Effects of two laser cutting modes on the magnetic properties of low and medium Si grain non-oriented electrical steels

Summary form only given. Laser cutting is a non-contact cutting technique, which also provides flexibility for the design of electrical components. Therefore it can appear as the ideal technical solution for electrical steels manufacturers. Nevertheless the laser cutting deteriorates more of the magnetic properties of the electrical steels than mechanical cutting. The magnetic properties have been measured on one mini-SST especially built for non conventional magnetic measurements. 3 grades have been selected, 2 fully-processed (FP): SC and EB with respectively 0.31 and 2.98% Si and one semiprocessed (SP): EC with 2.32% Si. The magnetic properties for EC after laser and mechanical cuttings are equivalent for all the samples. On the contrary, the 2 FP grades EB and SC are sensitive to the different modes of laser cutting. The obtained results emphasize the superiority of the SP grade EC and the difficulty to keep the magnetic quality of FP grades. Nevertheless the different magnetic behavior after laser cutting of coercive field (Hc), remanent induction (Br) and the maximum relative permeability (/spl mu/) for EB and SC points out the importance of the modes (pulsed or continuous) on the induced thermal stresses. An optimization of the laser parameters is thus possible.