A sensitivity calibration test block for a rail weld full-face scanning device

Abstract

The present application provides a sensitivity calibration test block for a steel rail weld full-face scanning device, comprising a rail head, a rail waist and a rail bottom, wherein the rail head, the rail waist and the rail bottom are each provided with a plurality of calibration holes; when the probe of the scanning device is multiple and each is a single probe, the scanning device is placed at the rail head or the rail waist or the rail bottom, one of the calibration holes on the rail head or the rail waist or the rail bottom corresponds to one probe of the scanning device, so that the incident angle of the probe is perpendicular to the axis of the calibration hole, and the probe is used for sensitivity calibration.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic nondestructive testing technology, and more specifically, to a sensitivity calibration test block for a full-section scanning device for rail welds. Background Technology

[0002] Railway rails are constructed by welding several rails together sequentially to form a usable long rail. During welding, a weld joint is formed at the weld point. Welding defects such as porosity, slag inclusions, sand inclusions, and cracks may occur. During service, fatigue loads on the weld joints from wheel fatigue cause damage primarily to fatigue cracks, affecting the service life of the weld joint and even leading to breakage and failure, thus jeopardizing train safety. Considering the practical issues of rail service condition, quantity, service life, and damage types, current domestic and international non-destructive testing of rail weld joints mainly uses conventional ultrasonic testing technology. Using ultrasonic waves to monitor welding defects and fatigue cracks in rail welds is the most direct and effective technical means and measure to reduce rail breakage and ensure safe train operation.

[0003] Before ultrasonic monitoring, the monitoring sensitivity of the equipment needs to be calibrated using a special calibration block for weld seams. With the significant increase in high-speed rail mileage, the task of weld seam inspection is extremely demanding, requiring very high efficiency and accuracy. Therefore, the inspection equipment and calibration blocks need to keep pace with these developments. Currently, the existing railway standard calibration block GHT-1 can only calibrate the sensitivity of dual probes, and the GHT-5 block can only calibrate the sensitivity of a single probe. To accurately calibrate the sensitivity of the probes in a full-section scanning device, the probes must be removed and calibrated one by one, which is too inefficient and no longer meets the requirements.

[0004] Existing single-probe or dual-probe scanning devices can no longer meet the efficiency and accuracy requirements for weld flaw detection. Currently, China has developed an array-type full-section weld flaw detector for detecting rail welds. This detector integrates probes with multiple angles and various detection methods within its full-section scanning device. For example, patent publication number CN116642945A discloses an ultrasonic flaw detection device for rail welds and rail base plates that does not require disassembly of fasteners. This device includes an A-side probe box and a B-side probe box, each containing six probes. Three of these six probes have different angles with the rail's extension direction. For example, [the patent details are missing from the original text]. Patent publication number CN218726913U discloses an ultrasonic flaw detection device for the arc-triangular area of ​​rail welds. It uses 10 probes to perform full-coverage flaw detection on the arc-triangular area cross-section through multi-channel K-type array flaw detection and multi-angle reflection flaw detection, thereby improving flaw detection efficiency. Therefore, from a developmental perspective, probes with multiple angles and multiple flaw detection methods are an inevitable trend. However, existing test blocks such as GHT-1 and GHT-5 lack calibration holes corresponding to the position and angle of the full-section scanning device, making it impossible to accurately and quickly calibrate the sensitivity of the probes of the full-section scanning device without removing the probes.

[0005] The existing sensitivity calibration test blocks have the following technical problems:

[0006] Previously, the calibration holes of the sensitivity calibration test block were all perpendicular to the end face or the longitudinal face of the sensitivity calibration test block. Therefore, the angle formed by the incident angle of each probe at that angle and the axial center line of the corresponding calibration hole could not form a right angle. As a result, the reflected ultrasonic waves could not return to the receiving point of the probe or were not received completely, resulting in low sensitivity calibration accuracy or calibration failure. The sensitivity calibration is most accurate only when the angle formed by the incident angle of each probe and the axial center line of the corresponding calibration hole is a right angle. Summary of the Invention

[0007] In view of this, in order to solve the above problems, since the GHT-1 test block only has Φ3 horizontal flat bottom holes on two end faces and a long section of the rail in the middle does not have calibration holes, this section can be effectively utilized. According to the required angle and position of the probe of the full-section scanning device, multiple calibration holes were designed to accurately and quickly calibrate the sensitivity of each probe of the full-section scanning device.

