Grain-oriented electrical steel plate and preparation method thereof

[0041] figure 1 The flow chart of the preparation process of common grain-oriented electrical steel sheets is shown.

[0042] like figure 1 As shown, the annealing and pickling process (APL: Annealing & Pickling Line) is a step of removing the scale of the hot-rolled sheet, securing the cold-rollability, and precipitating and dispersing the inhibitor (AlN) of the hot-rolled sheet so as to contribute to the magnetism. Next, the cold rolling process is a step of rolling the hot-rolled sheet to the thickness of the final product and securing the crystal orientation favorable for the magnetic properties. In addition, the primary recrystallization annealing process is a step of forming primary recrystallization by removing carbon in the cold-rolled sheet through a decarburizing and nitriding annealing process (DNL: Decarburizing & Nitriding Line) and performing a nitridation reaction at an appropriate temperature. Next, a metal oxide layer (MgO) is formed in a high temperature annea

[0107] Experimental Example 1: Properties by Type of Ceramic Precursor

[0109] A slab was prepared, which included silicon (Si): 3.4 wt %, aluminum (Al): 0.03 wt %, manganese (Mn): 0.10 wt %, antimony (Sb): 0.05 wt %, and tin (Sn): 0.05 wt%, and the balance consists of Fe and other unavoidable impurities.

[0110] After heating the slab at 1150° C. for 220 minutes, it was hot-rolled with a thickness of 2.3 mm to prepare a hot-rolled sheet.

[0111] The hot-rolled sheet was heated to 1120° C., held at 920° C. for 95 seconds, then quenched in water and pickled, and then cold-rolled with a thickness of 0.23 mm to prepare a cold-rolled sheet.

[0112] The cold-rolled sheet is put into a furnace (furnace) maintained at 850 ° C, and the dew point temperature and oxidation energy are adjusted. In a mixed gas atmosphere of hydrogen, nitrogen and ammonia, decarburization nitriding and a recrystallization annealing are simultaneously performed to prepare decarburization annealing. rear steel plate.

[0113] After that, the annealing separator was not coated