Step splicing type eddy current testing reference block
Through the step-stage-stitching structure, the problem of large opening width of the artificial defect of the existing eddy current detection test block is solved, and more accurate and sensitive detection results are achieved.
Patent Information
- Application Number
- CN202421835475.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-07-31
AI Technical Summary
The artificial defect opening of the existing eddy current detection test block is large in width, and it is impossible to effectively simulate the tiny gap of natural cracks, resulting in inaccurate detection results.
The step-stage-stitched structure is adopted, and two pieces of simultaneous sizes are spliced together to form multiple simulated cracks for eddy current detection sensitivity calibration of surface opening defects and buried defects.
The artificial defect opening gap is narrower, closer to the actual crack morphology, and improve the accuracy and sensitivity of the detection results.
Smart Images
Figure CN223005842U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of nondestructive testing, in particular to a stepped combined eddy current testing reference block. Background Art
[0002] Eddy current testing is a commonly used nondestructive testing technology in the aerospace industry. In recent years, it has also been widely applied in the industries of rail transit, energy power, nuclear power, automobiles, petroleum and petrochemicals, and special equipment. Eddy current testing utilizes the change of the electromagnetic properties of materials caused by defects to detect, locate, and quantify defects. Like other nondestructive testing methods, eddy current testing also requires the use of reference blocks containing known artificial defects to debug the testing system and set the sensitivity. Therefore, whether the artificial defects of the reference block can well simulate natural defects has an important impact on the eddy current testing results.
[0003] The main objects of eddy current testing are surface and near-surface crack-like defects. Therefore, the artificial defects of the reference block mainly simulate cracks. Usually, the opening gap of cracks is very small. Therefore, it is hoped that the opening width of the artificial defects is as narrow as possible on the premise of ensuring dimensional accuracy to be as similar as possible to the actual cracks.
[0004] The artificial defects of the existing eddy current reference blocks are mainly grooved, generally processed by wire cutting or electrical discharge machining. For the grooved upper and lower surfaces, wire cutting or electrical discharge machining can be directly used. For buried grooves, usually, a hole is drilled in the middle of the position where the groove needs to be processed to pass through the conductive molybdenum wire, and then the groove with the required height is cut vertically upward and downward by electrical discharge machining. Affected by the size of the electrical discharge electrode and the wire cutting molybdenum wire, the minimum grooved width that can be produced by these two processing technologies is about 0.13 mm. ， The grooved artificial defects obtained by the above processing technology have a large opening width and cannot well simulate the tiny gaps of natural cracks, resulting in inaccurate testing results. Moreover, the smaller the defect, the greater the deviation between the artificial groove and the actual morphology of the crack, and the greater the deviation of the testing results. Content of the Utility Model
[0005] The purpose of the utility model is to overcome the problems in the prior art and provide a stepped combined eddy current testing reference block.
[0006] The utility model provides a stepped combined eddy current testing reference block, which includes a first combined block and a second combined block. Both the first combined block and the second combined block have a combined surface. A plurality of stepped structures are arranged along the length direction on the combined surfaces of the first combined block and the second combined block. After the first combined block and the second combined block are combined, the plurality of stepped structures are combined with each other to form a plurality of simulated cracks, and the simulated cracks formed by the vertical combined surfaces of the plurality of stepped structures are used for the eddy current testing sensitivity calibration of surface opening defects and buried defects and the calibration of weld penetration measurement.
[0007] As a disclosure method, the two vertical mating surfaces of the stepped structure formed by the mating of the first mating block and the second mating block are in direct contact to simulate a closed crack.
[0008] As a disclosure method, an insulating film is padded between the two vertical mating surfaces of the stepped structure formed by the mating of the first mating block and the second mating block to simulate an open crack.
[0009] At least one of the two vertical mating surfaces of the stepped structure formed by the mating of the first mating block and the second mating block is sprayed with an insulating paint layer to simulate an open crack.
[0010] As a disclosure method, the two vertical mating surfaces of the stepped structure formed by the mating of the first mating block and the second mating block are vertical mating surfaces or inclined mating surfaces.
[0011] As a disclosure method, the selected step surface for the painted surface is the side with a convex surface.
[0012] As a disclosure method, the shallowest step of the first mating block corresponds to the thinnest covering surface of the second mating block, and there is a strengthening structure outside the thinnest covering surface of the second mating block.