[0008] This invention proposes a sensitivity calibration test block for a full-section scanning device for rail welds, comprising a rail head, rail web, and rail base. Each of the rail head, rail web, and rail base has multiple calibration holes. When the scanning device has multiple probes, each a single probe, the device is placed at the rail head, rail web, or rail base. One calibration hole on the rail head, rail web, or rail base aligns with one probe of the scanning device, ensuring the incident angle of the probe is perpendicular to the axis of the calibration hole. This is used for sensitivity calibration of the probe. Ideally, for example, the first probe mounted on the rail head is calibrated with the first calibration hole on the rail head, the second probe with the second calibration hole, and so on, with the Nth probe calibrated with the Nth calibration hole on the rail head. While the scanning device slides along the sensitivity calibration test block, the calibration of all probes on the scanning device is completed, allowing for rapid, one-time calibration of multiple probes without disassembly.

[0009] A sensitivity calibration test block for a full-section scanning device for rail welds includes a rail head, rail web, and rail base. The feature is that each of the rail head, rail web, and rail base has multiple calibration holes. When the scanning device has multiple probes, each a single probe, the scanning device is placed at the rail head, rail web, or rail base. One of the calibration holes on the rail head, rail web, or rail base aligns with one probe of the scanning device, such that the incident angle of the probe is perpendicular to the axis of the calibration hole. This is used to calibrate the sensitivity of the probe, allowing multiple probes of the scanning device to be calibrated in one go without disassembly.

[0010] Furthermore, the two ends of the sensitivity calibration test block are called end faces, and each end face is provided with multiple horizontal flat bottom holes perpendicular to the longitudinal plane of the rail, which are used to measure the sensitivity of the dual probes.

[0011] In some embodiments, the calibration holes on the rail head have different angles relative to the horizontal line, which are used to calibrate the sensitivity of the scanning device with multiple multi-angle probes installed on the rail head. This ensures that each probe of the scanning device with multiple multi-angle probes installed on the rail head can be matched with a calibration hole perpendicular to its incident angle, thus solving the problem of rapid calibration of the sensitivity of the probes of the full-section scanning device.

[0012] Furthermore, the rail head should have at least 5 calibration holes, the rail web should have at least 2 calibration holes, and the rail base should have at least 4 calibration holes.

[0013] In some embodiments, the rail head includes a tread and a jaw surface, the jaw surface being located on both sides of the lower end of the tread, and the calibration hole being a transverse semi-through hole with different deflection angles and distributed on the two jaw surfaces.

[0014] Furthermore, the diameter of the calibration hole in the rail head is 3mm.

[0015] Furthermore, the ultrasonic waves emitted by two adjacent calibration holes on the rail head do not interfere with each other.

[0016] Furthermore, the length of the horizontal flat bottom hole is denoted as L1. Both the transmitting and receiving probes are mounted on the rail head, and the distance between the receiving points of the transmitting and receiving probes is L2. The height of the sensitivity calibration block is denoted as H. The distance from the tread surface to the center of the horizontal flat bottom hole closest to the tread surface is h. The angle between the incident wave of the transmitting probe and the end face is α. Therefore, to avoid the calibration hole on the rail head affecting the detection of the horizontal flat bottom hole on the end face, the position of the calibration hole closest to the horizontal flat bottom hole on the rail head should be at least L away from the end face, as shown in the following formula:

[0017] L = L1 + L2;

[0018] L2 = 2*(H*tgα) - h*tgα;

[0019] In some embodiments, the rail base includes an upper surface and a lower surface, and the calibration holes of the rail base are vertical through holes perpendicular to the upper surface and the lower surface and penetrating the upper surface and the lower surface, and are evenly distributed on the left and right sides of the rail base.

[0020] Furthermore, the diameter of the calibration holes evenly distributed on the left and right sides of the rail bottom is 4mm.

[0021] Furthermore, the ultrasonic waves emitted by two adjacent calibration holes on the bottom of the rail do not interfere with each other.

[0022] Furthermore, the length of the horizontal flat bottom hole is denoted as L1. The transmitting probe and the receiving probe are respectively set at the rail head and rail bottom. The distance between the receiving points of the transmitting probe and the receiving probe is L2. The height of the sensitivity calibration test block is denoted as H. The center distance from the rail bottom to the horizontal flat bottom hole closest to the rail bottom is h. The angle between the incident wave of the transmitting probe and the end face is α. Therefore, in order to avoid the calibration hole at the rail bottom affecting the detection of the horizontal flat bottom hole at the end face, the position of the calibration hole at the rail head closest to the horizontal flat bottom hole should be at least L away from the end face, as shown in the following formula:

[0023] L = L1 + L2;

[0024] L2=(H*tgα)-h*tgα;

[0025] In some embodiments, the rail web includes a rail web surface and a low-curved surface. The low-curved surface is provided with a plurality of vertical through holes and vertical flat bottom holes, and the plurality of vertical through holes and vertical flat bottom holes are evenly distributed on both sides of the low-curved surface, for calibrating the sensitivity of each probe of the weld rail bottom triangular area scanning frame.

