Large-diameter thin-wall titanium alloy pipe ultrasonic detection device and detection method

Abstract

The invention provides an ultrasonic detection device and method for a large-diameter thin-wall titanium alloy pipe. Probe wafers of the ultrasonic detection device comprise the first probe wafer, the second probe wafer, the third probe wafer and the fourth probe wafer, and the first probe wafer and the second probe wafer are located at the two ends of a probe shell in the transverse direction respectively and used for scanning the pipe in the circumferential direction. The third probe wafer and the fourth probe wafer are located at the two ends of the probe shell in the longitudinal direction respectively and used for scanning a pipe in the axial direction, the first probe wafer and the second probe wafer form a group, the third probe wafer and the fourth probe wafer form a group, and the two probe wafers in the same group are connected in parallel and synchronously transmit and receive ultrasonic signals. According to the invention, the combined probe wafers are utilized, and the defect reflection waves and the straight-through wave signals which are reflected for multiple times between the wafers and penetrate through the pipe wall are utilized for judgment, so that different types of defects can be detected, and non-circumferential and non-axial defects and inner wall pits can be effectively detected.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic testing, and in particular to an ultrasonic testing device and a testing method for large-caliber thin-wall titanium alloy pipes. Background Art

[0002] Titanium alloys, with their high specific strength and corrosion resistance, are seeing increasing use annually in fields such as petrochemicals, nuclear power, shipbuilding, and marine engineering. With the advancement of tube rolling technology and the optimization of process adaptability, the rolled diameter of titanium alloy tubes has also achieved significant breakthroughs, increasing from tens of millimeters to over 200 mm, meeting the application needs of most scenarios in industries such as shipbuilding and petroleum.

[0003] Currently, ultrasonic testing of pipes utilizes pulse reflection technology, analyzing the reflected echoes of defects to assess quality. To accommodate pipes of varying specifications, the method is divided into immersion and contact testing. Immersion testing is primarily used for smaller diameter pipes, while contact testing is used for larger diameter pipes. Based on the manufacturing process characteristics of pipes, pipe defects are categorized as axial (longitudinal) and circumferential (transverse). Longitudinal defects are predominant, occurring parallel to the pipe axis and representing the typical defects of primary concern during current pipe testing. Based on these characteristics, ultrasonic testing of pipes involves placing probes circumferentially and axially to allow ultrasonic waves to propagate circumferentially and axially. Ultrasonic waves can propagate within a certain range, within which defects will reflect, and this reflected wave is used for defect assessment. Furthermore, to ensure complete inspection of the pipe, the probe must be moved to scan 100% of the entire pipe surface.

[0004] The ultrasonic inspection method for variable-wall and thick-wall pipes disclosed in CN101710102A utilizes a rotating workpiece, a horizontally moving inspection vehicle, and a multi-channel ultrasonic inspection host. Multiple longitudinal wave direct and refracted shear wave ultrasonic probes are used to scan for defects radially and circumferentially, respectively. The direct probe maintains radial incidence, while the refracted shear wave probe controls the incident angle by adjusting the eccentricity. With an eccentricity angle of 10-45°, defects in all directions of the pipe can be detected, and the detected defects can be accurately located and quantified. This method is applicable to the quality inspection of pipes for military applications and thick-wall boilers, and can detect defects within the pipes less than 1 mm in diameter, achieving precise location and quantification, and achieving 100% detection. This inspection method, primarily used to address the inspection challenges of thick-wall and variable-thickness pipes, relies on water immersion ultrasound, but still only uses the reflected signals of longitudinally and circumferentially incident sound waves to detect defects. This results in a complex inspection structure and certain limitations, including low sensitivity for irregularly oriented defects.

[0005] Therefore, the existing technology has great limitations: first, it uses oblique incident sound wave reflection to judge defects. Although it is more sensitive to axial and circumferential linear defects such as cracks, it has a low detection rate for irregular pits on the inner wall; second, it is unable to detect linear defects with non-circumferential and non-axial distributions, and the above-mentioned types of defects are very likely to occur in large-scale titanium alloy thin-walled pipes; third, when using the water immersion method for detection, the defect position needs to be calculated based on the water distance, eccentricity, etc. according to the wall thickness of the pipe, and the operation is very complicated. Summary of the Invention

