same way.

[0050] The calibration test block 30 is used to calibrate the resolution and positioning accuracy of the ultrasonic probe 10 and calibrate the detection sensitivity of the ultrasonic probe 10;

[0051] The ultrasonic signal transmitting and collecting device 40 is used to transmit, receive and process the ultrasonic signal and display the ultrasonic signal in a graphical way.

[0052] As Figure 2 shown, the ultrasonic probe 10 in the embodiment of the present invention includes a conventional ultrasonic probe 101 and a phased array ultrasonic probe 102; wherein the conventional ultrasonic probe 101 is used to detect the defects of the tie bolt counterbore from the end face of the turbine disk, usually using a longitudinal wave straight probe or a small-angle longitudinal wave straight probe, mainly for the detection of positions where phased array ultrasound is inaccessible. For positions where phased array ultrasound is accessible, a phased array ultrasonic probe should be preferentially selected for detection. Generally, the incident angle of a small-angle longitudinal wave straight probe is 5-8°, the center frequency is 5 MHz, and its detection sensitivity is generally lower than that of the phased array ultrasonic probe. The phased array ultrasonic probe 102 is used to detect the defects of the tie bolt counterbore from the arc surface of the turbine disk, usually using the direct-coupling transverse wave detection method, the array form is a linear array or a planar array, the number of array elements is generally not less than 16, and the center frequency is generally 2.5-5 MHz. It should be noted that the phased array ultrasonic probe 102 can only cover part of the part to be detected of the tie bolt counterbore, while the conventional ultrasonic probe 101 can cover all parts to be detected of the tie bolt.

[0053] As Figure 3 shown, the encoded scanning tooling 20 in the embodiment of the present invention includes a wheel encoder 201 and a clamping device 202; wherein the wheel encoder 201 is used to convert information such as the position and scanning speed of the ultrasonic probe into electrical signals, and transmit the electrical signals to the ultrasonic signal acquisition device 40. Generally, the number of wheel encoders 201 is 1, which is integrated on the sliding wheels of the encoded scanning tooling 20. Generally, the number of sliding wheels is 4, and a circular magnet is fixed on each sliding wheel, so that the encoded scanning tooling 20 can be fixed on the surface of the part to be detected by magnetic attraction. The four sliding wheels are respectively located at the four corners of the encoder scanning tooling 201; the clamping device 202 fixes the phased array ultrasonic probe 102 on the encoded scanning tooling 20, and applies a certain coupling pressure to the phased array ultrasonic probe 102 through a spring device to ensure good coupling with the surface of the part to be detected during the scanning process. The clamping device 202 is connected to the fixing holes on the wedge block of the phased array ultrasonic probe 102 by tightening screws through the threaded holes on the left and right side walls thereof.

[0054] As Figure 4 shown, the calibration test block 30 in the embodiment of the present invention includes a calibration test block base body 301 and a grooving 302. The shape and external dimensions of the calibration test block base body 301 are the same as those of the blind hole of the turbine disk tie rod bolt to be detected, and the material, sound velocity, and acoustic impedance are the same as or similar to those of the blind hole of the turbine disk tie rod bolt to be detected, and it can be processed by means of a lathe, a milling machine, etc. The surface roughness should be close to the surface of the part to be detected. The grooving 302 is processed at the part to be detected of the blind hole of the turbine disk tie rod bolt, and is used to simulate the characteristics such as the form, size, position, and trend of the defects that are likely to appear. Generally, it is processed at the fillet of the inner surface of the blind hole, and is processed by electric discharge machining. The spacing should at least ensure that the ultrasonic signals of adjacent grooves do not affect each other, and the trend is perpendicular to or forms a set angle with the axial direction of the tie rod bolt blind hole.

[0055] As Figure 5 shown, the ultrasonic signal transmitting and collecting device 40 in the embodiment of the present invention includes a transmitting module 401, a collecting module 402, and a processing module 403. The transmitting module 401 is used to transmit pulsed electrical signals with a certain repetition frequency to excite the ultrasonic probe 10 to generate ultrasonic waves; the collecting module 402 is used to receive the ultrasonic signals returned by the ultrasonic probe 10, convert them from analog signals to digital signals, and store and record them; the processing module 403 performs operations such as calibration, filtering, noise reduction, and transformation on the digital signals, and displays them in the form of waveforms or images. Generally, the digital signals should be able to be displayed in the forms of A-scan, C-scan, and S-scan, etc., so as to facilitate quantitative analysis of the position, size, trend, etc. of the defects.

