Test block special for phased array detection of fillet weld of heat exchange tube and tube plate

Abstract

A special test block for phased array detection of a fillet weld of a heat exchange tube and a tube plate comprises a cylindrical defect contrast area and a cylindrical TCG and ACG sensitivity setting area which are connected into a whole through a cylindrical connecting area, the aperture of a central hole of the cylindrical connecting area is equal to the inner diameter of the heat exchange tube; the wall thickness of the cylindrical defect contrast area is four times that of the heat exchange tube, the wall thickness of the cylindrical TCG and ACG sensitivity setting area is five times that of the heat exchange tube, and the wall thickness of the cylindrical connecting area is smaller than that of the heat exchange tube. The height of the cylindrical defect contrast area and the height of the cylindrical TCG and ACG sensitivity setting area are greater than the total height of the fillet weld of the detected heat exchange tube and the tube plate; the cylindrical defect comparison area is provided with a flat-bottom hole defect and an artificial defect, and the cylindrical TCG and ACG sensitivity setting area is provided with a long transverse through hole defect. By comparing a root defect imaging map with a real object detection defect, the quality of the root defect of the fillet weld between the heat exchange tube and the tube plate can be evaluated more accurately and effectively.

Description

Technical Field

[0001] The utility model relates to the technical field of nondestructive testing, in particular to a special test block for phased array testing of fillet welds between heat exchange tubes and tube sheets. Background Art

[0002] The fillet weld between the heat exchange tube and the tube sheet is a special welding structure, which cannot be implemented by conventional ultrasonic testing or conventional radiographic testing. This makes the quality control of the shell-and-tube heat exchanger very difficult. Due to the missed detection of the internal defects of the fillet weld between the heat exchange tube and the tube sheet, the accidental leakage rate of the heat exchanger during use remains high. The internal defects of the fillet weld between the heat exchange tube and the tube sheet are currently mainly detected by rod anode radiography, but the rod anode radiography detection cycle is long, the cost is high, and the efficiency is low. Therefore, many domestic organizations have conducted systematic research on the phased array detection technology for the fillet weld between the heat exchange tube and the tube sheet, and have achieved great breakthroughs and results, especially in the formulation of the phased array probe system and the verification of the test results. The special test block for phased array detection of the fillet weld between the heat exchange tube and the tube sheet is mainly used for sensitivity setting, gain setting, position calibration, etc. In the traditional series of test blocks, it is impossible to adjust the instrument and probe, accurately make the TCG (including ACG) curve to set the detection sensitivity, which is easy to cause problems such as missed detection, misjudgment, and inaccurate quantitative positioning of defects in the detection. Utility Model Content

[0003] The utility model provides a special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets. By comparing the root defect imaging map of the utility model with the actual detected defects, the root defects of the fillet welds between heat exchange tubes and tube sheets can be more accurately and effectively evaluated for quality.

[0004] The utility model provides the following technical solutions to achieve the above utility model objectives:

[0005] A special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets, comprising a cylindrical defect comparison area and a cylindrical TCG and ACG sensitivity setting area, which are connected as a whole through a cylindrical connection area; the central hole diameter of the cylindrical connection area is the inner diameter of the heat exchange tube; the wall thickness of the cylindrical defect comparison area is 4 times the wall thickness of the heat exchange tube, the wall thickness of the cylindrical TCG and ACG sensitivity setting area is 5 times the wall thickness of the heat exchange tube, and the wall thickness of the cylindrical connection area is less than the wall thickness of the heat exchange tube; the heights of the cylindrical defect comparison area and the cylindrical TCG and ACG sensitivity setting area are greater than the total height of the fillet welds between the heat exchange tube and the tube sheet to be inspected; flat-bottom hole defects and artificial defects are arranged on the cylindrical defect comparison area, and long transverse through hole defects are arranged on the cylindrical TCG and ACG sensitivity setting area.

[0006] The flat-bottom hole defects include first, second, third and fourth flat-bottom hole defects, all with diameters of Φ1mm. The length of the first flat-bottom hole defect is from the outer wall of the cylindrical defect comparison area to the outer wall of the heat exchange tube, the length of the second flat-bottom hole defect is from the outer wall of the cylindrical defect comparison area to the middle of the simulated weld, the length of the third flat-bottom hole defect is from the outer wall of the cylindrical defect comparison area to the groove of the simulated weld tube sheet, and the length of the fourth flat-bottom hole defect is from the outer wall of the cylindrical defect comparison area to the heat-affected zone of the simulated weld tube sheet; the simulated weld is arranged in the simulated weld area, and the simulated weld area is located at the junction of the cylindrical defect comparison area and the cylindrical connection area.

