NUMERICAL AND EXPERIMENTAL RESEARCH ON PIPELINE MAGNETIC FLUX LEAKAGE TESTING WITH INSPECTION DEVICE OF VARIABLE DIAMETERS

摘要

Finite element analysis model of magnetic flux leakage testing outside pipeline was established with analysis software in this paper. The leakage magnetic field characteristic curves of defects were obtained using this model. Also, the simulation on different diameter and depth of the cylindrical defects was carried out. And influence on flux leakage field, such as depth of defects corrosion defects was gotten. Then, detection device which can do inspection on pipeline with different diameters was manufactured based on the theory and finite element calculation results. The experiments with this device were carried out on the wall thickness of 8 mm and 6 mm pipeline with artificial defects above or under. And the results showed good agreement with simulation which meets engineering application of pipeline inspection.