A phased array ultrasonic testing block and testing method for stainless steel small diameter pipe welds

Abstract

The present invention discloses a phased array ultrasonic inspection test block and inspection method for a small-diameter stainless steel pipe weld. The test block has an overall strip shape and includes two parts: a comparison test block and a simulation test block. The comparison test block includes a left comparison test block body and a right comparison test block body; the simulation test block includes an upper simulation test block body and a lower simulation test block body. During the inspection, the front end of the probe is aligned with the corresponding reflector to produce an ACG curve; then the probe is turned around, the probe is moved to find the maximum reflected wave position, the sensitivity setting is debugged, and a DAC curve is produced; the probe is moved to the simulation test block area, the maximum reflected wave position is found, the detection sensitivity is corrected, and the on-site detection gain value is determined. The present invention has a compact structure and complete functions, and can simultaneously meet the requirements of phased array instrument equipment debugging, sensitivity setting, and detection process verification. There is no need to replace different test blocks to calibrate the phased array detection system. The operation is simple, and the manufacturing, use, and maintenance costs are low.

Description

Technical Field

[0001] The invention relates to a novel multifunctional comparison test block for phased array ultrasonic detection and a detection method, belonging to the technical field of ultrasonic detection. Background Art

[0002] Austenitic stainless steel has the characteristics of high temperature resistance and corrosion resistance, showing good performance, and also has excellent process performance. Therefore, it is widely used in high temperature and high pressure pipeline systems of thermal power generating units. Taking a million-kilowatt thermal power generating unit as an example, there are about 10,000 stainless steel small-diameter pipe welds in the boiler heating surface installation project alone, which accounts for a considerable proportion. In addition, stainless steel pipelines have high operating parameters and harsh operating environment. They are often used in core systems such as the final superheater and the final reheater. The quality of their welding directly affects the safe and stable operation of the unit and is the key inspection and monitoring part of the unit. The grains of austenitic stainless steel welds are coarse and uneven, and have significant anisotropic characteristics. When ultrasonic waves propagate in anisotropic welds, they will be distorted, separated, and the propagation path will change, resulting in greater attenuation and scattering, which will directly affect the sensitivity and accuracy of ultrasonic detection. In addition, the curvature of the small-diameter pipe is large, and there are many clutters and poor signal-to-noise ratio during on-site detection. Therefore, ultrasonic detection of austenitic stainless steel small-diameter pipe welds has always been a recognized technical problem in the industry. Phased array ultrasonic testing technology is currently an advanced and cutting-edge ultrasonic testing technology in the world, with the characteristics of high detection sensitivity, intuitive defect display, and accurate qualitative and quantitative analysis. Compared with conventional ultrasonic testing technology, this technology has many significant technical advantages, but it still belongs to the category of ultrasonic technology. In order to ensure the accuracy, repeatability and comparability of the test results, it is necessary to use a test block with a specific reflector to calibrate the detection system and set the sensitivity. The applicability of the test block directly affects the accuracy of phased array ultrasonic testing and the accuracy of the test results.

[0003] At present, there are two main test blocks for phased array ultrasonic testing of austenitic stainless steel small-diameter pipe welds: one is a comparison test block made of stainless steel with the same material as the workpiece to be tested, and processed according to the style and size of the conventional A-type ultrasonic test block; the other is a test block optimized on the basis of the first comparison test block, that is, a weld with the same material as the weld to be tested is set in the middle of the test block, and a transverse through hole is processed in the middle of the weld. The two commonly used test blocks both use the conventional A-type ultrasonic comparison test block style, and the applicability of the phased array ultrasonic detection probe and instrument is not strong, and the sensitivity of the reflected wave cannot be well calibrated; in addition, there are many specifications of austenitic stainless steel small-diameter pipes in the project, and the wall thickness is in the range of 4 to 20 mm. Using only one size of test block cannot truly reflect the sound wave propagation and sound field characteristics, so it has an adverse effect on the instrument debugging and sensitivity setting accuracy. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a multifunctional test block and a detection method for phased array ultrasonic detection of welds of small-diameter stainless steel pipes in view of the defects of the prior art.