[0006] In view of this, the present invention aims to propose an ultrasonic detection device and method for large-diameter thin-walled titanium alloy pipes to solve the problems in the existing technology of ultrasonic detection of large-diameter thin-walled titanium alloy pipes, such as the inability to detect non-axial and non-circumferential defects with random orientations, and the unsatisfactory detection effect of inner wall pits.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] In one aspect, the present invention provides an ultrasonic inspection device for large-diameter, thin-walled titanium alloy pipes. The device comprises a probe housing, a wedge, and probe wafers connected to the wedge. The probe wafers include a first probe wafer, a second probe wafer, a third probe wafer, and a fourth probe wafer. The four probe wafers are arranged in a cross shape. The first and second probe wafers are located at the transverse ends of the probe housing, respectively, for scanning the pipe circumferentially. The third and fourth probe wafers are located at the longitudinal ends of the probe housing, respectively, for scanning the pipe axially. The first and second probe wafers form a set, while the third and fourth probe wafers form a set. Each probe wafer in the same set can transmit an ultrasonic signal and receive ultrasonic signals transmitted by another probe wafer, which are reflected multiple times by the pipe wall and directly by defects. The ultrasonic inspection device of the present invention can detect different types of defects by simultaneously transmitting and receiving ultrasonic signals. Different conditions in the pipe can be reflected through different forms of the ultrasonic signal, such as signal strength and signal reception time.

[0009] Furthermore, the distance between the inner edge of the third probe wafer and the inner edge of the fourth probe wafer is not less than 5 times the pipe wall thickness. If the distance between the third probe wafer and the fourth probe wafer is too close, the transmitted ultrasonic signals will overlap, resulting in a detection blind spot and affecting the detection effect.

[0010] Furthermore, the ultrasonic detection device includes a dual-channel ultrasonic detector and a combined transducer. The combined transducer includes a first transducer interface and a second transducer interface. The probe wafer and the combined transducer are electrically connected. The first and second probe wafers are arranged in parallel on the first transducer interface, and the third and fourth probe wafers are arranged in parallel on the second transducer interface. Each transducer interface corresponds to a channel. Probe wafers in the same group are connected in parallel on the same transducer interface and can simultaneously transmit and receive ultrasonic signals. The dual-channel configuration is used to stimulate the two groups of probe wafers to operate in parallel, thereby simultaneously scanning and detecting the pipe in both the axial and circumferential directions, thereby improving efficiency.

[0011] Furthermore, the probe wafer is arranged on the inclined surface of the wedge, and a damping block is arranged on the side of the probe wafer away from the wedge, and the damping block has the functions of vibration control, clutter suppression and structural support.

[0012] Furthermore, the probe wafer is tilted to ensure that the angle of the ultrasonic refraction wave in the pipe is 45 degrees. When the ultrasonic refraction wave angle is 45 degrees, the reflection effect on the crack is the best.

[0013] Furthermore, a sound insulation layer is provided between adjacent wedges, which can isolate the transmitting and receiving sound paths and suppress signal crosstalk.

[0014] On the other hand, the present invention also provides a detection method of the ultrasonic detection device, comprising the following steps:

[0015] S1. Design of standard pipe samples;

[0016] S2. Calibration and debugging;

[0017] S3. Process validation;

[0018] S4. Scan and detect.

[0019] Furthermore, in step S1, the pipe standard sample has the same size and material as the pipe to be tested, and U-shaped grooves are processed at different positions of the pipe standard sample. There are n U-shaped grooves in total, which are divided into three types: longitudinal, transverse and 45° oblique. At least one U-shaped groove in each direction must be set on the inner and outer walls.

[0020] Furthermore, step S3 includes:

[0021] S31. Threshold setting: Scan the standard pipe sample at 90° intervals along the circumference and record the reduction in the straight-through amplitude of the U-shaped groove position at four different positions in the circumferential channel. The minimum value is recorded as A 周min , scan the pipe sample along the axial direction and record the reduction of the straight wave on the axis where the U-shaped grooves on the inner and outer walls are located. The minimum value is recorded as A轴min ;

[0022] S32. Assessment Rule Setting: During the scanning process, first, based on the change in the through-wave amplitude in the circumferential and axial channels, determine whether the change exceeds the through-wave amplitude reduction threshold. If so, the defect is assessed as unqualified and the location is recorded. Second, based on the defect reflection waves appearing in the circumferential and axial channel sound path distance-amplitude curves, if the amplitude exceeds the distance-amplitude curve, the defect is assessed as unqualified and the location is recorded.

[0023] S33. Scan and inspect the pipe standard sample using a spiral path. If all n preset defects in the pipe standard sample can be effectively detected and rated as unqualified, the process verification is passed. Otherwise, return to step S2.

