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

摘要

The present invention relates to a grain-oriented electrical steel sheet produced by applying the low-temperature slab heating method, the hot rolling operations, using the a separate annealing minimizes the addition of chloride a mixture of the addition of MgO and SiO ₂ in the production method of the grain-oriented electrical steel sheet Thereby, good coating workability of the glass film does not, want to offer a method of manufacturing the electrical steel sheet excellent in the other speech direction, 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 ~ 1200 ℃ 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 treatment in a wet atmosphere of near 840 ~ 890 ℃ of hydrogen and nitrogen mixture containing the ammonia gas, by applying an annealing separator 700 a take-up a large coil was dried at a temperature of ℃ less then 700 and then a temperature increase rate of 1200 ℃ interval at a temperature of 1190 ~ 1210 ℃ while maintaining 15 ℃ / hr over 20 hours cracks finish cooling subjected to a high temperature annealing a process for producing a grain-oriented electrical steel sheet by applying a tension coating agent,; The application of the annealing separator is selected from the group consisting of MgO and 5 to 20% of fine SiO ₂ powder or colo SiO ₂ of the month state for a MgO based on solids, CuCl _2, MgCl _2, and NiCl ₂ 1 paper 0.008 the plate surface decarburization × total amount of oxygen (ppm) relates to a process for the preparation of the punching properties are excellent low-temperature reheat oriented electrical steel sheet characterized in that the addition of a ± 0.2, and with the technical gist.