| 摘要 |
PCT No. PCT/JP83/00050 Sec. 371 Date Oct. 13, 1983 Sec. 102(e) Date Oct. 13, 1983 PCT Filed Feb. 18, 1983 PCT Pub. No. WO83/02957 PCT Pub. Date Sep. 1, 1983.Based on the investigation as to the correlative relationship between the composition of a steel material, particularly the content of carbon and a soaking temperature for the hot rolling, the improvements of the stretch formability, deep-drawability and aging resistance of the cold rolled steel sheet and the peculiar behaviors of the effective additive ingredients under the above correlative relationship, a cold rolled steel sheet having excellent press-formability is obtained by soaking at 800 DEG -1,100 DEG C., a steel slab consisting of not more than 1.2% by weight of Si, 0.05-1.00% by weight of Mn, not more than 0.150% by weight of P, at least one of elements selected from the group consisting of Nb, Cr, Ti, Al, B and W in a total amount of 0.002-0.150% by weight in an extremely low range of not more than 0.005% by weight of C, followed by ordinary hot rolling, cold rolling and recrystallization annealing. |