[0024] Furthermore, after the process verification is passed, the calibration and debugging status of the pipe standard is maintained and the pipe to be inspected is inspected.

[0025] Compared with the existing technology, the ultrasonic detection device and detection method for large-diameter thin-walled titanium alloy pipes described in the present invention have the following advantages:

[0026] (1) Through the setting and layout of the probe chip, and the simultaneous excitation and reception of ultrasonic signals, the defects of the pipe are detected by cleverly utilizing the mode combining the straight wave of the pipe wall and the defect reflection wave signal, thus solving the problem that the irregular orientation defects of the pipe and the pits on the inner wall cannot be effectively detected.

[0027] (2) The dual-pass 4-probe chip realizes bidirectional detection in the circumferential and axial directions, improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 It is a structural schematic diagram of the ultrasonic detection device of the present invention;

[0030] Figure 2 Schematic diagram of the circumferential channel structure of the probe wafer of the ultrasonic detection device of the present invention;

[0031] Figure 3 Schematic diagram of the axial channel structure of the probe wafer of the ultrasonic detection device of the present invention;

[0032] Figure 4 This is a schematic diagram of the distribution of U-shaped grooves in a standard pipe sample according to Example 1 of the present invention;

[0033] Figure 5This is a schematic diagram of the circumferential scanning at 90° intervals according to the present invention.

[0034] Description of reference numerals:

[0035] 1. Probe housing; 2. Sound-absorbing material; 3. Sound insulation layer; 4. Probe wafer; 41. First probe wafer; 42. Second probe wafer; 43. Third probe wafer; 44. Fourth probe wafer; 5. Wedge; 6. Damping block; 7. Combined transducer; 8. 0° scanning position; 9. 90° scanning position; 10. 180° scanning position; 11. 270° scanning position. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with specific embodiments. It should be noted that the data in the following experimental examples are obtained by the inventor through a large number of experiments. Due to space limitations, only a portion thereof is shown in the specification, and those skilled in the art can understand and implement the present invention under these data. These embodiments are merely intended to illustrate the present invention and are not intended to limit the scope of the present invention. It should also be understood that, after having read the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these changes or modifications also fall within the scope protected by this application.

[0037] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] like Figure 1 As shown, an ultrasonic detection device for large-diameter thin-walled titanium alloy pipes of the present invention includes a probe housing 1, a wedge 5 and a probe chip 4 connected to the wedge 5. The probe chip 4 includes a first probe chip 41, a second probe chip 42, a third probe chip 43, and a fourth probe chip 44. The four probe chips 4 are cross-shaped. The first probe chip 41 and the second probe chip 42 are a group and are respectively located at the two ends of the probe housing 1 in the transverse direction, and are used to scan the circumferential direction of the pipe. The third probe chip 43 and the fourth probe chip 44 are a group and are respectively located at the two ends of the probe housing 1 in the longitudinal direction, and are used to scan the axial direction of the pipe. Any probe chip 4 in the same group can emit an ultrasonic signal to form a direct wave, and receive the ultrasonic signal emitted by another probe chip 4 and reflected multiple times by the pipe wall and the ultrasonic signal directly reflected by the defect.

[0040] Since the first probe chip 41 and the second probe chip 42 are both located in the transverse direction, when there are no defects in the circumference of the pipe, the ultrasonic signal emitted by the first probe chip 41 reaches the second probe chip 42 unobstructed along the circumferential direction of the pipe and is received by the second probe chip 42. Similarly, the ultrasonic signal emitted by the second probe chip 42 reaches the first probe chip 41 unobstructed along the circumferential direction of the pipe and is received by the first probe chip 41.

[0041] When there is a defect in the circumferential direction of the pipe, if the defect is perpendicular to the emitted ultrasonic signal, the ultrasonic signals emitted by the first probe chip 41 and the second probe chip 42 will be reflected back to their respective chips when encountering the circumferential defect, and the energy of the sound waves that propagate directly through the pipe wall will be reduced. At this time, the corresponding detection channel will receive a clear defect reflection signal, and the amplitude of the sound wave signal that passes through the pipe wall will be reduced.

[0042] If a non-circumferential defect exists in the pipe, the ultrasonic signals emitted by the first and second probe chips 41 and 42 will also reflect upon encountering the non-circumferential defect. However, due to the tilted deflection of the reflected signal, it will be reflected in other directions and will not be reflected back to the transmitting chip. However, this will still reduce the energy of the sound wave that propagates directly through the pipe wall. In this case, the detection channel will not receive a clear defect reflection signal, and the amplitude of the sound wave signal that passes through the pipe wall will still be reduced.

