Effect of Residual Stress for Leakage Magnetic Flux Induced by RayleighWaves Propagating on Steel Plates

Abstract

A Rayleigh wave propagating on a structural steel plate generates a magnetic field by means of the inverse effect of magnetostriction, which makes the magnetic flux a circuit through the air from the surface of the specimen. Thus, a field is observed as an electromotive force induced in a sensing coil. The amount of flux depends on two type of stress: compressive stress due to Rayleigh waves and residual stress due to the manufacturing process. In this paper, an instrument for measuring these stresses is proposed and the electromotive forces induced by Rayleigh waves are measured in two strainless plates, as-received and heat-treated. The magnetic field dependence of the electromotive forces shows a clear difference between the two specimens.