[0013] As a disclosure method, multiple stepped structures form a gradient step.
[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0015] The novel test block structure designed by the present utility model uses the combination of two vertically spliced vertical surfaces with matching sizes and in contact with each other to replace the grooving as an artificial defect. It can make the opening gap of the artificial defect narrower. The buried artificial defect and the surface opening defect are formed by the mating of multiple stepped structures, which can simulate closed cracks and open cracks.
[0016] The new stepped mating type eddy current comparison test block of the present utility model has the advantages of compact structure, wide range of simulated defect types, reasonable setting of artificial defect sizes, simpler processing and measurement, etc. Description of the Drawings
[0017] Figure 1 It is a schematic structural diagram of the first mating block in the embodiment of the present utility model.
[0018] Figure 2 It is a schematic structural diagram of the second mating block in the embodiment of the present utility model.
[0019] Figure 3 It is a schematic structural diagram of the first mating block and the second mating block after mating in the embodiment of the present utility model.
[0020] Figure 4 This is a schematic diagram of the detection area of the first detection surface in the embodiment of the present utility model.
[0021] Figure 5 This is a schematic diagram of the detection area of the second detection surface in the embodiment of the present utility model.
[0022] Figure 6 This is a schematic diagram of three crack defects of the present utility model.
[0023] Explanation of reference numerals:
[0024] 1. First fitting block, 2. Second fitting block, 3. Step structure, 4. Simulated crack, 5. Reinforcing structure. Detailed implementation manners
[0025] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0026] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present utility model belongs. The "first", "second" and similar terms used in the present utility model do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before "including" or "comprising" cover the elements or objects listed after "including" or "comprising" and their equivalents, and do not exclude other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.
[0027] The eddy current flow direction in the conductor is parallel to the detection surface, and defects perpendicular to the eddy current flow direction will cause distortion of the eddy current field. Therefore, eddy current testing has better detection efficiency for defects perpendicular to the detection surface, while delamination defects parallel to the surface have no effect on eddy current testing. Based on this principle, two stepped fitting blocks with matching sizes can be fitted together to form a whole. Then, the horizontal plane of the step has no effect on the detection, while the vertical plane can be used to simulate defects perpendicular to the detection surface.
[0028] It should be noted that the width of the defect perpendicular to the eddy current flow direction, i.e., the vertical notch, will affect the distribution of the electromagnetic field between the metal and the gap. Therefore, the width of the vertical notch affects the eddy current detection result. However, for the horizontal thin-layer gap, when its horizontal dimension is larger than the eddy current influence area, the change in its horizontal dimension does not affect the distribution of the eddy current between the metal and the gap. Therefore, the formation of cracks by the horizontal mating surfaces of the multiple step structures 3 of the present utility model has no influence on the eddy current detection result. The simulated crack 4 formed by the vertical mating surfaces of the multiple step structures 3 of the present utility model can make the crack width narrower, thus solving the problem that the opening width of the grooved artificial defect is relatively large and it is impossible to well simulate the tiny gap of the natural crack, resulting in inaccurate detection results.
[0029] A stepped mating type eddy current detection comparison test block provided in this embodiment includes a first mating block 1 and a second mating block 2. The first mating block 1 and the second mating block 2 have mating surfaces. Along the length direction of the mating surfaces of the first mating block 1 and the second mating block 2, a plurality of step structures 3 are provided. The plurality of step structures 3 can be continuous gradient steps. After the first mating block 1 and the second mating block 2 are mated, the plurality of step structures 3 are mated with each other to form a plurality of simulated cracks 4. Among them, the simulated crack 4 formed by the vertical mating surfaces of the plurality of step structures is used for the eddy current detection sensitivity calibration of surface opening defects and buried defects and the calibration of the weld penetration measurement of laser welding or electron beam welding, as Figure 6 shown.
[0030] As a preferred mode, the two vertical mating surfaces of the mutually mated step structures 3 of the first mating block 1 and the second mating block 2 are in direct contact, which is used to simulate a closed crack.
[0031] As a preferred mode, an insulating film is padded between the two vertical mating surfaces of the mutually mated step structures 3 of the first mating block 1 and the second mating block 2, which is used to simulate an open crack.
[0032] As a preferred mode, at least one of the two vertical mating surfaces of the mutually mated step structures 3 of the first mating block 1 and the second mating block 2 is sprayed with an insulating paint layer, which is used to simulate an open crack.
