CN103868986A - Eddy detection probe for detecting internal surface defects in metal pipelines and detection method thereof - Google Patents

Abstract

Translated fromChinese

本发明公开了一种电涡流探头，该电涡流探头用于检测金属管道内部表面裂纹等缺陷。该电涡流探头由激励线圈阵列和检测线圈阵列组成，激励线圈阵列由与圆柱面垂直的圆周向线圈和通过圆柱轴所在平面的矩形线圈组成。检测线圈阵列分布于探头圆柱表面，位于圆周向和轴向检测线圈之间。检测线圈通过感测圆周向激励线圈产生的磁通受到圆周向裂纹扰动而产生的变化，可检测圆周向裂纹。检测线圈通过感测轴向激励线圈产生的涡电流受到圆周向裂纹扰动而产生的变化，也可检测圆周向裂纹。检测线圈通过感测圆周向激励线圈产生的涡电流受到轴向裂纹扰动而产生的变化，可检测轴向裂纹，通过探头沿管道方向扫查可以检测导电管道表面多个方向不同裂纹缺陷的存在，并可根据各检测线圈获得缺陷信号特征判断裂纹数量、方向及长、宽、深度等形状信息。

The invention discloses an eddy current probe, which is used for detecting defects such as cracks on the inner surface of metal pipes. The eddy current probe is composed of an excitation coil array and a detection coil array. The excitation coil array is composed of a circular coil perpendicular to the cylindrical surface and a rectangular coil passing through the plane where the cylinder axis is located. The detection coil array is distributed on the cylindrical surface of the probe, and is located between the circumferential and axial detection coils. The detection coil can detect the circumferential crack by sensing the change of the magnetic flux generated by the circumferential excitation coil when it is disturbed by the circumferential crack. The detection coil can also detect the circumferential crack by sensing the change of the eddy current generated by the axial excitation coil when it is disturbed by the circumferential crack. The detection coil can detect the axial crack by sensing the change of the eddy current generated by the circumferential excitation coil when it is disturbed by the axial crack. By scanning the probe along the direction of the pipeline, it can detect the existence of crack defects in multiple directions on the surface of the conductive pipeline. And according to the defect signal characteristics obtained by each detection coil, the number, direction, length, width, depth and other shape information of cracks can be judged.

Description

A kind of eddy current probe of metallic conduit defect in inner surface and detection method thereof

Technical field

The present invention relates to a kind of non-destructive control probe device and detection method thereof, particularly relate to a kind of metallic conduit crack defects of inner surface vortex flow detection probe and detection method.

Background technology

EDDY CURRENT is a kind of Dynamic Non-Destruction Measurement very widely that uses, principle of work is followed electromagnetic induction principle, when the drive coil that is connected with exchange current is during near conductor material, to in conductor material, produce alternating magnetic field, be called Primary field, this alternating magnetic field induces vortex flow at conductive surface simultaneously.Vortex flow in conductor also can produce magnetic field, is called secondary magnetic field.If there is defects i.e.cracks in conductor structure surface, will cause the variation of vortex flow, thereby the secondary magnetic field that vortex flow produces is also changed, cause magnetic test coil institute sensing electric signals to change.Just can judge accordingly the existence of conductor material surface imperfection.Vortex flow detects has the excellent properties such as speed is fast, effects on surface defect is quick on the draw.In the detection of many key equipments such as steam generator pipe, nuclear power station heat exchanging pipe, play an important role.For assessment apparatus structural safety, requirement obtains the information such as quantity, position and the shape of conductive conduits crack defects of inner surface.Tradition through mode probe is only suitable for detecting the crack defect of certain direction of pipeline, and wastes time and energy.In actual conditions, inner surface of pipeline crackle is often the situation of multiple directions, large to metallic conduit structural damage.If can not accurately judge the number of multiple cracks, trend and shape separately, easily cause undetectedly and mishandling, may cause serious security incident.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of eddy current probe device and detection method of conductive conduits surface cracks is provided.

The technical solution adopted for the present invention to solve the technical problems is: a kind of vortex flow detection probe of metallic conduit crack defects of inner surface, this probe drive coil and magnetic test coil are all made up of coil array.

Circumferential drive coil is cylindrical, and quantity is at least three, and each coil dimension is identical, is arranged in parallel each other.

Axial excitation coil is rectangular, and quantity is at least three, and each coil measure-alike waits angle to distribute each other, and they are all by the axis of cylindrical probe.

The magnetic test coil that is distributed in cylindrical probe surface is rectangular, and the quantity of a circumferential magnetic test coil is at least 6, and each coil is measure-alike, has two circumferential magnetic test coils at least, and is equidistantly arranged in parallel each other.