[0043] Similarly, for the third probe chip 43 and the fourth probe chip 44, since both are located in the longitudinal direction, when there are no defects in the axial direction of the pipe, the ultrasonic signals emitted by the third probe chip 43 and the fourth probe chip 44 are unobstructed along the axial direction of the pipe to reach the fourth probe chip 44 and are received by the fourth probe chip 44. Similarly, the ultrasonic signals emitted by the fourth probe chip 44 are unobstructed along the axial direction of the pipe to reach the third probe chip 43 and are received by the third probe chip 43.

[0044] When there is a defect in the axial direction of the pipe, if this defect is perpendicular to the emitted ultrasonic signal, the ultrasonic signals emitted by the third probe chip 43 and the fourth probe chip 44 will be reflected back to their respective chips when encountering the axial defect, and the sound wave energy propagating directly through the pipe wall will be reduced. At this time, the corresponding detection channel will receive a clear defect reflection signal, and the amplitude of the sound wave signal passing through the axial direction of the pipe wall will be reduced.

[0045] When there are defects in the non-axial direction of the pipe, the ultrasonic signals emitted by the third probe chip 43 and the fourth probe chip 44 will also be reflected when encountering the non-axial defects. However, since the reflected signals are tilted and deflected, they will be reflected in other directions, resulting in failure to reflect back to the transmitting chip, reducing the sound wave energy that propagates directly through the pipe wall. At this time, the detection channel will not receive a clear defect reflection signal, and the amplitude of the sound wave signal passing through the axial direction of the pipe wall will still be reduced.

[0046] Existing technologies, using only reflected waves, are unable to detect non-axial and non-circumferential defects. The ultrasonic detection device of the present invention, utilizing both reflected and direct ultrasonic signals, can detect different types of defects. Different conditions in pipes can be reflected through different forms of ultrasonic signals, such as signal strength and signal reception time. Specifically, for defect-free pipes, due to unimpeded propagation within the pipe, each probe chip 4 in the same group can receive all ultrasonic signals emitted by another probe chip 4. The ultrasonic waves received by the same probe chips 4 appear as a superposition of two signals. For circumferential or axial defects, the ultrasonic signal emitted by the probe chip 4 is reflected by the defect before reaching the opposite side of the pipe. The reflected signal is then received by the probe chip 4 that emitted the ultrasonic signal. Compared to defect-free pipes, the arrival time of circumferential or axial defects in pipes is different, so the arrival time of the two signals can be used to distinguish and judge. Non-circumferential or axial defects not only prevent ultrasonic signals from passing through the pipe wall and reaching the other probe element 4 in the same group, but can also reflect the ultrasonic signal emitted by the probe element 4 in other directions, causing the transmitting probe element 4 to be unable to receive the reflected signal or only receive a weak reflected signal, resulting in a reduced amplitude. Specifically, the amplitude of the direct wave and the acoustic path distance-amplitude curve can reflect different ultrasonic signal reception or reflection conditions.

[0047] The probe housing 1 of the present invention is rectangular. Each probe wafer 4 is connected to a corresponding wedge 5 , and the wedge 5 and the probe wafer 4 are arranged inside the probe housing 1 .

[0048] As a preferred embodiment of the present invention, the distance between the inner edge of the third probe element 43 and the inner edge of the fourth probe element 44 is no less than five times the pipe wall thickness. Given the high energy of ultrasonic excitation, if the distance between the third and fourth probe elements 43 and 44 is too close, the emitted ultrasonic signals will overlap, creating a blind spot and affecting detection effectiveness. Therefore, limiting the distance to five times the pipe wall thickness improves detection accuracy. Furthermore, since the third and fourth probe elements 43 and 44 are used for axial detection of pipes, increasing the distance between them helps increase the coverage of the ultrasonic signal.

[0049] There is no specific limit on the distance between the inner edge of the first probe chip 41 and the inner edge of the second probe chip 42. The distance between the two should be as close as possible while ensuring that the distribution direction of the two is consistent. Because the first probe chip 41 and the second probe chip 42 are used for circumferential detection of the pipe, the ultrasonic wave needs to travel around the circumference during transmission, making it difficult to detect the position between the first probe chip 41 and the second probe chip 42 that deviates from the ultrasonic emission direction. Therefore, the distance between the two probe chips should be minimized while ensuring that the two probe chips do not touch each other, thereby reducing blind spots.

