CN112834606A - Method and device for identifying defects of inner wall and outer wall based on focusing magnetic flux leakage composite detection - Google Patents
Method and device for identifying defects of inner wall and outer wall based on focusing magnetic flux leakage composite detection Download PDFInfo
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Abstract
The invention provides an inner and outer wall defect identification method and device based on focused flux leakage composite detection, wherein the device comprises the following steps: magnetic focusing iron yoke, pole shoe or steel brush, permanent magnet, iron yoke; wherein, the magnetic focusing iron yoke is in an eccentric position, and an air gap is reserved between the magnetic focusing iron yoke and a tested sample for forming an end magnetic field focusing effect; the permanent magnets comprise a left permanent magnet and a right permanent magnet which are symmetrically distributed and have opposite magnetization directions, are positioned above the pole shoe or the steel brush and are used for saturating and magnetizing the tested sample; the iron yoke is positioned above the magnetic focusing iron yoke and the permanent magnet and is used for forming a saturation magnetization loop; the pole shoes or the steel brushes are symmetrically distributed below the two permanent magnets with opposite magnetization directions. The invention can simultaneously realize magnetic flux leakage detection and inner and outer wall defect identification in the same mechanical link; the structure is more centralized, the reliability is higher, and the passing capacity of the device is stronger; the method has simple solving model, high defect distinguishing speed and good real-time property; the system has low power consumption.
Description
Technical Field
The invention relates to the technical field of nondestructive testing, in particular to a method and a device for identifying defects of an inner wall and an outer wall based on focusing magnetic flux leakage composite testing.
Background
Petroleum and natural gas storage and transportation facilities such as pipelines, storage tank bottom plates and the like are usually made of ferromagnetic materials with high strength and good toughness. However, these facilities are very hostile and most are buried in earth for long periods of time and are subject to corrosive damage. The erosion slowly evolves into defects that may occur on the inside and outside of the ferromagnetic material, i.e., inside and outside wall defects. The threat of the inner wall defect and the outer wall defect to oil and gas pipelines, storage tank bottom plates, rails and the like is different, so that the method has great significance for distinguishing the inner wall defect and the outer wall defect. However, the conventional magnetic flux leakage detection cannot well detect the inner and outer walls, and how to realize the separation of the inner and outer walls while completing the magnetic flux leakage detection is always the key and difficult point of the ferromagnetic material nondestructive testing technology.
In the related art, the main method for solving the problem of simultaneously realizing magnetic flux leakage detection and defect inner and outer wall distinguishing comprises the following steps: by additionally arranging the independent mechanical joint, other detection methods such as eddy current detection, permanent magnetic disturbance detection and the like are applied to the newly added mechanical joint. However, the skin effect of eddy current detection and the vertical magnetic field of the permanent magnetic disturbance detection method both require a special magnetic field environment, which is incompatible with the saturation magnetic field environment of magnetic flux leakage detection, and therefore, the special magnetic field environment must be located in a newly added separate mechanical joint, which may cause damages such as increase in length, increase in weight, decrease in structural reliability, and decrease in throughput capacity of the detection instrument.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.
Therefore, a first objective of the present invention is to provide an inner and outer wall defect identification device based on focused magnetic flux leakage composite detection, so as to implement a method of utilizing magnetic flux leakage detection and magnetic focusing detection composite detection, and to implement inner and outer wall distinguishing detection in the same mechanical joint while implementing magnetic flux leakage detection.
The second purpose of the invention is to provide a method for identifying the defects of the inner wall and the outer wall based on the focused leakage magnetic composite detection.
In order to achieve the above object, a first embodiment of the present invention provides an apparatus for identifying defects on inner and outer walls based on focused leakage magnetic composite detection, including: magnetic focusing iron yoke, pole shoe or steel brush, permanent magnet, iron yoke; wherein, the magnetic focusing iron yoke is in an eccentric position, and an air gap is reserved between the magnetic focusing iron yoke and a tested sample for forming an end magnetic field focusing effect; the permanent magnets comprise a left permanent magnet and a right permanent magnet which are symmetrically distributed and have opposite magnetization directions, are positioned above the pole shoe or the steel brush and are used for saturating and magnetizing the tested sample; the iron yoke is positioned above the magnetic focusing iron yoke and the permanent magnet and is used for forming a saturation magnetization loop; the pole shoes or the steel brushes are symmetrically distributed below the two permanent magnets with opposite magnetization directions.
Optionally, the method further includes: one of the two magnetic field measuring sensors is positioned above the sample to be tested, and the optimal magnetic leakage detection position point is used for completing measurement of magnetic leakage detection tangential and normal magnetic field components; and the other one of the two magnetic field measurement sensors is positioned above the sample to be tested and below the end face of the magnetic focusing iron yoke, and is used for measuring tangential and normal magnetic field components of magnetic focusing detection.
Optionally, the method further includes: a data processing unit and a data storage unit, wherein,
and the data processing unit is respectively connected with the two magnetic field measurement sensors and is used for analyzing and judging the magnetic field values returned by the magnetic field measurement sensors for magnetic flux leakage detection and magnetic focusing detection to obtain correct inner and outer wall defect identification and classification.
Optionally, the data processing unit controls the magnetic field measurement sensor for magnetic flux leakage detection, so as to realize magnetic flux leakage detection and judge whether the defect exists.
Optionally, the data processing unit controls a magnetic field measurement sensor for magnetic focusing detection, so as to implement magnetic focusing detection, and determine whether an internal defect exists; and the data processing unit identifies and classifies the defects of the inner wall and the outer wall by combining the magnetic flux leakage detection result and the magnetic focusing detection result.
