Ultrasonic phased array reference test block and use method thereof

Abstract

The invention discloses an ultrasonic phased array reference test block and a use method thereof. The ultrasonic phased array reference test block comprises a test block body, a surfacing layer, a transverse hole group, a first notch groove group and a second notch groove group, the first side surface of the test block body is provided with a convex part for simulating a boss at the orifice of a connecting pipe, the upper surface of the test block body is provided with a slope, and the lower surface of the test block body is provided with a concave inner bend angle; the surfacing layer is arranged on the upper surface and the first side surface of the test block body, the transverse hole group is arranged on the first surface of the test block body, the first notch groove group is arranged at the joint of the first side surface and the second surface, and the second notch groove group is arranged on the inner corner. According to the ultrasonic phased array reference test block, the surfacing layer, the slope, the inner bend and other structures are arranged according to the characteristics of a reactor pressure vessel barrel and a connecting pipe welding seam, the real structural characteristics of the reactor pressure vessel barrel and the connecting pipe welding seam are effectively simulated, and the influence of a complex structure on a phased array ultrasonic detection process is simulated.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing, and in particular to an ultrasonic phased array reference test block and a use method thereof. Background Art

[0002] The reactor pressure vessel is the core equipment in a nuclear power plant. During its service, it has been working under extremely complex conditions such as high temperature, high pressure, and high radiation. It cannot be replaced and plays a key role in the safe operation of nuclear power plants. Reactor pressure vessels are usually equipped with multiple inlet and outlet pipes for the circulation of the primary coolant. The connection weld between the pipe and the pressure vessel cylinder adopts a plug-in full-penetration structure design. The weld is a complex saddle-shaped structure with a thick weld wall. In the in-service inspection outline of nuclear power plants, ultrasonic non-destructive testing of the pipe and cylinder welds is a mandatory requirement. The large wall thickness (usually greater than 200mm), the complex saddle surface geometry, and the special geometry of the inlet and outlet pipes all make ultrasonic testing difficult.

[0003] Ultrasonic phased array inspection of reactor pressure vessel cylinder and nozzle welds requires the use of reference test blocks for ultrasonic sensitivity calibration. Traditional reference test blocks are regular rectangular blocks and cannot simulate the complex ultrasonic propagation sound field, various possible geometric structures, waveform transformation and other signals in the actual workpiece during the inspection process. In particular, the inner and outer surfaces of the weld are most affected. Not only will the sound field coverage of the ultrasonic probe be affected, but the inner and outer surfaces are also prone to produce non-correlated displays that are unrelated to the actual defects, which affects the determination of defects. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an ultrasonic phased array reference test block for reactor pressure vessel cylinder and pipe weld and a method for using the same.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide an ultrasonic phased array reference test block for ultrasonic phased array inspection of reactor pressure vessel cylinder and pipe welds, the ultrasonic phased array reference test block comprising a test block body, a cladding layer, a transverse hole group, a first groove group and a second groove group;

[0006] The test block body includes a first surface and a second surface facing each other, an upper surface and a lower surface respectively connected between the upper end and the lower end of the first surface and the second surface, and a first side surface and a second side surface respectively connected to opposite sides of the first surface and the second surface and connected to the upper surface and the lower surface;

[0007] A protrusion simulating a boss at a pipe port is provided on the first side surface of the test block body, a slope connected to the protrusion is provided on the upper surface of the test block body, and a concave inner bend is provided on the lower surface of the test block body;

[0008] The surfacing layer is arranged on the upper surface of the test block body and the surface of the protrusion, the transverse hole group is arranged on the first surface of the test block body, the first groove group is arranged at the connection between the first side surface and the second surface, and the second groove group is arranged on the inner bend angle.

[0009] In some embodiments, the transverse hole group includes three long transverse holes distributed at different heights on the first surface, and each of the long transverse holes is formed by a hole portion opened on the first surface and extending into the interior of the test block body.

[0010] In some embodiments, the diameter of the long horizontal hole is 6.4 mm to 11.1 mm, and the hole depth is 75 mm to 125 mm.

