A mosaic distributed combined interval magnetization method and detection method

Abstract

The present invention relates to a detection technology for surface defects and buried defects of ferromagnetic materials, and specifically discloses a mosaic distributed combined interval magnetization method and a detection method, the magnetization method comprising: a magnetization module composed of magnetic sources arranged at both ends of a yoke and having opposite magnetic properties; a magnetic sensor arranged between the two magnetic sources, the magnetic sensor being used to detect changes in the magnetic field direction of a test piece under inspection; the yoke and the magnetic source are wrapped to form a non-metallic wrapping structure of a detection component, the magnetization module being divided into a first magnetization module and a second magnetization module arranged symmetrically about the center of the first magnetization module. The invention solves the problem of inaccurate detection signals caused by defect diversification, thereby ensuring that defect classification and defect quantification will not occur during subsequent data analysis, leading to problems such as unclear defect classification and inaccurate defect quantification.

Description

Technical Field

[0001] The invention relates to a detection technology for surface defects and buried defects of ferromagnetic materials, and in particular to a mosaic distributed combined interval magnetization method and a detection method. Background Art

[0002] Regarding the internal and external quality inspection of pipelines, commonly used inspection technologies include magnetic flux leakage (MFL), EMAT, piezoelectric ultrasound, electromagnetic eddy current, etc. The most widely used is magnetic flux leakage inspection technology, which can detect internal and external defects of magnetic materials. It is specifically divided into the integral magnetization method of steel brush structure and magnetic shoe structure. The disadvantages of these two types of structural layouts are mainly:

[0003] 1. Different magnetization layout: Conventional magnetic leakage technology excitation structure, conventional magnetization method is the overall magnetization method, specifically, by using the central cylinder, front and rear sets of steel brushes and the test piece to form a longer magnetic circuit, the entire pipe section between the front and rear sets of steel brushes is magnetized as a whole, the effective range of the magnetic sensor instantaneous detection is the entire pipe section between the steel brushes, and the defects of the entire magnetized pipe section are detected.

[0004] 2. Long magnetization circuit: Due to the different layout structures, the axial space needs to reserve space for installing the magnetic sensor assembly, and the radial space needs to reserve space for installing the steel brush component. As a result, the magnetization circuit of conventional magnetic leakage technology is longer. If the test piece needs to be magnetized to a certain magnetic saturation state, the magnetic source with a higher magnetic strength is required.

[0005] 3. The magnetic circuit of the excitation structure is single: the magnetic flux lines are axially distributed in the material, and the circumferential defects with a large angle distribution with the direction of the magnetic flux lines can be detected. However, for the axial defects arranged parallel to the direction of the magnetic flux lines, the detection sensitivity is low or even cannot be detected.

[0006] 4. The structural layout of the equipment is quite different: conventional magnetic flux leakage detection equipment uses the central cylinder as the yoke iron magnetic conductive part in the magnetic circuit, which results in the central cylinder having strong magnetism as a whole. The energy supply unit (battery) and electronic hardware and other components susceptible to strong magnetic interference cannot be placed in the central cylinder. The integration is low, and it is mostly composed of several products connected in series. The equipment is long and heavy. Summary of the invention

[0007] The object of the present invention is to provide a mosaic distributed combined interval magnetization method and a detection method to solve the above-mentioned problems.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A mosaic distributed combined interval magnetization method, comprising:

[0010] A magnetizing module composed of magnetic sources arranged at both ends of the yoke and having opposite magnetic properties;

[0011] A magnetic sensor disposed between the two magnetic sources, the magnetic sensor being used to detect changes in the direction of the magnetic field of the test piece under inspection;

[0012] Wrapping the yoke iron and the magnetic source to form a non-metallic wrapping structure of the detection component;

[0013] The magnetization module is divided into a first magnetization module and a second magnetization module which is arranged symmetrically about the center of the first magnetization module, wherein:

[0014] The second magnetizing modules on both sides are lower than the horizontal plane of the first magnetizing modules to form a groove-shaped structure.

[0015] Preferably, the magnetic source is any one of a polygonal structure, a circular structure and an arc structure.

[0016] Preferably, the yoke is a plate-like structure of any curvature.

[0017] Preferably, the magnetic sensor maintains a predetermined distance L4 from the detection surface of the detection component.

[0018] Preferably, the value of L4 is inversely proportional to the sensitivity of detection by the magnetic sensor.

[0019] Preferably, a magnetized region is formed between the two magnetic sources, and the magnetic sensor is vertically located in the magnetized region, wherein:

[0020] The straight-line distance between the two magnetic sources is L2, and the height is L3, and the area of ​​the magnetized region is S=L2*L3.

