Method for identifying defect profile of pseudo three-dimensional magnetic flux leakage signal based on normal component

Abstract

The invention discloses a method for identifying a defect profile of a pseudo three-dimensional magnetic flux leakage signal based on a normal component. The method comprises the following steps: selecting an identification area from a piece to be tested; filtering detected data to obtain a normal component of a magnetic flux leakage signal; multiplying a horizontal differential signal by a firstpreset multiple to obtain a horizontal component of a pseudo magnetic leakage signal; multiplying a vertical differential signal by a second preset multiple to obtain a vertical component of the pseudo magnetic leakage signal; performing pseudo three-dimensional magnetic flux leakage signal synthesis operation on the normal component of the magnetic flux leakage signal, and the horizontal component and the vertical component of the pseudo magnetic flux leakage signal to obtain a synthesized magnetic flux leakage signal; and selecting a preset threshold value to obtain a defect identification profile. According to the method, an approximate value of the horizontal component and the vertical component of the magnetic flux leakage signal can be derived from the normal component of the magnetic flux leakage signal to further construct a pseudo three-dimensional magnetic flux leakage signal so as to realize defect profile identification; and the method has higher solving precision and better identification effect compared with the traditional one-dimensional magnetic flux leakage signal defect profile recognition.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing, in particular to a method for identifying defect contours of pseudo three-dimensional magnetic flux leakage signals based on normal components. Background technique [0002] Magnetic flux leakage testing is one of the more commonly used non-destructive testing methods. It is widely used in the defect detection and safety assessment of ferromagnetic test pieces such as oil and gas pipelines and storage tank bottom plates. The defect contour recognition based on the magnetic flux leakage detection signal is very important for the test piece. Detection and evaluation are of great significance. [0003] In recent years, with the continuous advancement and improvement of magnetic flux leakage detection technology, the requirements for defect detection and safety assessment have become increasingly stringent. Only using one-dimensional magnetic flux leakage detection signals for defect ...

AI Technical Summary

Problems solved by technology

[0003] In recent years, with the continuous advancement and improvement of magnetic flux leakage detection technology, the requirements for defect detection and safety assessment have become increasingly stringent. Only using one-dimensional magnetic flux leakage detection signals for defect analysis can no longer meet the requirements for defect identification accuracy. Analyze and process magnetic detection data to provide richer defect contour information and improve recognition accuracy

However, compared with one-dimensional magnetic flux leakage detection, three-dimensional magnetic flux leakage detection requires twice the number of magnetic sensors, and has higher requirements for the acquisition position and accuracy of three-dimensional magnetic flux leakage signals, which greatly increases the development cost and cost of magnetic flux leakage detection devices. Design Difficulty

However, there is no research on this 3D MFL signal derivation technique and related defect contour recognition methods

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