CN118311147A - Multi-probe ultrasonic imaging detection method for bonding nonmetallic anti-corrosion layer - Google Patents

Abstract

The invention discloses a multi-probe ultrasonic imaging detection method for bonding a nonmetallic anti-corrosion layer, which belongs to the technical field of nondestructive detection and comprises the steps of S1, detection preparation; s2, static debugging, mounting a track and a scanner, configuring a probe, and adjusting sound velocity and sensitivity of the probe; s3, dynamically debugging, and adjusting the sensitivity of the probe through verification and scanning; s4, scanning and result analysis, namely automatically scanning the detected pipeline by using multi-probe ultrasonic imaging detection equipment and analyzing the scanning result, and judging the bonding state of the anticorrosive layers of the detected pipelines of different types by scanning the image color. The invention adopts the multi-probe ultrasonic imaging detection method for bonding the nonmetallic anti-corrosion layer, adopts a unique integral sound velocity measurement method, combines an ultrasonic imaging technology to solve the problem of bonding quality of the anti-corrosion layer of the pipeline, and compared with the prior detection technology, the method has the advantages of advanced detection method, accurate result, high detection speed, high efficiency and low detection cost in bonding detection of the anti-corrosion layer of the pipeline.

Description

Multi-probe ultrasonic imaging detection method for bonding nonmetallic anti-corrosion layer

Technical Field

The invention relates to the technical field of nondestructive testing, in particular to a multi-probe ultrasonic imaging detection method for bonding a nonmetallic anti-corrosion layer.

Background

The pressure-bearing equipment comprises various boilers, pressure vessels, pressure pipelines, gas pipelines, oil gas long-distance pipelines and the like, belongs to important production equipment, and has very close connection with national economy production and daily life of people. However, the pressure-bearing equipment often has the characteristics of high temperature, high pressure, toxic medium and the like, and once accidents occur, the consequences are extremely serious. In order to avoid possible quality accidents, the pressure-bearing equipment is widely applied to nondestructive testing technology in the links of manufacturing, using, checking and the like.

The equipment closely related to daily life of people is mainly pipelines, such as power station buried pipelines, heating buried pipelines, urban gas pipelines, oil gas buried pipelines, offshore pipelines and pipelines on LNG ships, and the like, most of the pipelines are made of steel, the surfaces of the pipelines are subjected to corrosion prevention treatment, an anti-corrosion layer is generally added on the outer surfaces of the pipelines, and the welded junction positions of the pipelines are also provided with anti-corrosion layers, such as heat shrinkage belts or heat shrinkage sleeves, or the like, otherwise, the pipelines are corroded due to the existence of acid and alkali in soil due to the fact that the pipelines are buried underground, leakage is caused, and major safety accidents occur.

However, one of the key factors of the leakage of the pipeline due to corrosion is that the corrosion-resistant layer is adhered to a problem, namely the adhesion of the corrosion-resistant layer and the pipe body is not required, and the phenomena of non-adhesion and weak adhesion are generated. If damage phenomena such as scratch and the like appear on the outer surface of the pipeline at the unbonded and weakly bonded positions, serious corrosion phenomena can appear at the unbonded and weakly bonded positions, even leakage phenomena such as pipe perforation or large-area thinning and the like are caused, and serious safety accidents appear. In order to avoid possible quality accidents, leakage accidents caused by the adhesion problem of the pipeline anti-corrosion layer are reduced, and the pipeline anti-corrosion layer is inspected and monitored by adopting a nondestructive testing technology.

The advent of ultrasonic imaging technology has provided directionality, possibility, and accuracy for the detection of specific materials, enabling the detection of some specific objects to be realistic. Especially, the appearance of the full-automatic multi-probe ultrasonic imaging technology changes the detection which is not thought to be imagined in the past into the modern detection technology, thereby realizing imaging, automatic scanning and quick dynamic analysis and evaluation. The full-automatic multi-probe ultrasonic imaging detection method is characterized in that an object to be detected is divided into different areas, each area is detected by adopting different probes, and the probes have independence and do not interfere with each other. Therefore, the detection system is required to have a multi-channel function, and the detection results are displayed in the form of images and are divided into three display modes of A scanning, B scanning and C scanning. The scanner automatically scans and detects the detected area and automatically displays the detection result in the form of an image.

At present, whether the adhesion of the pipeline anti-corrosion layer meets the requirement or not is detected by adopting a destructive verification method, namely an annex K anti-corrosion layer peeling strength measuring method in GB/T23257-2017 Standard of buried steel pipeline polyethylene anti-corrosion layer. The standard specifies that the peel strength to steel pipes and polyethylene corrosion protection should not be less than 50N/cm and 80% of the surface exhibits cohesive failure. When the peeling strength exceeds 100N/cm, the surface can be broken, and the peeling surface primer should be completely adhered to the surface of the steel pipe. For the unbonded area with the size of phi 5 mm-phi 10mm, other surrounding parts are bonded well, a peel strength failure test is applied to the parts, the tensile force is not smaller than 50N/cm, and the misjudgment phenomenon exists.