[0056] Referring to Figure 6, a method for ultrasonic inspection of the counterbore of the turbine disk tie rod bolt provided by another embodiment of the present invention includes:

[0057] S501: Fix the ultrasonic probe on the coded scanning tooling, and connect the ultrasonic probe, the coded scanning tooling with the ultrasonic signal transmitting and collecting device.

[0058] S502: Fix the coded scanning tooling on the surface of the part to be detected on the calibration test block, and ensure good coupling of the ultrasonic probe. Excite the ultrasonic probe through the ultrasonic signal transmitting and collecting device to generate ultrasonic waves and scan the groove on the part to be detected to find the highest wave, and calibrate and set the sensitivity of ultrasonic inspection.

[0059] S503: Fix the coded scanning tooling and the ultrasonic probe on the surface of the counterbore of the turbine disk tie rod bolt to be detected, push the coded scanning tooling to drive the ultrasonic probe to scan. During the scanning process, record the position and scanning distance of the ultrasonic probe in real time through the wheel encoder. If the reflected echo of the part to be detected exceeds the reference, determine the defect position through the propagation time, detection angle, etc. of the ultrasonic wave, and quantify the defect.

[0060] In the ultrasonic inspection method, in S502: If the ultrasonic probe uses a longitudinal wave straight probe or a small angle longitudinal wave straight probe, calibrate and set the ultrasonic inspection sensitivity from the end face of the calibration test block of the counterbore of the turbine disk tie rod bolt to be detected, and do not use the coded scanning tooling. In S503: If the ultrasonic probe uses a longitudinal wave straight probe or a small angle longitudinal wave straight probe, scan from the end face of the counterbore of the turbine disk tie rod bolt to be detected, and do not use the coded scanning tooling.

[0061] In the ultrasonic inspection method, the focusing mode of the phased array ultrasonic probe adopts the projection focusing mode, and the projection focusing position is set near the part to be detected.

[0062] It should be noted that: The above embodiments are only specific embodiments of the present invention, which are used to illustrate the technical solutions of the present invention, rather than limiting them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: Any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the above embodiments or can easily think of changes, or perform equivalent replacements for some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An ultrasonic detection system for the counterbore of the tie bolt of a gas turbine turbine disk, characterized in that, It includes an ultrasonic probe, a coded scanning tooling, a calibration test block, and an ultrasonic signal transmitting and collecting device; The ultrasonic probe includes a conventional ultrasonic probe and a phased array ultrasonic probe; The conventional ultrasonic probe is used to detect the defects of the pull rod bolt counterbore from the end face of the turbine disk, and a longitudinal wave straight probe or a small angle longitudinal wave straight probe is adopted; The phased array ultrasonic probe is used to detect the defects of the pull rod bolt counterbore from the arc surface of the turbine disk, and a linear array or planar array transverse wave phased array ultrasonic probe is adopted; The phased array ultrasonic probe is installed on the coded scanning tooling, and both the phased array ultrasonic probe and the coded scanning tooling are connected to the ultrasonic signal transmitting and collecting device; The phased array ultrasonic probe is coupled to the surface of the part to be detected of the pull rod bolt counterbore of the turbine disk through the coded scanning tooling, emits ultrasonic waves under the excitation of the ultrasonic signal transmitting and collecting device, and receives the ultrasonic waves returned by the part to be detected of the pull rod bolt counterbore of the turbine disk, and converts the ultrasonic waves into ultrasonic signals and sends them to the ultrasonic signal transmitting and collecting device; The coded scanning tooling is used to clamp the phased array ultrasonic probe and record the position and scanning speed of the phased array ultrasonic probe; The calibration test block is used to calibrate the resolution and positioning accuracy of the ultrasonic probe and calibrate the detection sensitivity of the ultrasonic probe; The ultrasonic signal transmitting and collecting device is used to transmit, receive and process ultrasonic signals, and display the ultrasonic signals in a graphical way.

2. The ultrasonic detection system for the counterbore of the tie bolt of the gas turbine turbine disk according to claim 1, characterized in that, The incident angle of the small angle longitudinal wave straight probe is 5-8°; The detection sensitivity of the longitudinal wave straight probe or the small angle longitudinal wave straight probe is lower than that of the phased array ultrasonic probe.

3. The ultrasonic detection system for the counterbore of the tie bolt of the gas turbine turbine disk according to claim 1, characterized in that, The number of array elements of the phased array ultrasonic probe is not less than 16.

