| 摘要 |
PURPOSE: A method for manufacturing a hot rolled steel sheet(35 kg/mm¬2) for structure by mini mill process is provided. CONSTITUTION: The method includes the steps of melting scrap in electric furnace so that the steel melt comprises 0.07 wt.% or less of C, Mn 0.2-1.0 wt.%, 0.5 wt.% or less of Si, 0.04 wt.% or less of P, 0.02 wt.% or less of S, Soluble Al 0.01-0.10 wt.%, and N 0.005 to 0.020 wt.%, wherein among tramp elements from the scrap, Cu is controlled to be 0.2 wt.% or less, Sn is controlled to be 0.05 wt.% or less and Sb is controlled to be 0.05 wt.% or less; continuous casting the molten steel to thin slab with a thickness of less than 70 mm; finish hot rolling the thin slab in the range of austenite single phase by mini mill process; and winding the hot rolled steel sheet at 500 to 700°C.
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