Optionally, the method further includes: a data storage unit, wherein,
the data storage unit is connected with the data processing unit and used for storing the magnetic field data of the leakage magnetic field and the focusing magnetic field acquired by the data processing unit from the magnetic field sensor and storing the defect classification result of the data processing unit.
Optionally, the magnetic focusing yoke may be the same as the yoke used for magnetic conduction in magnetic flux leakage detection, and the material of the magnetic focusing yoke may be the same as the yoke used for magnetic conduction in magnetic flux leakage detection.
Optionally, the magnetic focusing iron yoke is made of a high magnetic conductivity material, and a new magnetic circuit branch is formed on the basis of detecting an existing magnetic circuit by magnetic flux leakage, so that magnetic circuit shunting occurs.
Optionally, the requirement of an air gap between the magnetic focusing iron yoke and the sample to be tested is sufficiently small, the magnetic field in the air gap satisfies a condition of magnetic field boundary continuity, because the magnetic permeability of the magnetic focusing iron yoke and the sample to be tested is much greater than the air permeability, the magnetic lines of force in the air gap are perpendicular to the boundary between the air and the magnetic focusing iron yoke and the boundary between the air gap and the sample to be tested, and when the air gap between the magnetic focusing iron yoke and the sample to be tested is sufficiently small, a phenomenon of magnetic field concentration, namely a magnetic focusing effect, is formed on the end face of the magnetic focusing iron yoke.
Optionally, the magnetization intensity during magnetic leakage detection is higher than a preset magnetization intensity, wherein the preset magnetization intensity is the magnetization intensity of a preset conventional magnetic leakage detection.
In order to achieve the above object, a second embodiment of the present invention provides an inner and outer wall defect identification method based on focused leakage magnetic composite detection, which is applied to the inner and outer wall defect identification apparatus based on focused leakage magnetic composite detection described in the first embodiment of the present invention, and includes the following steps:
determining an optimal magnetic flux leakage detection position point according to a magnetic circuit equal magnetic potential method;
acquiring a tangential component and a normal component of a leakage magnetic field at the optimal magnetic flux leakage detection position point through a magnetic field measuring sensor on the inner and outer wall defect identification device based on the focused magnetic flux leakage composite detection, wherein the tangential direction is the magnetization direction of the surface of the sample to be tested, and the normal direction is the direction vertical to the surface of the sample to be tested; judging whether the detected pattern has defects according to the tangential component and the normal component;
if the defect exists, carrying out magnetic focusing detection on the end face of the magnetic focusing iron yoke through the inner and outer wall defect identification device based on the focusing magnetic leakage composite detection, collecting a tangential component and a normal component of a focusing magnetic field at the end face, and judging whether the defect is an inner wall defect by utilizing the two components of the focusing magnetic field; and carrying out composite judgment through the inner and outer wall defect identification device based on the focusing magnetic leakage composite detection, and carrying out inner and outer wall defect classification on the defects.
Optionally, the determining an optimal leakage flux detection position point according to a magnetic circuit equipotential method includes:
and determining the points of the iron yoke on the focusing magnetic leakage composite detection-based inner and outer wall defect identification device and the points of the tested sample with equal magnetic potential as the optimal magnetic leakage detection position points.
Optionally, the magnetic focusing detection is performed at the end face of the magnetic focusing iron yoke by the inner and outer wall defect identification device based on the focusing leakage magnetic composite detection, including: when the focusing magnetic field of the end face of the magnetic focusing iron yoke only contains a normal component and does not contain a tangential component, determining that no defect or only an external defect exists on the tested sample; and when the focusing magnetic field at the end face of the magnetic focusing iron yoke simultaneously contains the tangential component and the normal component, determining that the tested sample has internal defects.
Optionally, through interior outer wall defect recognition device based on focus magnetic leakage composite detection carries out compound judgement, includes: if the tangential or normal component of the leakage magnetic field exists at the optimal leakage magnetic detection position point and the tangential and normal components of the focusing magnetic field exist at the end face of the magnetic focusing iron yoke, determining the defect as an internal defect;
optionally, through interior outer wall defect recognition device based on focus magnetic leakage composite detection carries out compound judgement, includes: if the tangential or normal component of the leakage magnetic field exists at the optimal leakage magnetic detection position point and only the normal component of the focusing magnetic field exists at the end face of the magnetic focusing iron yoke, determining the defect as an external defect;
optionally, through interior outer wall defect recognition device based on focus magnetic leakage composite detection carries out compound judgement, includes: and if no leakage magnetic field exists at the optimal magnetic leakage detection position point and only the normal component of the focusing magnetic field exists at the end face of the magnetic focusing iron yoke, determining that no defect exists.
