Corrosion shape recovery by Electromagnetic Acoustic Transducer and its application to pipe wastage management

This paper is concerned with the characterization of pipe wall thinning by Electro Magnetic Acoustic Transducer (EMAT). Two types of coils are made to investigate those sensitivities with respect to corrosion shape on the back surface of sample materials. SUS304 test samples are provided and an artificial corrosion characterized by an elliptic curve is fabricated for each sample. A method of recovering corrosion shape on the back surface is experimentally verified. The experiments were performed by scanning the sensors along the front surface of sample specimen. As a result, it is confirmed that the peak-to-peak voltage of the first reflective wave (B1) becomes smaller when sensor comes close to the edge of the corrosion on the back surface.