Examination of Stress-Relief Annealing Method of Ring Core Material by Using Induced Magnetic Field Strength

Abstract

　Magnetic properties of motor cores are deteriorated due to residual stress and outside load during manufacturing process. In this paper, new stress-relief annealing method of ring cores will be suggested by applying an induced magnetic field. The temperature distribution and temperature characteristic on the surface of the ring core is examined by changing the lamination number of the ring core. In addition, the ring core which cut by punching, wire discharge and laser process are annealed and the magnetic properties of these cores before and after the annealing is evaluated.