Method for manufacturing oriented electrical steel sheet of low temperature slab heating method with excellent magnetic properties

摘要

The present invention relates to a method for manufacturing a grain-oriented electrical steel sheet used in iron core materials such as transformers, generators and other electronic devices, in the manufacture of a grain-oriented electrical steel sheet of low-temperature slab heating method excellent in magnetic properties, carbon: 0.03- 0.07%, silicon: 2.90-3.30%, manganese: 0.15-0.30%, sulfur: ≤0.006%, acid-soluble aluminum: 0.010-0.023%, nitrogen: 0.007-0.012%, phosphorus ≤0.015%, copper: 0.3-0.6% , 150-350mm thick silicon steel slab made of nickel: 0.03-0.07%, chromium: 0.03-0.07% and the balance iron was prepared, and the silicon steel slab was heated at 1250-1320 ° C. for 1-10 hours and then 1.5-2.6. Hot rolled to a thickness of mm, the hot rolled plate was pre-decarbonized and annealed using wet nitrogen or an atmospheric atmosphere having a dew point of 10-70 ° C. for 30 seconds to 30 minutes at 800-1150 ° C., followed by pickling the annealing plate. The final thick plate is subjected to two cold rollings with intermediate decarbonization annealing performed in a humid atmosphere. The final cold rolled plate was recovered and annealed at a temperature at which primary recrystallization did not occur, and then an annealing separator containing MgO as a main component was applied to the secondary annealed plate, and then the coating plate was subjected to primary recrystallization. In order to form a recrystallized structure, finishing annealing is performed.