| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a hot rolled steel sheet having excellent surface property, which prevents the generation of red scale and flaws due to scale biting so as to minimize surface defects in manufacturing the hot rolled steel sheet. SOLUTION: In hot-rolling after continuously casting a steel containing 0.001-0.30% C, 0.10% or less Si, 1.0% or less Mn, 0.04% or less P, 0.02% or less S, 0.005-0.10% acid soluble Al and the balance being Fe and unavoidable impurities, the temperature of the steel sheet is made T1(°C) or higher denoted by formula (1) below and the impingement pressure of the high-pressure water is made 15.7 MPa or less, when the surface of the steel sheet is descaled with high-pressure water at the entry side of a finish rolling mill and the surface temperature of the steel sheet between the second-row and third-row stands of the finish rolling mill is made T2(°C) or lower denoted by formula (2) below. Formula (1) is expressed by T1≥998×Si(%)-1,283×P(%)+1,010 and formula (2) is expressed by T2≤599×Si(%)-770×P(%)+976. COPYRIGHT: (C)2011,JPO&INPIT
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