Research On Detection Of Pipeline Anticorrosion Layer Based On Ultrasonicon

As the most commonly used means of oil and natural gas transportation,the safety problem of pipeline anti-corrosion layer is particularly important.There are many ways to detect the anticorrosive coating,such as close interval potential detection technology,CIPS technology,multi frequency tube current method(PCM)and so on.Ultrasonic detection of pipeline anticorrosive coating has the advantages of high sensitivity and long propagation distance.The steel plate with epoxy resin is used instead of the pipeline with perfect anticorrosion layer,and the single layer steel plate is used to replace the completely stripped pipe of the anticorrosion layer,and the energy absorption by the anticorrosion layer is used to cause the energy attenuation,and the peeling of the anti-corrosion layer is detected by judging the change of the ultrasonic energy.The propagation mechanism and propagation path of oblique incidence of ultrasonic waves in a double-layer medium were studied for ultrasonic inspection of the peeling off of pipeline coatings.From the angle of energy,we can get the energy change of ultrasonic wave on the double layer plate,the completely stripped single layer steel plate and the coating layer on the edge of the coating.In the experiment,2.5MHz and K2(the angle of 63 degrees)were used to detect the intact double-layer plate of the anticorrosion layer and the completely stripped layer plate of the anticorrosion layer,and the energy was obtained.The energy of the left edge of the anticorrosion layer was smaller than that of the right edge of the anticorrosion layer.The propagation characteristics of ultrasonic vertical incident double-layer media are studied,and the energy change of ultrasonic propagation into each layer of double-layer media is further studied.In the experiment,we selected the single layer plate which was completely stripped by the vertical probe anticorrosion layer and the intact double-layer plate of the anticorrosion layer.The energy attenuation caused by the anticorrosion layer under the experimental condition was obtained.The quantitative analysis of the anticorrosion layer was used to test the stripped of the anticorrosive layer with different lengths,and the matlab algorithm and the C# programming language were used.The data is processed to obtain the energy value of the stripped edge of the anticorrosion layer.Using this value,the double-layer plate of the stripped length of the unknown anticorrosion layer is detected.The feasibility of the method is verified,and the detection of the stripping length of the anticorrosion layer of the experimental double-layer plate is realized.The results show that the energy of ultrasonic wave in the single plate is larger than that in the double plate.When the distance between the oblique probes is 1.8cm,the ultrasonic energy received is the largest.With the direct probe moving from single layer plate to double-layer plate,the energy attenuation of the ultrasonic wave is obtained.For the quantitative of the stripping of the rectangular anticorrosion layer of the length of 8cm,the detection result is 7.65 cm by using the direct probe of 2.5MHz,and the result is 7.76 cm using the direct probe of 5MHz,which is used in the engineering application.The probe provides a theoretical basis and a feasible plan for detecting the peeling off of the coating.