The phased array ultrasonic detection technology can also realize detection of the bonding of the pipeline anti-corrosion layer, and is the most advanced technology, but the phased array ultrasonic technology does not show advantages in detecting the bonding problem of the pipeline anti-corrosion layer, but rather has serious exposure of defects, including the problems of low detection efficiency, low speed, high detection cost, difficulty in realizing simultaneous detection of a plurality of probes and incapability of implementing detection in some places.

The root cause of the above phenomenon occurs: firstly, adopting a traditional destructive verification method; secondly, the root causing the corrosion damage of the pipeline is not found; thirdly, the material of the anti-corrosion layer is nonmetal, the material is special, and the sound velocity attenuation is large; fourth, the best, most reasonable and efficient detection means are not found.

Disclosure of Invention

The invention aims to provide a multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion-resistant layer, which aims to solve the problems in the background technology.

In order to achieve the above-mentioned purpose, the present invention provides a multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion-resistant layer, that is, a detection method for adjusting sound velocity according to thickness of a detected pipeline, adjusting sensitivity of each probe in a multi-probe ultrasonic imaging device by using a steel pipe bottom wave, automatically scanning and analyzing scanning results by combining the imaging device to the pipeline, and judging bonding states of corrosion-resistant layers of different types of pipelines by scanning image colors, comprising the following steps:

S1, detection preparation, namely determining the bonding part of an anti-corrosion layer of the pipeline to be detected according to different pipelines to be detected, wherein the steps are as follows:

(1) Four parts: the method comprises the steps of directly contacting a part of an anticorrosive layer (a heat shrinkage belt or a heat shrinkage sleeve) with a bare pipe, directly contacting a part of the anticorrosive layer (the heat shrinkage belt or the heat shrinkage sleeve) with the surface of a circumferential weld, contacting a part of the anticorrosive layer (the heat shrinkage belt or the heat shrinkage sleeve) with the anticorrosive layer of a pipe body, and contacting a part of the anticorrosive layer (the heat shrinkage belt or the heat shrinkage sleeve) with an inclined slope of the end part of the anticorrosive layer of the pipe body;

Or (2) two sites: the contact part of the anticorrosive coating and the bare pipe and the contact part of the anticorrosive coating and the pipe welding line;

The bonding parts of the pipeline anti-corrosion layer depend on specific detection objects, four bonding parts are detected by the pipeline circumferential weld joint thermal contraction belt (sleeve), and two bonding parts are detected by the pipeline anti-corrosion layer;

s2, static debugging, mounting a track and a scanner, configuring a probe, and adjusting sound velocity and sensitivity of the probe;

s3, dynamically debugging, and adjusting the sensitivity of the probe through verification and scanning;

s4, scanning and result analysis, namely automatically scanning the detected pipeline by using multi-probe ultrasonic imaging detection equipment and analyzing the scanning result, and judging the bonding state of the anticorrosive layers of the detected pipelines of different types by scanning the image color.

Preferably, the multi-probe ultrasonic imaging detection equipment has a multi-channel function, is not lower than 8 channels, each channel has independent A scanning, B scanning and C scanning modes, and the channels cannot interfere with each other; the probe adopts a longitudinal wave double-crystal straight probe, the probe frequency is not less than 2.5MHz, the wafer size is not less than 2mm, and the focal length is not less than 5mm.

Preferably, the anti-corrosion structure of the detected pipeline consists of a non-metal anti-corrosion layer and a steel pipe, and the sound speeds of the two materials are different and have great difference.

Preferably, the preparation for detection of S1 comprises the steps of:

S11, before detection, the number of probes arranged at different positions is calculated according to the bonding positions of the anti-corrosion layer of the detected pipeline; if the number of the equipment channels is limited, the detection can be performed by adopting a method of scanning and covering for multiple times. A probe is generally arranged at the contact part of the anticorrosive coating and the welding line of the pipe body, and a manual detection mode is adopted;

S12, arranging probes on a probe disc (the probe disc can be detached or can adjust the curvature and can detect a plane workpiece according to the curvature of a detected pipe fitting) of the scanner according to the bonding part of the anticorrosive coating, wherein the probes are arranged in a V-shaped or staggered parallel arrangement, and when the bonding part of the anticorrosive coating is detected, single-probe arrangement is adopted;

S13, the probe of each anticorrosive coating bonding part has a position adjusting function and a locking function, and the positions of the probes are independently adjusted according to the detection areas;

And S14, a motor is arranged on a driving part of the scanner and used for driving the scanner to move, an encoder is also arranged in the scanner, and acoustic positioning scanning can be adopted and used for recording scanning positions.

Preferably, the static debugging of S2 comprises the following steps:

s21, installing a track at one end of an anti-corrosion layer of a detected pipeline, wherein the distance between one end of the track and a detected area is not less than 50mm;

s22, installing the scanner on the track, correspondingly configuring probes according to different bonding positions of the pipeline anti-corrosion layer, wherein the number of the probes configured at each bonding position is different. And (3) adjusting the probes arranged at each bonding part to the optimal position, and fixing and locking.

