A METHOD FOR MANUFACTURING LOW TEMPERATURE REHEATED GRAIN-ORIENTED ELECTRICAL STEEL SHEET HAVING SUPERIOR PUNCHING PROPERTY

摘要

The present invention relates to a method of manufacturing a low-temperature reheat oriented electrical steel sheet, as the fusing agent of alumina sol and magnesium chloride (MgCl ₂₎ for the use of mixture was added a slurry of MgO powder, the coating workability is good and the glass film is oriented electrical steel sheet not provided to be in, to want to provide a method for producing the stricken other good low temperature reheat oriented electrical steel sheet, it is an object.; The present invention in weight%, Si: 2.9 ~ 3.4%, C: 0.045 ~ 0.062%, P: 0.015 ~ 0.035%, soluble Al: 0.022 ~ 0.032%, N: 0.006 ~ 0.009%, S: 0.004 ~ 0.010%, Mn: 0.008 ~ 0.012%, Cu: 0.012 ~ 0.021%, and the balance Fe and other unavoidable by a steel slab composition to be contained impurities low temperature reheating at a temperature of 1150 ~ 1190 ℃ after hot rolling, and temperatures below 1100 ℃ the hot-rolled sheet annealing at, and pickling and a cold rolling to the final thickness, and then subjected to simultaneous decarburization nitriding ammonia gas in the vicinity of the hydrogen and 840 and a humid atmosphere of nitrogen mixed ~ 890 ℃ contain, by applying a sealing agent 700 ℃ a take-up a large coil was dried at a temperature not higher than the next, 700 and then a temperature increase rate of 1200 ℃ interval at a temperature of 1200 ± 10 ℃ while maintaining more than 15 ℃ / hr over 20 hours cracks finish cooling subjected to a high temperature annealing, a method for producing a grain-oriented electrical steel sheet by applying a tension coating agent,; Of the fusing agent is MgO, and 2-6 parts by weight of alumina sol with a solid content based on the MgO, and here the following relation 1, the MgCl ₂ was added to the guests to the punching property, characterized by joseongdoem reheating excellent low-temperature orientation in electrical steel that relates to a process for the preparation, and to the technical aspect.; [Expression 1]; MgCl ₂ amount (%) = 9.5 × SiO ₂ amount (g / ㎡) ± 0.4; However, where the SiO ₂ amount is the amount of SiO ₂ present in the simultaneous decarburization a nitriding steel