PURPOSE: To lower the iron loss value of an oriented silicon steel sheet by carrying out secondary recrystallization annealing of the sheet at a state in which the sheet has a corrugated shape extending in a direction intersecting the longitudinal direction of the sheet and then leveling the corrugated shape.
CONSTITUTION: A silicon steel slab contg. Si<4% is hot rolled to an intermediate sheet of 2W3mm thickness. The sheet is then annealed at 1,150°C for 2hr, pickled, and cold rolled twice interposing process annealing, or finish rolled to the final thickness of 0.29mm by a time of cold rolling. At this time, using a roll having a corrugated shape extending in a direction intersecting the circumferential direction, the corrugated shape is provided to the sheet. A coil of this sheet is decarburization annealed, coated with MgO, and subjected to secondary recrystallization annealing. Thereafter, it is washed with water and subjected to strain relief annealing while leveling the corrugated shape under press. Thus, by forming a crystal structure whose [001] axis is inclined by 4° or below to the rolling plane, the iron loss of the sheet is lowered.
NOZAWA TADAO
SUNAKAWA SADAO
OOYA YOSHIHIRO
| JPS533918A | 1978-01-14 |