| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hot-rolled steel sheet excellent in scale adhesion, and a method of manufacturing the same. <P>SOLUTION: A steel raw material having a composition including, by mass%, ≤0.3% of C, ≤0.1% of Si, ≤2.0% of Mn, ≤0.05% of P, ≤0.02% of S, ≤0.10% of Al, and the balance of Fe and inevitable impurities is subjected to finish rolling including an oxidizing treatment, in which the steel raw material is kept in an atmosphere with a dew point of ≥50°C for 1.0 to 10 seconds in a finish rolling machine, and completing at a finish-rolling end temperature set at 700-900°C. After completing the finish rolling, the resultant material is cooled, and taken up in a roll at a taking-up temperature of 450-650°C. Thus, a scale layer including, by an area ratio, ≥50% of Fe<SB POS="POST">3</SB>O<SB POS="POST">4</SB>, and the balance of Fe and Fe<SB POS="POST">2</SB>O<SB POS="POST">3</SB>inevitably formed, and having pores of 0.10-3.0% by area ratio and a thickness of ≤10 μm is formed, with which scale adhesion is remarkably improved. <P>COPYRIGHT: (C)2012,JPO&INPIT |
