| 摘要 |
PROBLEM TO BE SOLVED: To provide an advantageous method for producing a grain-oriented electromagnetic steel sheet with low iron loss and high magnetic flux density.SOLUTION: A method for producing a grain-oriented electromagnetic steel sheet comprises a series of steps of: hot-rolling a steel material comprising 0.002 to 0.10 mass% of C, 2.0 to 8.0 mass% of Si, and 0.01 to 0.8 mass% of Mn to obtain a hot-rolled sheet; after the hot-rolled sheet is annealed as necessary, cold-rolling the steel one time, or at least two times between which is interposed an interim annealing, to obtain a cold-rolled sheet of final sheet thickness; and after primary recrystallization annealing, applying an annealing separator to the steel sheet surface and then performing a final annealing. In the method, a holding processing is carried out in which: a final cold rolling rate in the cold-rolling process is 82 to 97%; the temperature interval of 200-700°C is rapidly heated at a rate of 50°C/s or higher in the heating step of the primary recrystallization annealing to set any temperature of 250-600°C as a holding initiation temperature; and the average temperature change ratio for 1 to 10 seconds from the holding initiation temperature is controlled in the range of -5 to +10°C/s. |