[0050] Therefore, for the ultrasonic detection device of the present invention, the distance between the two probe crystals 4 in the transverse direction is smaller than the distance between the two probe crystals 4 in the longitudinal direction. The inner edge mentioned in the present invention refers to the inner edge of each probe crystal 4 facing the center position of the cross.

[0051] As a preferred embodiment of the present invention, the probe wafer 4 is tilted to ensure that the ultrasonic refraction wave angle in the pipe is 45°. The applicant has found that when the ultrasonic refraction wave angle is 45°, the reflection effect on the crack is the best.

[0052] The ultrasonic detection device includes a dual-channel ultrasonic detector and a combined transducer 7. The probe chip 4 is electrically connected to the combined transducer 7. The combined transducer 7 includes a first transducer interface and a second transducer interface. The first probe chip 41 and the second probe chip 42 are arranged in parallel on the first transducer interface, and the third probe chip 43 and the fourth probe chip 44 are arranged in parallel on the second transducer interface. Each transducer interface corresponds to a channel. The probe chips 4 of the same group are connected in parallel on the same transducer interface and can simultaneously transmit and receive ultrasonic signals. The dual-channel configuration is used to stimulate the two groups of probe chips 4 to operate in parallel, thereby simultaneously scanning and detecting the pipe in both the axial and circumferential directions, thereby improving efficiency.

[0053] Specifically, the dual-channel ultrasonic detector has a frequency bandwidth of no less than 0.5 MHz to 10 MHz, and the excitation pulse must meet the energy requirements for direct wave propagation through the pipe wall. The dual-channel ultrasonic detector uses square wave excitation, with a maximum transmit voltage of no less than 500 V. Each channel has dual gates, with intra-gate amplitude saturation prevention and amplitude tracking capabilities.

[0054] As a preferred example of the present invention, the probe wafer 4 is arranged on the inclined surface of the wedge 5, and a damping block 6 is arranged on the side of the probe wafer 4 facing away from the wedge 5. The damping block 6 has the functions of vibration control, clutter suppression and structural support.

[0055] The wedge 5 is made of polyurethane, a material with excellent wear resistance, flexibility, and sound permeability. The wedge 5 is machined according to the outer diameter of the pipe to ensure that the curved surface of the wedge 5 fits tightly against the pipe. Specifically, the curvature of the wedge 5 is consistent with the outer diameter of the pipe, and the maximum distance between the two does not exceed 0.3 mm.

[0056] The interior of the probe housing 1 is filled with a sound absorbing material 2, which contains a wedge 5, a probe wafer 4, and a damping block 6. The sound absorbing material 2 can absorb clutter, suppress aftershocks of the probe wafer 4, and shorten the pulse width.

[0057] A sound insulation layer 3 is provided between adjacent wedge blocks 5 , and the sound insulation layer 3 can isolate the transmitting and receiving sound paths and suppress signal crosstalk.

[0058] As a specific example of the present invention, the probe wafer 4 is rectangular in shape and has a size of 8 mm x 12 mm. The center frequency of each probe wafer 4 should be consistent, and the range should meet the detection requirements.

[0059] The present invention also provides a detection method of the ultrasonic detection device, comprising the following steps:

[0060] S1. Design of standard pipe samples;

[0061] Specifically, the standard pipe sample should be the same size and material as the pipe to be inspected, with a surface roughness Ra ≤ 6.3μm and uniform wall thickness with a maximum deviation of no more than 0.3mm. U-shaped grooves with a depth of 10-13% of the wall thickness and a length of 18-22mm are machined at different locations on the standard pipe sample. There are n total U-shaped grooves, divided into three types: longitudinal, transverse, and 45° oblique. At least one U-shaped groove must be provided in each direction on the inner and outer walls. The U-shaped grooves in different directions can simulate defects in axial, circumferential, non-axial, and non-circumferential directions.

[0062] As a preferred example of the present invention, a set of U-shaped inner wall grooves and a set of U-shaped outer wall grooves are respectively processed along the circumference of the standard pipe sample with a circumferential spacing of 180 degrees. That is, the spacing between adjacent U-shaped grooves in the circumferential direction is 180 degrees.

[0063] S2. Calibration and debugging;

[0064] Specifically, the ultrasonic testing device is adjusted to the working state, calibrated and debugged using the intact part of the pipe standard sample, the probe chip 4 is stably coupled to the pipe standard sample, and the sound velocity, delay, and sound path of the ultrasonic testing device are set. The excitation voltage and gain of the dual-channel ultrasonic detector are adjusted. The through-wave of the pipe wall in the corresponding circumferential and axial channels is found, its height is adjusted to 80% of the screen height, and the through-wave is selected using the tracking gate function;

[0065] On the basis of selecting the straight-through wave, the distance-amplitude curves of the corresponding channels were made respectively using the U-shaped grooves on the inner and outer walls of the circumferential and axial directions of the standard pipe sample.