[0033] As a preferred mode, the two vertical mating surfaces of the mutually mated step structures 3 of the first mating block 1 and the second mating block 2 are vertical mating surfaces or inclined mating surfaces. When the mating surface is an inclined mating surface, the inclined mating surface can simulate an inclined crack, and at the same time, the end vertical mating surface can be used to simulate a crack with a changing depth.
[0034] As a preferred mode, the side with the convex step surface is selected as the painted surface, which can prevent the problem that the paint layer at the concave inner corner causes an increase in the mating gap of the component due to the rounding caused by the surface tension.
[0035] As a preferred embodiment, the shallowest step of the first fitting block 1 corresponds to the thinnest covering surface of the second fitting block 2, and a strengthening structure is provided outside the thinnest covering surface of the second fitting block.
[0036] This embodiment also provides a crack simulation method for the above-mentioned stepped fitting type eddy current testing reference block, including the following steps:
[0037] Select material test blocks that are the same as or have similar electromagnetic characteristics to the workpiece to be detected as the two fitting test blocks of the reference block;
[0038] Make stepped structures on the fitting surfaces of the two fitting test blocks, and there are several steps on the fitting surface of each fitting test block;
[0039] The multiple stepped surfaces of the two fitting test blocks can be fitted to form multiple simulated cracks.
[0040] The design of the test block of the present utility model can simulate narrower cracks, which is closer to the actual detection object; it can simulate closed cracks and also open cracks, with a wide range of applications; buried cracks can be simulated by the same method without other processing means such as drilling.
[0041] The following will be described in the form of specific embodiments.
[0042] The design schemes of the first fitting block 1 and the second fitting block 2 in this embodiment are as follows:
[0043] Select a material that is the same as or has similar electromagnetic characteristics to the workpiece to be detected;
[0044] Use this material to make two test blocks with stepped fitting surfaces as shown in Figure 1 - Figure 2 , that is, the first fitting block 1 and the second fitting block 2. There are several steps on each component, and the distances from each stepped surface to the detection surface are h1, h2, h3... hn respectively;
[0045] As an example, h1 can be taken between 0.3 - 0.8 mm, h2 is taken as 2 times h1, h3 is taken as 3 times h1... hn is taken as n times h1. The above values meet the conventional requirements of the industry. Currently, the shallowest crack depth commonly seen in the industry is 0.5 mm. In some special industries with higher requirements, the shallowest crack depth may be 0.2 mm. Then, the distances from the multiple stepped surfaces to the detection surface can be increased in multiples after 0.2 mm according to the above value-taking principle.
[0046] Preferably, since the thickness of the h1 part is usually relatively thin, to maintain the structural stability and facilitate fixing, a thickened strengthening structure can be added to the side of the h1 part, and the thickness of the corresponding position of the other test block is reduced to achieve fitting;
[0047] The first splicing block 1 and the second splicing block 2 are spliced to form a new overall test block with a total thickness of T. The spliced test block is as shown in Figure 3 shown;
[0048] The spliced test block has two detection surfaces, upper and lower. Each detection surface has three available detection areas, as shown in Figure 4 and Figure 5 ;
[0049] When detecting on the first detection surface:
[0050] For area 1 of the first detection surface, area 1 of the first detection surface, it is the surface opening defect of the detection surface, and the self-heights are h1, h2, h3... hn respectively;
[0051] For area 2 of the first detection surface, it is the buried defect with no opening on both the upper and lower surfaces, which are the buried depths h1, the self-height h2 - h1, and the buried depth h2, the self-height h3 - h2, until the buried depth hn - 1, the self-height hn - hn - 1 respectively;
[0052] For area 3 of the first detection surface, it is the surface opening defect on the side far from the detection surface, and the buried depths from the detection surface are h1, h2... hn respectively;
[0053] Flip the spliced test block 180 degrees left and right. When detecting on the second detection surface:
[0054] For area 1 of the second detection surface, it is the surface opening defect on the side far from the detection surface, and the buried depths from the detection surface are T - hn, T - hn - 1... T - h1 respectively;
[0055] For area 2 of the second detection surface, it is the buried defect with no opening on both the upper and lower surfaces, which are the buried depths T - hn, the self-height hn - hn - 1, the buried depth T - hn - 1, the self-height hn - 1 - hn - 2, etc.;
[0056] For area 3 of the second detection surface, it is the surface opening defect of the detection surface, and the self-heights are T - hn, T - hn - 1... T - h1 respectively;
[0057] The spliced test block of the present utility model has a compact structure and a rich variety of artificial defects. A spliced test block has two detection surfaces, six detection areas, and three types of defects; and the defect sizes are reasonably set, and various defect sizes are distributed in a stepped manner, which is convenient for equipment debugging; the spliced test block of the present utility model is easy to process, the size is easier to control, and the size measurement is also simpler.