[0011] In some embodiments, the distances between the three long horizontal holes and the lower surface are 125.5 mm, 251 mm, and 376.5 mm, respectively.

[0012] In some embodiments, the first groove group includes three first grooves; the three first grooves are arranged at intervals along the height of the connection between the first side surface and the second surface.

[0013] In some embodiments, each of the first grooves has a length of 25 mm to 50 mm, a width of 0.5 mm to 6 mm, and a depth of 5 mm to 20 mm.

[0014] In some embodiments, the distances between the three first grooves and the lower surface are 50 mm, 100 mm, and 150 mm, respectively.

[0015] In some embodiments, the second groove group includes three second grooves, and the three second grooves are arranged at intervals along the height of the inner bend angle.

[0016] In some embodiments, each of the second grooves has a length of 25 mm to 50 mm, a width of 0.5 mm to 6 mm, and a depth of 5 mm to 20 mm.

[0017] In some embodiments, the distances between the three second grooves and the lower surface are 50 mm, 100 mm, and 150 mm, respectively.

[0018] In some embodiments, the slope has an inclination angle of 10° relative to the horizontal plane.

[0019] In some embodiments, the radius of the inner bend angle is 203 mm.

[0020] The present invention also provides a method for using an ultrasonic phased array reference test block, including using the ultrasonic phased array probe for benchmark sensitivity calibration, inner surface scanning sensitivity calibration, and outer surface scanning sensitivity calibration;

[0021] The frequency of the ultrasonic phased array probe is 1 MHz to 4 MHz, and the fan scanning angle is 0° to 45°.

[0022] The beneficial effects of the present invention are as follows: the reference block is provided with structures such as a weld overlay, a slope and an inner bend angle according to the characteristics of the reactor pressure vessel cylinder and the nozzle weld, effectively simulating the real structural characteristics of the reactor pressure vessel cylinder and the nozzle weld, and simulating the influence of the complex structure on the phased array ultrasonic detection process; it can complete the calibration of the time-gain correction (TCG) curve, inner surface scanning sensitivity and outer surface scanning sensitivity of the ultrasonic phased array probe to the reference block, and at the same time can provide a reliable judgment and analysis basis for the defect positioning and quantification of ultrasonic detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0024] Figure 1 is a schematic diagram of the three-dimensional structure of an ultrasonic phased array reference test block according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the longitudinal cross-sectional structure of an ultrasonic phased array reference test block according to an embodiment of the present invention;

[0026] Figure 3 yes Figure 1 Front view of

[0027] Figure 4 is a schematic diagram of an ultrasonic phased array reference test block used for benchmark sensitivity calibration according to an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of an ultrasonic phased array reference test block used for inner surface scanning sensitivity calibration according to an embodiment of the present invention;

[0029] Figure 6 The diagram is a schematic diagram of an ultrasonic phased array reference block used for external surface scanning sensitivity calibration according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0031] The ultrasonic phased array reference test block of the present invention is a reference test block used for ultrasonic sensitivity calibration in ultrasonic phased array inspection of reactor pressure vessel cylinders and pipe joint welds.

[0032] The ultrasonic phased array reference test block of the present invention is arranged according to the characteristics of the weld between the reactor pressure vessel cylinder and the nozzle, and is provided with structures such as a cladding layer, a slope and an inner bend angle corresponding to the connection characteristics between the pressure vessel cylinder and the nozzle.

[0033] like Figures 1 to 3 As shown, an ultrasonic phased array reference test block according to an embodiment of the present invention includes a test block body 10 , a surfacing layer 20 disposed on the test block body 10 , a transverse hole group 300 , a first groove group 100 and a second groove group 200 .

[0034] The test block body 10 is a polyhedral structure, and specifically may include a first surface 11 and a second surface 12 facing each other, an upper surface 13 and a lower surface 14 facing each other, and a first side surface 15 and a second side surface 16 facing each other. The upper surface 13 and the lower surface 14 are respectively connected between the upper end and the lower end of the first surface 11 and the second surface 12, forming the top surface and the bottom surface of the test block body 10. The first side surface 15 and the second side surface 16 are respectively connected to the opposite sides of the first surface 11 and the second surface 12, and are connected to the upper surface 13 and the lower surface 14.

