Evaluation of Pipe Cracks Based on Cloud Contour of Three-Dimensional Induced Eddy Current Field

Abstract

Considering the problem of non-destructive testing and quantitative evaluation of metal materials, an electromagnetic method for visual and quantitative evaluation of surface defects on metal pipe is proposed in this paper. The dual-excitation probe with the combination of arc-shaped and rectangular coils is constructed. The eddy current magnetic field on the outer cylindrical surface of metal pipe is calculated and analyzed by COMSOL Multiphysics finite-element software, and then the influences of crack location and geometric parameters on three-dimensional magnetic field characteristics are studied. The results show that the cloud contours constructed by the magnetic induction intensity norm can accurately evaluate the information such as the location, size, depth, and orientation of the surface crack. In addition, the cloud contours constructed separately by the magnetic induction intensity in three directions can be used for auxiliary judgment to further determine the relevant important parameters of the surface crack to be tested.