| 摘要 |
PURPOSE:To efficiently manufacture titled steel sheet, by executing the cold rolling with the high draft percentage and a specified diferential peripheral speed rolling rate, followed by annealing pass at temperatures above the recrystallization point. CONSTITUTION:At manufacturing the cold rolled steel sheet by the cold rolling facilities, the draft percentage is specified above 65%, and the differential speed rolling is executed under the condition to satisfy the formula I (in which, n is the number of rolling passes, V1 is the peripheral speed of rolls at upper stage, V2 is the peripheral speed of rolls at lower stage, and + means the normal rolling period and - means the reverse rolling period). After that, the annealing is executed at temperatures above the recrystallization point; hereby, the cold rolled steel sheet of high Lankford value (r-value) or of high mean value of Lankford values in the rolling direction, and of superior deep-drawability, is surely manufactured. Besides, the restrictive condition for both of hot rolling work and cold rolling work is moderated. |
