Image fusion-based metal magnetic material defect detection device

Abstract

The invention discloses an image fusion-based metal magnetic material defect detection device. Sine and cosine signals are applied to two pairs of mutual vertical U-shaped magnet yokes correspondingly, and a rotating magnetic field, of which the synthesis direction is uniformly changed along with time and the amplitude is not changed, serves as an excitation magnetic field for detection of a metalmagnetic material test piece. If the defect exists in the metal magnetic material test piece, a leakage magnetic field is generated above the defect, the leakage magnetic field information is converted into a magneto-optical image through a magneto-optical imaging system, a frequency domain image of a magneto-optical image sequence is normalized, linear weighted fusion is conducted, the image isconverted within the gray value range, and the defect image of the metal magnetic material test piece is acquired. A magnetic field excitation test piece is rotated by low frequency being below 50 Hz,the defect in each direction can be effective excited, the magneto-optical image in single excitation period is acquired by a magneto-optical imaging technology, the defect in each direction is subjected to linear weighted fusion in the frequency domain, and rapid visual detection of the defect in each direction is realized.

Description

technical field [0001] The invention belongs to the technical field of defect detection, and more specifically relates to a metal magnetic material defect detection device based on image fusion. Background technique [0002] In the defect detection of metal magnetic materials, magneto-optic imaging (MOI) technology combined with magnetic flux leakage detection has been rapidly developed because of its visualization, rapidity and accuracy. Based on the Faraday effect, the magneto-optical imaging detection technology converts the leakage magnetic field that reflects the defect information (the leakage magnetic field information generated by the defect) into light intensity information, that is, the leakage magnetic field image. By analyzing the leakage magnetic field image, the defect detection is realized, and then the The state of health of metallic magnetic materials. [0003] Among them, magnetic flux leakage testing is a traditional nondestructive testing technology, whi...

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Problems solved by technology

[0007] Among the above methods, the high-frequency excitation has weak detection ability to internal defects due to the skin effect of eddy current, and the leakage magnetic field signal generated is weak.

Static excitation can only detect defects in a single direction, although the leakage magnetic field signal is strong

The unidirectional low-frequency magnetic flux leakage detection is equivalent to the static excitation with variable amplitude, which takes a long time to detect and is only sensitive to unidirectional defects.

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