4. The ultrasonic detection system for the counterbore of the tie bolts of the gas turbine turbine disk according to claim 1, wherein, The coded scanning tooling includes a wheel encoder and a clamping device; The wheel encoder is used to convert the position and scanning speed information of the ultrasonic probe into electrical signals and transmit the electrical signals to the ultrasonic signal collecting device; There is 1 wheel encoder, which is integrated on one of the sliding wheels of the coded scanning tooling. There are 4 sliding wheels, which are located at the four corners of the coded scanning tooling respectively; The clamping device is used to fix the ultrasonic probe on the coded scanning tooling and ensure good coupling with the surface of the part to be detected during the scanning process.

5. An ultrasonic detection system for the counterbore of the tie bolts of a gas turbine turbine disk according to claim 1, characterized in that, The calibration test block includes a calibration test block base body and a groove; The shape and external dimensions of the calibration test block base body are the same as those of the pull rod bolt counterbore of the turbine disk to be detected, and the material, sound velocity, and acoustic impedance of the calibration test block base body are the same as or similar to those of the pull rod bolt counterbore of the turbine disk to be detected; The groove is machined at the part to be detected of the pull rod bolt counterbore of the turbine disk, and is used to simulate the form, size, position and trend characteristics of the defects that are likely to appear.

6. The ultrasonic detection system for the counterbore of the tie bolt of the gas turbine turbine disk according to claim 5, wherein, The groove is machined by an electric discharge machining method. The trend of the groove is perpendicular to or at a set angle with the axial direction of the pull rod bolt counterbore. When detecting the defect of the groove at a set angle by conventional ultrasonic testing, a small angle longitudinal wave probe is used for detection.

7. The ultrasonic inspection system for the counterbore of the tie bolt of the gas turbine turbine disk according to claim 1, wherein, The ultrasonic signal transmitting and collecting device includes a transmitting module, a collecting module and a processing module; The transmitting module is used to transmit pulsed electrical signals with a certain repetition frequency to excite the ultrasonic probe to generate ultrasonic waves. The acquisition module is used to receive the ultrasonic signals returned by the ultrasonic probe, convert them from analog signals to digital signals, and store and record them. The processing module is used to perform calibration, filtering, noise reduction, and transformation operations on the digital signals, and display them in the form of waveforms or images.

8. An ultrasonic inspection method for the counterbore of the tie bolts of a gas turbine turbine disk, characterized in that, This method is based on an ultrasonic detection system for the counterbore of the tie bolts of the turbine disk of a gas turbine as described in any one of claims 1 to 7, and includes the following steps: Step 1: Fix the ultrasonic probe on the encoded scanning tooling, and connect the ultrasonic probe, the encoded scanning tooling, and the ultrasonic signal transmitting and collecting device. Step 2: Fix the encoded scanning tooling on the surface of the part to be detected on the calibration test block, ensure good coupling of the ultrasonic probe, and use the ultrasonic signal transmitting and collecting device to excite the ultrasonic probe to generate ultrasonic waves, scan the groove on the part to be detected, and find the highest wave, and calibrate and set the sensitivity of the ultrasonic detection. Step 3: Fix the encoded scanning tooling and the ultrasonic probe on the surface of the counterbore of the tie bolts of the turbine disk to be detected, push the encoded scanning tooling to drive the ultrasonic probe to scan, and record the position and scanning distance of the ultrasonic probe in real time through the wheel encoder during the scanning process. If the reflected echo of the part to be detected exceeds the reference, determine the defect position based on the propagation time and detection angle of the ultrasonic wave, and quantify the defect.

9. A method for ultrasonic inspection of the counterbore of the tie bolts of a gas turbine turbine disk according to claim 8, characterized in that, In step 2, when the ultrasonic probe uses a longitudinal wave straight probe or a small-angle longitudinal wave straight probe, the ultrasonic detection sensitivity is calibrated and set from the end face of the calibration test block of the counterbore of the tie bolts of the turbine disk to be detected, and the encoded scanning tooling is not used; in step 3, when the ultrasonic probe uses a longitudinal wave straight probe or a small-angle longitudinal wave straight probe, the scanning is performed from the end face of the counterbore of the tie bolts of the turbine disk to be detected, and the encoded scanning tooling is not used. The focusing mode of the phased array ultrasonic probe adopts the projection focusing mode, and the projection focusing position is set near the part to be detected.

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