[0066] Among them, setting the sound velocity, delay, sound path, excitation voltage and gain, and selecting the through wave are existing technologies and will not be described in detail here.

[0067] S3. Process validation;

[0068] S31. Threshold setting: Scan the standard pipe sample at 90° intervals along the circumference, corresponding to 0° scanning position 8, 90° scanning position 9, 180° scanning position 10, and 270° scanning position 11. Record the reduction in the straight-through amplitude of the U-shaped groove position at four different positions in the circumferential channel, with the minimum value recorded as A. 周min , scan the pipe sample along the axial direction and record the reduction of the straight wave on the axis where the U-shaped grooves on the inner and outer walls are located. The minimum value is recorded as A 轴min The amplitude reduction thresholds of the circumferential and axial through waves are A 周min and A 轴min ;

[0069] S32. Assessment Rule Setting: During the scanning process, first, based on the change in the through-wave amplitude in the circumferential and axial channels, determine whether the change exceeds the through-wave amplitude reduction threshold. If so, the defect is assessed as unqualified and the location is recorded. Second, based on the defect reflection waves appearing in the circumferential and axial channel sound path distance-amplitude curves, if the amplitude exceeds the distance-amplitude curve, the defect is assessed as unqualified and the location is recorded.

[0070] S33. Scan and inspect the standard pipe sample using a spiral path. If all n preset defects in the standard pipe sample can be effectively detected and rated as unqualified, the process verification is passed. Otherwise, return to step S2, adjust the sound velocity, delay, and sound range of the ultrasonic detection device, and adjust the excitation voltage and gain of the dual-channel ultrasonic detector before retesting.

[0071] Specifically, when performing omnidirectional scanning inspections on standard pipe samples using a spiral path, the scanning speed and spiral spacing must meet the acoustic beam coverage requirements. More specifically, the scanning speed should not exceed 100 mm / s, and the spiral spacing should not exceed 8 mm.

[0072] S4. Scanning and testing;

[0073] After the process verification is passed, the calibration and debugging status of the pipe standard is maintained, and the inspection is carried out after confirming that the surface condition of the pipeline to be inspected meets the inspection requirements. When an abnormal waveform occurs, the part is scanned and judged in detail. If it is judged to be unqualified, the unqualified position of the pipe is marked.

[0074] The present invention provides an ultrasonic detection device and method for large-diameter, thin-walled titanium alloy pipes. By setting and arranging the probe wafer 4, two probe wafers 4 in the circumferential and axial directions are connected in parallel, synchronously exciting and receiving ultrasonic signals. The device cleverly utilizes a combination of the pipe wall direct wave and the defect reflection wave signal to detect pipe defects, solving the problem of the inability to effectively detect irregular orientation defects and inner wall pits in the pipe. The use of a dual-pass 4-probe wafer 4 realizes bidirectional detection in the circumferential and axial directions, improving detection efficiency. In addition to being able to effectively detect crack defects in all directions of the inner and outer walls, the ability to effectively detect inner wall pits can also assist in the evaluation of the flatness and wall thickness uniformity of the inner and outer walls of the pipe.

[0075] Example 1

[0076] The material of the pipe to be tested is TA22, the outer diameter of the pipe is 133mm, and the wall thickness is 7mm.

[0077] The probe chip 4 of the ultrasonic detection device used is in a cross-shaped structure. The first probe chip 41 and the second probe chip 42 are arranged at the two ends of the cross-shaped structure in the transverse direction for scanning the circumferential direction of the pipe. The third probe chip 43 and the fourth probe chip 44 are arranged at the two ends of the cross-shaped structure in the longitudinal direction for scanning the axial direction of the pipe.

[0078] Each probe wafer 4 is made of piezoelectric composite material, is rectangular in shape, and measures 8 mm x 12 mm. The center frequency of each probe wafer 4 is 2.25 MHz. Testing has shown that the center frequency error of each probe wafer 4 is within 10%.

[0079] like Figure 2 As shown, a first probe element 41 and a second probe element 42 are arranged in a set, distributed along the circumference of the pipe and electrically connected in parallel to the first transducer interface, serving as both the transmitting and receiving elements. The first and second probe elements 41 and 42 are both tilted at a 15.7° angle, ensuring a 45° angle for ultrasonic refraction in the pipe.

