Imaging Research Of Magnetic Testing

Magnetic testing technology has been widely used in ferromagnetic materialstesting field with its advantages of detection speed and simple operation, but the currentresearch largely confined to the orientation and quantitative of defects, and thequalitative aspects in the defect analysis for less. This paper realizes the two and onehalf dimension field source imaging using the imaging technology and the methodanalytical continuation, and makes the magnetic testing have the advantage ofvisualization, so we’ll talk about the quantitative and qualitative to defect on that basis.This paper according to the analysis of magnetic field theory, from the angle oftransformation of gravity and magnetic, expound to the formulae of magnetic fieldpattern of the sphere, cylinder, cuboid defects ect. and made new elaboration signal tomagnetic anomaly of defects; In magnetic anomaly data processing, This paper realizesthe two and one half dimension field source imaging Using the downward continuation andmulti-channel magnetic method detector; the Q235steels with the defects of the levelcylinder and the upright cylinders and cuboid are inspected and validated, and the resultshows that: the magnetic anomaly measured curve of the inhomogeneous defectsidentical with oretical analysis, imaging results not only can accurately reflect defectsposition, and can better make the quantitative and qualitative analysis for the aboveseveral defect size and shape; In the end of this paper, the buried pipeline with corrosiondefects and groove defect detection images show: in the test plane1.2m from the pipe,This method not only can effectively detect the large defects of corrosion depth for2mm, and detection effect more apparent for the small area corrosion defects forcorrosion depth5mm; the detection of the pipeline with groove defects results show that:this method can effectively detected the longitudinal defects with no less than length30mm, this result can achieve the desired objective, and will impel the buried pipelinetrenchless detection technology development.