[0005] In order to solve this technical problem, the present invention provides a phased array ultrasonic inspection test block for welds of small-diameter stainless steel pipes. The test block has an overall strip shape and includes two parts: a comparison test block and a simulation test block. The comparison test block includes a left comparison test block body and a right comparison test block body. The left comparison test block body and the right comparison test block body are arranged at two ends of the test block. A left quarter-circular arc reflector is processed at one end of the left comparison test block body, and a left series of transverse through holes of the same diameter are processed at the other end. A right quarter-circular arc reflector is processed at one end of the right comparison test block body, and a right series of transverse through holes of the same diameter are processed at the other end. The simulation test block includes an upper simulation test block body and a lower simulation test block body. A rectangular cavity is arranged in the middle of the test block. The upper simulation test block body and the lower simulation test block body are arranged in the middle of the test block. An upper weld and an upper series of transverse through holes are arranged in the middle of the upper simulation test block body, and a lower weld and a lower transverse through hole are arranged in the lower simulation test block body.

[0006] The left series of transverse through holes and the right series of transverse through holes are multiple transverse through holes arranged in sequence, the centers of each transverse through hole are on a vertical line, the cross-section of each transverse through hole is circular, the diameter is the same, and in the same series, the spacing between two adjacent transverse through holes is the same; the transverse through holes in the left series of transverse through holes and the right series of transverse through holes are staggered in the vertical direction, and the depth values ​​of each transverse through hole are different.

[0007] A left probe placement surface and a right probe placement surface are respectively arranged at the upper and lower ends of the left comparison test block body and the right comparison test block body, and the left probe placement surface and the right probe placement surface are processed into curved surfaces, and the curvature value thereof is the same as the curvature value of the inspected small-diameter pipe; the phased array probe is placed on the left probe placement surface and the right probe placement surface and moved left and right, and corresponding calibration operations are performed using the left quarter-circular arc reflector, the right quarter-circular arc reflector, the left series of transverse through holes, and the right series of transverse through holes.

[0008] The thickness of the upper simulation test block body and the lower simulation test block body are different; an upper series of transverse through holes are set at the center line of the upper weld of the upper simulation test block body, and a lower transverse through hole is set at the center line of the lower weld of the lower simulation test block body. The upper series of transverse through holes are composed of two transverse through holes of the same diameter, and the depth values ​​of the two transverse through holes are different. The number of transverse through holes can also be increased according to actual needs. The lower transverse through hole is located in the center of the lower weld, and the diameter of the transverse through hole is the same as that of the transverse through hole in the upper series. The number of transverse through holes can also be increased according to actual needs. The greater the thickness of the simulation test block body, the more transverse through holes can be processed.

[0009] The test block substrate is made of austenitic stainless steel, which is the same material as the workpiece being tested; the material of the weld set in the middle of the test block is the same as the material and welding process of the weld of the pipeline being tested.

[0010] The left comparison test block body and the right comparison test block body are centrally symmetrical, and the upper simulation test block body and the lower simulation test block body are vertically symmetrically arranged.

[0011] The present invention also provides a phased array ultrasonic testing method for a small-diameter stainless steel pipe weld using the test block, comprising the following steps:

[0012] Step 1: Place the phased array probe equipped with a curvature wedge on the left probe placement surface or the right probe placement surface, and align the front end of the probe with the corresponding left quarter arc reflector or right quarter arc reflector. Move the probe left and right to find the maximum reflected wave position of each chip one by one, debug the phased array detector to correct the probe angle gain, and make an ACG curve.

[0013] Step 2: Turn the probe so that the front end of the probe is aligned with the corresponding left series of SDHs or right series of SDHs. Move the probe left and right to find the maximum reflected wave position of SDHs of different depths one by one. Debug the phased array detector to set the detection sensitivity and make a DAC curve.

[0014] Step 3: Continue to move the probe forward to the upper simulated test block or the lower simulated test block area, align the front end of the probe with the upper series of transverse through holes or the lower transverse through holes on the weld, move the probe left and right to find the maximum reflected wave position of transverse through holes of different depths one by one, debug the phased array detector to correct the detection sensitivity, and determine the appropriate on-site detection gain value;

[0015] Or: directly set the detection sensitivity and make the DAC curve in the upper simulated test block or the lower simulated test block area, and similarly move the probe left and right to find the position of the maximum reflected wave of the side-drilled holes of different depths one by one, debug the phased array detector, and no longer need to correct the detection sensitivity. Increase the corresponding gain (dB) value to meet the relevant standard requirements as the on-site detection gain value.

