Test block for assessing detection sensitivity of alternating electromagnetic field instruments

Abstract

The test block described in this utility model for evaluating the detection sensitivity of an AC electromagnetic field instrument belongs to the field of electromagnetic flaw detection technology. It comprises a base material part, a weld part, and several crack defect mechanisms. The weld part has a fan-shaped cross-section, and the crack defect mechanisms are elliptical grooves. The first and second crack defect mechanisms are located at the weld toes on the left and right sides of the weld, with their depth direction parallel to the upper surface of the base material part. The third crack mechanism is inclinedly located at the weld toe on the right side of the weld part, with its depth direction parallel to the radius of the weld fan-shaped cross-section. The fourth crack mechanism is located in the middle of the weld, with its depth direction perpendicular to the upper surface of the base material part. By simulating multiple types of cracks, the instrument's detection sensitivity to defects in different locations and directions can be comprehensively verified, ensuring the accuracy and reliability of the detection instrument.

Description

Technical Field

[0001] This utility model belongs to the field of electromagnetic flaw detection technology, specifically relating to a test block for evaluating the detection sensitivity of AC electromagnetic field instruments. Background Technology

[0002] Alternating current electromagnetic field (AC) testing technology is a non-destructive testing technique for surface and near-surface defects. It is used to detect surface and near-surface cracks in various ferromagnetic and non-ferromagnetic materials. It features non-contact measurement and minimal influence from the workpiece surface, and can be widely applied to weld inspection of various base materials such as carbon steel, stainless steel, titanium, bronze, chromium-nickel-iron alloys, and aluminum. It can also be used for thread inspection, underwater inspection, and other inspections in high-temperature, special operating environments. Currently, the calibration test block used in AC ...

[0003] The prior art, disclosed in CN118914346A, describes a magnetic particle testing block and its application method for inductive current testing. The block itself is a ring-shaped cylindrical structure fitted onto the iron core of the magnetic particle testing system. Grooves are engraved on the inner, outer, and side surfaces of the block as artificial defects to verify the system's sensitivity, particularly suitable for full-circumference testing of ring-shaped components. However, these artificial defects are simple grooves with a single direction, failing to simulate the complex and diverse crack conditions of actual applications, resulting in insufficient dimensions for sensitivity verification. Utility Model Content

[0004] The technical problem solved by this utility model is to overcome the defects in the existing technology and provide a test block for evaluating the detection sensitivity of AC electromagnetic field instruments.

[0005] The technical solution adopted in this utility model is as follows: The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument, as described in this utility model, includes a test block body, which comprises a base material part, a weld part, and several crack defect mechanisms. The crack defect mechanisms are respectively located at the weld toe positions on both sides of the weld part and above the weld part. The crack defect mechanisms are elliptical artificial grooves, and the crack defect mechanisms cooperate with the probe of the AC electromagnetic field instrument.

[0006] The crack defect mechanism includes a first crack defect mechanism, a second crack defect mechanism, a third crack defect mechanism, and a fourth crack defect mechanism.

[0007] The first crack defect mechanism is located at the right weld toe of the weld portion, and the depth direction of the first crack defect mechanism is parallel to the upper surface of the base material portion.

[0008] The second crack defect mechanism is located at the left weld toe of the weld portion, and the direction and depth of the second crack defect mechanism are parallel to the upper surface of the base material portion.

[0009] The fourth crack defect mechanism is located in the middle of the weld section, and the depth direction of the fourth crack defect mechanism is perpendicular to the upper surface of the base material section.

[0010] The base material is made of 20# carbon steel.

[0011] The cross-section of the weld is fan-shaped.

[0012] The third crack defect mechanism is inclinedly set at the right weld toe of the weld section, and the depth direction of the third crack defect mechanism is parallel to the radius direction of the sector section of the weld section.

[0013] This utility model has the following beneficial effects: 1. The base material section, weld section, and several crack defect mechanisms, by simulating the real weld structure and various types of crack defects, can comprehensively evaluate the detection sensitivity of AC electromagnetic field instruments in different positions and directions, thereby improving the comprehensiveness and accuracy of the calibration.

[0014] 2. The elliptical groove simulates the geometric characteristics of a real crack, more accurately reflecting the instrument's response to the shape of the crack defect mechanism, and enhancing the reliability of the verification results.

[0015] 3. The first crack defect mechanism and the second crack defect mechanism are located at common crack locations on the left and right sides of the weld section. They are used to verify the sensitivity of the instrument to cracks in the parallel direction and ensure the instrument's detection capability in the weld toe area.

[0016] 4. The fan-shaped cross-section of the weld section simulates the actual welding shape, and the third crack defect mechanism can verify the instrument's ability to detect asymmetric defects, thus enhancing the practicality of the test block.

[0017] 5. The depth direction of the fourth crack is perpendicular to the upper surface of the base material and is located in the middle of the weld, which realizes the sensitivity of the verification instrument to vertical defects and further expands the verification range. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the entire present invention from one perspective; Figure 2 This is a schematic diagram of the entire utility model from another perspective; Figure 3 This is a top view of the present invention; Figure 4 This is a right view of the present invention; Figure 5 Left view of this utility model Figure 6 for Figure 1 Enlarged view of part A in the image; Figure 7 for Figure 1 Enlarged view of part B in the image; Figure 8 for Figure 2 Enlarged view of section C in the image; Figure 9 for Figure 2 A cross-sectional view along plane D.