The embodiment of the invention at least has the following technical effects:
magnetic flux leakage detection and inner and outer wall defect identification can be simultaneously realized in the same mechanical link; the structure is more centralized, the reliability is higher, and the passing capacity of the device is stronger; the method has simple solving model, high defect distinguishing speed and good real-time property; the system has low power consumption.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
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The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic structural diagram of an embodiment of an inner and outer wall defect identification apparatus based on focused leakage flux composite detection according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method for identifying defects on inner and outer walls based on focused flux leakage composite detection according to an embodiment of the present invention;
fig. 3 is a schematic view showing the distribution of magnetic lines of force by the end magnetic field focusing effect of the magnetic focusing iron yoke according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of an equivalent magnetic circuit model and an equivalent magnetic potential method of a magnetic circuit according to an embodiment of the present invention;
FIG. 5 is a schematic view of the magnetic flux distribution when magnetic focusing detection identifies an internal defect according to one embodiment of the present invention;
FIG. 6 is a diagram illustrating magnetic flux distribution when internal defects are identified by magnetic flux leakage detection according to an embodiment of the present invention;
FIG. 7 is a graph of the results of collected tangential and normal magnetic field signals when magnetic flux leakage detection identifies internal and external wall defects, in accordance with one embodiment of the present invention;
FIG. 8 is a graph of the results of collected tangential magnetic field signals when magnetic focusing detection identifies internal and external wall defects according to one embodiment of the present invention;
description of reference numerals: 100-an inner and outer wall defect recognition device based on focusing leakage magnetic composite detection, 1-a sample to be tested made of a ferromagnetic material, 2-a magnetic field measuring sensor for magnetic focusing detection, 3-a defect, 4 and 10-pole shoes or steel brushes, 5 and 9-permanent magnet pairs with opposite magnetization directions, 6-an iron yoke, 7-a magnetic field measuring sensor for leakage magnetic detection, 8-a magnetic focusing iron yoke, 11-a data processing unit and 12-a data storage unit.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The method and the device for identifying the defects of the inner wall and the outer wall based on the focused leakage flux composite detection are described below with reference to the accompanying drawings.
Fig. 1 is a block diagram of a structure of an inner and outer wall defect identification apparatus based on focused leakage flux composite detection according to an embodiment of the present invention.
The apparatus 100 comprises: a magnetic focusing iron yoke 8, pole shoes or steel brushes 4 and 10, permanent magnet pairs 5 and 9, and an iron yoke 6. Wherein, the magnetic focusing iron yoke 8 is in an eccentric position, and an air gap is left between the magnetic focusing iron yoke and the tested sample 1 for forming an end magnetic field focusing effect; the pole shoes or the steel brushes 4 and 10 are positioned at two sides of the composite detection system 100, are symmetrically distributed, and are used for improving the contact area of the surface of a sample, improving a saturated magnetization loop of the contact surface and improving the magnetization efficiency; the permanent magnet pairs 5 and 9 comprise left and right permanent magnets with opposite magnetization directions, are symmetrically distributed, are positioned on two sides of the composite detection system 100, are positioned above the pole shoe or the steel brush 4 and 10, and are used for saturating and magnetizing the tested sample 1; the iron yoke 6 is positioned above the magnetic focusing iron yoke 8 and the permanent magnet pairs 5 and 9 and is used for forming a saturation magnetization loop, reducing a background magnetic field and improving magnetization efficiency.
It should be noted that the sample 1 to be tested made of ferromagnetic material may be an oil and gas pipeline, a rail, a storage tank bottom plate, etc.
Further, the embodiment of the present invention further includes: the magnetic field measuring device comprises two magnetic field measuring sensors 2 and 7, a data processing unit 11 and a data storage unit 12, wherein one magnetic field measuring sensor 7 is positioned above a sample to be tested 1 and is used for measuring magnetic leakage detection tangential and normal magnetic field components; the other magnetic field measurement sensor 2 is positioned above the sample 1 to be tested and used for measuring the tangential magnetic field component of the magnetic focusing detection; the data processing unit 11 is respectively connected with the two magnetic field measurement sensors 2 and 7, and is used for analyzing and judging the magnetic field values returned by the magnetic field measurement sensors for magnetic flux leakage detection and magnetic focusing detection to obtain correct inner and outer wall defect identification classification; the data storage unit 12 is connected to the data processing unit 11, and is configured to store the magnetic field data acquired by the data processing unit 11 from the magnetic field sensors 2 and 7, and also store the defect classification result of the data processing unit 11.
Further, in an embodiment of the present invention, the data processing unit 11 is specifically configured to:
controlling the magnetic field measuring sensor 7 for magnetic flux leakage detection to realize magnetic flux leakage detection and judging whether defects exist or not; controlling the magnetic field measuring sensor 2 for magnetic focusing detection to realize magnetic focusing detection and judging whether internal defects exist or not; and (4) classifying the defects of the inner wall and the outer wall by combining the magnetic leakage detection result and the magnetic focusing detection result.
That is, the sample 1 to be tested is magnetized by the permanent magnets 5 and 9 on both sides of the device 100, when a defect occurs, a leakage magnetic field is generated first, the magnetic field measurement sensor 7 collects tangential and normal signals of the leakage magnetic field, and returns to the data processing unit 11 to judge whether the defect exists; then, a magnetic field focusing effect is generated through the magnetic focusing iron yoke 8, the magnetic field measuring sensor 2 collects tangential signals of a focusing magnetic field and transmits the tangential signals back to the data processing unit 11 to judge whether internal defects exist or not. The data processing unit 11 combines the results of the magnetic flux leakage detection and the magnetic focusing detection to judge whether the defect exists or not and distinguish the inner wall and the outer wall of the defect. Meanwhile, all the magnetic field values measured by the magnetic flux leakage detection and the magnetic focus detection are stored in the data storage unit 12. That is, it is finally achieved that the magnetic flux leakage detection and the defect inner and outer wall discrimination are simultaneously achieved at the same mechanical position.
It can be understood that the data processing unit adopted in the embodiment of the invention is an STM32L4 low-power consumption series single chip microcomputer of the ST group; the data storage unit adopts W25Q64 series of Huabang company (Winbond), and the storage space is 64M-bit; the magnetic field measurement sensor employs a GMR series magnetic sensor available from NVE Corporation. The selection can be made by those skilled in the art according to practical situations, and is not specifically limited herein.
