Pipeline longitudinal mode ultrasonic guided wave magnetostrictive probe and method thereof

Abstract

The invention discloses a pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe which comprises a lower support, a middle support, an upper support, a handle, a flexible coil, a permanent magnet and a silicon steel armature. An ultrasonic guided wave probe is installed on the surface of a pipeline, a permanent magnet and a silicon steel armature generate a pipeline axial static bias magnetic field in the ferromagnetic material pipeline, high-frequency pulse current is introduced into a flexible coil, and an axial high-frequency pulse magnetic field is generated in the pipeline; and longitudinal mode ultrasonic guided waves propagating in the axial direction of the pipeline are excited and received based on the magnetostrictive effect. The pipeline longitudinal mode ultrasonic guided wave magnetostrictive probe provided by the invention can excite and receive pipeline longitudinal mode ultrasonic guided wave signals, and has the advantages of being convenient to disassemble and assemble, convenient and fast to use and high in guided wave mode selectivity.

Description

Technical Field

[0001] The invention relates to the field of nondestructive testing equipment, and in particular to a pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe and a method thereof. Background Art

[0002] Ferromagnetic material pipelines have been widely used in oil and gas transportation, chemical industry, municipal engineering and other fields due to their safety, reliability, low cost, high efficiency and speed. During their service, ferromagnetic material pipelines will be subjected to harsh working conditions such as temperature changes, chemical corrosion, and external load damage. They are prone to cracks, corrosion and other damages and eventually fail. Ultrasonic guided waves have the characteristics of strong penetration, concentrated energy and good directionality. They can propagate over long distances in the tested pipeline, are highly sensitive to pipeline damage, and can achieve large-scale detection. Therefore, ultrasonic guided waves have broad application prospects in non-destructive monitoring of ferromagnetic material pipelines. Common pipeline longitudinal modal ultrasonic guided wave probes are piezoelectric, Lorentz force and magnetostrictive.

[0003] However, the pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe currently used for pipeline detection requires dozens of turns of coils to be manually wound and pasted on the pipeline surface, which is inconvenient to disassemble and assemble, time-consuming and labor-intensive; and the coils wound and pasted on the pipeline surface are prone to fall off and damage, resulting in a short probe life and a high failure rate, making the existing probes less practical. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe, which is non-contact, easy to disassemble and assemble, and not easy to damage. By installing the probe on the outer surface of the measured pipeline, long-distance detection of the pipeline can be achieved.

[0005] In order to achieve the above object, the present invention adopts the following scheme.

[0006] A pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe comprises: a permanent magnet and a silicon steel armature, the permanent magnet and the silicon steel armature generate a pipeline axial bias magnetic field in the measured pipeline; a pulse current is passed through the coil, and the positive section of the coil generates a pipeline axial high-frequency pulse magnetic field in the measured pipeline.

[0007] Optionally, longitudinal modal ultrasonic guided waves propagating axially along the pipeline are excited and received based on the magnetostrictive effect.

[0008] Optionally, two axially arranged permanent magnets and a silicon steel armature form a set of magnets.

[0009] Optionally, the polarities of the two permanent magnets are in opposite directions, and the silicon steel armature is used to close the magnetic circuit and enhance the magnetic field.

[0010] Optionally, the magnetostrictive probe further includes: a lower bracket, a middle bracket, an upper bracket, and a handle.

[0011] Optionally, the magnetostrictive probe further includes: an upper probe and a lower probe; when the magnetostrictive probe is in working state, the upper probe and the lower probe are installed on the outer surface of the measured pipe; the structures of the upper probe and the lower probe are completely consistent.