[0026] Furthermore, the diameter of the multiple vertical through holes and vertical flat bottom holes on the low-waisted arc-shaped surface is 3mm.

[0027] Furthermore, the ultrasonic waves emitted by two adjacent calibration holes on the rail web do not interfere with each other.

[0028] The beneficial effects of this invention are as follows: This invention proposes a sensitivity calibration test block for a full-section scanning device for rail welds, comprising a rail head, rail web, and rail base. Each of the rail head, rail web, and rail base has multiple calibration holes. When the scanning device has multiple probes, each a single probe, the scanning device is placed at the rail head, rail web, or rail base. One calibration hole on the rail head, rail web, or rail base aligns with one probe of the scanning device, such that the incident angle of the probe is perpendicular to the axis of the calibration hole. This is used to calibrate the sensitivity of the probe. Ideally, for example, the first probe installed on the rail head is calibrated with the first calibration hole on the rail head, the second probe is calibrated with the second calibration hole on the rail head, and so on, with the Nth probe calibrated with the Nth calibration hole on the rail head. While the scanning device slides along the sensitivity calibration test block, the calibration of all probes on the scanning device is completed, allowing multiple probes of the scanning device to be calibrated quickly and in one go without disassembly. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0030] Figure 2 This is a bottom view of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0031] Figure 3 This is a side view of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0032] Figure 4 This is a top view of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0033] Figure 5 This is a perspective view of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0034] Figure 6 This is a schematic diagram showing the position of the calibration hole closest to the transverse flat bottom hole on the rail head of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0035] Figure 7 This is a schematic diagram showing the position of the calibration hole closest to the transverse flat bottom hole on the rail bottom of the sensitivity calibration test block for the rail weld full-section scanning device of the present invention.

[0036] Explanation of main component symbols

[0037]

[0038] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0039] like Figures 1-5 As shown, a sensitivity calibration test block for a full-section scanning device for rail welds includes a rail head, rail web, and rail base. Each of the rail head, rail web, and rail base has multiple calibration holes. When the scanning device has multiple probes, each a single probe, the scanning device is placed at the rail head, rail web, or rail base. One of the calibration holes on the rail head, rail web, or rail base aligns with one of the probes of the scanning device, such that the incident angle of the probe is perpendicular to the axis of the calibration hole. This is used to calibrate the sensitivity of the probe, allowing multiple probes of the scanning device to be calibrated in one go without disassembly.

[0040] Since each calibration hole has a certain diameter, the probe calibrates the echo to 80% of the wave height. When encountering a flaw in the field, the difference between this flaw and 80% of the wave height can be used to roughly estimate whether the size of the damage is larger or smaller than the diameter of the opening.

[0041] The two ends of the sensitivity calibration test block are called end faces 6. Each end face 6 is provided with multiple horizontal flat bottom holes 5 perpendicular to the longitudinal plane of the rail, for measuring the sensitivity of the dual probes.

[0042] The calibration holes on the rail head have different angles relative to the horizontal line, used to calibrate the sensitivity of the scanning device with multiple multi-angle probes installed on the rail head. This ensures that each probe of the scanning device can be matched with a calibration hole perpendicular to its incident angle, solving the problem of rapid sensitivity calibration of probes in a full-section scanning device. Since more probes result in a wider area covered by the emitted ultrasonic waves, the scanning device can comprehensively scan the sensitivity calibration test block. However, too many probes can lead to complex connectivity issues and higher costs. Therefore, selecting the optimal number of probes is crucial for the scanning device. Research indicates that a probe count of 2-8 is optimal. Different parts of the sensitivity calibration test block require different numbers of probes. For example, at least 5 probes are needed at the rail head, at least 2 probes at the rail waist, and at least 4 probes at the rail bottom. This ensures that the ultrasonic emission coverage of the probes is staggered and overlapping, allowing the scanning device to scan more comprehensively at the corresponding locations. Therefore, the number of probes corresponds to the number of calibration holes. Hence, at least 5 calibration holes are needed at the rail head, at least 2 at the rail waist, and at least 4 at the rail bottom.

