| 摘要 |
PURPOSE:To produce a cold-rolled steel plate of high ductility for deep drawing by subjecting the aluminum-killed steel which is limited of a compsn. range of C, Mn, Al, N, P, etc., and a compsn. relation of Mn and S and is reduced of C, N, P to continuous annealing under adequate conditions. CONSTITUTION:After the low carbon aluminum-killed steel contg. 0.02-0.045% C, 0.10-0.35% Mn, >=0.7 S by weight ratio of Mn/S, 0.01-0.06% Al, <=0.0040% N, and <=0.010% P is hot-rolled at finishing temp. higher than the Ar3 point and is coiled at >=650 deg.C, the hot-rolled plate is cold-rolled to a prescribed thickness and is then subjected to the continuous annealing wherein the rolled plate is subjected to an overaging treatment for >=1min at 350-450 deg.C after it is soaked for >=10sec at temp. higher than the recrystallization temp. and lower than 850 deg.C, whereby a cold-rolled steel plate for deep drawing having excellent ductility is produced without application of skin pass rolling. The above-mentioned content of C is decreased to the extent of not requiring any vacuum degassing device, whereby costs are reduced. |
