Bidirectional magnetization device for improving magnetic powder detection capability

Abstract

The utility model relates to the technical field of detection, and particularly discloses a bidirectional magnetization device for improving the magnetic powder detection capability. According to the device, a small thin test piece is placed between two metal plates, the small thin test piece is tightly attached to the surfaces of the two metal plates, the two metal plates are tightly attached between two pieces of soft iron, and on the basis of the electromagnetic induction principle and the principle that the effective magnetization depth of a magnetic field generated by bidirectional excitation magnetization on the test piece is doubled, a bidirectional parallel plate magnetization method is adopted; the two metal plates are respectively electrified, magnetic fields generated around the two metal plates bidirectionally magnetize the test piece, and the two soft irons have a magnetic field gathering function to reinforce a detected area, so that the surface and the interior of the test piece obtain more effective leakage magnetic fields, and escape of the leakage magnetic fields at surface defects and internal defects of the test piece is facilitated. Therefore, the magnetic powder is easier to adsorb and gather at the magnetic leakage position, and the detection capacity of the magnetic powder on the defects of the test piece is greatly improved in the magnetic powder detection excitation magnetization mode.

Description

Technical Field

[0001] This utility model relates to the field of detection technology, and specifically discloses a bidirectional magnetization device for improving the detection capability of magnetic particles. Background Technology

[0002] Magnetic particle testing is a commonly used non-destructive testing method for detecting defects in ferromagnetic specimens. The basis of magnetic particle testing is the interaction between the leakage magnetic field at the defect and the magnetic particles. It utilizes the difference in magnetic permeability between the surface and near-surface of the ferromagnetic specimen (such as cracks, inclusions, and hairline cracks) and the permeability of steel. After magnetization, the magnetic field at these discontinuous areas of the material will be distorted, resulting in partial magnetic flux leakage from the specimen surface, generating a leakage magnetic field. This attracts magnetic particles, causing them to accumulate at the defect location. Under appropriate lighting conditions, the location and shape of the defect become apparent.

[0003] Currently, conventional DC and AC magnetization are used for small and thin test pieces. Excessive current will cause the small and thin test pieces to burn out. Therefore, there is an urgent need to develop a new magnetization device to magnetize small and thin test pieces and realize the detection of surface and internal defects of the test pieces. Utility Model Content

[0004] The present invention adopts the following technical solution:

[0005] This utility model discloses a bidirectional magnetization device for improving magnetic particle detection capability, including a first metal plate 2, a second metal plate 3, a first soft iron 4, and a second soft iron 5;

[0006] The first metal plate 2 and the second metal plate 3 are symmetrical, and the thin test specimen 1 to be tested is tightly sandwiched in the middle; the first metal plate 2 and the second metal plate 3 are respectively connected to the outer side of the first soft iron 4 and the second soft iron 5; the contact area between the first soft iron 4 and the second soft iron 5 and the first metal plate 2 and the second metal plate 3 is larger than the contact area between the thin test specimen 1 and the first metal plate 2 and the second metal plate 3.

[0007] A pair of wires are connected to the two opposite sides of the first metal plate 2 and the second metal plate 3 to a power source.

[0008] Preferably, the thickness of the first soft iron 4 and the second soft iron 5 is greater than that of the first metal plate 2 and the second metal plate 3.

[0009] Furthermore, the cross-sectional areas of the first soft iron 4 and the second soft iron 5 are smaller than those of the first metal plate 2 and the second metal plate 3.

[0010] Preferably, the first metal plate 2 and the second metal plate 3 are copper plates.

[0011] Preferably, the power supply connected to the first metal plate 2 and the second metal plate 3 includes direct current and alternating current.

[0012] Furthermore, the first metal plate 2 and the second metal plate 3 are connected to the power supply and generate current in the same direction.

[0013] Preferably, the first soft iron 4 and the second soft iron 5 are cuboid blocks, the thin test piece 1 is a cuboid sheet, and the bidirectional magnetization device is axially symmetrical.

[0014] The principle of this utility model is as follows:

[0015] When performing magnetic particle testing on small, thin specimens, conventional electromagnetization methods can lead to specimen burnout. This device places a batch of small, thin specimens between a first metal plate 2 and a second metal plate 3, with the specimens in close contact with the surfaces of the first and second metal plates 2 and 3. The first and second metal plates 2 and 3 are in close contact with the first soft iron 4 and the second soft iron 5. Based on the principle of electromagnetic induction and the principle that the magnetic field generated by bidirectional parallel plate excitation magnetization can effectively magnetize the specimen to twice the depth, a bidirectional parallel plate magnetization method is used. The first metal plate 2 and the second metal plate 3 are energized respectively, and the magnetic field generated around the first metal plate 2 and the second metal plate 3 magnetizes the specimen bidirectionally. The first soft iron 4 and the second soft iron 5 have the function of focusing the magnetic field, thereby strengthening the inspected area and enabling the specimen surface and interior to obtain more effective leakage magnetic field. This facilitates the escape of leakage magnetic field at surface and internal defects, making it easier for magnetic powder to be attracted and accumulated at the leakage magnetic field. This greatly improves the detection capability of magnetic powder for specimen defects from the perspective of magnetic particle detection excitation magnetization method.