S23, moving the scanner to a scanning starting point, keeping the scanner in a static state, flushing and coupling each probe, keeping a certain pressure of water flow, enabling the coupling to be in a stable state, and adjusting sound velocity at the position by utilizing a longitudinal wave double-crystal probe through the thickness of a detected pipeline, so that the position displayed by a bottom wave signal of each probe is the position of the bottom surface of the steel pipe;

S24, adjusting the sensitivity of the probe by utilizing the bottom wave of the steel pipe at the bonding positions of different corrosion-resistant layers, wherein the bottom wave height is not less than 80% of the full screen height, independently debugging the probe at each position, adjusting the probe to be at the optimal position if the probe is not good, adjusting the bottom wave heights of the probes at the bonding positions to 80% +/-0-5% of the full screen height, wherein the sensitivity is the reference sensitivity, and fixedly locking the probe; the adjustment at this point is called static debugging;

and S25, after the static debugging is finished, performing coupling compensation on each channel probe, and generally increasing the value by 0-12dB on the basis of the reference sensitivity, wherein the increasing of the dB depends on the dynamic debugging.

Preferably, the dynamic debugging of S3 comprises the following steps:

s31, calculating a scanning speed, setting the scanning speed of a motor on a scanner, and scanning according to the speed; the scanning speed can also be set according to field detection experience;

s32, calibrating the encoder, and moving the scanner to a scanning starting point after calibration is completed; for one-time full coverage scanning detection, an encoder is adopted; when the full coverage detection is realized by adopting multiple scanning, two encoders are adopted, wherein one encoder is used for recording the annular position of the pipe, and the other encoder is used for recording the axial position of the pipe;

s33, flushing each probe, and maintaining the water pressure;

S34, verifying and scanning, wherein the height of the bottom wave of each channel probe steel tube is not lower than 80% of the full screen height, if the height of the bottom wave of each channel probe steel tube is lower than the value, the sensitivity of the channel probe is adjusted, and 0-12dB is increased, but the height of the bottom wave of each channel probe steel tube is not higher than the full screen height;

s35, verifying that the scanning speed is the same as the scanning speed of actual detection, and after the detected pipeline is scanned for one circle, the A scanning waveform, the B scanning image and the C scanning image displayed by each channel are uniform.

Preferably, the scanning in S4 is as follows:

(1) Before scanning, determining the scanning times of the anticorrosive coating region according to the number of channels of the multi-probe ultrasonic imaging detection equipment, if the number of the channels is not less than 48 channels, adopting a one-time full-coverage mode for scanning, if the number of the channels is less than 48 channels, adopting a multi-time scanning coverage mode for scanning, and controlling the scanning through software of the multi-probe ultrasonic imaging equipment during the multi-time scanning;

When the single probe is used for detection of the corrosion-resistant layer bonding spot check, the probe can be used for grid scanning, acoustic positioning scanning can be used for mechanical scanning, manual scanning can be used for manual movement scanning detection of the single probe on the welding seam for the welding seam part of the pipe.

(2) When scanning starts, the scanner is moved to a scanning starting point position, the scanner automatically walks through a motor, collected data are stored after scanning is finished, and complete A-scan, B-scan and C-scan images are displayed on a display screen of the multi-probe ultrasonic imaging detection device;

a. if the bonding part cannot be completely covered by one-time circumferential scanning, returning the scanner to the starting point, adjusting the probe in the scanner to an uncovered position, and performing circumferential scanning for a plurality of times to finally realize the detection of the whole anticorrosive coating region; the detection sensitivity of four different bonding parts can be adopted to be scanned four times respectively, the full coverage can be realized from one end of the anticorrosive coating to the other end, and then the extraction and the synthesis can be carried out through equipment software;

b. Scanning times of the circumferential weld part and the slope part of the end part of the steel pipe anti-corrosion layer are not less than one time, and other parts can realize the detection of the whole anti-corrosion layer through one or more times of scanning;

c. The software of the multi-probe ultrasonic imaging detection equipment has the function of synthesizing the image data of the scanning result, so that the scanning image of the whole anticorrosive coating detection part C can be conveniently displayed on an interface.

Preferably, the analysis of the scanning result in S4 is to automatically display and save the acquired data in the form of an image, convert the wave height of the a scan into a corresponding color of the C scan image, judge the bonding state of the anti-corrosion layer according to the color of the image displayed by the C scan, realize the automatic analysis of the bonding result of the anti-corrosion layer, and determine the bonding state according to the echo height of the bottom surface of the steel tube in the a scan, namely:

(1) The first bottom surface echo height (h) of the steel pipe is less than 40% of the full screen height, and the part is an unbonded area;

(2) The first bottom surface echo height (h) of the steel pipe is less than 70% of the full screen height and is more than or equal to 40% of the full screen height, and the part is a weak unbonded area;

(3) The first bottom surface of the steel pipe has a echo height (h) which is more than or equal to 70% of the full screen height, and the part is a bonding area.