[0016] Beneficial effects: The present invention has a compact structure and complete functions. It can simultaneously meet the requirements of phased array instrument equipment debugging, sensitivity setting and detection process verification. It does not need to replace different test blocks to calibrate the phased array detection system. It is easy to operate and has low manufacturing, use and maintenance costs. The present invention provides a structural form in which a comparison test block and a simulation test block are set in the same body, which is easy to carry and use, and has high detection efficiency. The curvature is processed on the upper and lower ends of the present invention, and the curvature of the test block is the same as the curvature of the inspected pipeline. Therefore, the same curvature is used in the instrument debugging, sensitivity setting and detection process verification process, which makes up for the sensitivity loss in the instrument debugging process, ensures the consistency and consistency of the detection system calibration, and improves the phased array detection accuracy. The welding process and material of the weld in the middle of the test block of the present invention are the same as those of the inspected workpiece, which can truly reflect the characteristics of the sound field. On the other hand, after the test block is manufactured, two thicknesses of simulation test blocks are provided at a time, which can simulate the reflected wave sound beam and truly reflect the characteristics of sound propagation. Therefore, the sensitivity setting using the patented test block is closer to the actual detection situation and has high detection accuracy. The test block is particularly suitable for phased array ultrasonic testing of small-diameter austenitic stainless steel pipe welds, and can realize the debugging and sensitivity setting of the detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 It is a schematic front view of the structure of the present invention;

[0019] Figure 3 It is a schematic front view of the structure of an embodiment of the present invention;

[0020] Figure 4 It is an enlarged schematic diagram of an upper weld embodiment of the present invention;

[0021] Figure 5 It is an enlarged schematic diagram of a lower weld embodiment of the present invention;

[0022] Figure 6 It is a schematic side view of the structure of an embodiment of the present invention.

[0023] In the figure: 1, left comparison test block; 1', right comparison test block; 2, upper simulation test block; 2', lower simulation test block; 11, left quarter-arc reflector; 11', right quarter-arc reflector; 12, left probe placement surface; 12', right probe placement surface; 13, left series of transverse through holes; 13', right series of transverse through holes; 21, upper series of transverse through holes; 21', lower transverse through holes; 22, upper weld; 22', lower weld. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] like Figure 1-Figure 6 As shown, the present invention provides a phased array ultrasonic testing block for stainless steel small-diameter pipe welds. The overall shape of the test block is a long strip, including a comparison test block and a simulation test block. The comparison test block includes a left comparison test block body 1 and a right comparison test block body 1'. The left comparison test block body 1 and the right comparison test block body 1' are arranged at both ends of the test block. A left quarter arc reflector 11 is processed at one end of the left comparison test block body 1 for phased array probe angle gain correction and ACG curve production; a left series of transverse through holes 13 of the same diameter are processed at the other end for detection sensitivity setting and DAC curve production; the right comparison test block body A right quarter arc reflector 11' is processed at one end of 1' for phased array probe angle gain correction and ACG curve preparation; a right series of transverse through holes 13' of the same diameter are processed at the other end for detection sensitivity setting and DAC curve preparation; the simulation test block includes an upper simulation test block body 2 and a lower simulation test block body 2', a rectangular cavity is arranged in the middle of the test block, the upper simulation test block body 2 and the lower simulation test block body 2' are arranged in the middle of the test block, an upper weld 22 and an upper series of transverse through holes 21 are arranged in the middle of the upper simulation test block body 2, and a lower weld 22' and a lower transverse through hole 21' are arranged in the lower simulation test block body 2'.

[0026] The left series of transverse through holes 13 and the right series of transverse through holes 13' are multiple transverse through holes arranged in sequence, the centers of each transverse through hole are on a vertical line, the cross-section of each transverse through hole is circular, the diameter is the same, and in the same series, the spacing between two adjacent transverse through holes is the same; the transverse through holes in the left series of transverse through holes 13 and the right series of transverse through holes 13' are staggered in the vertical direction, and the depth values ​​of each transverse through hole are different.

[0027] A left probe placement surface 12 and a right probe placement surface 12' are respectively arranged at the upper and lower ends of the left comparison test block body 1 and the right comparison test block body 1'. The left probe placement surface 12 and the right probe placement surface 12' are processed into curved surfaces, and the curvature value thereof is the same as the curvature value of the inspected small-diameter pipe. The phased array probe is placed on the left probe placement surface 12 and the right probe placement surface 12' and can be moved left and right. The left quarter-circular reflector 11, the right quarter-circular reflector 11' and the left series of transverse through holes 13 and the right series of transverse through holes 13' are respectively used for corresponding calibration operations.