[0021] Preferably, the number of the magnetic sensors perpendicular to the magnetic source is several, wherein:

[0022] The plurality of magnetic sensors may be arranged along a single-axis linear array or along a two-axis linear array and arranged in a staggered manner.

[0023] Preferably, the magnetization module comprises at least three groups of magnetic sources arranged in a linear array along the axial direction of the groove-shaped structure, wherein:

[0024] The three magnetic sources on a single axial side have opposite magnetic properties to form two horizontal magnetization regions and two vertical magnetization regions.

[0025] Preferably, the magnetic sensors of the two magnetic sources with opposite magnetic properties between the first magnetization module and the second magnetization module are also centered and perpendicular to the magnetic field to form an inclined magnetization region.

[0026] Preferably, the four magnetic sensors in two magnetic sources in two adjacent rows of the axial linear array arrangement are of different models.

[0027] A mosaic distributed combined interval magnetization detection method, based on the mosaic distributed combined interval magnetization method described in the above scheme, the detection method comprises the following steps:

[0028] S01, the test piece passes through the magnetization module;

[0029] S02, the magnetization module and the tested piece form a closed magnetic loop to form a stable magnetization area;

[0030] S03, the magnetic sensor detects a leakage magnetic field formed in one of the magnetized regions on the buried defect portion of the test piece;

[0031] S04, creating a three-dimensional model of the test piece using the collected data, and locating the coordinates (X L , Y L , Z L ) for display.

[0032] Preferably, the magnetization module in step S01 is composed of a plurality of inclined magnetization regions, two horizontal magnetization regions and two vertical magnetization regions to form an interval magnetization field;

[0033] The buried defect portion can be at least detected in the horizontal, vertical and tilted manner when the tested piece passes through the interval magnetization field.

[0034] Preferably, the coordinates (X L , Y L , Z L )middle:

[0035] X L The length of the buried defect is v*t, where v is the constant moving speed and t is the consumed time;

[0036] Y L is the width of the buried defect;

[0037] Z L is the height of the buried defect.

[0038] As a preferred method, obtain Y L A data set is composed of multiple data, and each magnetic sensor in the data set is N, and the width of the buried defect detected by each N is A. N consecutive magnetic sensors detect defect signals in the buried defect, then Y L=A*N.

[0039] Preferably, the coordinates (X L , Y L , Z L ),include:

[0040] S41, continuously collect the continuous point coordinates of the width of the buried defect according to the predetermined window period n: n1 (X L1 )、n2(X L2 )、...、n n (X LN );

[0041] S42, corresponding to the continuous acquisition point n1 under the window period n (Y L1 )、n2(Y L2 )、...、n n (Y LN );

[0042] S43, corresponding to the continuous acquisition point n1 under L5 under the window period n (Z L1 )、n2(Z L2 )、...、n n (Z LN );

[0043] S44, collect n in the same cycle n (X LN )、n n (Y LN ) and n n (Z LN ) create a three-dimensional shape of the buried defect portion.

[0044] Preferably, the first magnetization module and the two second magnetization modules form a group one and a group two respectively, and the inclined magnetization region forms a group three located between the group one and the group two, and the three-dimensional morphology corresponding to the buried defect portion (51) includes:

[0045] Group 1: (n n (X LN ), n n (Y LN ), n n (Z LN ) 1 ;

[0046] Group 2: (n n (X LN ), n n (Y LN ), n n (Z LN )2 ;

[0047] Group 3: (n n (X LN ), n n (Y LN ), n n (Z LN ) 3 .

[0048] In the above technical solution, the present invention provides a mosaic distributed combined interval magnetization method and detection method, which have the following beneficial effects:

[0049] 1. The stable magnetization area formed by a single excitation structure is small. The sizes of L2 and L3 are both small. The area of ​​this stable magnetization area is less than 10% of the magnetization area of ​​a conventional magnetic flux leakage detection device. The area of ​​instantaneous detection by a single potted magnetic sensor is a stable magnetization area, which avoids the superposition effect of defect diversity (multiple defects and multiple defects) in a large-scale magnetization area, thereby affecting the defect classification and defect quantification during subsequent data analysis, resulting in unclear defect classification and inaccurate defect quantification.