Therefore, the multi-probe ultrasonic imaging detection method for bonding the nonmetallic corrosion-resistant layer has the following beneficial effects:

(1) Adopting a unique integral sound velocity measurement method, regarding the nonmetallic anti-corrosion layer and the steel pipe as a whole, and not measuring the sound velocity of the nonmetallic anti-corrosion layer and the sound velocity of the steel pipe respectively;

(2) The problem of the bonding quality of the anti-corrosion layer of the pipeline is solved by a multi-probe ultrasonic imaging detection technology for the first time, and the ultrasonic detection of a plurality of probes is realized by adopting a multi-channel technology;

(3) The number of probes can be arranged according to the detection area, so that the detection speed is high and the efficiency is high;

(4) Realizing automatic scanning control, and displaying the bonding state of the anticorrosive coating by the detection result in an imaging mode;

(5) The detection system is easy to debug, simple to operate and wide in application range.

The technical scheme of the invention is further described in detail through the drawings and the embodiments.

Drawings

FIG. 1 is a schematic view of a scanner of the present invention;

FIG. 2 is a schematic view of the structure of the probe disc of the present invention;

FIG. 3 is a schematic view of the circumferential anticorrosive coating of the pipeline according to the first embodiment of the present invention;

FIG. 4 is a schematic view showing the arrangement of probes in the bonding sites of the corrosion protection layer according to the first embodiment of the present invention;

fig. 5 is a schematic diagram of data collected by scanning an anti-corrosion layer test board according to a second embodiment of the present invention, wherein (a) is a complete data schematic diagram of a scan (a), and (b) is a complete data schematic diagram of C scan;

fig. 6 is a state diagram showing an unbonded portion of the second anti-corrosion layer according to the embodiment of the invention.

Reference numerals

1. A driving section; 2. a probe disc.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Example 1

The test anti-corrosion layer is adhered to the simulated defect pipe, the pipe material is X65, the thickness is 10mm, the specification of the pipe is phi 508mm multiplied by 10mm, and the length is 2000mm. The polyethylene anti-corrosion layer is adopted, the two-layer structure is adopted, the thickness of the adhesive layer is 1.2mm, and the thickness of the polyethylene layer is 1.8mm. The primer thickness was about 0.4mm. The width of the anticorrosive coating is 520mm. And detecting the bonding state of the anticorrosive coating by adopting a full-automatic multi-probe ultrasonic imaging technology. The simulated defect pipe simulates the pipeline girth weld corrosion-resistant layer, namely the adhesion detection of the corrosion-resistant layer at the joint of the pipeline is basically consistent with the corrosion-resistant layer at the joint of the actual pipeline. Four parts exist in the anticorrosive coating at the joint coating of the pipeline, namely: the direct contact part of the heat shrinkage belt (sleeve) and the bare pipe, the direct contact part of the heat shrinkage belt (sleeve) and the circumferential weld surface, the contact part (double layers) of the heat shrinkage belt (sleeve) and the pipe body anti-corrosion layer and the slope part of the heat shrinkage belt (sleeve) and the pipe body anti-corrosion layer end part are shown in figure 3.

Wherein A is the contact part of the anticorrosive layer and the pipe body anticorrosive layer; b is the slope contact part of the anticorrosive coating and the pipe body anticorrosive coating; c is the contact part of the anticorrosive coating and the bare pipe; d is the contact part of the anticorrosive coating and the circumferential weld of the pipe body; e is a pipe body anti-corrosion layer; f is a heat shrink band (sleeve); phi is the diameter of the tube; the width of the heat-shrinkable tape (sleeve) was 520mm.

The first step, selecting a full-automatic multi-probe ultrasonic imaging device:

The device model is ISONIC-MG ultrasonic imaging device (produced by Israel, the device can realize multi-probe ultrasonic detection, phased array ultrasonic detection, namely a conventional ultrasonic module function, and a phased array ultrasonic module function, wherein the conventional ultrasonic module channel number generally comprises 8 channels, 16 channels, 24 channels, 32 channels, 48 channels, 64 channels, 128 channels and the like, the number of the selected channels is determined according to the requirement of a detection object, and the 48 channels are adopted in the first embodiment to sufficiently meet the requirement of bonding detection of all anticorrosive layers. The test is to test a simulated defect test piece of the pipe.

Secondly, selecting a longitudinal wave double crystal straight probe:

longitudinal wave twin crystal straight probe: the wafer size was 20mm, the frequency was 5MHz, and the depth of focus was 10mm. The test is to test a simulated defect test piece of the pipe. 45 longitudinal wave double crystal straight probes are needed to realize.

Thirdly, arranging probes at four positions of the anticorrosive coating at the joint of the pipeline:

(1) And before detection, the number of probes arranged at different positions is calculated according to the bonding positions of the detection objects. If the number of the equipment channels is limited, the detection can be performed by adopting a method of scanning and covering for multiple times.

1) The contact part of the heat shrinkage belt (sleeve) and the pipe body anti-corrosion layer:

The width of the part is 100mm, the part exists on two sides of the girth weld, 9 probes are respectively arranged on two sides, and 18 probes are total.

