| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-rolled steel sheet having uniform qualities of a material such as tensile characteristics and a structure close to a ferrite single phase, and to provide a hot-dipped steel sheet. SOLUTION: This hot-rolled steel sheet comprises, by mass%, 0.03-0.2% C, 0.6-2.0% Mn, 0.02-0.15% Al, 1.0% or less Si, 0.04% or less P, 0.003% or less S, 0.010% or less N, 0.2% or less in total of Cu, Ni, Cr and Mo, 0.01% or less in total of Nb, V andTi, 0.01% or less B, and the balance Fe with unavoidable impurities; and has a structure having the ferrite phase controlled to 90% or more by area rate, and further the fluctuating values of tensile strength in the longitudinal direction of a coil controlled within a range of±15 MPa. COPYRIGHT: (C)2004,JPO&NCIPI
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