| 摘要 |
PURPOSE:To form a uniform and periodical high strain region and to improve magnetic flux density by applying, prior to annealing, light draft rolling to a hot rolled plate under specific conditions by using a rolling roll having longitudinal grooves in the peripheral direction of the roll. CONSTITUTION:A hot rolled strip of a steel having a composition consisting of, by weight, <=0.01% C, <=7.0% Si, 0.1-1.5% Mn, <=0.1% P, <0.01% S, <=0.001% or 0.05-1.0% Al, <=0.005% N, and the balance Fe is used. After descaling, this steel strip is cold- rolled or warm-rolled by using a rolling roll having longitudinal grooves in the periph eral direction of the roll under the conditions satisfying inequalities I, II. Successively, this steel strip is annealed at a temp. not lower than the recrystallization temp., cold- rolled or warm-rolled to the final sheet thickness by means of a smooth roll, and then annealed. In the above inequalities, (t0) means the initial thickness of the stock to be rolled, (t) means the sheet thickness, in the recessed part, of the stock to be rolled after rolling by means of the longitudinally grooved roll, (l) means the pitch of the groove in the longitudinally grooved roll, and (Wt) means the width of the region of the sheet thickness (t) within the groove pitch (l), and further, these are expressed in millimetric units. |