In one embodiment of the present invention, the height of the air gap between the magnetic focusing iron yoke and the sample to be tested may be generally selected to be 1-10 mm, and in one embodiment of the present invention, the height of the air gap is 2.5 mm.
According to the inner and outer wall defect identification device based on the focusing magnetic flux leakage composite detection, the problems of magnetic flux leakage detection and defect inner and outer wall distinguishing at the same mechanical position are solved, the structure is more concentrated, the reliability is higher, and the passing capacity of the device is stronger; the solution model is simple, the defect discrimination speed is high, and the real-time performance is good; the system has low power consumption.
The following description focuses on the method for identifying defects of inner and outer walls based on the focus leakage magnetic composite detection, wherein the method for identifying defects of inner and outer walls based on the focus leakage magnetic composite detection is applied to the apparatus for identifying defects of inner and outer walls based on the focus leakage magnetic composite detection shown in fig. 1, as shown in fig. 2, and the method includes:
and step 101, determining an optimal magnetic flux leakage detection position point according to a magnetic potential position method of a magnetic circuit.
It can be understood that in this embodiment, an eccentric magnetic focusing yoke is added to the magnetic flux leakage detection structure to form the magnetic path shunt and the magnetic field focusing effect at the end of the yoke.
In an embodiment of the present invention, the magnetic focusing yoke may be made of the same material as that of the yoke for magnetic conduction in magnetic flux leakage detection.
In one embodiment of the invention, the magnetic focusing iron yoke is not at the center of symmetry of the composite detection model, but eccentrically near one side of one of the permanent magnets. The magnetic focusing yoke is processed eccentrically mainly to reduce the influence of a branch magnetic circuit formed by the magnetic focusing yoke on magnetic leakage detection.
Specifically, in the embodiment of the present invention, as shown in fig. 1, the magnetic focusing iron yoke is not located at the center of the composite detection system, but is located at an eccentric position, which is biased to the rear permanent magnet side.
Further, in an embodiment of the present invention, the magnetic focusing iron yoke is made of a high magnetic permeability material, and a new magnetic circuit branch is formed on the basis of detecting an existing magnetic circuit by magnetic flux leakage, so that magnetic circuit shunting occurs.
For example, as shown in fig. 3, based on the existing magnetic circuit for magnetic flux leakage detection, the magnetic focusing yoke is introduced to form a magnetic circuit branch of one core at the same time, so as to form a magnetic circuit shunt.
Further, in one embodiment of the present invention, a small air gap is left between the magnetic focusing iron yoke and the sample under test. The magnetic field in the air gap meets the condition of magnetic field boundary continuity, and because the magnetic permeability of the magnetic focusing iron yoke and the tested sample is far larger than the air permeability, the magnetic force lines in the air gap are perpendicular to the boundary between the air and the magnetic focusing iron yoke and the boundary between the air and the tested sample. When the air gap between the magnetic focusing iron yoke and the sample to be tested is small enough, the end face of the magnetic focusing iron yoke will form a phenomenon of magnetic field concentration, i.e. magnetic focusing effect.
Specifically, the height of the air gap between the magnetic focusing iron yoke and the sample to be tested can be generally selected to be 1-10 mm, and in the embodiment of the invention, the height of the air gap is 2.5 mm.
For example, as shown in fig. 3, since the air gap between the magnetic focusing iron yoke and the sample to be tested is 2.5mm, the air gap height is sufficiently small, and the magnetic permeability of the magnetic focusing iron yoke and the sample to be tested is much greater than the air permeability, the magnetic field in the air gap between the magnetic focusing iron yoke and the sample to be tested has only a normal component and is concentrated at the end of the magnetic focusing iron yoke.
In an embodiment of the present invention, the optimal leakage magnetic detection position point is a position point where the background magnetic field is weakest, and the magnetic sensor is placed at the position to minimize the suppression effect of the background magnetic field, so that the leakage magnetic detection signal is maximized, and the leakage magnetic detection is better achieved.
Further, in an embodiment of the present invention, the magnetic potential equivalent method is based on an equivalent magnetic circuit model, wherein a point where the magnetic potentials of the iron yoke and the sample to be measured are equal is a weakest point of the background magnetic field.
For example, as shown in fig. 4, the focus leakage magnetic composite detection system can be equivalent to an equivalent magnetic circuit model. In the figure, NI is magnetic field excitation in the equivalent magnetic circuit model, corresponding to the permanent magnet in the focus leakage flux composite detection system, wherein '±' indicates the NS pole magnetization direction of the permanent magnet. Ryoke1，Ryoke2And Ryoke3Representing the reluctance of the corresponding segmented yoke, Rair1And Rair3Represents the reluctance of the corresponding segment of air, Rspec1，Rspec2And Rspec3Is the equivalent reluctance of the corresponding segmented sample. Ryoke4Represents the magnetic resistance of the magnetic focusing iron yoke introduced, and Rair2Representing the reluctance of the air gap between the magnetic focusing iron yoke and the sample under test. Combining fig. 3 and fig. 4, it can be found that the point where the magnetic potentials in the equivalent magnetic circuit model are equal is the weakest point of the background magnetic field.
Further, in one embodiment of the present invention, the magnetic circuit equipotential method indicates that if there is no magnetic focusing iron yoke, the left and right magnetic resistances are the same, and thus the equipotential point is located in the middle of the two permanent magnets, i.e., the optimal leakage magnetic detection position point is in the middle of the permanent magnets.
