PURPOSE: To manufacture a cold rolling steel plate which is excellent in a deep drawing property and ductility, by executing hot rolling for winding steel which contains C, Mn, S, Al, N, etc. by a limited composition quantity and specified composition relation, within a specified temperature range, and after that, executing cold rolling and recrystallization annealing.
CONSTITUTION: Steel which contains 0.015W0.045% C, 0.04W0.18% Mn, ≤0.020% S, 0.020W0.080% Sol.Al, ≤0.0018% N, and Fe and inevitable impurities as remains, and also has been manufactured so as to satisfy relation of 0≤(Sol.Al)- [(C)+0.05(Mn)]≤0.03 is wound at 500W720°C at the stage of hot rolling, and subsequently, by executing cold rolling and recrystallization annealing, a cold rolling steel plate having excellent deep drawing property and ductility especially for press molding is obtained. Above all, among composition components of said steel, when N and Sol.Al are added by a suitable quantity, ductility of a material can be elevated remarkably.
ARAKI KENJI
SUDA TOYOJI
ISHIGURO MORIYUKI