[0016] The beneficial effects of this utility model are:

[0017] The bidirectional magnetization device used in this invention can detect surface and internal defects of small and thin specimens, making it easier for magnetic powder to be attracted and accumulated at magnetic leakage points. This greatly improves the ability of magnetic powder to detect specimen defects by changing the magnetic powder detection excitation magnetization method. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a bidirectional magnetization device for improving magnetic particle detection capability according to the present invention. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] In the attached diagram, all identical reference numerals refer to the same components.

[0021] Example 1

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] like Figure 1 As shown, a bidirectional magnetization device for improving magnetic particle detection capability includes a first metal plate 2, a second metal plate 3, a first soft iron 4, and a second soft iron 5.

[0024] The first metal plate 2 and the second metal plate 3 are symmetrical, and the thin test specimen 1 to be tested is tightly sandwiched in the middle; the outer sides of the first metal plate 2 and the second metal plate 3 are respectively connected to symmetrical first soft iron 4 and second soft iron 5; the contact area between the first soft iron 4 and the second soft iron 5 and the first metal plate 2 and the second metal plate 3 is larger than that between the thin test specimen 1 to be tested and the first metal plate 2 and the second metal plate 3; the first metal plate 2 and the second metal plate 3 are copper plates.

[0025] The first soft iron 4 and the second soft iron 5 are cuboid blocks, the thin-measuring specimen 1 is a cuboid sheet, and the bidirectional magnetization device is axially symmetrical. The thickness of the first soft iron 4 and the second soft iron 5 is greater than that of the first metal plate 2 and the second metal plate 3. The cross-sectional area of ​​the first soft iron 4 and the second soft iron 5 is smaller than that of the first metal plate 2 and the second metal plate 3.

[0026] A pair of wires are connected to the two opposite sides of the first metal plate 2 and the second metal plate 3 to a power source.

[0027] The specific steps for use are as follows:

[0028] The first step is pretreatment, removing oil, rust, scale, fuzz, welding slag, and other contaminants from the test piece surface. The second step is magnetization, using a bidirectional parallel plate magnetization method. Current I1 is passed through the left copper plate and current I2 through the right copper plate, with the values ​​of I1 and I2 being the same. Based on the principle of electromagnetic induction, a magnetic field is generated around the left and right copper plates, penetrating the test piece and creating a more effective leakage magnetic field on and inside the test piece. The left and right soft iron plates have the function of focusing the magnetic field, strengthening the inspected area and facilitating the generation of leakage magnetic fields on and inside the test piece. The third step is applying magnetic powder or magnetic suspension, evenly sprinkling it onto the surface of the test piece. The fourth step is observing, evaluating, and recording magnetic traces, promptly observing and evaluating the magnetic traces on the test piece, and recording any important traces. The fifth step is demagnetization and post-treatment, demagnetizing the test piece and cleaning any residual magnetic powder or magnetic suspension, markings, etc., from the test piece surface.

[0029] The above description is merely a detailed description of the present utility model, but the present utility model is not intended to limit itself to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, any modifications, equivalents, substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A bidirectional magnetization device for improving magnetic particle detection capability, characterized in that, It includes a first metal plate (2), a second metal plate (3), a first soft iron (4), and a second soft iron (5); The first metal plate (2) and the second metal plate (3) are symmetrical, and the thin test piece (1) to be tested is tightly sandwiched in the middle; the outer sides of the first metal plate (2) and the second metal plate (3) are respectively connected to the first soft iron (4) and the second soft iron (5); the contact area between the first soft iron (4) and the second soft iron (5) and the first metal plate (2) and the second metal plate (3) is larger than that between the thin test piece (1) to be tested and the first metal plate (2) and the second metal plate (3); A pair of wires are connected to the two opposite sides of the first metal plate (2) and the second metal plate (3) to a power source.

2. The bidirectional magnetization device for improving magnetic particle detection capability according to claim 1, characterized in that, The thickness of the first soft iron (4) and the second soft iron (5) is greater than that of the first metal plate (2) and the second metal plate (3).

3. The bidirectional magnetization device for improving magnetic particle detection capability according to claim 2, characterized in that, The cross-sectional areas of the first soft iron (4) and the second soft iron (5) are smaller than those of the first metal plate (2) and the second metal plate (3).

4. The bidirectional magnetization device for improving magnetic particle detection capability according to claim 1, characterized in that, The first metal plate (2) and the second metal plate (3) are copper plates.

5. The bidirectional magnetization device for improving magnetic particle detection capability according to claim 1, characterized in that, The power sources connected to the first metal plate (2) and the second metal plate (3) include direct current and alternating current.

6. The bidirectional magnetization device for improving magnetic particle detection capability according to claim 5, characterized in that, The first metal plate (2) and the second metal plate (3) are connected to the power source and generate current in the same direction.

7. The bidirectional magnetization device for improving magnetic particle detection capability according to claim 1, characterized in that, The first soft iron (4) and the second soft iron (5) are cuboid blocks, the thin test piece (1) is a cuboid sheet, and the bidirectional magnetization device is axially symmetrical.

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