For example, as shown in fig. 4, if there is no introduction of the yoke of the magnetic focusing iron shown by the dotted line portion, the magnetic resistances on the left and right sides in the equivalent model of the magnetic circuit are equal, that is,
Rspec1+Rspec2＝Rspec3
Ryoke1+Ryoke2＝Ryoke3
therefore, the isomagnetic potential point is located in the middle of the two permanent magnets, namely the optimal magnetic flux leakage detection position point is located in the middle of the two permanent magnets.
Further, in an embodiment of the present invention, the magnetic circuit equipotential method indicates that, when a magnetic focusing iron yoke is introduced, in an equivalent magnetic circuit model, a new magnetic circuit branch is formed equivalently by introducing a magnetic resistance including the magnetic focusing iron yoke and an air gap magnetic resistance. Therefore, an appropriate division point of the sample to be measured is selected to ensure that the magnetic resistances of the left and right portions are balanced again. The point is the weakest position point of the background magnetic field, namely the best position point of the magnetic flux leakage detection. In the case of introducing the magnetic focusing iron yoke, the magnetic flux leakage detection optimum position point is no longer located at the intermediate position, but eccentrically close to the magnetic focusing iron yoke side.
For example, as shown in fig. 4, due to the introduction of the magnetic focusing iron yoke, the magnetic resistances of the magnetic focusing iron yoke and the air gap are equivalent to those of the magnetic focusing iron yoke indicated by the dotted line, so that the magnetic resistances of the left and right sides are not equal. Therefore, it is necessary to reselect the appropriate division point of the sample to be measured to ensure that the magnetic resistances of the left and right parts are balanced again. At this time, the point is the weakest position point of the background magnetic field, that is, the best position point for magnetic flux leakage detection. In the case of introducing the magnetic focusing iron yoke, the magnetic flux leakage detection optimum position point is no longer located at the intermediate position, but eccentrically close to the magnetic focusing iron yoke side. Specifically, in the embodiment of the present invention, as shown in fig. 1, the magnetic focusing iron yoke is not located at the center of the composite detection system, but is located at an eccentric position, which is biased to the rear permanent magnet side.
102, acquiring a tangential component and a normal component of a leakage magnetic field at the optimal magnetic flux leakage detection position point through the magnetic field measurement sensor on the inner and outer wall defect identification device based on the focused magnetic flux leakage composite detection, wherein the tangential direction is the magnetization direction of the surface of the sample to be tested, and the normal direction is the direction vertical to the surface of the sample to be tested.
And 103, judging whether the detected pattern has defects according to the tangential component and the normal component.
In one embodiment of the invention, the leakage flux detection requires a higher magnetization to ensure that the sample under test is under saturation magnetization.
Specifically, in the embodiment of the present invention, the surface residual magnetic field strength of the permanent magnet employed is 1.39T, which is slightly higher than 1T of the conventional leakage flux detection.
Further, in one embodiment of the invention, the leakage flux detection comprises a magnetic field measurement sensor. The magnetic field measuring sensor acquires the tangential component and the normal component of the leakage magnetic field and judges whether the defects exist or not.
In the embodiment of the present invention, the tangential direction is the magnetization direction of the sample surface, and the normal direction is the direction perpendicular to the sample surface to be tested.
For example, as shown in fig. 6 and 7, when a test sample is saturated and magnetized, and a defect is generated on the test sample, a leakage magnetic field is generated on both the inner wall and the outer wall of the test sample. The tangential and normal magnetic field sizes of the inner wall defect and the outer wall defect measured by the magnetic field measurement sensor for magnetic flux leakage detection in the composite detection system are shown in fig. 6. Therefore, the magnetic flux leakage detection in the composite detection system can well detect the defects of the inner wall and the outer wall, but the defects of the inner wall and the outer wall cannot be obviously distinguished.
And 104, if the defect exists, performing magnetic focusing detection on the end face of the magnetic focusing iron yoke through the inner and outer wall defect identification device based on the focusing leakage magnetic composite detection, collecting a tangential component and a normal component of a focusing magnetic field at the end face, and judging whether the defect is an inner wall defect by utilizing the two components of the focusing magnetic field.
In one embodiment of the invention, the magnetic focusing detection is satisfied that when no defect or only an external defect exists on a tested sample, a magnetic field in an air gap only contains a normal component; when an internal defect exists on the sample, the magnetic field lines are perpendicular to the boundary between the defect and the air, the magnetic field balance state with only the normal component in the air gap is damaged, the magnetic field in the air gap no longer has only the normal component, and therefore the magnetic focusing detection can identify the existence of the internal defect by detecting the existence of the tangential magnetic field component in the air gap.
For example, as shown in FIG. 3, in one embodiment of the present invention, the magnetic focus detection is such that the magnetic field in the air gap contains only a normal component when there are no defects or only external defects on the test specimen being tested.
For example, as shown in fig. 5, in one embodiment of the present invention, when an internal defect exists on the test piece, the magnetic field lines will be perpendicular to the boundary between the defect and the air, the state of magnetic field equilibrium with only the normal component in the air gap will be destroyed, and the magnetic field in the air gap no longer has only the normal component, so by detecting the presence or absence of the tangential magnetic field component in the air gap, magnetic focusing detection can identify the presence or absence of the internal defect.
For example, as shown in fig. 8, the tangential magnetic field signals of the inner wall defect and the outer wall defect are obtained by magnetic focusing detection, so that the inner wall defect can be identified, and no obvious response is caused to the outer wall defect.