[0012] Optionally, the magnetostrictive probe further includes: a flexible coil, and the flexible coil is made by a flexible printed circuit board (FPCB) process.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects:

[0014] The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe provided by the present invention can excite and receive pipeline longitudinal modal ultrasonic guided wave signals, and has the advantage of high selectivity for guided wave modes. In addition, the ultrasonic guided wave probe uses a flexible coil installed on the probe to replace the manually wound and pasted coil on the measured pipeline, which is easy to disassemble and assemble, and is convenient and quick to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings illustrate exemplary embodiments of the present invention and together with the description serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0016] Figure 1 This is an axonometric diagram of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0017] Figure 2 This is an exploded view of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0018] Figure 3 This is a front view of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0019] Figure 4 This is a right side view of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0020] Figure 5 is a top view of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0021] Figure 6 This is a cross-sectional view of the AA section of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0022] Figure 7 This is a cross-sectional view of an ultrasonic guided wave probe BB according to an embodiment of the present invention;

[0023] Figure 8 It is a schematic diagram of a flexible coil of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0024] Fig. 9 This is a schematic diagram of the working principle of an ultrasonic guided wave probe according to an embodiment of the present invention;

[0025] Among them, the measured pipeline 1, the upper probe 2, the lower probe 3, the lower bracket 4, the middle bracket 5, the upper bracket 6, the handle 7, the flexible coil 8, the permanent magnet 9, and the silicon steel armature 10;

[0026] A pipeline axial high frequency pulse magnetic field 11, a pipeline axial static bias magnetic field 12;

[0027] Coil connector 801 , coil forward section 802 , coil reverse section 803 , coil axial section 804 , and coil electromagnetic shielding layer 805 . DETAILED DESCRIPTION

[0028] The following is combined with Figures 1 to 9 The present invention is further described in detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant contents, rather than to limit the present invention. It is also necessary to explain that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings.

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] Unless otherwise specified, the exemplary embodiments / embodiments shown will be understood as exemplary features that provide various details of some ways in which the technical concept of the present invention can be implemented in practice. Therefore, unless otherwise specified, the features of the various embodiments / embodiments can be combined, separated, interchanged and / or rearranged without departing from the technical concept of the present invention.

[0031] The use of cross-hatching and / or shading in the accompanying drawings is generally used to make the boundaries between adjacent components clear. As such, unless otherwise specified, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for the specific materials, material properties, dimensions, proportions, commonalities between the components shown, and / or any other characteristics, attributes, properties, etc. of the components. In addition, in the accompanying drawings, the sizes and relative sizes of the components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific process sequence can be performed in a different order than described. For example, two successively described processes can be performed substantially simultaneously or in an order opposite to the described order. In addition, the same figure numbers represent the same components.

[0032] When a component is referred to as being "on" or "over," "connected to," or "coupled to" another component, the component may be directly on, directly connected to, or directly coupled to the other component, or intervening components may be present. However, when a component is referred to as being "directly on," "directly connected to," or "directly coupled to" another component, there are no intervening components. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, etc., with or without intervening components.

[0033] For descriptive purposes, the present invention may use spatially relative terms such as "below", "beneath", "under", "lower", "above", "upper", "above", "higher", and "side (e.g., as in "sidewall")" to describe the relationship of one component to another (other) component as shown in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, components described as "below" or "beneath" other components or features would then be positioned "above" the other components or features. Thus, the exemplary term "below" can encompass both the "above" and "below" orientations. Furthermore, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0034] The terms used here are for the purpose of describing specific embodiments, and are not intended to be restrictive. As used here, unless the context clearly indicates otherwise, the singular forms "one (kind, person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise" and / or "include" and their variations are used in this specification, it is explained that there are stated features, integral bodies, steps, operations, parts, assemblies and / or their groups, but it is not excluded that there are or add one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups. It should also be noted that, as used here, the terms "substantially", "approximately" and other similar terms are used as approximate terms and not as degree terms, so that they are used to explain the inherent deviations of the measured values, calculated values ​​and / or the values ​​provided that will be recognized by those of ordinary skill in the art.

[0035] In one embodiment, the present invention provides a pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe, which includes: a permanent magnet and a silicon steel armature, which generate a pipeline axial bias magnetic field in the pipeline being measured; a pulse current is passed through the coil, and the positive section of the coil generates a pipeline axial high-frequency pulse magnetic field in the pipeline being measured.

[0036] Optionally, longitudinal modal ultrasonic guided waves propagating axially along the pipeline are excited and received based on the magnetostrictive effect.

[0037] Optionally, two axially arranged permanent magnets and a silicon steel armature form a set of magnets.

