| 摘要 |
PURPOSE:To homogenize the steel structures of the inside, outside and intermediate parts of a hot rolled coil and to stabilize the magnetic characteristics by preheating a heating furnace to a temp. which is above the desired annealing temp. by a specified temp. or below, putting the hot rolled coil in the furnace, and changing the set temp. of the furnace to the annealing temp. or below. CONSTITUTION:A nonoriented electrical steel slab is hot rolled and coiled at >=750 deg.C. This hot rolled coil is put in a heating furnace at one, and the hot rolled plate is annealed by making use of its potential heat. At this time, the heating furnace is preheated to a temp. which is above the desired annealing temp. by <=100 deg.C, and after putting the hot roller coil, the set temp. of the furnace is changed to the annealing temp. or below. |