2) The heat shrinkage belt (sleeve) and the end slope part of the pipe body anti-corrosion layer:

the width of the part is 20mm, the two sides of the girth weld are provided with 1 probe, and the total number of the probes is 2.

3) The direct contact part of the heat shrinkage belt (sleeve) and the bare pipe:

the width of the part is 260mm, the part exists on two sides of the girth weld, and 12 probes are respectively arranged on two sides of the girth weld, and the total number of the probes is 24.

4) The direct contact part of the heat shrinkage belt (sleeve) and the circumferential weld surface:

The width of the part is 20mm, and 1 probe is arranged on the girth weld.

(2) The probes are arranged on a probe disc 2 in the scanner according to the bonding part of the anti-corrosion layer, the scanner structure is shown in fig. 1-2, and the probes are arranged in a V shape or in staggered parallel arrangement, as shown in fig. 4.

Wherein a is the width of the contact part of the anticorrosive layer and the pipe body anticorrosive layer, and is generally 100mm; b is the width of the slope contact part of the anticorrosive coating and the pipe body anticorrosive coating, and is generally 20mm; c is the width of the contact part of the anticorrosive coating and the bare pipe, and is generally 260mm; d is the width of the contact part of the corrosion-resistant layer and the circumferential weld of the pipe body, and is generally 20mm.

1) The contact part of the heat shrinkage belt (sleeve) and the pipe body anti-corrosion layer:

The width of the part is 100mm, the probes are respectively arranged on two sides of the girth weld, and the probes are respectively arranged on 9 sides of the girth weld, are arranged in nine rows and are arranged in a staggered parallel mode. The scans were covered with a coverage of 50% of the wafer size. The whole part is scanned once.

2) The heat shrinkage belt (sleeve) and the end slope part of the pipe body anti-corrosion layer:

the width of the part is 20mm, the part exists on two sides of the girth weld, 1 probe is respectively arranged on two sides, and the whole part is scanned once.

3) The direct contact part of the heat shrinkage belt (sleeve) and the bare pipe:

The width of the part is 260mm, the two sides of the girth weld are provided with 12 probes respectively, and the probes are arranged in a staggered parallel manner. The scans were covered with a coverage of 50% of the wafer size. The whole part is scanned once.

4) The direct contact part of the heat shrinkage belt (sleeve) and the circumferential weld surface:

the width of the part is 20mm, and 1 probe is arranged on the girth weld. The whole part is scanned once.

(3) And the position of each probe at the bonding part is adjusted and locked, and each probe also has an independent position adjusting function according to the detection area.

(4) A motor is provided in the driving part 1 of the scanner for driving the scanner and the probe to move. An encoder is also provided in the scanner for recording the scanning position.

Fourth step, calibrating the encoder:

and calibrating the encoder, namely moving the encoder by 300mm, wherein the display distance and the actual walking distance are less than or equal to 1%, otherwise, recalibrating.

Fifth step, static debugging:

(1) And (3) moving the scanner to a scanning starting point, keeping the scanner in a static state, flushing and coupling each probe, and keeping a certain pressure on water flow to ensure that the coupling is in a stable state. And adjusting sound velocity to 4100m/s by using a longitudinal wave double-crystal straight probe at the position, so that the detection part corresponding to the bottom wave signal of each probe is the position of the bottom surface of the steel pipe.

(2) And adjusting the sensitivity of the longitudinal wave double-crystal straight probe by utilizing bottom waves of different bonding parts. The bottom wave height of the probe corresponding to each part is adjusted to 80% +/-0-5% of the full screen height, the sensitivity is the reference sensitivity, the probe is fixedly locked, and the adjustment is called static debugging. Namely:

1) The bottom wave at the contact part of the heat shrinkage belt (sleeve) and the pipe body anti-corrosion layer is 57dB when the height of the full screen is 80%.

2) The bottom wave at the slope contact part of the heat shrinkage belt (sleeve) and the end part of the pipe body anti-corrosion layer is 70dB when the height of the full screen is 80%.

3) The bottom wave of the direct contact part of the heat shrinkage belt (sleeve) and the bare pipe is 46dB when the height of the heat shrinkage belt (sleeve) is 80% of the full screen.

4) The bottom wave of the direct contact part of the heat shrinkage belt (sleeve) and the circumferential weld surface is adjusted to 62dB when the full screen height is 80%.

(5) After static debugging is finished, coupling compensation is carried out on each channel probe, and the reference sensitivity is generally improved by 0-12 dB. How much dB value is increased depends on dynamic debugging.

Sixth step, dynamic debugging:

(1) And calculating the scanning speed, setting the motor scanning speed to 65mm/s, and setting the scanning speed according to field detection experience.

(2) Setting the encoder step. The encoder step is set to 1mm and the scanner is moved to the scan start point.

(3) Each probe is flushed and the water pressure is maintained.