[0080] like Figure 3 As shown, the third probe element 43 and the fourth probe element 44 are grouped together, distributed along the pipe's axial direction and electrically connected in parallel to the second transducer interface, serving as both the transmitting and receiving elements. The third and fourth probe elements 43 and 44 are both tilted at a 15.7° angle, ensuring a 45° refraction angle for ultrasonic waves in the pipe. The distance between the two inner walls is 50 mm.

[0081] The wedge block 5 is processed according to the outer diameter of the pipe to ensure that the arc surface of the wedge block 5 and the pipe fit tightly, and the maximum gap is no more than 0.3mm.

[0082] Each transducer interface corresponds to a channel, resulting in a dual-channel ultrasonic detector. This dual-channel ultrasonic detector has a bandwidth range of 0.5MHz to 15MHz, a square wave excitation pulse, and a maximum transmit voltage of 700V, which can meet the propagation energy requirements of direct waves through the pipe wall. Each channel of the dual-channel ultrasonic detector is equipped with dual gates, which provide amplitude monitoring and anti-saturation functions.

[0083] When the ultrasonic detection device of the present invention is used to detect the pipe to be detected in Example 1, the following steps are included:

[0084] S1. Design of standard pipe samples;

[0085] The outer diameter of the standard pipe sample is 133mm, the wall thickness is 7mm, the material is TA22, the surface roughness is Ra ≤ 6.3μm, and the length is 500mm. The wall thickness is measured using a thickness gauge, and the maximum deviation is about 0.2mm. A set of inner wall grooves and outer wall grooves are respectively processed on the circumference of the standard pipe sample with a circumferential spacing of 180°. The shape of the inner wall grooves and outer wall grooves is U-shaped to form a U-shaped groove. The depth of the U-shaped groove is 0.875mm and the length is 20mm. Figure 4 As shown, there are six U-shaped grooves, oriented longitudinally, transversely, and at a 45° angle. The grooves are evenly spaced, and the distance between the U-shaped grooves and the pipe opening of the standard pipe sample is no less than 100 mm. The dotted lines indicate that the U-shaped grooves are located on the inner wall of the standard pipe sample, while the solid lines indicate that the U-shaped grooves are located on the outer wall of the standard pipe sample.

[0086] S2. Calibration and debugging;

[0087] Adjust the ultrasonic testing device to the working state and perform calibration and debugging using the intact part of the pipe standard sample. Stably couple the probe chip 4 to the pipe standard sample using water as the coupling agent. Confirm the sound velocity and delay through automatic calibration. Set the circumferential channel sound path to 900 mm, the axial channel sound path to 200 mm, and the excitation voltage to 500 V. Adjust the gain to find the pipe wall direct wave in the corresponding circumferential and axial channels respectively. Adjust its height to 80% of the screen height and select the direct wave using the tracking gate function.

[0088] On the basis of selecting the straight-through wave, the distance-amplitude curves of the corresponding channels were made respectively using the U-shaped grooves on the inner and outer walls of the circumferential and axial directions of the standard pipe.

[0089] S3. Process validation;

[0090] S31. Threshold setting: Scan the pipe sample at 90° intervals along the circumference, such as Figure 5 As shown in the figure, the reduction of the through wave amplitude at the U-shaped groove position in the circumferential channel at four different directions is recorded, which are A 周1 =4.5dB, A周2 =6.1dB, A 周3 =5.1dB, A 周4 =5.9dB, of which the minimum value is 4.5dB; scan along the axial direction on the pipe standard sample and record the reduction of the direct wave on the axis of the U-shaped groove on the inner and outer walls, which are A 轴1 =5.9dB and A 轴2 =6.7dB, of which the minimum value is 5.9dB. The amplitude reduction thresholds of the circumferential and axial direct waves are 4.5dB and 5.9dB respectively;

[0091] S32. Assessment Rule Setting: During the scanning process, first observe the amplitude changes of the through-wave in the circumferential and axial channels. If the change exceeds the set thresholds (i.e., 4.5dB and 5.9dB), the defect is assessed as unqualified and the location is recorded. Second, observe the defect reflection waves appearing in the distance-amplitude curves of the circumferential and axial channels. If the amplitude exceeds the distance-amplitude curve, the defect is assessed as unqualified and the location is recorded.

[0092] S33. Scan and inspect the standard pipe sample using a spiral path at a scanning speed no greater than 100 mm / s and a spiral pitch of 5 mm. All six pre-defined defects in the standard pipe sample are effectively detected and rated as unqualified, indicating that the process verification has passed.