[0050] 2. Because when the non-metallic package structure of a single detection component is attached to the test piece, the excitation structure encapsulated in the non-metallic package structure is close to the test piece, and the air magnetic resistance is small, so L1 in the magnetization circuit formed by the present application is small. And the dimension parameter L2 in the magnetization circuit is also much smaller than the distance between the two steel brushes in the conventional magnetic flux leakage detection device, so the length of the stable closed magnetic circuit formed by the present application is much smaller than the length of the magnetic circuit formed by the conventional magnetic flux leakage detection device, and the length of the magnetic circuit of the present application is less than 10% of the length of the magnetic circuit of the conventional magnetic flux leakage detection device.

[0051] 3. Under the premise of the same magnetic source strength, the structure of the patent application will form a stronger magnetization intensity in the material of the test piece under test. The increase in magnetization intensity not only meets the magnetization requirements of the test piece with a small wall thickness, but also meets the magnetization requirements of the test piece with a large wall thickness.

[0052] 4. Under the same magnetization intensity condition in the ferromagnetic material being tested, the magnetic source required by the structure of the patent application has a lower magnetism, which reduces the adsorption force between the non-metallic wrapping structure of a single testing component and the tested test piece. During the test, the non-metallic wrapping structure of a single testing component and the tested test piece move relative to each other, and the friction between the non-metallic wrapping structure and the tested test piece is reduced, thereby reducing the wear resistance requirements of the potting material of the non-metallic wrapping structure.

[0053] 5. Because the conventional magnetic leakage detection device uses the central cylinder as the yoke iron magnetic conductive part in the magnetic circuit, the central cylinder as a whole has strong magnetism, and the power supply unit (battery) and electronic hardware and other components susceptible to strong magnetic interference cannot be placed in the central cylinder. However, the magnetic circuit of the patent application is shorter, and under the same magnetization intensity requirements of the test piece, the magnetic source in a single non-metallic wrapping structure has a lower magnetism; furthermore, when establishing the magnetic circuit, the central cylinder is not used as part of the magnetic circuit, and the non-metallic wrapping structure of a single detection component is far away from the central cylinder, making the central cylinder completely non-magnetic, and then the central cylinder of the detection device designed based on the mosaic distributed combined interval magnetization method of the patent application can completely place power supply units (batteries) and electronic hardware and other components susceptible to strong magnetic interference.

[0054] 6. In a limited space, more detection units can be arrayed. For the same specifications and models, the number of detection units is increased by about 70%, which improves the detection resolution, is conducive to defect imaging, and intuitively reflects the morphological characteristics of the detected defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0056] Figure 1 A schematic diagram of a magnetic circuit of a single detection component provided in an embodiment of the present invention;

[0057] Figure 2 The embodiment of the present invention provides Figure 1 Bottom view of

[0058] Figure 3 A schematic diagram of the magnetization layout of mosaic combination intervals provided in an embodiment of the present invention;

[0059] Figure 4 The embodiment of the present invention provides Figure 1 A partial enlarged schematic diagram of the defective part;

[0060] Figure 5 The embodiment of the present invention provides Figure 2 Schematic diagram of the stable magnetization region on the basis;

[0061] Figure 6 A signal diagram of different L4 value detection data provided by an embodiment of the present invention;

[0062] Figure 7 A schematic diagram of the arrangement of magnetic sensors A and B provided in an embodiment of the present invention;

[0063] Figure 8 A schematic diagram of the magnetization layout of two combined intervals provided in an embodiment of the present invention.

[0064] Description of reference numerals:

[0065] 1-magnetic source, 2-yoke, 3-magnetic sensor, 4-non-metallic packaging structure, 5-test piece, 51-buried defect, 511-horizontal defect, 512-inclined defect, 513-vertical defect, 6-magnetized area. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. Embodiment 1

[0067] like Figure 1 As shown, a mosaic distributed combined interval magnetization method includes: a magnetization module composed of magnetic sources 1 arranged at both ends of a yoke 2 and having opposite magnetic properties, the magnetization module is used to detect the end face of a test piece 5 under inspection;

[0068] A magnetic sensor 3 is arranged between the two magnetic sources 1, and is used to detect changes in the direction of the magnetic field of the test piece 5 under inspection;

[0069] The yoke 2 and the magnetic source 1 are wrapped to form a non-metallic wrapping structure 4 of the detection component.

[0070] Specifically, the non-metallic wrapping structure 4 in the embodiment is formed by encapsulating a polymer material (polyurethane) with high elasticity and high wear resistance in a mold, such as a large flat plate form, an arc form, etc.

[0071] Magnetic source 1: a permanent magnet or a magnetizing coil or other device capable of generating magnetism. The magnetic source 1 is any one of a polygonal structure, a circular structure and an arc structure.

