Eddy current flaw detection is an alternating magnetic field generated by an alternating current that acts on the conductive material to be detected, inducing eddy currents. If there are defects in the material, it will interfere with the generated eddy currents, creating an interference signal.
The status of the defect can be known by detecting its interference signal with an eddy current flaw detector. There are many factors that affect eddy currents, which means that eddy currents carry a wealth of signals. These signals are related to many factors of the material. How to separate the useful signals from the many signals one by one is a difficult problem for current eddy current researchers. , some progress has been made over the years, and some problems can be solved under certain conditions, but it is still far from meeting the requirements of the site and needs to be vigorously developed.
The distinctive feature of eddy current flaw detection is that it can work on conductive materials, not necessarily ferromagnetic materials, but the effect on ferromagnetic materials is poor. Secondly, the smoothness, flatness, edge, etc. of the surface of the workpiece to be inspected have a great influence on eddy current flaw detection. Therefore, eddy current flaw detection is often used for flaw detection of non-ferromagnetic workpieces such as copper pipes with regular shapes and smooth surfaces.'
