| 摘要 |
PURPOSE: Duplex stainless steel with an excellent surface quality and a manufacturing method thereof are provided to roll a steel sheet up to a target thickness by controlling the draft percentage. CONSTITUTION: Duplex stainless steel with an excellent surface quality contains C of 0~0.03wt.%, Si of 0~1.0wt.%, Mn of 0~2.0wt.%, P of 0~0.04wt.%, S of 0~0.004wt.%, Cu of 0~0.5wt.%, Ni of 4.5~6.5wt.%, Cr of 22~23wt.%, Mo of 3.0~3.5wt.%, and N of 0.14~0.20wt.%. A duplex stainless steel with an excellent surface quality comprises residual Fe and inevitable impurities. The ratio(Creq/Nieq) of nickel equivalent and chromium equivalent defined according to the following formula; Nieq=%Ni+30%C+0.5%Mn+0.33%Cu+30(%N-0.045) and Creq=%Cr+%Mo+1.5%Si+0.73%W is 2.2~3.0.
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