[0035] It can be understood that in the present invention, the surface of the reference test block used for placing the ultrasonic phased array probe is used as the upper surface, and the other opposite surface is used as the lower surface.

[0036] According to the characteristics of the reactor pressure vessel cylinder and the pipe weld, a protrusion 30 is provided on the first side surface 15 of the test block body 10 to simulate the boss at the pipe mouth. Therefore, the shape and curvature of the protrusion 30 are set corresponding to the boss at the pipe mouth.

[0037] exist Figure 1 In the illustrated embodiment, the protrusion 30 is located at the upper end of the first side surface 15 , and a surface of the protrusion 30 is connected to the upper surface 13 .

[0038] According to the characteristics of the reactor pressure vessel cylinder and the pipe weld, the upper surface 13 of the test block body 10 is provided with a slope 50 connected to the protrusion 30. In combination with the setting of the slope 50, the upper surface 13 of the test block body 10 includes a horizontal plane extending horizontally, an inclined plane connected to the horizontal plane and extending obliquely downward, and the inclined plane is connected between the horizontal plane and the protrusion 30, and the inclined plane forms the slope 50.

[0039] In some embodiments, the slope 50 has an inclination angle of 10° relative to the horizontal plane.

[0040] When the reference test block is in use, the ultrasonic phased array probe 400 is placed on the upper surface 13 of the test block body 10 .

[0041] Furthermore, the upper surface is a curved surface that is concave downwards, ensuring that the coupling condition with the ultrasonic phased array probe 400 is consistent. Alternatively, the radius of the curved surface may be, but is not limited to, 393.5 mm.

[0042] According to the characteristics of the reactor pressure vessel cylinder and the pipe weld, the lower surface 14 of the test block body 10 is provided with a concave inner bend angle 40. Specifically, a concave groove is provided at one end of the lower surface 14 of the test block body 10, and the groove and the protrusion 30 are located at the diagonal angle of the test block body 10. The groove extends along the length of the lower surface 14, and the inner surface of the end portion close to the first side surface 15 is set in a circular arc surface, thereby forming the inner bend angle 40.

[0043] The inner bend angle 40 simulates the bend angle structure of the connection between the outer side of the pipe and the cylinder of the pressure vessel.

[0044] Alternatively, the radius of the inner bend corner 40 may be, but is not limited to, 203 mm.

[0045] The surfacing layer 20 is arranged on the upper surface 13 and the first side surface 15 of the test block body 10, including the surface of the protrusion 30, simulating the surfacing layer on the inner surface of the connecting pipe and the pressure vessel cylinder, and is usually a stainless steel surfacing layer with a thickness of 6 mm.

[0046] The transverse hole group 300 is disposed on the first surface 11 of the test block body 10 , the first groove group 100 is disposed at the connection between the first side surface 15 and the second surface 12 , and the second groove group 200 is disposed on the inner bend corner 40 .

[0047] In some embodiments, the transverse hole group 300 includes three long transverse holes 301 distributed at different heights on the first surface 11, and each long transverse hole 301 is formed by a hole portion opened on the first surface 11 and extending into the inside of the test block body 10. The three long transverse holes 301 are also distributed on different horizontal planes and staggered with each other.

[0048] The diameter of the long horizontal hole 301 is 6.4 mm to 11.1 mm, and the hole depth is 75 mm to 125 mm. In a selective embodiment, the diameter of the long horizontal hole 301 is 9.5 mm, and the hole depth is 75 mm.

[0049] The distances between the three long horizontal holes 301 and the lower surface 14 may be 125.5 mm, 251 mm, and 376.5 mm respectively.

[0050] In some embodiments, the first groove group 100 includes three first grooves 101 ; the three first grooves 101 are arranged at intervals along the height of the connection between the first side surface 15 and the second surface 12 .

[0051] The first groove 101 is preferably a rectangular groove, which is perpendicular to the edge of the first side surface 15 .