[0007] The artificial defects include first, second, third and fourth artificial defects, which are distributed on the circumferential surface in the middle of the simulated weld area at intervals of 90°. The width of the first, second, third and fourth artificial defects is 0.3mm, the depth of the simulated weld is 0.3mm, 0.5mm, 0.8mm and 1mm respectively, and the length is an arc-shaped groove artificial defect of 1 / 24 of the outer circumference of the heat exchange tube.

[0008] The long transverse through hole defects include the first, second, third and fourth long transverse through hole defects, all of which have a diameter of Φ1mm and are arranged at 90° intervals. They are respectively located on the circumference of the outer diameter of the heat exchange tube, the circumference of the outer diameter of the heat exchange tube plus twice the wall thickness of the heat exchange tube, the circumference of the outer diameter of the heat exchange tube plus four times the wall thickness of the heat exchange tube, and the circumference of the outer diameter of the heat exchange tube plus six times the wall thickness of the heat exchange tube.

[0009] The material of the special test block has the same or similar sound velocity and attenuation coefficient as the material of the heat exchange tube-tube sheet fillet weld, and the connecting welds in the cylindrical defect comparison area and the cylindrical connection area are consistent with the actual test welds.

[0010] The advantages of the utility model are as follows:

[0011] The utility model is an integrated structure with artificial defects set on the cylinders at both ends. One end is used for TCG curve production to set the detection sensitivity, which solves the difficulty in producing TCG (ACG) curves for phased array detection of corner welds between heat exchange tubes and tube sheets; the other end is used for detection process verification and root defect comparison. The utility model verifies the phased array detection capability of the corner joints of heat exchange tubes and tube sheets to ensure that defects in welds can be detected; by comparing the root defect imaging map of the utility model with the actual detection defects, the root defects of the corner welds of heat exchange tubes and tube sheets can be more accurately and effectively evaluated in quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is the front view of the utility model;

[0013] Figure 2 It is the main sectional view of the utility model;

[0014] Figure 3It is a side sectional view of the utility model;

[0015] Figure 4 It is a defect arrangement diagram of the cylindrical defect comparison area of ​​the utility model;

[0016] Figure 5 It is a defect arrangement diagram of the sensitivity setting area of ​​the cylindrical TCG (including ACG) of the utility model;

[0017] Figure 6 It is a partial schematic diagram of the heat exchange tube and tube sheet structure;

[0018] Figure 7 This is a schematic diagram of phased array detection of fillet welds between heat exchange tubes and tube sheets;

[0019] Figure 8 It is a schematic diagram of the arrangement of phased array probes in the test block. DETAILED DESCRIPTION

[0020] The utility model is further described below in conjunction with the accompanying drawings.

[0021] The utility model is a phased array detection device for the fillet welds of heat exchange tubes and tube sheets. Figure 6 , Figure 7 As shown, the size of the heat exchange tube is Φ38×4mm, the center distance of the heat exchange tube is 50mm, the size of the tube sheet bridge is 12mm, and the arrangement is dense. Phased array detection cannot be performed on the tube sheet side, and can only be performed on the inner wall of the heat exchange tube using a special phased array probe (5). The preparation and process verification of the phased array detection TCG (including ACG) curve of the fillet weld between the heat exchange tube and the tube sheet must be carried out on the special test block for phased array detection of the fillet weld between the heat exchange tube and the tube sheet of the utility model.

[0022] The main defects of the fillet weld structure between the heat exchange tube and the tube sheet are lack of fusion on the outer wall of the tube, lack of fusion on the groove side of the tube sheet, incomplete penetration at the root, cracks, pores, tungsten inclusions, etc. The TCG (including ACG) curve is made in the cylindrical TCG (including ACG) sensitivity setting area 3, which should cover the entire weld area.

[0023] like Figures 1 to 5As shown, a special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets comprises a cylindrical defect comparison area 1 and a cylindrical TCG (including ACG) sensitivity setting area 3, which are connected as a whole through a cylindrical connection area 2; the central hole diameter of the cylindrical connection area 2 is the inner diameter of the heat exchange tube; the wall thickness of the cylindrical defect comparison area 1 is 4 times the wall thickness of the heat exchange tube, the wall thickness of the cylindrical TCG (including ACG) sensitivity setting area 3 is 5 times the wall thickness of the heat exchange tube, and the wall thickness of the cylindrical connection area 2 is less than the wall thickness of the heat exchange tube; the heights of the cylindrical defect comparison area 1 and the cylindrical TCG (including ACG) sensitivity setting area 3 are greater than the total height of the fillet welds between the heat exchange tube and the tube sheet to be inspected; the cylindrical defect comparison area 1 is provided with flat-bottom hole defects and artificial defects, while the cylindrical TCG (including ACG) sensitivity setting area 3 is provided with long transverse through hole defects.