(4) Scanning. Firstly, performing verification scanning, requiring that the bottom wave height of each channel probe is not lower than 80% of the full screen height, and if the bottom wave height is lower than the full screen height, adjusting the sensitivity of the channel probe. After the scanning is verified, the sensitivity of some channels is found to be basically between 70% and 75% of the full screen height, and in order to ensure that the bottom wave height of each channel is not lower than 80% of the full screen height, the bottom wave height is increased by 6dB, so that the bottom wave height is always in a state of being greater than or equal to 80% of the full screen height, but the bottom wave height cannot be in a state of exceeding 200% of the full screen height. The sensitivity is dynamic sensitivity, i.e. the final detection sensitivity, and this process is called dynamic tuning.

Seventh, setting a scanning range through equipment:

and setting a scanning length and width range. The scan length was 508mm×3.14=1595 mm≡1600mm, and the scan length was set to 1650mm considering a coverage of 50mm. The width is 520mm.

Eighth step, carrying out overall scanning:

After the dynamic debugging is finished, the whole scanning is carried out (48 channels of adopted equipment can realize one-time full coverage of the anti-corrosion layer area to carry out the whole scanning). The scanning speed is set to 65mm/s, and the speed is the on-site detection scanning speed and is consistent with the dynamic scanning speed. And (3) starting the water pump to flush the water for coupling, and keeping the water pressure and water flow stable, so that the coupling is in an intact state. Scanning is started through software control, and after scanning is finished, scanning data of all channels are stored.

Ninth step, data synthesis:

And finally integrating the detection data of each channel into a C scanning image of the complete thermal contraction band through equipment software. The wave height of the A scanning is converted into the corresponding color of the C scanning image, and the bonding state of the anti-corrosion layer can be judged from the color displayed by the image.

Tenth step, save the scanning data:

After the scanning is finished, the scanner automatically stops and automatically stores the acquired data. The scan data is presented in the form of a scan, B scan, and C scan. And finally, integrating the detection data of each channel into a C scanning image of a complete thermal contraction zone by using the function of equipment software, and displaying the C scanning image on a display screen (for the detection of implementing multiple scanning, the scanning data of each channel is synthesized into a complete C scanning image by using the equipment software for displaying). And directly displaying the bonding state of the anticorrosive coating in the form of an A scanning waveform and a C scanning image.

Example two

The test board for simulating defects by bonding the anti-corrosion layer is made of Q345R, and has the thickness of 10mm, and the specification of 300mm in length and 300mm in width. The polyethylene anti-corrosion layer is adopted, the two-layer structure is adopted, the thickness of the adhesive layer is 1.2mm, and the thickness of the polyethylene layer is 1.8mm. The primer thickness was about 0.4mm. And detecting the bonding state of the anticorrosive coating by adopting a full-automatic multi-probe ultrasonic imaging technology. The simulated defect test board simulates the self anti-corrosion layer of the pipe body and is basically consistent with the actual pipe body. The corrosion-resistant layer of the pipe body has two parts, namely a contact part of the corrosion-resistant layer and the bare pipe and a contact part of the corrosion-resistant layer and a pipe-making welding seam (spiral welding seam and straight welding seam). The simulated defect test board only simulates the contact position detection of the anticorrosive coating and the bare pipe (namely, simulating the pipe with the pipe diameter more than 500mm, and the pipe can be replaced by a planar test board in the range), and single-probe grid scanning is adopted.

The first step, selecting a full-automatic multi-probe ultrasonic imaging device:

The apparatus was identical to that employed in the first embodiment.

Secondly, selecting a longitudinal wave double crystal straight probe:

Longitudinal wave twin crystal straight probe: the wafer size was 20mm, the frequency was 5MHz, and the depth of focus was 10mm. The test is to test a test board, and can be realized by only one longitudinal wave double-crystal straight probe.

Thirdly, selecting a scanner:

The scanner is provided with a probe bracket, and the probe bracket has the functions of adjusting the position of the probe and locking. An encoder is arranged in the scanner, and the encoder has the function of recording the scanning position. The scanner is driven by a motor, and the walking speed is adjustable. The probe movement on the scanner has a biaxial movement function (i.e., bi-directional movement). In the test, the simulated defect test board is tested, the scanner is only fixed above the test board, and the probe is clamped to move on the test board through the double-axial movement function of the probe support.

Fourth step, calibrating the encoder and step setting:

And calibrating the encoder, namely moving the encoder by 300mm, wherein the display distance and the actual walking distance are less than or equal to 1%, otherwise, recalibrating. Two encoders are used, one for recording the position of the test plate in the length direction and the other for recording the position of the test plate in the width direction. The length direction encoder step was set to 1mm and the width direction encoder step was set to 5mm.

Fifth step, static debugging (adjusting reference sensitivity):

The probe is arranged on a probe bracket of the scanner, and flushing coupling is carried out on the probe. The probe is calibrated by initial wave on the multi-probe ultrasonic imaging equipment, and the thickness of the corrosion-resistant layer and the thickness of the steel plate are used for adjusting and calibrating sound velocity to 4100m/s. And then simulating the bottom wave of the defect test plate by using the anti-corrosion layer to calibrate the thickness. Finally, under the condition that the probe is not moving, the A scanning bottom wave height is adjusted to 80% +/-0-5% of the full screen height to serve as the reference sensitivity, the adjustment process is called static adjustment, namely 52dB is used when the bottom wave height of the corrosion-resistant layer test plate is adjusted to 80% of the full screen height, and the reference sensitivity value is the reference sensitivity value.

