[China Instrument Network Instrument R&D] On April 19, the relevant unit learned that Shenyang University of Technology has successfully developed a comprehensive ultra-high-definition magnetic flux leakage detection system for long-distance transmission pipelines. This system has made up for domestic gaps and reached the international advanced level.
Magnetic flux leakage detection means that a ferromagnetic material is magnetized and a leakage magnetic field is formed on the surface due to a flaw on the surface or near surface of the test piece. One can detect defects by detecting a change in the leakage magnetic field. The so-called leakage magnetic field is when the material has the defect that cuts the magnetic force line, the material surface defect or the tissue state change will cause the magnetic permeability to change, because the magnetic permeability of the defect is very small, the magnetic resistance is very big, make the magnetic flux in the magnetic circuit Distortion occurs. The flow direction of the magnetic flux will change, except that part of the magnetic flux will directly pass through the defect or the material to bypass the defect, and some of the flux will leak over the surface of the material. By bypassing the defect, the air will enter the material again. The surface of the material forms a leakage magnetic field.
Magnetic flux leakage inspection is a very important non-destructive testing method and it is widely used. When used in combination with other methods, it can provide fast and inexpensive evaluation of workpieces of ferromagnetic materials. With the advancement of technology, people are paying more and more attention to the automation of the detection process. This not only can reduce the labor intensity of the inspection work, but also can improve the reliability of the test results and reduce the influence of human factors.
At present, the confidence level of internal magnetic flux leakage testing equipment at home and abroad is 80%. The main reason is that the existing internal magnetic flux leakage detection technology cannot detect axial defects, pipe cracks, and weld cracks. In response to this problem, the on-line inspection and research team of oil and gas long-distance transmission pipelines led by Prof. Yang Lijian of Shenyang University of Technology developed an all-around ultra-high-definition magnetic flux leakage inspection system for long-distance transmission pipelines with independent intellectual property rights. The success of this system test indicates that China has mastered the full range of ultra-high-definition magnetic flux leakage detection methods for pipelines, making the in-pipe detection technology in China more systematic and scientific, making up for domestic gaps, and making China's pipeline inspection technology enter the international advanced level. .
(Initial title: Long-distance transmission pipeline magnetic leakage detection system successfully tested in Shenyang)