In one embodiment of the present invention, when the focusing magnetic field at the end face of the magnetic focusing iron yoke only contains a normal component and not a tangential component, it is determined that there is no defect or only an external defect on the test specimen, and when the focusing magnetic field at the end face of the magnetic focusing iron yoke contains both the tangential component and the normal component, it is determined that there is an internal defect on the test specimen.
And 105, carrying out composite judgment through the inner and outer wall defect identification device based on the focus flux leakage composite detection, and classifying the defects of the inner and outer walls.
In one embodiment of the invention, the condition that the defects in the focus leakage flux composite detection judgment meet the defect can be identified by the leakage flux detection and the magnetic focus detection at the same time. If there is the tangential or normal component of leaking magnetic field in best magnetic leakage detection position point department, and during magnetic focusing iron yoke terminal surface department had the tangential and normal component of focusing magnetic field simultaneously, the definite defect was interior defect, if there was the tangential or normal component of leaking magnetic field in best magnetic leakage detection position point department, and when magnetic focusing iron yoke terminal surface department only had the normal component of focusing magnetic field, the definite defect was outer defect, if there was not leaking magnetic field in best magnetic leakage detection position point department, and when only having the normal component of focusing magnetic field in magnetic focusing iron yoke terminal surface department, the definite defect that does not exist. Further, in an embodiment of the present invention, the condition for determining the external defect by the focus leakage magnetic composite detection is that the defect can only be identified by leakage magnetic detection and cannot be identified by magnetic focus detection.
Further, in one embodiment of the present invention, the focus leakage flux composite detection determines that the condition of no defect satisfies the condition that the defect cannot be identified by the leakage flux detection and the magnetic focus detection.
For example, as shown in fig. 7 and 8, the inner wall defect can be identified by both magnetic flux leakage detection and magnetic focusing detection, while the outer wall defect can be identified only by magnetic flux leakage detection. The focusing magnetic leakage composite detection can realize the distinguishing and detection of the defects of the inner wall and the outer wall.
Therefore, the method solves the problems of realizing magnetic flux leakage detection and defect inner and outer wall distinguishing at the same mechanical position, has more concentrated structure, higher reliability and stronger device passing capacity; the solution model is simple, the defect discrimination speed is high, and the real-time performance is good; the system has low power consumption.
According to the method for identifying the defects of the inner wall and the outer wall based on the focusing leakage magnetic composite detection, which is provided by the embodiment of the invention, the eccentric magnetic focusing iron yoke is additionally arranged in the leakage magnetic detection structure to form the magnetic path shunting and the magnetic field focusing effect at the end part of the iron yoke; further designing an optimal magnetic flux leakage detection position point according to a magnetic circuit equal magnetic potential method; further carrying out magnetic flux leakage detection and judging whether the defects exist or not; further carrying out magnetic focusing detection and judging whether the defect is an inner wall defect; and finally, carrying out focusing magnetic flux leakage composite detection judgment, and carrying out inner and outer wall defect classification on the defects. Meanwhile, magnetic flux leakage detection and inner and outer wall defect identification are realized; the magnetic flux leakage detection and the inner and outer wall defect identification can be realized in the same mechanical link.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (16)
1. The utility model provides an interior outer wall defect recognition device based on compound detection of focus magnetic leakage which characterized in that includes: magnetic focusing iron yoke, pole shoe or steel brush, permanent magnet, iron yoke; wherein,
the magnetic focusing iron yoke is in an eccentric position, and an air gap is reserved between the magnetic focusing iron yoke and a tested sample for forming an end magnetic field focusing effect;
the permanent magnets comprise a left permanent magnet and a right permanent magnet which are symmetrically distributed and have opposite magnetization directions, are positioned above the pole shoe or the steel brush and are used for saturating and magnetizing the tested sample;
the iron yoke is positioned above the magnetic focusing iron yoke and the permanent magnet and is used for forming a saturation magnetization loop;
the pole shoes or the steel brushes are symmetrically distributed below the two permanent magnets with opposite magnetization directions.
2. The apparatus of claim 1, further comprising: two magnetic field measuring sensors, wherein,
one of the two magnetic field measuring sensors is positioned above the sample to be tested, and the optimal magnetic flux leakage detection position point is used for completing the measurement of magnetic flux leakage detection tangential and normal magnetic field components;
and the other one of the two magnetic field measurement sensors is positioned above the sample to be tested and below the end face of the magnetic focusing iron yoke, and is used for measuring tangential and normal magnetic field components of magnetic focusing detection.
3. The apparatus of claim 1, further comprising: a data processing unit for, among other things,
and the data processing unit is respectively connected with the two magnetic field measurement sensors and is used for analyzing and judging the magnetic field values returned by the magnetic field measurement sensors for magnetic flux leakage detection and magnetic focusing detection to obtain correct inner and outer wall defect identification and classification.
4. The method of claim 3,
the data processing unit controls a magnetic field measuring sensor for magnetic flux leakage detection, realizes magnetic flux leakage detection, and judges whether defects exist or not.
5. The method of claim 3,
the data processing unit controls a magnetic field measuring sensor for magnetic focusing detection, realizes the magnetic focusing detection and judges whether internal defects exist or not;
and the data processing unit identifies and classifies the defects of the inner wall and the outer wall by combining the magnetic flux leakage detection result and the magnetic focusing detection result.
