| 摘要 |
PURPOSE:To manufacture a hot rolled steel sheet having superior adhesion to scale by refining a steel having a specified composition and by hot rolling it under specified conditions. CONSTITUTION:A steel consisting of, by weight, 0.03-0.25% C, 0.04-0.5% Si, 0.2-2% Mn, <=0.025% P, <=0.015% S, <=0.08% Al and the balance Fe with inevitable impurities is refined. A billet of the steel formed by a continuous casting method or an ingot making method is put in a heating furnace and heated. The billet may be cooled once and reheated. The heated billet is hot rolled at the Ar3 point + 50 deg.C or below, the resulting steel sheet is rapidly cooled at >=40 deg.C/sec cooling rate by pouring water within 5sec after the hot rolling and the cooled steel sheet is taken up at 360-500 deg.C.
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