| 摘要 |
The invention refers to ferrous metallurgy, in particular, to production of grain-oriented electrical steel deployed in a manufacture of power transformer cores. Ensuring high magnetic permeability of steel and homogeneity of the magnetic properties requires slab casting, slab heating, rough and finishing hot rolling, cooling, pickling, double cold rolling with an intermediary decarburizing annealing, MgO coating application, box annealing and flattening annealing distinctive in that the steelmaking is implemented at the following ratio of the components, % wt: C = 0,018-0,035; Mn = 0,15-0,40; Si = 3,15-3,50; Al= 0,010-0,035; N 2 = 0,0090,015; Cu = 0,4-0,6 with the balance of Fe and unavoidable impurities, at the carbon-silicon concentration chosen so that during the finishing hot rolling within the range of 1130- 1280°C the austenite ratio comes to 2-10%, and with the rolling at the total deformation ratio of 80-95% and the rolling end temperature of 950-1030°C; cooling of strips after rolling starts in less than two seconds, and the heating for the high-temperature annealing in the temperature range of 400-700°C is carried out at the rate of 20-25°C/hour. |
