An electromagnetic detection method based on defect leakage magnetic field source and active detection magnetic source

Abstract

The invention belongs to the field of electromagnetic nondestructive testing, and discloses an electromagnetic detection method based on a defect leakage magnetic field source and an active detection magnetic source. The method comprises the steps that firstly, a to-be-detected component is magnetized, so that the to-be-detected component forms a leakage magnetic field at a defect of the to-be-detected component, wherein the leakage magnetic field is a micro-magnetic source space domain with the defect as the circle center and the radius of r1; secondly, a detection magnetic source with a magnetic sensitive element is swept over the defect, so that the leakage magnetic field and the magnetic field of the detection magnetic source are subjected to magnetic superposition to form magnetic disturbance, wherein the magnetic field of the detection magnetic source is a detection magnetic space domain with the detection magnetic source as the circle center and the radius of r2; thirdly, magnetic disturbance is picked up by the magnetic sensitive element in the lift-off range which is r1+r2 away from the surface of the to-be-detected component, and electromagnetic detection of the defect is completed. According to the method, active detection is achieved; meanwhile, the detection lift-off distance is increased, the problems of contact abrasion and shaking caused when a sensor is tightly attached for detection are avoided, and increase of detection signals in the same lift-off detection state is also achieved.

Description

technical field [0001] The invention belongs to the field of electromagnetic nondestructive testing, and more specifically relates to an electromagnetic testing method based on a defect leakage magnetic field source and an active detection magnetic source. Background technique [0002] Electromagnetic nondestructive testing technology is a nondestructive testing technology based on electromagnetic induction. With the development of electronic technology and computer technology, electromagnetic nondestructive testing technology has made breakthroughs in development and application; electromagnetic nondestructive testing is the use of materials that appear under the action of electromagnetic fields. A type of test method for judging the structure and related properties of the tested material by changing the electromagnetic characteristics. In non-destructive testing, no matter what the method or method is, it can be attributed to the mode of excitation + detection, that is, one...

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Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides an electromagnetic detection method based on defect leakage magnetic field source and active detection magnetic source, and adopts the method of active detection magnetic source detection after exciting the defect magnetic field, thereby solving the problem of Contact wear and vibration during probing, as well as technical problems that make it difficult to detect small defects

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