Nondestructive evaluation of reactor pressure vessel steels using the giant magnetoimpedance sensor

Abstract

Recently, the giant magnetoimpedance (GMI) effect found in amorphous wires has been noticed as a method for sensing a magnetic field. The GMI sensor was applied to nondestructive evaluation of microstructural changes for reactor pressure vessel steels passing through the refining process. They were measured by using a GMI sensor and the measured GMI signals were strongly influenced by the microstructural features. The signals are closely related to the grain size, carbide morphology, lath width, and lath boundary that act as a barrier to irreversible domain wall motion.