[0043] The rail web includes a rail web surface 11 and a low arc-shaped curved surface 12. The low arc-shaped curved surface 12 is provided with multiple vertical through holes 3 and vertical flat bottom holes 4, and the multiple vertical through holes 3 and vertical flat bottom holes 4 are evenly distributed on both sides of the low arc-shaped curved surface 12. It is used to calibrate the sensitivity of each probe of the weld rail bottom triangular area scanning frame. The diameter of the multiple vertical through holes 3 and vertical flat bottom holes 4 on the low arc-shaped curved surface 12 is 3mm. The ultrasonic waves emitted by two adjacent calibration holes on the rail web do not interfere with each other.

[0044] The rail head includes a tread surface 8 and a lower jaw surface 9. The lower jaw surface 9 is located on both sides of the lower end of the tread surface 8. The calibration holes are transverse semi-through holes 2 with different deflection angles and are distributed on the two lower jaw surfaces 9. The diameter of the calibration holes of the rail head is 3mm. The ultrasonic waves emitted by two adjacent calibration holes on the rail head do not interfere with each other.

[0045] The rail base includes an upper surface 14 and a lower surface 15. The calibration holes of the rail base are vertical through holes 3 that are perpendicular to the upper surface 14 and the lower surface 15 and penetrate through the upper surface 14 and the lower surface 15, and are evenly distributed on the left and right sides of the rail base. The diameter of the calibration holes evenly distributed on the left and right sides of the rail base is 4 mm. The ultrasonic waves emitted by two adjacent calibration holes on the rail base do not interfere with each other.

[0046] like Figure 6 As shown, the length of the horizontal flat bottom hole 5 is denoted as L1. Both the transmitting and receiving probes are mounted on the rail head, and the distance between the receiving points of the transmitting and receiving probes is L2. The height of the sensitivity calibration block is denoted as H. The center distance from the tread surface 8 to the center of the horizontal flat bottom hole 5 closest to the tread surface 8 is h. The angle between the incident wave of the transmitting probe and the end face 6 is α. Therefore, to avoid the calibration hole of the rail head affecting the detection of the horizontal flat bottom hole 5 on the end face 6, the position of the calibration hole closest to the horizontal flat bottom hole 5 on the rail head should be at least L away from the end face 6, as shown in the following formula:

[0047] L = L1 + L2;

[0048] L2 = 2*(H*tgα) - h*tgα;

[0049] L1 = 70mm;

[0050] H=176mm;

[0051] h=10mm;

[0052] Typically, the dual-probe detection rail uses an angle with a K value of 0.8 and tgα=0.8. Therefore, the distance between the receiving probe and the end face 6 is: L=70+2*(176*0.8)-0.8*10=343.6mm.

[0053] Therefore, in order to avoid the calibration hole of the rail head affecting the detection of the transverse flat bottom hole 5 on the end face 6, the position of the calibration hole of the rail head should be at least 343.6 mm away from the end face 6.

[0054] like Figure 7 As shown, the length of the horizontal flat bottom hole 5 is denoted as L1. The transmitting probe and the receiving probe are respectively set at the rail head and the rail bottom. The distance between the receiving points of the transmitting probe and the receiving probe is L2. The height of the sensitivity calibration test block is denoted as H. The center distance from the rail bottom to the horizontal flat bottom hole 5 closest to the rail bottom is h. The angle between the incident wave of the transmitting probe and the end face 6 is α. Therefore, in order to avoid the calibration hole at the rail bottom affecting the detection of the horizontal flat bottom hole 5 on the end face 6, the position of the calibration hole at the rail head closest to the horizontal flat bottom hole 5 should be at least L away from the end face 6, as shown in the following formula:

[0055] L = L1 + L2;

[0056] L2=(H*tgα)-h*tgα;

[0057] L1 = 70mm;

[0058] H=150mm;

[0059] h=8mm;

[0060] Typically, the dual-probe K-type detection rail base plate uses a probe with a K value of 1 and tgα=1.

[0061] L = 70 + (150 * 1) - 8 * 1 = 212 mm.

[0062] Therefore, in order to avoid the vertical holes of the rail plate affecting the detection of the horizontal flat bottom hole 5 on the end face 6, the position of the vertical holes of the rail base plate should be at least 212mm away from the end face 6.

[0063] The beneficial effects of this invention are as follows: This invention proposes a sensitivity calibration test block for a full-section scanning device for rail welds, comprising a rail head, rail web, and rail base. Each of the rail head, rail web, and rail base has multiple calibration holes. When the scanning device has multiple probes, each a single probe, the scanning device is placed at the rail head, rail web, or rail base. One calibration hole on the rail head, rail web, or rail base aligns with one probe of the scanning device, such that the incident angle of the probe is perpendicular to the axis of the calibration hole. This is used to calibrate the sensitivity of the probe. Ideally, for example, the first probe installed on the rail head is calibrated with the first calibration hole on the rail head, the second probe is calibrated with the second calibration hole on the rail head, and so on, with the Nth probe calibrated with the Nth calibration hole on the rail head. While the scanning device slides along the sensitivity calibration test block, the calibration of all probes on the scanning device is completed, allowing multiple probes of the scanning device to be calibrated quickly and in one go without disassembly.