[0072] It should be noted that the yoke 2 is a plate-like structure of any arc, and the outer arc top is arranged on one side of the magnetic source 1. In the embodiment, the two magnetic sources 1 have the same magnetic strength, opposite magnetic properties, and the same geometric size, so the two magnetic sources 1 form a Figure 2 The structure of the stable magnetization interval shown, that is, the magnetization region 6 ( Figure 5 as shown).

[0073] Conventional magnetic flux leakage detection devices use the central cylinder as the yoke 2 in the magnetic circuit, which results in the central cylinder having strong magnetism as a whole. The power supply unit (battery) and electronic hardware that are susceptible to strong magnetic interference cannot be placed in the central cylinder. However, the magnetic circuit of this example is shorter. Under the same magnetization intensity requirement of the test piece 5, the magnetic source 1 in the single non-metallic wrapping structure 4 has lower magnetism. Furthermore, when establishing the magnetic circuit, the central cylinder is not used as part of the magnetic circuit, and the non-metallic wrapping structure 4 of the single detection component is far away from the central cylinder.

[0074] Moreover, more detection units can be arrayed in a limited space. For the same specification and model, the number of detection units is increased by about 70%, which improves the detection resolution, is conducive to defect imaging, and intuitively reflects the morphological characteristics of the detected defects. Embodiment 2

[0075] Figure 1 The single detection components shown are all formed by encapsulating a polymer material with high elasticity and high wear resistance in a mold. The small-sized excitation structure is encapsulated into the non-metallic encapsulation structure 4, and the polymer encapsulation material completely encapsulates the excitation structure of this part. The magnetic sources 1 are respectively arranged at both ends of the yoke 2, and the north and south poles of the magnetic fields formed by the two magnetic sources 1 are opposite, respectively. The magnetic sensor 3 is arranged in the middle position of the two magnetic sources 1, and the magnetic sensor 3 is completely encapsulated in the polymer encapsulation material. There is a certain distance L4 between the magnetic sensor 3 and the outer surface of the non-metallic encapsulation structure 4. The size of the distance L4 is determined according to the detection performance of the magnetic sensor 3 and parameters such as the magnetization intensity. That is: combined with Figure 1 As shown, the magnetic sensor 3 maintains a predetermined distance L4 from the detection surface of the detection component. The value of L4 is inversely proportional to the sensitivity of the magnetic sensor 3.

[0076] like Figure 3 It is shown that, under the premise of forming the same magnetic circuit with the same excitation structure, different types of magnetic sensors 3 can have different effective detection lift-off ranges (i.e., distance L4), and the size of the distance L4 is determined according to the effective detection lift-off range values ​​of different types of magnetic sensors 3. Therefore, when the effective detection lift-off L4 of the magnetic sensor 3 is smaller ( Figure 6 The closer the magnetic sensor 3 is to the test piece 5, the greater the leakage magnetic field strength at that position, and the stronger the detection signal. Figure 6 In B), the farther the magnetic sensor 3 is from the test piece 5, the smaller the leakage magnetic field strength at that position is, and the weaker the detection signal is.

[0077] It should be noted that when the material of the test piece 5 is different, the magnetization intensity formed in the test piece 5 will also be different. At this time, different types of magnetic sensors 3 can be selected or the detection distance L4 of the magnetic sensor 3 can be changed to ensure that the intensity of the signal measured by the magnetic sensor 3 is adjusted to achieve the best detection effect. For example, when the magnetization intensity formed in the test piece 5 is weak, using a magnetic sensor 3 with higher sensitivity or reducing the size of the distance L4 can enable the magnetic sensor 3 to collect better detection data, which is conducive to subsequent data analysis.

[0078] When there is a buried defect 51 in the test piece 5 (such as Figure 4 ), at this time, a leakage magnetic field will be formed on the surface of the test piece 5 to be tested, as shown by the dotted line in the figure. When the material, excitation structure and defect size of the test piece 5 to be tested are determined, the leakage magnetic field strength formed at the defect is determined. The closer to the surface of the test piece 5 to be tested, the greater the leakage magnetic field strength, and the easier it is for the magnetic sensor 3 to detect the leakage magnetic field information at that location. When the material is determined and the excitation structure is determined, when the defect size is larger, the leakage magnetic field strength is greater, and the easier it is for the magnetic sensor 3 to detect the leakage magnetic field information at that location, that is:

[0079] 1) When the distance L4 between the magnetic sensor 3 and the test piece 5 is determined, the leakage magnetic field is small when passing through a small defect. If the detection sensitivity of the magnetic sensor 3 is small at this time, the leakage magnetic field strength is lower than the detection threshold of the magnetic sensor 3, and the magnetic sensor 3 cannot detect the small defect at this location. If the magnetic sensor 3 with high detection sensitivity is replaced, the leakage magnetic field strength reaches the detection threshold of the magnetic sensor 3, and the small defect can be detected.

