| 摘要 |
PURPOSE: A steel sheet having tensile strength of greater than 40 kg/mm¬2 and superior workability suitable for use in outer panel for automobile and a method for manufacturing the same are provided. CONSTITUTION: The method includes the steps of soaking an aluminum killed steel comprising 0.01 wt.% or less of C, 0.7 wt.% or less of Mn, P 0.04 to 0.10 wt.%, 0.015 wt.% or less of S, 0.06 wt.% or less of Sol.Al, 0.005 wt.% or less of N, Cu 0.5 to 1.0 wt.%, Ti 0.01 to 0.04 wt.%, a balance of Fe and incidental impurities in the temperature range of 1200 to 1250 deg.C, wherein Nb content satisfies below: 6.63£C|<=Nb<=6.63£C|+0.02 wt.%; finish hot rolling the aluminum killed steel after soaking at higher than Ar3 transformation temperature; coiling the hot rolled aluminum killed steel sheet at 550 to 700 deg.C, followed by cold rolling; continuous annealing at higher than 800 deg.C, followed by temper rolling.
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