[0093] S4. Scan and inspect the pipes;

[0094] The pipe standard was maintained in a calibrated and debugged state. The surface roughness of the pipe to be inspected was Ra ≤ 6.3μm. The pipe was then tested and evaluated. A total of five unqualified items were detected, two using the through wave and three using the reflected wave. Visual inspection confirmed that the defects were external wall cracks, internal wall cracks, and internal wall pits.

[0095] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. An ultrasonic testing device for large-caliber thin-walled titanium alloy pipes, comprising a probe housing (1), a wedge (5), and a probe wafer (4) connected to the wedge (5), characterized in that: The probe chip (4) includes a first probe chip (41), a second probe chip (42), a third probe chip (43), and a fourth probe chip (44). The four probe chips (4) are in a cross shape. The first probe chip (41) and the second probe chip (42) form a group and are respectively located at the two ends of the transverse direction of the probe housing (1) for scanning the circumferential direction of the pipe. The third probe chip (43) and the fourth probe chip (44) form a group and are respectively located at the two ends of the longitudinal direction of the probe housing (1) for scanning the axial direction of the pipe. Any probe chip (4) in the same group can emit ultrasonic signals and receive ultrasonic signals emitted by another probe chip (4) that are reflected multiple times by the pipe wall and ultrasonic signals directly reflected by defects.

2. The ultrasonic detection device according to claim 1, characterized in that The distance between the inner edge of the third probe chip (43) and the inner edge of the fourth probe chip (44) is not less than 5 times the thickness of the pipe wall.

3. The ultrasonic detection device according to claim 1, characterized in that The ultrasonic detection device comprises a dual-channel ultrasonic detector and a combined transducer (7), wherein the combined transducer (7) comprises a first transducer interface and a second transducer interface, the probe chip (4) and the combined transducer (7) are connected, the first probe chip (41) and the second probe chip (42) are arranged in parallel on the first transducer interface, the third probe chip (43) and the fourth probe chip (44) are arranged in parallel on the second transducer interface, and each transducer interface corresponds to one channel.

4. The ultrasonic detection device according to claim 1, characterized in that The probe chip (4) is arranged on the inclined surface of the wedge block (5), and a damping block (6) is arranged on the side of the probe chip (4) facing away from the wedge block (5).

5. The ultrasonic detection device according to claim 1, characterized in that: The probe chip (4) is tilted, and the tilt angle is used to ensure that the angle of the ultrasonic refraction wave in the pipe is 45°.

6. The ultrasonic detection device according to claim 1, characterized in that A sound insulation layer (3) is provided between adjacent wedge blocks (5).

7. A detection method of the ultrasonic detection device according to any one of claims 1 to 6, characterized in that: The steps include: S1. Design of standard pipe samples; S2. Calibration and debugging; S3. Process validation; S4. Scan and detect.

8. The detection method of the ultrasonic detection device according to claim 7, characterized in that: In step S1, the pipe standard sample has the same size and material as the pipe to be tested, and U-shaped grooves are processed at different positions of the pipe standard sample. There are n U-shaped grooves in total, which are divided into three types: longitudinal, transverse and 45° oblique. At least one U-shaped groove in each direction must be set on the inner and outer walls.

9. The detection method of the ultrasonic detection device according to claim 7, characterized in that: Step S3 includes: S31. Threshold setting: Scan the standard pipe sample at 90° intervals along the circumference and record the reduction in the straight-through amplitude of the U-shaped groove position at four different positions in the circumferential channel. The minimum value is recorded as A 周min , scan the pipe sample along the axial direction and record the reduction of the straight wave on the axis where the U-shaped grooves on the inner and outer walls are located. The minimum value is recorded as A 轴min ; S32. Assessment Rule Setting: During the scanning process, first, based on the change in the through-wave amplitude in the circumferential and axial channels, determine whether the change exceeds the through-wave amplitude reduction threshold. If so, the defect is assessed as unqualified and the location is recorded. Second, based on the defect reflection waves appearing in the circumferential and axial channel sound path distance-amplitude curves, if the amplitude exceeds the distance-amplitude curve, the defect is assessed as unqualified and the location is recorded. S33. Scan and inspect the pipe standard sample using a spiral path. If all n preset defects in the pipe standard sample can be effectively detected and rated as unqualified, the process verification is passed. Otherwise, return to step S2.

10. The detection method of the ultrasonic detection device according to claim 7, characterized in that: After the process verification is passed, the calibration and debugging status of the pipe standard is maintained and the pipe to be inspected is tested.

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