| 摘要 |
PURPOSE:To certainly enhance the deep drawing property of the edge part in a cold annealed steel plate in low cost, by a method wherein aluminum killed steel containing C, Mn, Sol, Al, P and N respectively in a predetermined ratio is continuously cast to obtain a steel piece which is then succeedingly heated to a specific temp. or more to be subjected to hot rolling. CONSTITUTION:Aluminum killed steel containing, on a wt. ratio, 0.10%- or less C, 0.50% or less Mn, 0.10% or less P, 0.010-0.100% Sol, Al and 0.0010-0.0100% N and comprising the remainder of Fe and inevitable impurities is continuously cast to prepare a steel piece. Suceedingly, the vicinity of this steel piece is heated to 1,150 deg.C or more for a short time to raise the temp. thereof and, after precipitated AlN is re-melted, the heated steel piece is hot rolled so that a finish temp. is brought to an Ar3-deformation temp. or more. That is, the latent heat possessed by the high temp. steel piece directly after continuous casting is effectively utilized to directly connect hot rolling to continuous casting and a cold annealed steel plate having aforementioned characteristics is obtained. |