Adopt the method for this probe detection conductive conduits surface cracks as follows.Drive coil array produces electromagnetic field and the vortex flow of different directions in larger region of detected inner surface of pipeline, be subject to crackle disturbance and will produce path and Strength Changes, by in probe with the different electrical signals of many magnetic test coils institute sensing of the parallel distribution of detected inner surface of pipeline, can detect the crackle of diverse location, different directions distribution, and can be according to the shape of institute's picked up signal distribution and height analysis crackle.

For conductive conduits inside axial crack, can realize the detection of vortex flow by magnetic test coil; The vortex flow that circumferential drive coil excites is in the time running into axial crack, and vortex flow is disturbed will be along direction of check shunting, and this vortex flow of being shunted can be detected with the nearest magnetic test coil of this crackle, is embodied in the changes in amplitude maximum of this coil signal.

For the circumferential crackle of conductive conduits inside surface, can detect by the following method.Circumferential drive coil inspires axial magnetic flux, this magnetic flux will occur to move towards to change along crackle in the time running into the circumferential crackle perpendicular with it, there is the flux component of vertical pipe inside surface to produce, this flux component can be detected by the magnetic test coil of close this crackle, be embodied in this coil and obtain maximum signal amplitude.

Axial excitation coil axially produces vortex flow at pipe interior in addition, and this vortex flow will change along crackle generation direction in the time running into the circumferential crackle perpendicular with it, and the variation of this vortex flow also can be detected by the magnetic test coil of close this crackle.

Accompanying drawing explanation

Fig. 1 is the cylindrical swirl sonde configuration figure that the present invention detects conductive conduits surface cracks;

Fig. 2 is the cylindrical swirl sonde configuration axial view that the present invention detects conductive conduits surface cracks

Fig. 3 is conductive conduits surface cracks illustraton of model

Fig. 4 is that the present invention pops one's head at the schematic diagram of the inner scanning crackle of conductive conduits

Fig. 5 is that the present invention pops one's head in the axial view of the inner scanning crackle of conductive conduits

Fig. 6 be the present invention pop one's head in utilize electromagnetic field change detect circumferential crackle schematic diagram

Fig. 7 is that the present invention pops one's head in and utilizes vortex flow to change to detect axial crack schematic diagram

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

In the Non-Destructive Testing of crucial pipe-line equipment, adopt traditional eddy current probe and method to be difficult to detect the crack defect of multiple directions, therefore need to improve the ability of number, direction and SHAPE DETECTION to multi-direction crackle, avoid occurring the undetected generation that causes security incident.

Shown in Fig. 1, Fig. 2, it is conductive conduits surface cracks current vortex detection probe structural drawing of the present invention.This eddy current probe includes drive coil array and magnetic test coil array; Drive coil array is bycircumferential coil 1a, 1b, 1c andsquare coil 2a, 2b, the 2c of cylinder axis form excessively.Magnetic test coil array is made up of 3a, the 3b, 3c, 3d, 3e, 3f, 4a, 4b, 4c, 4d, 4e, the 4f coil that are positioned on the probe face of cylinder.

Circumferential drive coil 1a, 1b, 1c are rounded, measure-alike, are arranged in parallel each other.

Axial excitation coil 2a, 2b, 2c are rectangular, measure-alike, by cylinder axis, wait each other angle to arrange.

Magnetic test coil 3a, 3b, 3c, 3d, 3e, 3f, 4a, 4b, 4c, 4d, 4e, 4f are rectangular, and are certain radian and are positioned at periphery, and each magnetic test coil is measure-alike and equidistantly arrange each other.

It shown in Fig. 3, is conductive conduits surface cracks model.Onconductive conduits 4 surfaces,crackle 5a, 5b are shown.Whereincrackle 5a is positioned at circumferencial direction.Crackle 5b is positioned at axially.

Figure 4 shows that by the situation of vortex flow probe scanning conductive conduits of thepresent invention 4 underbead cracks.Fig. 5 is that the present invention pops one's head in the axial view of the inner scanning crackle of conductive conduits.

Fig. 6 be the present invention pop one's head in utilize electromagnetic field change detect circumferential crackle schematic diagram.In order to detectcircumferential crackle 5a, carry out as follows scanning program.Probe is along the direction scanning from left to right ofpipeline 4 inside, the axialmagnetic flux 6 that the inner exchange current ofdrive coil 1a, 1b produces has part by detectedconductive conduits 4, owing to havingcircumferential crackle 5a at detectedpipeline 4 inside surfaces, and the direction ofcrackle 5a andmagnetic flux 6 directions are perpendicular, because the characteristics such ascrackle 5a region magnetic permeability, conductivity are different from conductor material, the path ofmagnetic flux 6 will be subject to the interference ofcrackle 5a, and the magnetic flux above measuredmaterial 4 inside surfaces becomes unordered.Can produce the magnetic flux of somevertical pipe 4 inside surfaces and pass throughmagnetic test coil 3c, and inmagnetic test coil 3c, producing an electromotive force, this electromotive force is presented as flaw indication 8.If in probe scanning process, as shown in Fig. 6 A, 6C, the edge of magnetic test coil winding 3c approaches respectively,leaves crackle 5a, andmagnetic test coil 3c will obtain respectively theflaw indication 8 of an opposite polarity.If as shown in Figure 6B,magnetic test coil 3c center is throughcrackle 5a, and themagnetic flux 6 that passes in and outmagnetic test coil 3c offsets, and just can in magnetic test coil, not produce electromotive force, and nowflaw indication 8 is zero.