[0028] The thickness of the upper simulation test block 2 and the lower simulation test block 2' are different; an upper series of transverse through holes 21 is set at the center line of the upper weld 22 of the upper simulation test block 2, and a lower transverse through hole 21' is set at the center line of the lower weld 22' of the lower simulation test block 2'. The upper series of transverse through holes 21 is composed of two transverse through holes of the same diameter, and the depth values ​​of the two transverse through holes are different. The number of transverse through holes can also be increased according to actual needs. The lower transverse through hole 21' is located at the center of the lower weld 22', and the diameter of the transverse through hole is the same as that of the transverse through hole in the upper series of transverse through holes 21. The number of transverse through holes can also be increased according to actual needs. The greater the thickness of the simulation test block, the more transverse through holes can be processed.

[0029] The test block substrate is made of austenitic stainless steel, which is the same material as the workpiece being tested; the material of the weld set in the middle of the test block is the same as the material and welding process of the weld of the pipeline being tested.

[0030] The left comparison test block body 1 and the right comparison test block body 1 ′ are centrally symmetrical, and the upper simulation test block body 2 and the lower simulation test block body 2 ′ are vertically symmetrically arranged.

[0031] The present invention also provides a phased array ultrasonic testing method for a small-diameter stainless steel pipe weld using the test block, comprising the following steps:

[0032] Step 1: Place the phased array probe equipped with the curvature wedge on the left probe placement surface 12 or the right probe placement surface 12', and align the front end of the probe with the corresponding left quarter arc reflector 11 or right quarter arc reflector 11', move the probe left and right to find the maximum reflected wave position of each chip one by one, debug the phased array detector to correct the probe angle gain, and make an ACG curve;

[0033] Step 2: Turn the probe so that the front end of the probe is aligned with the corresponding left series of transverse through holes 13 or right series of transverse through holes 13', move the probe left and right to find the maximum reflected wave position of transverse through holes of different depths one by one, debug the phased array detector to set the detection sensitivity, and make a DAC curve;

[0034] Step 3: Continue to move the probe forward to the upper simulated test block 2 or the lower simulated test block 2' area, align the front end of the probe with the upper series of transverse through holes 21 or the lower transverse through holes 21' on the weld, move the probe left and right to find the maximum reflected wave position of transverse through holes of different depths one by one, debug the phased array detector to correct the detection sensitivity, and determine the appropriate on-site detection gain value;

[0035] Or directly set the detection sensitivity and make the DAC curve in the upper simulation test block 2 or the lower simulation test block 2' area. Similarly, move the probe left and right to find the maximum reflection wave position of the transverse through holes of different depths one by one, debug the phased array detector, and no longer need to correct the detection sensitivity. Increase the corresponding gain (dB) value to meet the relevant standard requirements as the on-site detection gain value.

[0036] The present invention provides a structural form in which a comparison test block and a simulation test block are arranged in the same body, which is convenient to carry and use, and has high detection efficiency; the curvature is processed at the upper and lower ends of the present invention, and the curvature of the test block is the same as the curvature of the inspected pipe. Therefore, the same curvature is used in the instrument debugging, sensitivity setting and detection process verification process, which makes up for the sensitivity loss in the instrument debugging process, ensures the consistency and consistency of the detection system calibration, and improves the phased array detection accuracy; the welding process and material of the weld in the middle of the test block of the present invention are the same as those of the inspected workpiece, which can truly reflect the characteristics of the sound field. On the other hand, after the test block is made, two thicknesses of simulation test blocks are provided at a time, which can simulate the reflected wave sound beam and truly reflect the characteristics of sound wave propagation. Therefore, using the test block of the present invention to set the sensitivity is closer to the actual detection situation, and the detection accuracy is high; the test block is particularly suitable for phased array ultrasonic detection of austenitic stainless steel small-diameter pipe welds, and can realize the debugging and sensitivity setting of the detection system; the present invention has a compact structure and complete functions, and can simultaneously meet the requirements of phased array instrument equipment debugging, sensitivity setting and detection process verification, and does not need to replace different test blocks to calibrate the phased array detection system, which is easy to operate and has low manufacturing, use and maintenance costs.

[0037] The above embodiments of the present invention are merely illustrative and not exclusive, and all modifications within the scope of the present invention or equivalent to the scope of the present invention are encompassed by the present invention.