[0080] 2) When the detection sensitivity of the magnetic sensor 3 is determined, reduce the size of L4: when there is a small defect, the small defect will not be missed because of the reduction of L4; when there is a large defect, because L4 is reduced, the magnetic sensor 3 is placed in an area with a greater leakage magnetic field intensity, and the leakage magnetic field intensity range is within the optimal detection range of the magnetic sensor 3. At this time, the signal detected by the magnetic sensor 3 is larger, and better detection data is collected, which is conducive to subsequent data analysis.

[0081] 3) When using 8mm thick 45 steel plate, the excitation structure is the same, the sensitivity of magnetic sensor 3 is the same, the distance value of L4 is adjusted, and the same defect is detected, two sets of data are measured. The data signal is shown below Figure 6 It is shown that the L4 value of A in the figure is 1mm smaller than the L4 value of B, and the amplitude of the defect signal is significantly improved. Embodiment 3

[0082] A magnetized region 6 is formed between the two magnetic sources 1, and the magnetic sensor 3 is vertically located in the magnetized region 6, wherein:

[0083] The straight-line distance between the two magnetic sources 1 is L2, and the height is L3, so the area S of the formed stable magnetized region 6 is = L2*L3.

[0084] Furthermore, the number of magnetic sensors 3 perpendicular to the magnetic source 1 is several, wherein:

[0085] A plurality of magnetic sensors 3 may be arranged in a linear array along an axis ( Figure 7 A) / Linear array along two axes, and staggered arrangement ( Figure 7 B in the figure).

[0086] The magnetization module is divided into a first magnetization module and a second magnetization module which is arranged symmetrically about the center of the first magnetization module, wherein:

[0087] The second magnetizing modules on both sides are lower than the horizontal plane of the first magnetizing module to form a groove-type structure.

[0088] Furthermore, the magnetization module comprises at least three groups of magnetic sources 1 arranged in an axial linear array along the groove-shaped structure, wherein:

[0089] refer to Figure 3 as well as Figure 8 As shown, the three magnetic sources 1 on a single axis have opposite magnetic properties to form two horizontal magnetization regions 6 and two vertical magnetization regions 6. Secondly, the magnetic sensors 3 of the two magnetic sources 1 with opposite magnetic properties between the first magnetization module and the second magnetization module are also centered and perpendicular to the magnetic field to form inclined magnetization regions 6.

[0090] In practice, when the defect direction is parallel to the direction of the magnetic flux line, the leakage magnetic field formed is minimal, and when the defect direction is perpendicular to the direction of the magnetic flux line, the leakage magnetic field strength formed is maximum. For the same defect, the defect direction and the direction of the magnetic flux line will form an angle. It should be noted that the above angle value is 0°→90°, and the leakage magnetic field strength formed gradually increases, with 0° being the minimum and 90° being the maximum ( Figure 4 The leakage magnetic field direction of the buried defect portion 51 is shown in FIG. 1 , that is, the V-shaped protrusion of the dotted line).

[0091] Therefore, if there is only a single-direction magnetization region 6, defects parallel to the magnetic field direction will definitely be missed. When two mutually perpendicular magnetization regions 6 are arranged, the angle between the defect at any angle and the magnetic flux line is between 45° and 90°, that is, the inclined defect 512 ( Figure 8 ), a leakage magnetic field will be formed in at least one of the magnetized regions 6, so that the defect will not be missed.

[0092] Furthermore, the four magnetic sensors 3 in the two adjacent rows of two magnetic sources 1 arranged in the axial linear array are of different models. Different magnetic sensors 3 are used to cooperate with the magnetized area 6 composed of the two adjacent rows of two magnetic sources 1 to form different detections, that is, multiple magnetic sensors 3 located on the same water surface detect the leakage magnetic field in multiple magnetized areas 6 located on the same water surface and take the average value, thereby ensuring that the contour data of the tilt defect 512 obtained by the detected leakage magnetic field is more realistic.