[0038] Optionally, the polarities of the two permanent magnets are in opposite directions, and the silicon steel armature is used to close the magnetic circuit and enhance the magnetic field.

[0039] Optionally, the magnetostrictive probe further includes: a lower bracket, a middle bracket, an upper bracket, and a handle.

[0040] Optionally, the magnetostrictive probe further includes: an upper probe and a lower probe; when the magnetostrictive probe is in working state, the upper probe and the lower probe are installed on the outer surface of the measured pipe; the structures of the upper probe and the lower probe are completely consistent.

[0041] Optionally, the magnetostrictive probe further includes: a flexible coil, and the flexible coil is made by a flexible printed circuit board (FPCB) process.

[0042] In one embodiment, referring to Figures 1 to 7 The present invention provides a pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe, comprising: a lower bracket 4, a middle bracket 5, an upper bracket 6, a handle 7, a flexible coil 8, a permanent magnet 9, and a silicon steel armature 10;

[0043] exist Figure 2 The various parts of the waveguide probe can be clearly seen in the figure, among which the flexible coil 8 is bent into a semicircular arc shape and then bonded and fixed in the groove on the lower surface of the lower bracket 4, and the lower surface of the middle bracket 5 is fitted with the upper surface of the lower bracket 4. The permanent magnet 9 and the silicon steel armature 10 are bonded and fixed in the grooves of the lower bracket 4 and the middle bracket 5, and the permanent magnet 9 and the silicon steel armature 10 are fixed in the lower bracket 4 and the middle bracket 5 through the upper grooves of the lower bracket 4 and the middle bracket 5. The lower surface of the upper bracket 6 is fitted with the upper surface of the middle bracket 5, and the handle 7 is installed on the upper surface of the upper bracket 6. The lower bracket 4, the middle bracket 5, the upper bracket 6 and the handle 7 are fixed with M3 bolts.

[0044] Reference Figure 6 and Figure 7, wherein the lower bracket 4 is in the shape of a semicircular arc in the middle, and is straight on both sides. A 2mm deep groove is opened close to the inner surface of the semicircular arc, and its length and width are consistent with the flexible coil 8, which is used to paste and install the flexible coil 8. The circumferential position of the groove for installing the flexible coil 8 is that the 1 / 4 width of the groove is at the axial symmetry axis of the waveguide probe, so that the center line of the forward section 802 of the flexible coil 8 installed here can coincide with the symmetry axis of the waveguide probe, so that the position of the forward section 802 of the flexible coil 8 receiving the waveguide signal can be equal to the center line position of the waveguide probe, and the center line position of the waveguide probe can be used to represent the installation position of the waveguide probe. The outer surface of the semicircular arc portion of the lower bracket 4 is opened with two groups, each group of 4, a total of 8 rectangular grooves, the length and width of the rectangular grooves are consistent with the permanent magnet 9, and the depth is half of the permanent magnet 9, which is used to paste and install the permanent magnet 9. The circumferential spacing of each group of rectangular grooves is equal, and the axial positions are parallel. The axial distance between the two groups of rectangular grooves is half of the width of the flexible coil 8 plus a certain margin.

[0045] The middle bracket 5 is in the shape of a semicircular arc, with an inner diameter equal to the outer diameter of the lower bracket 4, and a thickness equal to the sum of half the thickness of the permanent magnet 9 and the thickness of the silicon steel armature 10. The middle bracket 5 is also provided with two groups of 4 rectangular grooves, a total of 8 grooves, and these grooves penetrate the middle bracket, and the positions correspond to the grooves of the lower bracket 4, which play the role of installing and fixing the permanent magnet 9 and the silicon steel armature 10. The upper bracket 6 is in the shape of a semicircular arc, and its inner diameter is consistent with the outer diameter of the middle bracket 5, which plays the role of covering and protecting the present waveguide probe.

[0046] A 3.5 mm through hole is opened in the lower bracket 4, the middle bracket 5, the upper bracket 6 and the handle 7, and the lower bracket 4, the middle bracket 5, the upper bracket 6 and the handle 7 are fixed by M3 bolts. The handle 7 is used to carry, install and disassemble the waveguide probe.