[0064] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A sensitivity calibration test block for a full-section scanning device for rail welds, comprising rail head, rail web, and rail base, characterized in that: The rail head, rail web, and rail bottom are each provided with multiple calibration holes. When the scanning device has multiple probes, each of which is a single probe, the scanning device is placed at the rail head, rail web, or rail bottom. One of the calibration holes on the rail head, rail web, or rail bottom aligns with one of the probes of the scanning device, so that the incident angle of the probe is perpendicular to the axis of the calibration hole. This is used to calibrate the sensitivity of the probe, allowing multiple probes of the scanning device to be calibrated at once without disassembly. The two ends of the sensitivity calibration test block are called end faces (6), and each end face (6) is provided with multiple horizontal flat bottom holes (5) perpendicular to the longitudinal plane of the rail, used for measuring... The sensitivity of the dual probes is that the multiple calibration holes on the rail head have different deflection angles relative to the horizontal line. This is used to calibrate the sensitivity of the scanning device with multiple multi-angle probes installed on the rail head, so that each probe of the scanning device with multiple multi-angle probes installed on the rail head can be matched with a calibration hole perpendicular to its incident angle. This solves the problem of rapid calibration of the sensitivity of the probes of the full-section scanning device. The rail head includes a tread surface (8) and a jaw surface (9). The jaw surface (9) is located on both sides of the lower end of the tread surface (8). The calibration holes are transverse semi-through holes (2) with different deflection angles and are distributed on the two jaw surfaces (9).

2. The sensitivity calibration test block for the rail weld full-section scanning device as described in claim 1, characterized in that: The rail head has at least 5 calibration holes, the rail web has at least 2 calibration holes, and the rail bottom has at least 4 calibration holes.

3. The sensitivity calibration test block for the rail weld full-section scanning device as described in claim 1, characterized in that: The length of the horizontal flat bottom hole (5) is denoted as L1. Both the transmitting probe and the receiving probe are set on the rail head. The distance between the receiving points of the transmitting probe and the receiving probe is L2. The height of the sensitivity calibration test block is denoted as H. The center distance from the tread surface (8) to the horizontal flat bottom hole (5) closest to the tread surface (8) is h. The angle between the incident wave of the transmitting probe and the end face (6) is α. Therefore, in order to avoid the calibration hole of the rail head affecting the detection of the horizontal flat bottom hole (5) on the end face (6), the position of the calibration hole closest to the horizontal flat bottom hole (5) on the rail head should be at least L away from the end face (6). The formula is as follows: L = L1 + L2; L2=2*(H*tgα)-h*tgα.

4. The sensitivity calibration test block for the rail weld full-section scanning device as described in claim 1, characterized in that: The rail base includes an upper surface (14) and a lower surface (15). The calibration holes of the rail base are vertical through holes (3) that are perpendicular to the upper surface (14) and the lower surface (15) and penetrate the upper surface (14) and the lower surface (15) and are evenly distributed on the left and right sides of the rail base.

5. The sensitivity calibration test block for the rail weld full-section scanning device as described in claim 1, characterized in that: The length of the horizontal flat bottom hole (5) is denoted as L1. The transmitting probe and the receiving probe are respectively set at the rail head and the rail bottom. The distance between the receiving points of the transmitting probe and the receiving probe is L2. The height of the sensitivity calibration test block is denoted as H. The center distance from the rail bottom to the horizontal flat bottom hole (5) closest to the rail bottom is h. The angle between the incident wave of the transmitting probe and the end face (6) is α. Therefore, in order to avoid the calibration hole at the rail bottom affecting the detection of the horizontal flat bottom hole (5) at the end face (6), the position of the calibration hole closest to the horizontal flat bottom hole (5) at the rail head should be at least L away from the end face (6). The formula is as follows: L = L1 + L2; L2=(H*tgα)-h*tgα.

6. The sensitivity calibration test block for the rail weld full-section scanning device as described in claim 1, characterized in that: The rail waist includes a rail waist surface (11) and a low-curved surface (12). The low-curved surface (12) is provided with multiple vertical through holes (3) and vertical flat bottom holes (4). The multiple vertical through holes (3) and vertical flat bottom holes (4) are evenly distributed on both sides of the low-curved surface (12) to calibrate the sensitivity of each probe of the weld rail bottom triangular area scanning frame.

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