[0024] The flat-bottom hole defects include the first, second, third and fourth flat-bottom hole defects a, b, c and d, all of which have a diameter of Φ1mm. The length of the first flat-bottom hole defect a is from the outer wall of the cylindrical defect comparison area 1 to the outer wall of the heat exchange tube, the length of the second flat-bottom hole defect b is from the outer wall of the cylindrical defect comparison area 1 to the middle of the simulated weld, the length of the third flat-bottom hole defect c is from the outer wall of the cylindrical defect comparison area 1 to the simulated weld tube sheet groove, and the length of the fourth flat-bottom hole defect d is from the outer wall of the cylindrical defect comparison area 1 to the simulated weld tube sheet heat affected zone; the simulated weld is arranged at the simulated weld area 4, which is located at the connection between the cylindrical defect comparison area 1 and the cylindrical connection area 2. The first, second, third and fourth flat-bottom hole defects a, b, c and d are respectively used to verify the outer wall side defects of the heat exchange tube and the tube sheet corner weld, the internal defects of the weld, the defects on the tube sheet groove side, the heat affected zone defects, and the phased array detection capabilities.

[0025] The artificial defects include the first, second, third, and fourth artificial defects e, f, g, and h, which are distributed at intervals of 90° on the central circumferential surface of the simulated weld zone 4. The width of the first, second, third, and fourth artificial defects e, f, g, and h are all 0.3 mm, and the depth is 0.3 mm, 0.5 mm, 0.8 mm, and 1 mm, respectively, and the length is an arc-shaped groove artificial defect of 1 / 24 of the outer circumference of the heat exchange tube. The first, second, third, and fourth artificial defects e, f, g, and h are used to simulate the root defects of the fillet weld of the heat exchange tube and the tube sheet of different depths, and are used to verify the detection capability of the root defects of the fillet weld of the heat exchange tube and the tube sheet.

[0026] The long transverse through hole defects include the first, second, third, and fourth long transverse through hole defects i, j, k, and l, all with a diameter of Φ1mm, arranged at intervals of 90°, and respectively located on the circumference of the outer diameter of the heat exchange tube, the circumference of the outer diameter of the heat exchange tube plus 2 times the wall thickness of the heat exchange tube, the circumference of the outer diameter of the heat exchange tube plus 4 times the wall thickness of the heat exchange tube, and the circumference of the outer diameter of the heat exchange tube plus 6 times the wall thickness of the heat exchange tube. Setting 4 equally spaced long transverse hole defects ensures that the TCG (including ACG) curve production covers the weld scanning range; the long transverse holes are distributed at 90° intervals to avoid the production of TCG (including ACG) curves for phased array detection of long transverse holes.

[0027] The material of the special test block has the same or similar sound velocity and attenuation coefficient as the material of the heat exchange tube-tube sheet fillet weld, and the connecting weld between the cylindrical defect comparison area 1 and the cylindrical connection area 2 is consistent with the actual test weld. This ensures that the material and weld structure of the special test block are consistent with the object being tested.

[0028] The test block manufacturing process of the utility model is as follows:

[0029] Step 1: Process the upper ring plate and the lower cylinder according to the tube head form of the fillet weld workpiece of the heat exchange tube and tube sheet to be tested.

[0030] Step 2: The ring plate and the cylinder are welded according to the welding process of the heat exchange tube and the tube sheet to form a cylinder.

[0031] Step 3: Process a center hole in the center of the cylinder, process a cylindrical defect comparison area 1 at the cylindrical ring plate connection end, and process a cylindrical TCG (including ACG) sensitivity setting area 3 in the lower cylindrical area.

[0032] Step 4: In the cylindrical defect comparison area 1, flat-bottom holes and arc grooves are processed in sequence according to the above-mentioned dimensions and angles.

[0033] Step 5: In the cylindrical TCG (including ACG) sensitivity setting area 3, long transverse through holes are processed in sequence according to the above-mentioned dimensions and angles.

[0034] The use process of the utility model is as follows:

[0035] Step 1, the phased array probe is placed in the cylindrical TCG (including ACG) sensitivity setting area 3 of the test block, and each hole is adjusted in turn to make TCG (including ACG curve);

[0036] Step 2: Figure 8 As shown, the phased array probe 5 is placed in the cylindrical defect comparison area 1 to detect artificial defects and verify the feasibility of the process;

[0037] Step 3: After the instrument is adjusted and the process is verified to be qualified, move to the workpiece for inspection.