[0047] In one embodiment, if Figure 6 and Figure 7 As shown, two axially arranged permanent magnets 9 and a silicon steel armature 10 form a group of magnets, wherein the polarities of the two permanent magnets 9 are opposite to each other, and the silicon steel armature 10 is used to close the magnetic circuit and enhance the magnetic field.

[0048] In one embodiment, considering the cost and the performance of the permanent magnet, N25 NdFeB rare earth magnet is selected as the permanent magnet 9, which is 30 mm long, 20 mm wide and 20 mm high. The width of the silicon steel armature 10 is the same as the width of the permanent magnet 9, which is 20 mm, and the length is the sum of the length of the two permanent magnets 9 and the distance between the permanent magnets, and the thickness is 6 mm.

[0049] In order to enhance the strength of the static axial bias magnetic field 12 of the pipeline 1 under test and ensure that the probe is easy to process and manufacture, each probe is evenly arranged with four groups of magnets, and each group of magnets is spaced 22.5° apart. During use, the upper probe 2 and the lower probe 3 contain a total of eight groups of magnets evenly arranged in the circumference of the pipeline.

[0050] In one embodiment, if Figure 8 As shown, the flexible coil 8 is made by a flexible printed circuit board (FPCB) process; the flexible coil 8 is a double-sided flexible printed circuit board, and the shape of the coil thereon is a runway shape; the flexible coil 8 includes: a coil connector 801, a coil forward section 802, a coil reverse section 803, a coil axial section 804, and a coil electromagnetic shielding layer 805; the coil electromagnetic shielding layer 805 covers the front and back sides of the coil reverse section 803; the width of the coil forward section 802 and the coil reverse section 803 are both half the wavelength of the ultrasonic guided wave.

[0051] In one embodiment, the copper foil thickness of the flexible coil 8 is 35 um to reduce the impedance of the flexible coil 8 and improve the signal conversion efficiency. The board thickness is selected to be 0.2 mm, and the covering film thickness is 25 um to increase the strength of the flexible coil 8.

[0052] The present invention uses a flexible coil installed on the probe to replace the manually wound and pasted coil on the measured pipeline, which is easy to disassemble and assemble and is convenient and quick to use.

[0053] In one embodiment, referring to Figure 1 , Figure 3 , Figure 4 , Figure 5 When the waveguide probe is used, two waveguide probes need to be prepared. The two probes are respectively used as an upper probe 2 and a lower probe 3. They are adsorbed on the surface of the measured pipe 1 by magnetic force to completely wrap the measured pipe 1. The flexible coils 8 of the two probes are connected by a circuit series method.

[0054] like Figure 1 and Fig. 9 As shown, the detection principle of the waveguide probe is as follows:

[0055] When in use, two probes, namely the upper probe 2 and the lower probe 3, are installed on the outer surface of the measured pipeline 1. The two probes are connected in series and arranged symmetrically. The permanent magnet 9 of the probe and the silicon steel armature 10 generate a pipeline axial static bias magnetic field 12 in the measured pipeline 1. A high-frequency pulse current is passed through the flexible coil 8, and the forward section 802 of the coil generates a pipeline axial high-frequency pulse magnetic field 11 in the measured pipeline 1. Based on the axial magnetostrictive effect, longitudinal modal ultrasonic guided waves propagating along the axial direction of the pipeline can be excited and received in the measured pipeline 1.

[0056] According to the basic principle of axial magnetostrictive effect, the ultrasonic guided wave efficiency is higher when the probe excitation and receiving vibration direction is parallel to the pipeline axial static bias magnetic field 12, and the ultrasonic guided wave efficiency is lower when the excitation and receiving vibration direction is not parallel to the pipeline axial static bias magnetic field 12. In this probe, the pipeline axial static bias magnetic field 12 is parallel to the pipeline axis, so the ultrasonic guided wave modal efficiency is higher when the probe excitation and receiving vibration direction is parallel to the pipeline axis, and the ultrasonic guided wave modal efficiency is lower when the excitation and receiving vibration direction is not parallel to the pipeline axis, and the waveguide mode selectivity is high.