[0058] More specifically, the first splicing block 1 and the second splicing block 2 are made of 7075 aluminum alloy by mechanical processing.
[0059] The first fitting block 1 and the second fitting block 2 are both 240 mm in length, 80 mm in width, and 5.5 mm in height, and the heights of h1 to h5 are 0.5, 1.0, 1.5, 2.0, and 2.5 mm respectively.
[0060] The thickness of the left strengthening part of the second fitting block 2 is 2.5 mm, and the thickness of the corresponding position of the first fitting block 1 is 3.0 mm.
[0061] Each step plane is a rectangle of 40×40 mm, the left strengthening area is 20×40 mm, and the rightmost step extends 20 mm for setting the fixing mechanism.
[0062] The size of the test block after fitting is 240 mm in length, 120 mm in width, and 5.5 mm in height.
[0063] The areas 6 - 10 in the first detection surface 1 are detection surface opening defects, and their own heights are 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm respectively.
[0064] The areas 11 - 14 in the first detection surface 2 are buried defects with their own height of 0.5 mm, and the burial depths are 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm respectively.
[0065] The areas 15 - 19 in the first detection surface 3 are opening defects on the side far from the detection surface, and the burial depths from the detection surface are 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm respectively.
[0066] The areas 20 - 24 in the second detection surface 1 are opening defects on the side far from the detection surface, and the burial depths from the detection surface are 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, and 5.0 mm respectively.
[0067] The areas 25 - 28 in the second detection surface 2 are buried defects with their own height of 0.5 mm, and the burial depths are 3.0 mm, 3.5 mm, 4.0 mm, and 4.5 mm respectively.
[0068] The areas 29 - 33 in the second detection surface 3 are detection surface opening defects, and their own heights are 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, and 5.0 mm respectively.
[0069] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A step-jointed eddy current test comparison block, characterized in that: The invention comprises a first assembly block (1) and a second assembly block (2), wherein the first assembly block (1) and the second assembly block (2) are both provided with an assembly surface for being assembled with each other, and the assembly surfaces of the first assembly block (1) and the second assembly block (2) both include a plurality of step structures (3). After the assembly surfaces of the first assembly block (1) and the second assembly block (2) are assembled, the plurality of step structures (3) are assembled to form a plurality of simulated cracks (4), wherein the simulated cracks (4) formed by the vertical assembly surfaces of the plurality of step structures (3) are used for eddy current detection sensitivity calibration.
2. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: The two vertical joint surfaces of the mutually jointed step structures (3) of the first joint block (1) and the second joint block (2) are in direct contact, so as to simulate a closed crack.
3. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: An insulating film is provided between two vertical joint surfaces of the mutually jointed step structures (3) of the first joint block (1) and the second joint block (2) to simulate an open crack.
4. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: At least one of the two vertical joint surfaces of the mutually jointed step structure (3) of the first joint block (1) and the second joint block (2) is sprayed with an insulating paint layer to simulate an open crack.
5. The step-jointed eddy current testing comparison test block according to claim 4, characterized in that: The paint spraying surface selects the side where the step surface is the convex surface.
6. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: The two vertical joining surfaces of the mutually joined step structures (3) of the first joining block (1) and the second joining block (2) are vertical joining surfaces or inclined joining surfaces.
7. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: The materials of the first assembly block (1) and the second assembly block (2) are the same as or have similar electromagnetic properties to the workpiece to be inspected.
8. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: The shallowest step of the first assembly block (1) corresponds to the thinnest covering surface of the second assembly block (2), and a reinforcing structure (5) is provided outside the thinnest covering surface of the second assembly block (2).
9. The step-jointed eddy current testing comparison test block according to claim 1, characterized in that: A plurality of step structures (3) constitute gradient steps.