| 摘要 |
PURPOSE: A method for manufacturing oriented electrical steel sheets is provided to give superior magnetic and decarburizing properties to the oriented electrical steel sheets, therefore it is applicable for use in a current transformer without magnetic aging. CONSTITUTION: The oriented electrical steel sheet is manufactured by the processes of reheating a steel slab comprising Si 2.9-3.3wt.%, C 0.025-0.055wt.%, P 0.015wt.% or less, sol-Al 0.008-0.027wt.%, N 0.0080-0.012wt.%, S 0.007wt.% or less, Ni 0.02-0.08wt.%, Mn 0.32wt.% or less, Cu 0.60wt.% or less, a balance of Fe and inevitable impurities in the temperature range of 1250 to 1330deg.C; hot rolling; annealing the hot rolled steel sheet at below 1000deg.C; preliminary cold rolling; process annealing in the temperature range of 920 to 960deg.C; final cold rolling at the reduction rate of 54 to 69%; decarburizing annealing in the temperature range of 800 to 860deg.C under wet atmospheric condition; applying MgO agent; final annealing where the steel sheet is heat treated in such a manner that temperature elevation rate is controlled to 15deg.C/hr or more over the temperature range of 700 to 1200deg.C and then the steel sheet is heat treated in the temperature range of 1190 to 1210deg.C for at least 20hrs.
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