Effect of hardness and thickness of non-oriented electrical steel sheets on iron loss deterioration by shearing process

Non-oriented electrical steels are widely used as the core material of motors. The magnetic properties of non-oriented electrical steel sheets have large influence on a motor efficiency. Punching is general manufacturing process in automatic fabrication of motor cores. This process is known to degrade the magnetic properties of non-oriented electrical steel sheets by plastic strain and elastic strain [1]. Therefore, the influence of the material characteristics such as grain size, hardness, and thickness on the deterioration of magnetic properties needs to be studied. In previous studies, the influence of grain size on the deterioration of magnetic properties was reported [2]. However, it is not clear about the influence of material characteristics except the grain size. The purpose of this study is to clarify the influence of thickness and hardness of non-oriented electrical steel sheets on the deterioration of iron loss by shearing process.