Integrity evaluation of steel products using EMATs

This paper presents work performed on steel samples at one inspection using electro-magnetic acoustic transducers (EMATs), allowing the inspection of internal and surface defects at the same time. Here, a spiral EMAT in the presence of a normal magnetic field is used to generate shear waves to detect internal and surface defects. B-scans are produced first by finite element calculation and then experimental measurement. The measurement procedure for inspecting the steel sample integrity is presented and two examples of internal and surface defects are given, thereby demonstrating the usefulness of the method