Sixth, setting a scanning range through equipment:

The overall specification of the test board is 300mm multiplied by 300mm, and the actual probe scanning range is set to be 200mm multiplied by 200mm in consideration of the problem of edge probe coupling. I.e. the interval in which the probe is travelling.

Seventh, dynamically debugging:

Dynamically debugging the scanner on the anticorrosive layer test board, wherein the dynamic debugging requires the scanner to move, and whether the bottom wave debugged at the intact part of the test board is above 80% of the full screen height or not is checked, but the full screen height is not required to be exceeded by 100%. Therefore, the walking process is required to ensure that the scanning bottom wave height of the intact part A of the test block is more than 80% of the full screen height, if the scanning bottom wave height is not reached, searching the reason to see whether the scanning bottom wave height is a surface coupling problem, and then increasing the dB (gain) value by a certain value to ensure that the bottom wave height is always more than 80% of the full screen height, but not more than 100% of the full screen height. And the whole scanning can be performed after the requirements are met. The bottom wave height of the intact part of the anticorrosive coating test plate is between 80% and 85% of the full screen height during dynamic scanning, so that the need of improving the gain value is eliminated. The final determined scanning (detection) sensitivity was 52dB.

Eighth step, carrying out overall scanning:

And after the dynamic debugging is finished, carrying out integral scanning, wherein the integral scanning speed is the same as the actual scanning speed. The scanning speed was set to 50mm/s. And (3) starting the water pump to flush the water for coupling, and keeping the water pressure and water flow stable, so that the coupling is in an intact state. The scanning is started through software control, the scanner carries the probe to scan according to a preset path (grid), and a complete C scanning image display is formed after the scanning is finished.

Ninth, saving scanning data:

After the scanning is finished, the scanner automatically stops and automatically stores the acquired data. The scan data is presented in the form of a scan, B scan, and C scan. The bonding state of the anticorrosive coating test plate is directly displayed in the form of A scanning waveform and C scanning image, and is shown in fig. 5.

Tenth step, scanning data are analyzed:

(1) Fig. 6 shows the non-bonded portion of the corrosion protection layer. The bottom wave height of the anti-corrosion layer simulation defect test block is 9.46% of the full screen height. The bottom wave is obviously disappeared as the bottom wave is reduced from 80% below the full screen height to 9.46%. The unbound region at this location was measured as: the width ranges from 170mm to 190mm, and the length ranges from 180mm to 200mm.

(2) The adhesion characteristics at different locations of the corrosion barrier can be estimated by displaying different color states in fig. 6.

The bonding state was verified to be unbonded here by a tensile failure test. The primer is intact, the adhesive layer melts, and the adhesive layer is peeled off from the primer, so that interface damage is presented. The pulling force at this position was 4.8N. The length of the unbonded portion was measured macroscopically by using a vernier caliper to be 14.7mm. The embodiment shows that the method for solving the problem of adhesion of the anti-corrosion layer by adopting the full-automatic multi-probe ultrasonic imaging detection technology is feasible and reliable, and is far superior to a verification method by adopting tension fracture.

Therefore, the invention adopts the multi-probe ultrasonic imaging detection method for bonding the nonmetallic anti-corrosion layer, adopts a unique integral sound velocity measurement method, combines an ultrasonic imaging technology to solve the problem of bonding quality of the anti-corrosion layer of the pipeline, and compared with the existing detection technology, the method has the advantages of advanced detection method, accurate result, high detection speed, high efficiency and low detection cost on bonding detection of the anti-corrosion layer of the pipeline.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention and not for limiting it, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that: the technical scheme of the invention can be modified or replaced by the same, and the modified technical scheme cannot deviate from the spirit and scope of the technical scheme of the invention.

Claims (8)

1. The multi-probe ultrasonic imaging detection method for bonding the nonmetallic corrosion-resistant layer is characterized by comprising the following steps of:

s1, detecting preparation, namely determining the bonding part of an anticorrosive coating according to different detected pipelines;

s2, static debugging, mounting a track and a scanner, configuring a probe, and adjusting sound velocity and sensitivity of the probe;

s3, dynamically debugging, and adjusting the sensitivity of the probe through verification and scanning;

S4, scanning and result analysis, namely automatically scanning and analyzing scanning results of the detected pipeline by using multi-probe ultrasonic imaging detection equipment, and judging the bonding states of the anticorrosive layers of the detected pipelines of different types by scanning image colors;

s1, determining the bonding part of the anticorrosive coating according to different detected pipelines, wherein the steps are as follows:

(1) Four parts: the corrosion-resistant layer is in direct contact with the bare pipe, the corrosion-resistant layer is in direct contact with the surface of the circumferential weld, the corrosion-resistant layer is in contact with the corrosion-resistant layer of the pipe body, and the corrosion-resistant layer is in slope contact with the end part of the corrosion-resistant layer of the pipe body;

Or (2) two sites: the contact part of the anticorrosive coating and the bare pipe and the contact part of the anticorrosive coating and the pipe welding line.

