A test block for ultrasonic testing resolution of tube-tube sheet welded joints

Abstract

This utility model discloses an ultrasonic testing block for resolving tube-to-tube sheet welded joints, comprising a cylindrical test block. Its features include: two or more sets of axial blind holes arranged axially in each set on the outer circumference of one end of the test block; the axial blind holes in each set are spaced apart on the circumference, and the axial spacing between the two blind holes in each set is unequal; three or more circumferential blind holes are provided along the same circumference on the outer circumference of the test block, and the circumferential spacing between adjacent circumferential blind holes is unequal. This utility model allows testing personnel to quickly complete axial and circumferential defect resolving tests, thereby determining whether the testing process is reasonable and avoiding potential quality hazards caused by missed defects due to unreasonable processes.

Description

Technical Field

[0001] This utility model relates to an ultrasonic testing resolution test block, and more particularly to an ultrasonic testing resolution test block for pipe-to-tube sheet welded joints. Background Technology

[0002] To ensure the weld quality of heat exchanger tube-tube sheet welded joints, radiographic testing was previously widely used for quality control. However, due to the need for special protective environments, low testing efficiency, and high costs associated with radiographic testing, phased array ultrasonic testing is now widely adopted. This method enables on-site testing during production operations, offering high testing efficiency and low cost, and has broad application prospects.

[0003] The rationality of the phased array ultrasonic testing process directly affects the defect detection capability and the stable and safe operation of the heat exchanger. Heat exchanger tube-to-tube sheet welded joints are characterized by thin walls, small diameters, and complex weld structures. The inspectable area of ​​the weld is small, with an effective width of less than 5mm and an effective height of less than 3mm. During phased array ultrasonic testing, the limited display range of the tube and weld echo signals makes defect identification difficult. An unreasonable testing process can lead to missed defects in the weld and leakage accidents. Ultrasonic resolution test blocks are an important tool for verifying the rationality of the testing process. However, existing ultrasonic resolution test blocks are mostly used for tracks or rods, whose workpiece shapes and internal defect types differ significantly from those of heat exchanger tube-to-tube sheet welded joints, making them unsuitable. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned shortcomings of the existing technology by providing an ultrasonic testing block for the resolution of tube-to-tube sheet welded joints. This block allows testing personnel to quickly and easily complete axial and circumferential defect resolution tests, thereby determining whether the testing process is reasonable and avoiding potential quality risks caused by missed defects due to unreasonable processes.

[0005] To achieve the above objectives, this utility model provides an ultrasonic testing block for resolving power of a tube-to-tube sheet welded joint, comprising a cylindrical test block; characterized in that: one end of the test block has two or more sets of axial blind holes arranged axially in two groups on its outer circumference, with each group having two axial blind holes arranged axially at intervals on the circumference, and the axial spacing between the two axial blind holes in each group being unequal; and three or more circumferential blind holes are provided along the same circumference on the outer circumference of the test block, with the circumferential spacing between adjacent two circumferential blind holes being unequal.

[0006] The inner diameter of the test block is the same as that of the heat exchanger tube. During testing, the phased array wedge is placed inside the test block, and the curvature of the phased array wedge matches the inner diameter of the test block. A coupling agent is applied between the phased array wedge and the test block, and the phased array wedge is rotated along the circumferential direction to ensure that each group of axial blind holes and each group of circumferential blind holes are detected. When two axial blind holes in the same group or two adjacent circumferential blind holes are connected together, it means that they cannot be identified. Conversely, if they can be distinguished, it means that the axial resolution and circumferential resolution of the current phased array testing process are the corresponding spacing values. This allows testing personnel to quickly complete the axial and circumferential defect resolution test, thereby determining whether the testing process is reasonable and avoiding potential quality hazards caused by defect omissions due to unreasonable processes. As a further improvement of this utility model, both the axial blind hole and the circumferential blind hole are flat-bottomed holes, which makes the sound wave reflection efficiency high and the image clear. As a further improvement of this utility model, the axial blind holes are arranged at intervals on the circumference, which facilitates processing and inspection. As a further improvement of this utility model, the distance between the inner end of each flat-bottomed hole and the inner wall of the test block is equal to the wall thickness of the heat exchanger tube; it can be used to detect crack defects that are not fused near the tube wall or parallel to the tube wall surface. In summary, this utility model allows inspection personnel to quickly complete axial and circumferential defect resolution tests, thereby determining whether the inspection process is reasonable and avoiding potential quality hazards caused by undetected defects due to unreasonable processes. Attached Figure Description

[0007] Figure 1 This is a front view of an embodiment of the present utility model.

[0008] Figure 2 for Figure 1 A bottom view.

[0009] Figure 3 for Figure 1 The left view.

[0010] Figure 4 This is a front view of the axial resolution detection embodiment of this utility model.

