Microstructure and texture evolution of the non-oriented silicon steel during punching

The iron core of motors is mainly manufactured using a punching process from rolled non-oriented silicon steel, and this leads to deformation and texture evolution at cutting edge. According to this, circular samples of a non-oriented silicon steel were prepared by punching with blunt punch tools. In this work, two positions along the RD and TD directions at the cutting edge were analyzed. The main mechanisms of deformation for both positions are dislocation slip and formation of shear bands. These two mechanisms lead to similar texture evolutions for both positions. The dislocation slip leads to the formation of the {221}〈uvw〉 component in the unbending area (200 µm away from cutting edge) and in the intermediate continuum bent area. In addition, the evolution of the texture from the {111} γ fiber to the {110} fiber was observed at the extremity of the cutting edge with formation of shear bands.