Magnetic characteristic of strain metal materials

In a nuclear power plant, when external stresses such a huge earthquake are added, residual strain may have occurred in the structure. In this research, SUS316L and SS400 which applied the stress and added residual strain, are created, and the possibility of diagnosing of the residual strain nondestructively from the magnetic characteristic of test pieces are examined. The basic magnetic characteristics were measured by a coil wound up the specimen directly, and the nondestructive measurements were carried out by a coil wound up the yoke. In addition, Barkhausen noises are measured and evaluated. (author)