[0093] like Figure 2 The figure shows a schematic diagram of a single detection component. When the single detection components are arranged in multiple groups in a staggered manner, the single detection components are respectively arranged with an N pole and an S pole, and the N pole can be in front and the S pole in the back, or the S pole can be in front and the N pole in the back; the polarity arrangement of the magnetic source 1 of adjacent single detection components can be the same, or opposite, or can be arranged in an integrated combination according to needs. That is, it forms a Figure 3 The mosaic distributed combined interval magnetization layout shown, reference Figure 3 As shown:

[0094] 1. ①-S, ①-N, ②-N, ②-S, ③-N, ③-S, etc. are all magnetic sources 1 arranged in an array, and respective magnetized regions 6 are formed between the magnetic sources 1. Magnetic sensors 3 are arranged in the middle of the magnetized regions 6 formed respectively. The magnetic sensors 3 are perpendicular to the magnetic flux lines formed in the magnetized regions 6. The magnetic sensors 3 can be arranged closely in a single row, staggered in double rows, or arranged in an arc shape according to actual detection requirements.

[0095] 2. ②-N, ②-S, ⑤-S, ⑤-N, respectively form four magnetized regions 6 between NS, and the specific details include:

[0096] ②-N and ②-S, ⑤-S and ⑤-N respectively form two horizontally arranged magnetized regions 6. The horizontally arranged magnetized regions 6 have a high sensitivity to vertically distributed defects, but a low sensitivity to horizontally distributed defects.

[0097] ②-N and ⑤-S, ②-S and ⑤-N respectively form two vertically arranged magnetized regions 6. The vertically arranged magnetized regions 6 have a high sensitivity to the detection of horizontally distributed defects, but a low sensitivity to the detection of vertically distributed defects.

[0098] The two horizontally arranged magnetized regions 6 and the two vertically arranged magnetized regions 6 are distributed and combined together, and have a high detection sensitivity for defects distributed at any angle.

[0099] 3. ②-N, ②-S, ③-N, ④-S, ⑤-S, ⑤-N, ⑥-S, ⑦-N, respectively form four obliquely distributed magnetized regions 6 between NS, and the specific details include:

[0100] ②-N and ④-S, ⑤-S and ⑦-N respectively form two upper left (inclined) distributed magnetized regions 6, and the upper left distributed magnetized region 6 has a higher detection sensitivity to the upper right distributed defects, but a lower detection sensitivity to the upper left distributed defects;

[0101] ②-S and ③-N, ⑤-N and ⑥-S respectively form two upper right (inclined) distributed magnetized regions 6, and the upper right distributed magnetized region 6 has a higher detection sensitivity to the upper left distributed defects, but a lower detection sensitivity to the upper right distributed defects;

[0102] The above two magnetized regions 6 distributed in the upper left (oblique) direction and the two magnetized regions 6 distributed in the upper right (oblique) direction are distributed and combined together, and have a high detection sensitivity for defects distributed at any angle.

[0103] In summary, this embodiment uses combined analysis to achieve the quantification accuracy of the defects of the test piece 5 under inspection. When the magnetized regions 6 in four directions are arranged so that the angle between the defect in any direction and the magnetic flux lines is between 67.5° and 90°, at least one of the magnetized regions 6 in the four directions forms a stronger leakage magnetic field, and a stronger defect signal is detected, thereby improving the quantification accuracy of the defect. The same defect will form leakage magnetic fields of different intensities in the magnetized regions 6 in the four directions, and four defect models of different intensities are detected. Combined with the planar layout of the magnetized regions 6 in the four directions, a comprehensive analysis can be performed to obtain the angle between the defect and the directions of the magnetized regions 6 in the four directions, and the planar direction of the defect can be accurately known.

[0104] According to actual needs, highly sensitive magnetic sensors 3 should be arranged in the horizontal and vertical magnetized areas 6, mainly used to detect the size of quantitative defects, and magnetic sensors more sensitive to directionality should be arranged in the other two oblique magnetized areas 6, used to measure the directional parameters of defects. In this way, the combined analysis of the two types of data can obtain more accurate quantization accuracy and more accurate defect direction. Embodiment 4

[0105] Based on the first and second embodiments, a combined interval magnetization detection method for internal detection of low-pressure and low-flow-rate pipelines and pipelines containing inner coatings is implemented, and the detection method includes the following steps:

[0106] S01, the test piece 5 passes through the magnetization module;

[0107] S02, the magnetization module and the test piece 5 form a closed magnetic loop to form a stable magnetization region 6;

[0108] S03, the magnetic sensor 3 detects the leakage magnetic field formed in one of the magnetized regions 6 on the buried defect 51 of the test piece 5;

[0109] S04, creating a three-dimensional model of the test piece 5 using the collected data, and locating the coordinates (X L , Y L , Z L ) for display.