Axial excitation coil 2a, 2b, 2c axially produce vortex flow at pipe interior, this vortex flow will change along crackle generation direction in the time running into thecircumferential crackle 5a perpendicular with it, and the variation of this vortex flow also can be detected by the magnetic test coil of close this crackle.

Fig. 7 is that the present invention pops one's head in and utilizes vortex flow to change to detect the inner axial crack schematic diagram of conductive conduits.Figure 7 shows that at detected inner surface of pipeline and have an axial crack 5b.Circumferential drive coil 1a, 1b, 1c produce the direction of vortex flows 7 atpipeline 4 inwalls relevant with the direction ofexcitation winding 1a, 1b, 1c inside exchange current.Therefore, the mobile direction ofvortex flow 7 is vertical withaxial crack 5b, the mobile interference that is subject tocrackle 5b of vortex flow 7.Therefore, the secondary magnetic flux thatvortex flow 7 produces is by disturbance, along with probe moves scanning at pipe interior, as shown in Fig. 7 A, 7C, in the time thatmagnetic test coil 3a approaches and leavescrackle 5b, the magnetic flux that flows throughmagnetic test coil 3a both sides is asymmetric, produce electromotive force difference onmagnetic test coil 3a both sides, inmagnetic test coil 3a, produce a total electromotive force, and be presented as aflaw indication 8, and two kinds of situation acquisition electromotive force polarity are contrary.Ifmagnetic test coil 3a is positioned atcrackle 5b center, the mobilemagnetic test coil 3a that is symmetrical in of vortex flow, like this, is exactly balance by the magnetic flux ofmagnetic test coil 3a, just can not produce the electromotive force that represents flaw indication, andrespective signal 8 is 0.

Claims (8)