Claims

1. A phased array ultrasonic testing block for stainless steel small diameter pipe welds, characterized in that: The test block has an overall strip-shaped appearance and comprises a comparison test block and a simulation test block. The comparison test block comprises a left comparison test block body (1) and a right comparison test block body (1'). The left comparison test block body (1) and the right comparison test block body (1') are arranged at two ends of the test block. One end of the left comparison test block body (1) is processed with a left quarter-circular arc reflector (11), and the other end is processed with a left series of transverse through holes (13') of the same diameter. One end of the right comparison test block body (1') is processed with a right quarter-circular arc reflector (11'), and the other end is processed with a right series of transverse through holes (13') of the same diameter. The simulation test block comprises an upper simulation test block body (2) and a lower simulation test block body (2'). A rectangular cavity is arranged in the middle of the test block. The upper simulation test block body (2) and the lower simulation test block body (2') are The block (2') is arranged in the middle of the test block, the upper simulated test block (2) is provided with an upper weld (22) and an upper series of transverse through holes (21) in the middle, and the lower simulated test block (2') is provided with a lower weld (22') and a lower transverse through hole (21'); the left series of transverse through holes (13) and the right series of transverse through holes (13') are a plurality of transverse through holes arranged in sequence, the centers of the transverse through holes are on a vertical line, the cross-sections of the transverse through holes are circular, the diameters are the same, and in the same series, the spacing between two adjacent transverse through holes is the same; the transverse through holes in the left series of transverse through holes (13) and the right series of transverse through holes (13') are arranged in a staggered manner in the vertical direction, and the depth values ​​of the transverse through holes are different; the upper simulated test block (2) and the lower simulated test block (2') have different thicknesses; A left probe placement surface (12) and a right probe placement surface (12') are respectively arranged at the upper and lower ends of the left comparison test block (1) and the right comparison test block (1'); the left probe placement surface (12) and the right probe placement surface (12') are processed into curved surfaces, and the curvature value thereof is the same as the curvature value of the small-diameter pipe to be inspected; the phased array probe is placed on the left probe placement surface (12) and the right probe placement surface (12') and moved left and right, and corresponding calibration operations are performed using the left quarter-circular reflector (11), the right quarter-circular reflector (11'), the left series of transverse through holes (13), and the right series of transverse through holes (13'); An upper series of transverse through holes (21) is arranged at the center line of the upper weld (22) of the upper simulation test block (2), and a lower transverse through hole (21') is arranged at the center line of the lower weld (22') of the lower simulation test block (2'). The upper series of transverse through holes (21) is composed of two transverse through holes of the same diameter, and the two transverse through holes have different depth values. The lower transverse through hole (21') is located at the center of the lower weld (22'), and the diameter of the transverse through hole is the same as that of the transverse through hole in the upper series of transverse through holes (21).

2. The phased array ultrasonic testing block for stainless steel small diameter pipe weld according to claim 1 is characterized in that: The test block substrate is made of austenitic stainless steel, which is the same material as the workpiece being tested; the material of the weld set in the middle of the test block is the same as the material and welding process of the weld of the pipeline being tested.

3. A phased array ultrasonic testing method for stainless steel small diameter pipe welds using the test block according to claim 1 or 2, characterized in that: The steps include: Step 1: Place the phased array probe equipped with the curvature wedge on the left probe placement surface (12) or the right probe placement surface (12'), and align the front end of the probe with the corresponding left quarter-circular arc reflector (11) or the right quarter-circular arc reflector (11'), move the probe left and right to find the maximum reflected wave position of each chip one by one, debug the phased array detector to perform probe angle gain correction, and produce an ACG curve; Step 2: Turn the probe so that the front end of the probe is aligned with the corresponding left series of transverse through holes (13) or right series of transverse through holes (13'), move the probe left and right to find the maximum reflected wave position of the transverse through holes of different depths one by one, debug the phased array detector to set the detection sensitivity, and make a DAC curve; Step 3: Continue to move the probe forward to the upper simulated test block (2) or the lower simulated test block (2') area, align the front end of the probe with the upper series of transverse through holes (21) or the lower transverse through holes (21') on the weld, move the probe left and right to find the maximum reflected wave position of the transverse through holes of different depths one by one, debug the phased array detector to correct the detection sensitivity, and determine the appropriate on-site detection gain value; Or: directly set the detection sensitivity and create the DAC curve in the upper simulated test block (2) or the lower simulated test block (2') area, and similarly move the probe left and right to find the maximum reflected wave position of the transverse through holes of different depths one by one, debug the phased array detector, and no longer need to correct the detection sensitivity. Increase the corresponding gain dB value to meet the requirements of the relevant standards as the on-site detection gain value.

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