[0011] Figure 5 This is a front view of the circumferential resolution detection embodiment of the present invention. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings.

[0013] like Figures 1 to 3As shown, this embodiment of the ultrasonic testing resolution test block for tube-tube sheet welded joints includes a cylindrical test block 1. Four sets of axial blind holes are provided on the outer circumference of one end of the test block 1. Each set of axial blind holes includes two axially arranged blind holes 2 and 3, or 4 and 5, or 6 and 7, or 8 and 9. The axial blind holes are evenly spaced on the circumference. The axial distance between blind holes 2 and 3 is 0.5 mm, the axial distance between blind holes 4 and 5 is 1.5 mm, the axial distance between blind holes 6 and 7 is 1.0 mm, and the axial distance between blind holes 8 and 9 is... The axial spacing is 2.0 mm; five circumferential blind holes 10-14 are arranged sequentially along the same circumference on the outer circumference of the other end of the test block 1. Each circumferential blind hole is located in the radial direction of the test block 1. The circumferential spacing between the inner ends of circumferential blind holes 10 and 11 is 0.5 mm, the circumferential spacing between the inner ends of circumferential blind holes 11 and 12 is 1.0 mm, the circumferential spacing between the inner ends of circumferential blind holes 12 and 13 is 1.5 mm, and the circumferential spacing between the inner ends of circumferential blind holes 13 and 14 is 2.0 mm. Each axial blind hole 2-9 and each circumferential blind hole 10-14 is a flat-bottomed hole, and the distance t between the inner end of each flat-bottomed hole and the inner wall of the test block 1 is equal to the heat exchanger tube wall thickness.

[0014] The inner diameter of test block 1 is the same as the inner diameter of the heat exchanger tube; during testing, if... Figure 4 As shown, after connecting the phased array wedge 15 to the phased array probe 16, it is placed inside the test block 1. The curvature of the phased array wedge 15 matches the inner diameter of the test block 1, and the axial length of the wedge 15 should ensure that it covers the axial dimensions of each axial blind hole 2-9. During scanning, a coupling agent is applied between the phased array wedge 15 and the test block 1, and then the phased array wedge 15 is rotated along the circumferential direction (clockwise or counterclockwise) with a rotation angle greater than 360 degrees to ensure that each axial blind hole 2-9 is detected. Then, the view in the phased array image is used to confirm whether each axial blind hole 2-9 with different spacing can be effectively identified. When two axial blind holes in the same group are connected, it means that they cannot be identified. When two axial blind holes can be distinguished, it represents the axial resolution of the current phased array detection process. For example, if axial blind holes 2 and 3 cannot be identified, but axial blind holes 6 and 7 can be identified, then the axial resolution of the current detection process is 1 mm. Similarly, if Figure 5As shown, when scanning each circumferential blind hole 10-14, if circumferential blind holes 11 and 12 cannot be identified, but circumferential blind holes 12 and 13 can be identified, then the circumferential resolution of the current inspection process is 1.5 mm. This device allows inspection personnel to quickly complete axial and circumferential defect resolution tests, thereby determining whether the inspection process is reasonable and avoiding potential quality hazards caused by undetected defects due to unreasonable processes. All axial and circumferential blind holes are flat-bottomed holes, resulting in high acoustic wave reflection efficiency and clear images. The distance t is equal to the heat exchanger tube wall thickness and can be used to detect crack defects that are not fused near the tube wall or parallel to the tube wall surface. This utility model is not limited to the above-described embodiments. For example, the number of axial blind holes and the number of circumferential blind holes can be increased, and the difference between the spacings can be smaller, so as to improve the accuracy of resolution. The above embodiments have been used to illustrate the invention, but it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the invention to the scope of the described embodiments.

Claims

1. A test block for resolution testing of ultrasonic examination of a tube-to-tubesheet welded joint, comprising a section of round tube; characterized by: The outer circumference of one end of the test block is provided with two or more sets of axial blind holes, each set having two holes arranged along the axial direction. The axial blind holes in each set are arranged at intervals on the circumference, and the axial spacing between the two axial blind holes in each set is not equal. There are three or more circumferential blind holes along the same circumference on the outer circumference of the test block, and the spacing between each pair of adjacent circumferential blind holes on the circumference is not equal.

2. The ultrasonic resolution test block for tube-to-tube sheet welded joints as described in claim 1, characterized in that: Both the axial blind hole and the circumferential blind hole are flat-bottomed holes.

3. A test block for ultrasonic testing resolution of tube-to-tube sheet welded joints as described in claim 1 or 2, characterized in that: The axial blind holes are evenly spaced on the circumference.

4. The ultrasonic resolution test block for tube-to-tube sheet welded joints as described in claim 2, characterized in that: The distance between the inner end of each flat-bottomed hole and the inner wall of the test block is equal to the wall thickness of the heat exchanger tube.

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