Translated fromChinese

1.一种检测金属管道内表面裂纹缺陷的涡电流探头，其特征在于：包括有激励线圈阵列与检测线圈阵列；激励线圈阵列由圆周向线圈阵列(1a)、(1b)、(1c)和经过圆柱轴的矩形线圈(2a)、(2b)、(2c)组成。检测线圈阵列由分布在圆柱面表面的矩形线圈(3a)、(3b)、(3c)、(3d)、(3e)、(3f)与(4a)、(4b)、(4c)、(4d)、(4e)、(4f)阵列组成。1. An eddy current probe for detecting crack defects on the inner surface of metal pipes is characterized in that: it includes an excitation coil array and a detection coil array; the excitation coil array consists of circumferential coil arrays (1a), (1b), (1c) and Composed of rectangular coils (2a), (2b) and (2c) passing through the cylinder axis. The detection coil array consists of rectangular coils (3a), (3b), (3c), (3d), (3e), (3f) and (4a), (4b), (4c), (4d) distributed on the cylindrical surface ), (4e), (4f) arrays.2.根据权利要求1所述的检测导电管道内表面裂纹的探头，其特征在于：圆周向激励线圈(1a)、(1b)、(1c)呈圆柱形，数量至少为三个，相互之间平行排列。2. The probe for detecting cracks on the inner surface of conductive pipes according to claim 1, characterized in that: the circumferential excitation coils (1a), (1b), (1c) are cylindrical in shape, and the number is at least three, and the distance between them parallel arrangement.3.轴向激励线圈(2a)、(2b)、(2c)呈矩形，各线圈尺寸相同，数量至少为三个，线圈平面都通过圆柱轴，且相互之间夹角相等。3. The axial excitation coils (2a), (2b), and (2c) are rectangular in shape, each coil has the same size, and the number is at least three. The planes of the coils all pass through the axis of the cylinder, and the angles between them are equal.4.根据权利要求1所述的检测导电管道内表面裂纹的探头，其特征在于：激励线圈(1a)、(1b)之间检测线圈为(3a)、(3b)、(3c)、(3d)、(3e)、(3f)，位于圆柱表面，呈曲面矩形，数量至少为6个。激励线圈(1b)、(1c)之间检测线圈为(4a)、(4b)、(4c)、(4d)、(4e)、(4f)，数量至少为6个。4. The probe for detecting cracks on the inner surface of conductive pipes according to claim 1, characterized in that: the detection coils between the excitation coils (1a), (1b) are (3a), (3b), (3c), (3d ), (3e), (3f), located on the surface of the cylinder, in the form of a curved rectangle, the number of which is at least 6. The detection coils between the excitation coils (1b) and (1c) are (4a), (4b), (4c), (4d), (4e), (4f), and the number is at least 6.5.一种金属管道内表面裂纹缺陷的涡电流检测方法，其特征在于：激励线圈阵列(2a)、(2b)、(2c)与(1a)、(1b)、(1c)分别在被检测管道(4)内表面一个较大的区域产生不同方向的电磁场与涡电流，在电磁场与涡电流的通路上，裂纹的存在将会引起电磁场与涡电流的扰动，通过检测线圈(3a)、(3b)、(3c)、(3d)、(3e)、(3f)与(4a)、(4b)、(4c)、(4d)、(4e)、(4f)可感测电磁场的变化，也可感测涡电流的变化，利用此感测线圈阵列可以同时检测导电管道内表面不同方向分布裂纹的存在。可以确定裂纹的数量，并根据所获得缺陷信号分布及幅度可判断裂纹的形状。5. An eddy current detection method for crack defects on the inner surface of metal pipes, characterized in that: the excitation coil arrays (2a), (2b), (2c) and (1a), (1b), (1c) are detected respectively A large area on the inner surface of the pipeline (4) produces electromagnetic fields and eddy currents in different directions. On the path of the electromagnetic fields and eddy currents, the existence of cracks will cause disturbances of the electromagnetic fields and eddy currents. Through the detection coils (3a), ( 3b), (3c), (3d), (3e), (3f) and (4a), (4b), (4c), (4d), (4e), (4f) can sense the change of the electromagnetic field, and also The change of the eddy current can be sensed, and the existence of cracks distributed in different directions on the inner surface of the conductive pipeline can be detected simultaneously by using the sensing coil array. The number of cracks can be determined, and the shape of the cracks can be judged according to the distribution and amplitude of the obtained defect signals.6.根据权利要求5所述的检测导电管道内表面裂纹的方法，其特征在于：导电管道(4)内表面轴向裂纹(5b)，可以通过圆周向激励线圈(1a)、(1b)、(1c)产生的涡电流受裂纹扰动变化引起磁场变化的检测实现；圆周向激励线圈(1a)、(1b)、(1c)激发的涡电流(7)在遇到轴向裂纹(5b)时将沿裂纹分流，这个被分流的涡电流可以被与该裂纹最近的检测线圈检测到，体现在该线圈信号的幅值变化最大。6. The method for detecting cracks on the inner surface of conductive pipes according to claim 5, characterized in that: the axial cracks (5b) on the inner surface of the conductive pipe (4) can be excited by the circumferential direction coils (1a), (1b), The eddy current generated by (1c) is detected by the change of the magnetic field caused by the crack disturbance; the eddy current (7) excited by the circumferential excitation coils (1a), (1b), (1c) encounters the axial crack (5b) The current will be shunted along the crack, and the shunted eddy current can be detected by the detection coil closest to the crack, which is reflected in the largest change in the amplitude of the coil signal.7.根据权利要求5所述的检测导电管道内表面裂纹的方法，其特征在于：圆周向激励线圈(1a)、(1b)、(1c)激发的与该线圈表面垂直的磁通在遇到圆周向裂纹(5a)时受到该裂纹的扰动后使磁通(6)方向改变，将有垂直被检测管道(4)内表面的磁通分量产生，这个磁通分量在检测线圈(3a)、(3b)、(3c)、(3d)、(3e)、(3f)与(4a)、(4b)、(4c)、(4d)、(4e)、(4f)中某一个与该裂纹最接近的线圈中产生最大的信号幅度，据此可知在该检测线圈附近有圆周向裂纹(5a)。7. The method for detecting cracks on the inner surface of conductive pipes according to claim 5, characterized in that: the magnetic flux perpendicular to the coil surface excited by the circumferential excitation coils (1a), (1b), (1c) encounters When the circumferential crack (5a) is disturbed by the crack, the direction of the magnetic flux (6) changes, and a magnetic flux component perpendicular to the inner surface of the detected pipeline (4) will be generated, and this magnetic flux component will be generated in the detection coil (3a), One of (3b), (3c), (3d), (3e), (3f) and (4a), (4b), (4c), (4d), (4e), (4f) is closest to the crack The largest signal amplitude is generated in the closest coil, from which it is known that there is a circumferential crack (5a) in the vicinity of the detection coil.8.检测线圈通过感测轴向激励线圈产生的涡电流受到圆周向裂纹扰动而产生的变化，也可检测圆周向裂纹。8. The detection coil can also detect the circumferential crack by sensing the change of the eddy current generated by the axial excitation coil when it is disturbed by the circumferential crack.

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