[0057] The ultrasonic guided wave probe is in the shape of a semi-cylindrical shell as a whole. The working method of this type of probe is to install two identical ultrasonic guided wave probes, an upper probe 2 and a lower probe 3, on the measured pipe 1, and the upper probe 2 and the lower probe 3 are installed on the outer surface of the measured pipe; the upper probe 2 and the lower probe 3 are completely consistent in structure, and the installation state is centrally symmetrical; the coils of the upper probe 2 and the lower probe 3 are connected in series with the circuit.

[0058] The invention is an ultrasonic guided wave probe installed outside a pipeline, which is suitable for pipelines with a diameter of 50mm-200mm.

[0059] During the use of the ultrasonic guided wave probe, the permanent magnet 9 and the silicon steel armature 10 generate a static bias magnetic field 12 in the pipeline 1 under test; a high-frequency pulse current with a center frequency of 100kHz-200kHz is passed through the flexible coil 8, and the forward section 802 of the coil generates a high-frequency pulse magnetic field 11 in the pipeline 1 under test, and based on the magnetostrictive effect, longitudinal modal ultrasonic guided waves with a center frequency of 100kHz-200kHz propagating along the pipeline axial direction are excited and received. The longitudinal modal ultrasonic guided waves in this frequency range have a nearly constant wave velocity, which is easy to use for pipeline damage detection.

[0060] In one embodiment, the present invention further provides a pipeline longitudinal waveguide magnetostrictive probe detection method, comprising the following steps:

[0061] Step 1: prepare a pipeline 1 to be tested made of ferromagnetic material, and two pipeline longitudinal mode ultrasonic guided wave magnetostrictive probes, namely an upper probe 2 and a lower probe 3, and install the upper probe 2 and the lower probe 3 on the outer surface of the pipeline 1 to be tested. The upper probe 2 and the lower probe 3 need to be arranged in a central symmetrical manner;

[0062] Step 2: Connect a wire to the coil connector 801 on the flexible coil 8 of the probe to connect the upper probe 2 and the lower probe 3 in series;

[0063] Step 3: The permanent magnet 9 of the probe and the silicon steel armature 10 generate a pipeline axial static bias magnetic field 12 in the pipeline 1 under test, and a high-frequency pulse current is passed through the flexible coil 8. The forward section 802 of the coil generates a pipeline axial high-frequency pulse magnetic field 11 in the pipeline 1 under test. Based on the magnetostrictive effect, longitudinal modal ultrasonic guided waves propagating along the axial direction of the pipeline can be excited and received in the pipeline 1 under test.

[0064] The invention provides a non-contact, easy-to-assemble and disassemble pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe which is not prone to damage. By installing the probe on the outer surface of the pipeline to be tested, long-distance detection of the pipeline can be achieved.

[0065] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0066] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe, characterized in that: The magnetostrictive probe comprises a permanent magnet and a silicon steel armature, which generate an axial bias magnetic field in the measured pipeline. A pulse current is passed through the coil, and the positive section of the coil generates an axial high-frequency pulse magnetic field in the measured pipeline.

2. The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe according to claim 1, characterized in that: Preferably, the longitudinal mode ultrasonic guided waves propagating along the axial direction of the pipeline are excited and received based on the magnetostrictive effect.

3. The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe according to claim 2, characterized in that: Two axially arranged permanent magnets and a silicon steel armature form a set of magnets.

4. The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe according to claim 3, characterized in that: The polarities of the two permanent magnets are in opposite directions, and the silicon steel armature is used to close the magnetic circuit and enhance the magnetic field.

5. The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe according to claim 2, characterized in that: The magnetostrictive probe further comprises: a lower bracket, a middle bracket, an upper bracket and a handle.

6. The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe according to claim 1, characterized in that: The magnetostrictive probe also includes: an upper probe and a lower probe; when it is in working state, the upper probe and the lower probe are installed on the outer surface of the measured pipeline; the upper probe and the lower probe have completely the same structure.

7. The pipeline longitudinal modal ultrasonic guided wave magnetostrictive probe according to claim 2, characterized in that: The magnetostrictive probe further comprises: a flexible coil, and the flexible coil is made by a flexible printed circuit board (FPCB) process.

Images