2. The multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion-resistant layer according to claim 1, wherein the method comprises the following steps: the multi-probe ultrasonic imaging detection equipment has a multi-channel function and is not lower than 8 channels, and each channel has independent A scanning, B scanning and C scanning modes; the probe adopts a longitudinal wave double-crystal straight probe, the probe frequency is not less than 2.5MHz, the wafer size is not less than 2mm, and the focal length is not less than 5mm.

3. The multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion-resistant layer according to claim 1, wherein the method comprises the following steps: the anticorrosion structure of the detected pipeline consists of a nonmetallic anticorrosion layer and a steel pipe.

4. The multi-probe ultrasonic imaging detection method for adhesion of a nonmetallic corrosion-resistant layer according to claim 1, wherein the detection preparation of S1 comprises the following steps:

s11, before detection, the number of probes arranged at different positions is calculated according to the bonding positions of the anti-corrosion layer of the detected pipeline;

s12, arranging probes on a probe disc of the scanner according to the bonding part of the anticorrosive coating, wherein the probes are arranged in a V-shaped or staggered parallel arrangement, and when the bonding part of the anticorrosive coating is inspected, single-probe arrangement is adopted;

S13, the probe of each anticorrosive coating bonding part has a position adjusting function and a locking function, and the positions of the probes are independently adjusted according to the detection areas;

and S14, a motor is arranged on a driving part of the scanner and used for driving the scanner to move, and an encoder is also arranged in the scanner and used for recording the scanning position or adopting sound positioning scanning to record the scanning position.

5. The multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion prevention layer according to claim 1, wherein the static debugging of S2 comprises the following steps:

s21, installing a track at one end of an anti-corrosion layer of a detected pipeline, wherein the distance between one end of the track and a detected area is not less than 50mm;

S22, mounting the scanner on a track, and adjusting the position of each probe;

S23, moving the scanner to a scanning starting point, keeping the scanner in a static state, performing flushing coupling on each probe, and adjusting sound velocity through the thickness of a detected pipeline by using the probes;

s24, adjusting the sensitivity of the probe by utilizing the bottom wave of the steel pipe at the bonding part of different anti-corrosion layers, wherein the bottom wave height is not less than 80% of the full screen height, the sensitivity is the reference sensitivity, and the probe is fixedly locked;

And S25, performing coupling compensation on each probe.

6. The multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion prevention layer according to claim 1, wherein the dynamic debugging of S3 comprises the following steps:

S31, calculating a scanning speed, setting the scanning speed of a motor on a scanner, and scanning according to the speed;

s32, calibrating the encoder, and moving the scanner to a scanning starting point after calibration is completed;

s33, flushing each probe, and maintaining the water pressure;

S34, verifying and scanning, wherein the bottom wave height of each channel probe steel tube is not lower than 80% of the full screen height, if the bottom wave height of each channel probe steel tube is lower than the value, the sensitivity of the channel probe is adjusted, the sensitivity is increased by 0-12dB, and the bottom wave height of each channel probe steel tube does not exceed the full screen height;

s35, verifying that the scanning speed is the same as the scanning speed of actual detection, and after the detected pipeline is scanned for one circle, the A scanning waveform, the B scanning image and the C scanning image displayed by each channel are uniform.

7. The multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion-resistant layer according to claim 1, wherein the scanning in S4 is specifically as follows:

(1) Before scanning, determining the scanning times of the anticorrosive coating region according to the number of channels of the multi-probe ultrasonic imaging detection equipment, if the number of the channels is not less than 48 channels, adopting a one-time full-coverage mode for scanning, if the number of the channels is less than 48 channels, adopting a multi-time scanning coverage mode for scanning, and controlling the scanning through software of the multi-probe ultrasonic imaging equipment during the multi-time scanning;

for the detection of a single probe, the probe movement adopts grid scanning or acoustic positioning scanning, and the acoustic positioning scanning adopts mechanical scanning or manual scanning;

(2) When scanning starts, the scanner is moved to a scanning starting point position, the scanner automatically walks through a motor, collected data are stored after scanning is finished, and complete A-scan, B-scan and C-scan images are displayed on a display screen of the multi-probe ultrasonic imaging detection device;

a. if the bonding part cannot be completely covered by one-time circumferential scanning, returning the scanner to the starting point, adjusting the probe in the scanner to an uncovered position, and performing circumferential scanning for a plurality of times;

b. scanning times of the circumferential weld part and the slope part of the end part of the steel pipe anticorrosive coating are not less than one time;

c. the software of the multi-probe ultrasonic imaging detection device has the function of synthesizing the image data of the scanning result.

8. The multi-probe ultrasonic imaging detection method for bonding a nonmetallic corrosion-resistant layer according to claim 1, wherein the method comprises the following steps: and S4, the scanning result analysis is to automatically display and store the acquired data in an image form, convert the wave height of the A scanning into a corresponding C scanning image color, and judge the bonding state of the anti-corrosion layer according to the image color displayed by the C scanning.