[0110] Furthermore, the magnetization module in step S01 is composed of a plurality of inclined magnetization regions 6, two horizontal magnetization regions 6 and two vertical magnetization regions 6 to form an interval magnetization field;

[0111] When the test piece 5 passes through the interval magnetization field, it is at least capable of detecting the buried defect portion 51 in the horizontal, vertical and tilted directions.

[0112] Furthermore, the coordinates (X L , Y L , Z L )middle:

[0113] X L The length of the buried defect portion 51 is v*t, where v is the constant moving speed and t is the consumed time;

[0114] Y L is the width of the buried defect 51;

[0115] Z L is the height of the buried defect 51.

[0116] Specifically, X L The starting value and the ending value of the buried defect 51 in the tested test piece 5 under the moving state detected by the magnetic sensor 3. The starting value is the data value of the first point where the buried defect 51 is located in the total length of the tested test piece 5, so as to locate the section of the tested test piece 5 where the buried defect 51 is located;

[0117] Combination Figure 8 It can be seen that the multiple inclined magnetized regions 6, the two horizontal magnetized regions 6 and the two vertical magnetized regions 6 constitute the interval magnetized field pair Y. L and Z L , to obtain the depth and width of the buried defect portion 51. Thus, a good detection rate is achieved for defects in any direction without missed detection.

[0118] It should be noted that obtaining Y L A data set is composed of multiple data, and each magnetic sensor 3 in the data set is N, and the width of the buried defect part 51 detected by each N is A. N consecutive magnetic sensors 3 detect defect signals in the buried defect part 51, then Y L=A*N. That is, because different magnetic sensors 3 are placed in the four types of magnetized regions 6 in this embodiment, different defect characteristics can be detected emphatically, and the number of magnetic sensors 3 arranged between the two magnetic sources 1 in the embodiment can be Figure 7 A or Figure 7 B shown, so the actual Y during the detection process L Should be the value of A*N.

[0119] The buried defect portion 51 obtained in step S04 is located at the coordinate (X L , Y L , Z L ),include:

[0120] S41, continuously collecting the continuous point coordinates of the width of the buried defect portion 51 according to a predetermined window period n: n1 (X L1 )、n2(X L2 )、...、n n (X LN );

[0121] S42, corresponding to the continuous acquisition point n1 under the window period n (Y L1 )、n2(Y L2 )、...、n n (Y LN );

[0122] S43, corresponding to the continuous acquisition point n1 under L5 under the window period n (Z L1 )、n2(Z L2 )、...、n n (Z LN );

[0123] S44, collect n in the same cycle n (X LN )、n n (Y LN ) and n n (Z LN ) creates a three-dimensional shape of the buried defect portion 51.

[0124] It should be noted that the first magnetization module and the two second magnetization modules form a group 1 and a group 2 respectively, and the inclined magnetization region 6 forms a group 3 located between the group 1 and the group 2. The corresponding three-dimensional morphology of the buried defect portion 51 includes:

[0125] Group 1: (n n (X LN ), n n (Y LN ), n n (Z LN )1 ;

[0126] Group 2: (n n (X LN ), n n (Y LN ), n n (Z LN ) 2 ;

[0127] Group 3: (n n (X LN ), n n (Y LN ), n n (Z LN ) 3 .

[0128] Specifically, by collecting points in a continuous window period, the plane data of the first point of group one, group two and group three are connected to form a three-dimensional shape, and the horizontal defects 511, inclined defects 512 and vertical defects 513 in the pipeline are obtained simultaneously through combined magnetic detection.

[0129] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A mosaic distributed combined interval magnetization method, characterized in that: include: A magnetizing module composed of magnetic sources (1) arranged at both ends of a yoke (2) and having opposite magnetic properties; A magnetic sensor (3) arranged between the two magnetic sources (1), the magnetic sensor (3) being used to detect changes in the direction of the magnetic field of the test piece (5) being tested; Wrapping the yoke (2) and the magnetic source (1) to form a non-metallic wrapping structure (4) of the detection component; The magnetization module is divided into a first magnetization module and a second magnetization module which is arranged symmetrically about the center of the first magnetization module, wherein: The second magnetizing modules on both sides are lower than the horizontal plane of the first magnetizing modules to form a groove-shaped structure; A magnetized region (6) is formed between the two magnetic sources (1), and the magnetic sensor (3) is vertically located in the magnetized region (6), wherein: The straight-line distance between the two magnetic sources (1) is L2, and the height is L3, and the area S of the magnetized region (6) is L2*L3; The magnetization module comprises at least three groups of magnetic sources (1) arranged in a linear array along the axial direction of the groove-shaped structure, wherein: The three magnetic sources (1) on a single side have opposite magnetic properties, so as to form two horizontal magnetized regions (6) and two vertical magnetized regions (6); The magnetic sensors (3) of the two magnetic sources (1) with opposite magnetic properties between the first magnetizing module and the second magnetizing module are also centered and perpendicular to the magnetic field to form an inclined magnetizing region (6).