6. The apparatus of claim 3, further comprising: a data storage unit, wherein,
the data storage unit is connected with the data processing unit and used for storing the magnetic field data of the leakage magnetic field and the focusing magnetic field acquired by the data processing unit from the magnetic field sensor and storing the defect classification result of the data processing unit.
7. The apparatus of claim 1, wherein the magnetic focusing yoke is made of the same material as a yoke used for magnetic conduction in magnetic flux leakage detection.
8. The apparatus of claim 1, wherein the magnetic focusing yoke is made of a high magnetic permeability material, and a new magnetic circuit branch is formed on the basis of an existing magnetic circuit for magnetic flux leakage detection, so that magnetic circuit shunting occurs.
9. The apparatus of claim 1, wherein an air gap between the magnetic focusing iron yoke and the sample to be tested is required to be small enough, a magnetic field in the air gap satisfies a magnetic field boundary continuity condition, since the magnetic permeability of the magnetic focusing iron yoke and the sample to be tested is much larger than the air permeability, magnetic lines of force in the air gap are perpendicular to the boundary between the air and the magnetic focusing iron yoke and the boundary between the air gap and the sample to be tested, and when the air gap between the magnetic focusing iron yoke and the sample to be tested is small enough, a phenomenon of magnetic field concentration, namely a magnetic focusing effect, is formed on an end face of the magnetic focusing iron yoke.
10. The apparatus of claim 2, wherein the magnetization at the time of the magnetic leakage detection is higher than a preset magnetization, wherein the preset magnetization is a magnetization preset for a conventional magnetic leakage detection.
11. A method for identifying defects of inner and outer walls based on focused leakage magnetic composite detection, which is applied to the device for identifying defects of inner and outer walls based on focused leakage magnetic composite detection as claimed in any one of claims 1 to 10, and comprises the following steps:
determining an optimal magnetic flux leakage detection position point according to a magnetic circuit equal magnetic potential method;
acquiring a tangential component and a normal component of a leakage magnetic field at the optimal magnetic flux leakage detection position point through a magnetic field measuring sensor on the inner and outer wall defect identification device based on the focused magnetic flux leakage composite detection, wherein the tangential direction is the magnetization direction of the surface of the sample to be tested, and the normal direction is the direction vertical to the surface of the sample to be tested;
judging whether the detected pattern has defects according to the tangential component and the normal component;
if the defect exists, carrying out magnetic focusing detection on the end face of the magnetic focusing iron yoke through the inner and outer wall defect identification device based on the focusing magnetic leakage composite detection, collecting a tangential component and a normal component of a focusing magnetic field at the end face, and judging whether the defect is an inner wall defect by utilizing the two components of the focusing magnetic field;
and carrying out composite judgment through the inner and outer wall defect identification device based on the focusing magnetic leakage composite detection, and carrying out inner and outer wall defect classification on the defects.
12. The method of claim 10, wherein said determining an optimal leakage flux detection position point according to a magnetic circuit equipotential method comprises:
and determining the points of the iron yoke on the focusing magnetic leakage composite detection-based inner and outer wall defect identification device and the points of the tested sample with equal magnetic potential as the optimal magnetic leakage detection position points.
13. The method of claim 10, wherein the magnetic focusing detection is performed at the end face of the magnetic focusing iron yoke by the inner and outer wall defect identification device based on the focus leakage magnetic composite detection, and comprises the following steps:
when the focusing magnetic field of the end face of the magnetic focusing iron yoke only contains a normal component and does not contain a tangential component, determining that no defect or only an external defect exists on the tested sample;
and when the focusing magnetic field at the end face of the magnetic focusing iron yoke simultaneously contains the tangential component and the normal component, determining that the tested sample has internal defects.
14. The method of claim 10, wherein the composite judgment by the inner and outer wall defect identification device based on focus leakage magnetic composite detection comprises:
and if the tangential or normal component of the leakage magnetic field exists at the optimal leakage magnetic detection position point and the tangential and normal components of the focusing magnetic field exist at the end face of the magnetic focusing iron yoke, determining the defect as an internal defect.
15. The method of claim 10, wherein the composite judgment by the inner and outer wall defect identification device based on focus leakage magnetic composite detection comprises: and if the tangential or normal component of the leakage magnetic field exists at the optimal leakage magnetic detection position point and only the normal component of the focusing magnetic field exists at the end face of the magnetic focusing iron yoke, determining the defect as an external defect.