[0038] Description of the detection effect of this utility model:

[0039] The joint form of the fillet weld between the heat exchange tube and the tube sheet of the final sulfur cooler equipment is as follows Figure 6 , Figure 7 As shown, a TCG (including ACG) curve is made on the cylindrical TCG (including ACG) sensitivity setting area 3 of the phased array test block for heat exchange tube and tube sheet fillet weld of the utility model, and the detection process verification is performed in the cylindrical defect comparison area 1. Phased array detection is performed on the product heat exchange tube and tube sheet fillet weld, and defects are found in some heat exchange tube and tube sheet fillet welds. Two heat exchange tube and tube sheet fillet welds with defects are selected: the first heat exchange tube and tube sheet fillet weld defect has a measured length of 2mm and a defect height of 0.8mm; the second heat exchange tube and tube sheet fillet weld defect has a root defect length of 5mm and a defect height of 1.3mm. Rod anode detection was performed on two defective fillet welds between heat exchange tubes and tube sheets, and defects were found in both. The defect of the first fillet weld between heat exchange tubes and tube sheets was a pore, and the long diameter was 2.2 mm measured by the negative image. The defect of the second fillet weld between heat exchange tubes and tube sheets was a root failure, and the root defect length was 12.6 mm and the defect height was 1.6 mm measured by the negative image. The feasibility and reliability of phased array detection were verified by rod anode detection.

[0040] The application scope of the present utility model is not limited to the description of the above specific embodiments.

Claims

1. A special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets, characterized in that: The invention comprises a cylindrical defect comparison area (1) and a cylindrical TCG and ACG sensitivity setting area (3), which are connected as a whole via a cylindrical connection area (2); the central hole diameter of the cylindrical connection area (2) is the inner diameter of the heat exchange tube; the wall thickness of the cylindrical defect comparison area (1) is 4 times the wall thickness of the heat exchange tube, the wall thickness of the cylindrical TCG and ACG sensitivity setting area (3) is 5 times the wall thickness of the heat exchange tube, and the wall thickness of the cylindrical connection area (2) is less than the wall thickness of the heat exchange tube; the height of the cylindrical defect comparison area (1) and the cylindrical TCG and ACG sensitivity setting area (3) is greater than the total height of the fillet weld between the inspected heat exchange tube and the tube sheet; the cylindrical defect comparison area (1) is provided with a flat bottom hole defect and an artificial defect, and the cylindrical TCG and ACG sensitivity setting area (3) is provided with a long transverse through hole defect.

2. A special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets according to claim 1, characterized in that: The flat bottom hole defects include first, second, third and fourth flat bottom hole defects (a, b, c and d), each having a diameter of Φ1 mm. The length of the first flat bottom hole defect (a) is from the outer wall of the cylindrical defect comparison area (1) to the outer wall of the heat exchange tube, the length of the second flat bottom hole defect (b) is from the outer wall of the cylindrical defect comparison area (1) to the middle of the simulated weld, the length of the third flat bottom hole defect (c) is from the outer wall of the cylindrical defect comparison area (1) to the groove of the simulated weld tube sheet, and the length of the fourth flat bottom hole defect (d) is from the outer wall of the cylindrical defect comparison area (1) to the heat affected zone of the simulated weld tube sheet; the simulated weld is arranged at the simulated weld area (4), and the simulated weld area (4) is located at the connection between the cylindrical defect comparison area (1) and the cylindrical connection area (2).

3. A special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets according to claim 1, characterized in that: The artificial defects include first, second, third and fourth artificial defects (e, f, g, h), which are distributed at intervals of 90° on the central circumferential surface of the simulated weld zone (4), wherein the first, second, third and fourth artificial defects (e, f, g, h) are 0.3 mm wide and 0.3 mm, 0.5 mm, 0.8 mm and 1 mm deep, respectively, into the simulated weld, and are arc-shaped groove artificial defects with a length of 1 / 24 of the outer circumference of the heat exchange tube.

4. A special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets according to claim 1, characterized in that: The long transverse through hole defects include the first, second, third and fourth long transverse through hole defects (i, j, k, l), all of which have a diameter of Φ1mm and are arranged at 90° intervals. They are respectively located on the circumference of the outer diameter of the heat exchange tube, the circumference of the outer diameter of the heat exchange tube plus 2 times the wall thickness of the heat exchange tube, the circumference of the outer diameter of the heat exchange tube plus 4 times the wall thickness of the heat exchange tube, and the circumference of the outer diameter of the heat exchange tube plus 6 times the wall thickness of the heat exchange tube.

5. The special test block for phased array detection of fillet welds between heat exchange tubes and tube sheets according to claim 1, characterized in that: The material of the special test block has the same or similar sound velocity and attenuation coefficient as the material of the heat exchange tube-tube sheet fillet weld, and the connecting welds of the cylindrical defect comparison area (1) and the cylindrical connecting area (2) are consistent with the actual test welds.

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