2. A mosaic distributed combined interval magnetization method according to claim 1, characterized in that: The magnetic source (1) is any one of a polygonal structure, a circular structure and an arc structure.

3. A mosaic distributed combined interval magnetization method according to claim 1, characterized in that: The yoke (2) is a plate-shaped structure with any curvature.

4. A mosaic distributed combined interval magnetization method according to claim 1, characterized in that: The magnetic sensor (3) maintains a detection distance L4 from the horizontal plane of the detection component.

5. A mosaic distributed combined interval magnetization method according to claim 4, characterized in that: The value of L4 is inversely proportional to the sensitivity of detection of the magnetic sensor (3).

6. A mosaic distributed combined interval magnetization method according to claim 1, characterized in that: The number of the magnetic sensors (3) perpendicular to the magnetic source (1) is several, wherein: The plurality of magnetic sensors (3) can be arranged along a single-axis linear array or along a two-axis linear array and arranged in a staggered manner.

7. A mosaic distributed combined interval magnetization method according to claim 1, characterized in that: The four magnetic sensors (3) in two adjacent rows of two magnetic sources (1) arranged in an axial linear array are of different models.

8. A mosaic distributed combined interval magnetization detection method, characterized in that: Based on the mosaic distributed combined interval magnetization method according to any one of claims 1 to 7, the detection method comprises the following steps: S01, the test piece (5) passes through the magnetization module; S02, the magnetization module and the test piece (5) form a closed magnetic loop to form a stable magnetization region (6); S03, the magnetic sensor (3) detects a leakage magnetic field formed in one of the magnetized regions (6) on the buried defect portion (51) on the test piece (5); S04, creating a three-dimensional model of the test piece (5) to be inspected based on the collected data, and locating the coordinates (X L , Y L , Z L ) to display.

9. A mosaic distributed combined interval magnetization detection method according to claim 8, characterized in that: The magnetization module in step S01 is composed of a plurality of inclined magnetization regions (6), two horizontal magnetization regions (6) and two vertical magnetization regions (6) to form an interval magnetization field; When the test piece (5) under inspection passes through the interval magnetization field, it is at least capable of detecting the horizontal, vertical and tilted positions of the buried defect portion (51).

10. A mosaic distributed combined interval magnetization detection method according to claim 8, characterized in that: The buried defect portion (51) acquired in step S04 is located at the coordinate (X L , Y L , Z L )middle: The X L The length of the buried defect portion (51) is v*t, wherein v is a constant moving speed and t is a consumption time; The Y L is the width of the buried defect portion (51); The Z L is the height of the buried defect (51).

11. A mosaic distributed combined interval magnetization detection method according to claim 10, characterized in that: Get Y L A data set is composed of a plurality of data, and each magnetic sensor (3) in the data set is N, and the width of the buried defect portion (51) detected by each of the N is A, and consecutive N magnetic sensors (3) all detect defect signals in the buried defect portion (51), then Y L =A*N.

12. A mosaic distributed combined interval magnetization detection method according to claim 8, characterized in that: The buried defect portion (51) acquired in step S04 is located at the coordinate (X L , Y L , Z L ),include: S41, continuously collecting the continuous point coordinates of the width of the buried defect portion (51) according to a predetermined window period n: n1(X L1 )、n2(X L2 ),...,n n (X LN ); S42, corresponding to the continuous acquisition point n1 (Y L1 )、n2(Y L2 ),...,n n (Y LN ); S43, corresponding to the continuous acquisition point n1 (Z L1 )、n2(Z L2 ),...,n n (Z LN ); S44, collect n in the same cycle n (X LN )、n n (Y LN ) and n n (Z LN ) creates a three-dimensional shape of the buried defect portion (51).

13. A mosaic distributed combined interval magnetization detection method according to claim 12, characterized in that: The first magnetization module and the two second magnetization modules respectively form a group one and a group two, and the inclined magnetization region (6) forms a group three located between the group one and the group two, and the three-dimensional morphology corresponding to the buried defect portion (51) includes: Group 1: (n n (X LN ), n n (Y LN ), n n (Z LN )) 1 ; Group 2: (n n (X LN ), n n (Y LN ), n n (Z LN )) 2 ; Group 3: (n n (X LN ), n n (Y LN ), n n (Z LN )) 3 .

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