[0052] Each first groove 101 has a length of 25 mm to 50 mm, a width of 0.5 mm to 6 mm, and a depth of 5 mm to 20 mm. In a selective embodiment, each first groove 101 has a length of 25 mm, a width of 2.5 mm, and a depth of 15 mm.

[0053] The distances between the three first grooves 101 and the lower surface 14 may be 50 mm, 100 mm, and 150 mm respectively.

[0054] In some embodiments, the second groove group 200 includes three second grooves 201 , and the three second grooves 201 are arranged at intervals along the height of the inner bend corner 40 .

[0055] The second groove 201 is preferably a rectangular groove, which is perpendicular to the tangent line of the arc at the inner bend corner 40.

[0056] Each second groove 201 has a length of 25 mm to 50 mm, a width of 0.5 mm to 6 mm, and a depth of 5 mm to 20 mm. In a selective embodiment, each second groove 201 has a length of 25 mm, a width of 2.5 mm, and a depth of 15 mm.

[0057] The distances between the three second grooves 201 and the lower surface 14 are 50 mm, 100 mm, and 150 mm respectively.

[0058] When the ultrasonic phased array reference test block of the present invention is used, it is used in conjunction with an ultrasonic phased array probe for benchmark sensitivity calibration, inner surface scanning sensitivity calibration and outer surface scanning sensitivity calibration.

[0059] According to the characteristics of the reactor pressure vessel cylinder and the nozzle welds, by selecting appropriate parameters such as the number, combination, and excitation order of the chips, the energy, angle, and focal distance of the sound beam can be changed to obtain a sound beam energy convergence area of ​​corresponding depth, which can improve the sensitivity of defect inspection and thus improve the signal-to-noise ratio and quantitative accuracy.

[0060] The parameters of the ultrasonic phased array probe are set as follows: probe frequency 1MHz~4MHz, number of array elements 32~64, array element width 1mm, array element gap 0.5mm~1mm (such as 0.1mm, etc.), secondary axis width 28mm; the wedge is an inclined wedge 20° longitudinal wave; the sound beam angle is set to a fan scan of 0°~45°, the fan scan angle resolution is 1°, the focusing method is sound path focusing, and the coupling medium is water.

[0061] Among them, the ultrasonic phased array probe with a frequency of 1 to 4 MHz and a fan scanning angle of 0 to 45° is used to improve the resolution and signal-to-noise ratio of the probe in complex structures and thick-walled welds, and reduce the scanning blind area of ​​the probe.

[0062] The operations for baseline sensitivity calibration are as follows:

[0063] refer to Figure 4 , place the ultrasonic phased array probe 400 on the upper surface 13 of the reference test block, move the ultrasonic phased array probe 400 back and forth, find the long horizontal hole 301 with the strongest echo signal amplitude and sound path among the three long horizontal holes 301, and adjust the echo amplitude of the long horizontal hole 301 to 80% of the amplitude scale. Keep the gain unchanged, use the three long horizontal holes 301 to make a TCG curve, so that the echo amplitude of each long horizontal hole 301 can reach 80% of the amplitude scale, and apply the TCG curve to all angles.

[0064] The operation for internal surface scanning sensitivity calibration is as follows:

[0065] refer to Figure 5 , place the ultrasonic phased array probe 400 on the upper surface 13 of the reference test block, move the ultrasonic phased array probe 400 back and forth, find the first groove 101 with the strongest echo signal amplitude and sound path among the three first grooves 101, and adjust the echo amplitude of the first groove 101 to 80% of the amplitude scale. Keep the gain unchanged, find the other two first groove 101 signal echoes, so that the echo amplitude of each first groove 101 signal can reach 80% of the amplitude scale, and use this as the inner surface scanning sensitivity G1. When inspecting the inner surface of the reactor pressure vessel cylinder and the pipe weld, use G1 as the inner surface reference sensitivity to facilitate signal recognition and help improve the defect detection rate. Record the display signal with the maximum echo amplitude greater than or equal to 20% (-14dB) of the inner surface reference sensitivity.