16. The method of claim 10, wherein the composite judgment by the inner and outer wall defect identification device based on focus leakage magnetic composite detection comprises:
and if no leakage magnetic field exists at the optimal magnetic leakage detection position point and only the normal component of the focusing magnetic field exists at the end face of the magnetic focusing iron yoke, determining that no defect exists.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114705750A (en) * | 2022-04-06 | 2022-07-05 | 清华大学 | Defect identification method and device |
| CN115060793A (en) * | 2022-08-16 | 2022-09-16 | 北京航空航天大学 | On-line detection device, method, medium and equipment for defects of airborne towed antenna |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4445088A (en) * | 1980-05-10 | 1984-04-24 | Institut Dr. Friedrich Forster Prufgeratebau | Method and arrangement for evaluating a defect signal by comparing the ratio of maximum signal rise and maximum signal magnitude to a predetermined value |
| GB9225190D0 (en) * | 1991-12-13 | 1993-01-20 | Nippon Kokan Kk | Method and apparatus for detecting defects of a steel material |
| JPH07198683A (en) * | 1993-12-28 | 1995-08-01 | Tokyo Gas Co Ltd | Method for magnaflux inspection |
| JPH08193980A (en) * | 1995-01-19 | 1996-07-30 | Yoshihiro Murakami | Method and device for magnetic flaw detection |
| CN101216460A (en) * | 2008-01-11 | 2008-07-09 | 清华大学 | AC and DC composite magnetisation based leakage detection recognition method for inside and outside wall defect |
| US20090301206A1 (en) * | 2005-12-17 | 2009-12-10 | Andre Yashan | Method and System for Non-destructively Testing a Metallic Workpiece |
| WO2011056040A2 (en) * | 2009-11-09 | 2011-05-12 | 한국표준과학연구원 | Non-destructive detecting apparatus using a magnetic flux leakage measurement |
| CN102759567A (en) * | 2012-07-18 | 2012-10-31 | 南昌航空大学 | Eddy current testing recognition and evaluation method for defects of inner wall and outer wall of steel pipe under direct current magnetization |
| CN103175891A (en) * | 2013-02-28 | 2013-06-26 | 厦门大学 | Permanent magnet and pulsed eddy current composite magnetic flux leakage detection method |
| CN103353479A (en) * | 2013-06-28 | 2013-10-16 | 厦门大学 | Electromagnetic ultrasonic longitudinal guided wave and magnetic leakage detection compounded detection method |
| CN103353478A (en) * | 2013-06-28 | 2013-10-16 | 厦门大学 | Magnetoacoustic tomography and magnetic leakage tomography compounded non-destructive detection method |
| CN104990977A (en) * | 2015-06-29 | 2015-10-21 | 清华大学 | Three-dimensional magnetic flux leakage inspection and defect compound inversion imaging method |
| CN207196096U (en) * | 2017-08-25 | 2018-04-06 | 上海市特种设备监督检验技术研究院 | Detection inside and outside wall defect distinguishing sensor in pipe leakage |
| CN108226277A (en) * | 2017-12-28 | 2018-06-29 | 哈尔滨工业大学 | The outer detection probe of a kind of leakage field, electromagnetic acoustic and vortex composite pipeline |
-
2021
- 2021-01-07 CN CN202110018225.XA patent/CN112834606B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4445088A (en) * | 1980-05-10 | 1984-04-24 | Institut Dr. Friedrich Forster Prufgeratebau | Method and arrangement for evaluating a defect signal by comparing the ratio of maximum signal rise and maximum signal magnitude to a predetermined value |
| GB9225190D0 (en) * | 1991-12-13 | 1993-01-20 | Nippon Kokan Kk | Method and apparatus for detecting defects of a steel material |
| JPH07198683A (en) * | 1993-12-28 | 1995-08-01 | Tokyo Gas Co Ltd | Method for magnaflux inspection |
| JPH08193980A (en) * | 1995-01-19 | 1996-07-30 | Yoshihiro Murakami | Method and device for magnetic flaw detection |
| US20090301206A1 (en) * | 2005-12-17 | 2009-12-10 | Andre Yashan | Method and System for Non-destructively Testing a Metallic Workpiece |
| CN101216460A (en) * | 2008-01-11 | 2008-07-09 | 清华大学 | AC and DC composite magnetisation based leakage detection recognition method for inside and outside wall defect |
| WO2011056040A2 (en) * | 2009-11-09 | 2011-05-12 | 한국표준과학연구원 | Non-destructive detecting apparatus using a magnetic flux leakage measurement |
| CN102759567A (en) * | 2012-07-18 | 2012-10-31 | 南昌航空大学 | Eddy current testing recognition and evaluation method for defects of inner wall and outer wall of steel pipe under direct current magnetization |
| CN103175891A (en) * | 2013-02-28 | 2013-06-26 | 厦门大学 | Permanent magnet and pulsed eddy current composite magnetic flux leakage detection method |
| CN103353479A (en) * | 2013-06-28 | 2013-10-16 | 厦门大学 | Electromagnetic ultrasonic longitudinal guided wave and magnetic leakage detection compounded detection method |
| CN103353478A (en) * | 2013-06-28 | 2013-10-16 | 厦门大学 | Magnetoacoustic tomography and magnetic leakage tomography compounded non-destructive detection method |
| CN104990977A (en) * | 2015-06-29 | 2015-10-21 | 清华大学 | Three-dimensional magnetic flux leakage inspection and defect compound inversion imaging method |
| CN207196096U (en) * | 2017-08-25 | 2018-04-06 | 上海市特种设备监督检验技术研究院 | Detection inside and outside wall defect distinguishing sensor in pipe leakage |
| CN108226277A (en) * | 2017-12-28 | 2018-06-29 | 哈尔滨工业大学 | The outer detection probe of a kind of leakage field, electromagnetic acoustic and vortex composite pipeline |
Non-Patent Citations (4)
| Title |
|---|
| JUNJIE CHEN, ET AL.: "Three-dimensional defect reconstruction from magnetic flux leakage signals in pipeline inspection based on a dynamic taboo search procedure", 《INSIGHT》 * |
| YAN SHI, ET AL.: "Theory and Application of Magnetic Flux Leakage Pipeline Detection", 《SENSORS》 * |
| 杨理践等: "弱磁场中漏磁检测技术的研究", 《仪表技术与传感器》 * |
| 王学彬 等: "管道三维漏磁检测仿真分析及研究", 《理论与方法》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114705750A (en) * | 2022-04-06 | 2022-07-05 | 清华大学 | Defect identification method and device |
| CN115060793A (en) * | 2022-08-16 | 2022-09-16 | 北京航空航天大学 | On-line detection device, method, medium and equipment for defects of airborne towed antenna |
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|---|---|
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