Identification of defects in a ferromagnet by solving the inverse problem of magnetostatics

Abstract

For many industries, the problem of detecting and classifying surface defects by a magnetic method is very important. Wherein the mutual configuration of magnetic converters and the object under study can be shown on the example of a device for in-pipe inspection of large-diameter pipes of gas pipelines. In this case, the magnetic transducers are located in the device inside the pipe, while the defects are located on the outer surface of the pipe. The data obtained from magnetic Hall transducers, measuring the magnetic field of scattering over the entire surface of the pipe, allows us to solve the inverse problem of magnetostatics on the restoration of magnetic fields to their sources. Due to the fact, that the pipes are made of a magnetically soft ferromagnet, it becomes possible to solve the problem of restoring the geometry of the surface corrosion defect in the metal. The proposed work contains an algorithm for reconstructing the geometry of surface defects of corrosion of an arbitrary shape from the measured magnetic scattering field over the metal surface opposite to surface, which contained the defect.