[0066] The sensitivity calibration for external surface scanning is performed as follows:

[0067] refer to Figure 6 , place the ultrasonic phased array probe 400 on the upper surface 13 of the reference test block, move the ultrasonic phased array probe 400 back and forth, find the second groove 201 with the strongest echo signal amplitude and sound path among the three second grooves 201, and adjust the second groove 201 echo amplitude to 80% of the amplitude scale. Keep the gain unchanged, find the remaining two second groove 201 signal echoes, so that the echo amplitude of each second groove 201 signal can reach 80% of the amplitude scale, and use this as the outer surface scanning sensitivity G2. When inspecting the outer surface of the reactor pressure vessel cylinder and the pipe weld, use G2 as the outer surface reference sensitivity to facilitate signal recognition and help improve the defect detection rate. Record the display signal with the maximum echo amplitude greater than or equal to 20% (-14dB) of the outer surface reference sensitivity.

[0068] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ultrasonic phased array reference test block, characterized in that: Used for ultrasonic phased array inspection of reactor pressure vessel cylinder and pipe welds, the ultrasonic phased array reference test block comprises a test block body, a cladding layer, a transverse hole group, a first groove group and a second groove group; The test block body includes a first surface and a second surface facing each other, an upper surface and a lower surface respectively connected between the upper end and the lower end of the first surface and the second surface, and a first side surface and a second side surface respectively connected to opposite sides of the first surface and the second surface and connected to the upper surface and the lower surface; A protrusion simulating a boss at a pipe port is provided on the first side surface of the test block body, a slope connected to the protrusion is provided on the upper surface of the test block body, and a concave inner bend is provided on the lower surface of the test block body; The surfacing layer is arranged on the upper surface, the first side surface and the surface of the protrusion of the test block body, the transverse hole group is arranged on the first surface of the test block body, the first groove group is arranged at the connection between the first side surface and the second surface, and the second groove group is arranged on the inner bend angle.

2. The ultrasonic phased array reference test block according to claim 1, characterized in that: The transverse hole group includes three long transverse holes distributed at different heights on the first surface, and each of the long transverse holes is formed by a hole portion opened on the first surface and extending toward the inside of the test block body.

3. The ultrasonic phased array reference test block according to claim 2, characterized in that: The diameter of the long horizontal hole is 6.4mm-11.1mm, and the hole depth is 75mm-125mm; The distances between the three long horizontal holes and the lower surface are 125.5 mm, 251 mm, and 376.5 mm respectively.

4. The ultrasonic phased array reference test block according to claim 1, characterized in that: The first groove group includes three first grooves; the three first grooves are arranged at intervals along the height of the connection between the first side surface and the second surface.

5. The ultrasonic phased array reference test block according to claim 4, characterized in that: The length of each of the first grooves is 25 mm to 50 mm, the width is 0.5 mm to 6 mm, and the depth is 5 mm to 20 mm; the distances between the three first grooves and the lower surface are 50 mm, 100 mm, and 150 mm, respectively.

6. The ultrasonic phased array reference test block according to claim 1, characterized in that: The second groove group includes three second grooves, and the three second grooves are arranged at intervals along the height of the inner bend angle.

7. The ultrasonic phased array reference test block according to claim 6, characterized in that: The length of each of the second grooves is 25 mm to 50 mm, the width is 0.5 mm to 6 mm, and the depth is 5 mm to 20 mm; the distances between the three second grooves and the lower surface are 50 mm, 100 mm, and 150 mm, respectively.

8. The ultrasonic phased array reference test block according to claim 1, characterized in that: The slope has an inclination angle of 10° relative to the horizontal plane.

9. The ultrasonic phased array reference test block according to claim 1, characterized in that: The radius of the inner bend angle is 203 mm.

10. A method for using the ultrasonic phased array reference test block according to any one of claims 1 to 9, characterized in that: Including using ultrasonic phased array probes for reference sensitivity calibration, inner surface scanning sensitivity calibration and outer surface scanning sensitivity calibration; The frequency of the ultrasonic phased array probe is 1 MHz to 4 MHz, and the fan scanning angle is 0° to 45°.

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