Effect of hot-band grain size on magnetic properties of non-oriented electrical steels

Hot-band grain size of 0.5% Si steels was changed from 42 to 115 μm by various combinations of several hot rolling and annealing conditions. The hot-bands were cold rolled from 2.3 to 0.50 mm and finally annealed for 1 min at several temperatures between 750 °C and 950°C. The values of magnetic induction B50 in the directions of 0° and 90° from the rolling direction increase, whereas that of 45° direction decreases a little with an increase in the hot-band grain size. The core loss W15/50 in 0°, 45° and 90° directions decreases altogether with an increase in the hot-band grain size. The change in B50 with an increase in the hot-band grain size is caused by decreases of (110) component in the annealing texture. The change in W15/50 with an increase in the hot-band grain size is accounted for both of the grain size and texture effects.