[0019] The components are: 1. Base material; 2. Weld seam; 3. First crack defect mechanism; 4. Second crack defect mechanism; 5. Third crack defect mechanism; 6. Fourth crack defect mechanism. Detailed Implementation

[0020] like Figures 1 to 9 As shown, the test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to this utility model includes a test block body, which includes a base material part 1, a weld part 2, and several crack defect mechanisms. The crack defect mechanisms are respectively located at the weld toe positions on both sides of the weld part 2 and above the weld part 2. The crack defect mechanism is an elliptical artificial groove, and the crack defect mechanism cooperates with the probe of the AC electromagnetic field instrument.

[0021] The crack defect mechanism includes a first crack defect mechanism 3, a second crack defect mechanism 4, a third crack defect mechanism 5, and a fourth crack defect mechanism 6.

[0022] The first crack defect mechanism 3 is located at the right weld toe of the weld portion 2, and the depth direction of the first crack defect mechanism 3 is parallel to the upper surface of the base material portion 1.

[0023] The second crack defect mechanism 4 is located at the left weld toe of the weld portion 2, and the direction and depth of the second crack defect mechanism 4 are parallel to the upper surface of the base material portion 1.

[0024] The fourth crack defect mechanism 6 is located in the middle of the weld portion 2, and the depth direction of the fourth crack defect mechanism 6 is perpendicular to the upper surface of the base material portion 1.

[0025] The base material 1 is made of 20# carbon steel.

[0026] The cross-section of weld section 2 is fan-shaped.

[0027] The third crack defect mechanism 5 is inclinedly arranged at the right weld toe of the weld section 2, and the depth direction of the third crack defect mechanism 5 is parallel to the radius direction of the sector section of the weld section 2.

[0028] Specifically, the test block body is a strip-shaped cuboid structure, made of 20# carbon steel. The test block body includes the base material part 1, the weld part 2, and several artificially cut grooves to simulate crack defects.

[0029] Specifically, taking a test block body with dimensions of 200mm*150mm*6mm as an example, four crack defect mechanisms are set on the test block body. The crack defect mechanisms are respectively set on the left and right weld toes of the weld portion 2 and on the weld portion 2. The crack defect mechanisms include a first crack defect mechanism 3, a second crack defect mechanism 4, a third crack defect mechanism 5 and a fourth crack defect mechanism 6. The first crack defect mechanism 3, the second crack defect mechanism 4, the third crack defect mechanism 5 and the fourth crack defect mechanism 6 are all elliptical grooves cut using electrical discharge machining technology.

[0030] Specifically, taking one end of weld portion 2 as the starting end, the first crack defect mechanism 3 is set at the right weld toe position of weld portion 2, 40mm away from the starting end, with a groove length of 3mm and a depth of 0.5mm, and its depth direction is parallel to the upper surface of the base material portion 1; the second crack defect mechanism 4 is set at the left weld toe position of weld portion 2, 80mm away from the starting end, with a groove length of 6mm and a depth of 2.5mm, and its depth direction is parallel to the upper surface of the base material portion 1; the third crack defect mechanism 5 is set at the right weld toe position of weld portion 2, 120mm away from the starting end, with a groove length of 6mm and a depth of 2.5mm, and its depth direction is parallel to the radius direction of the fan-shaped cross section of weld portion 2; the fourth crack defect mechanism 6 is set at the middle position of weld portion 2, 160mm away from the starting end, with a groove length of 6mm and a depth of 2.5mm, and its depth direction is perpendicular to the upper surface of the base material portion 1.

[0031] Specifically, the detection probe of the AC electromagnetic field instrument is placed on the main body of the test block, and the probe is positioned at the weld toe of weld section 2 for scanning. The probe is scanned at a uniform speed along the crack defect structure on the main body of the test block, and the graphic display in the software of the AC electromagnetic field instrument is observed. When the probe scans the corresponding crack defect structure, it is determined whether the graphic display is a typical defect signal. If a defect signal is displayed, it indicates that the sensitivity of the AC electromagnetic field instrument has reached the standard for that crack defect structure; otherwise, it has not.

Claims

1. A test block for evaluating the detection sensitivity of an AC electromagnetic field instrument, comprising a test block body, characterized in that, The test block body includes a base material part (1), a weld part (2) and several crack defect mechanisms. The crack defect mechanisms are respectively located at the weld toe positions on both sides of the weld part (2) and above the weld part (2). The crack defect mechanism is an elliptical artificial groove. The crack defect mechanism is in conjunction with the probe of the AC electromagnetic field instrument.

2. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 1, characterized in that, The crack defect mechanism includes a first crack defect mechanism (3), a second crack defect mechanism (4), a third crack defect mechanism (5), and a fourth crack defect mechanism (6).

3. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 2, characterized in that, The first crack defect mechanism (3) is located at the right weld toe of the weld portion (2), and the depth direction of the first crack defect mechanism (3) is parallel to the upper surface of the base material portion (1).

4. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 2, characterized in that, The second crack defect mechanism (4) is located at the left weld toe of the weld portion (2), and the direction and depth of the second crack defect mechanism (4) are parallel to the upper surface of the base material portion (1).

5. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 2, characterized in that, The fourth crack defect mechanism (6) is located in the middle of the weld portion (2), and the depth direction of the fourth crack defect mechanism (6) is perpendicular to the upper surface of the base material portion (1).

6. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 1, characterized in that, The base material (1) is made of 20# carbon steel.

7. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 2, characterized in that, The cross-section of the weld portion (2) is fan-shaped.

8. The test block for evaluating the detection sensitivity of an AC electromagnetic field instrument according to claim 7, characterized in that, The third crack defect mechanism (5) is inclinedly arranged at the right weld toe of the weld portion (2), and the depth direction of the third crack defect mechanism (5) is parallel to the radius direction of the fan-shaped section of the weld portion (2).

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