| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot dipped galvanized steel sheet or an alloyed hot-dip galvanized steel sheet, which has a tensile strength of 980 MPa or more, exhibits a high yield ratio and is also excellent in both of a TS-El balance and a TS-λ balance.SOLUTION: The hot dipped galvanized steel sheet or the alloyed hot-dip galvanized steel sheet, each having a tensile strength of 980 MPa or more, having excellent processability and having a high yield ratio and high strength is characterized by containing 0.12 to 0.3% by mass of C, 0.1% by mass or less (excluding 0%) of Si, 2.0 to 3.5% by mass of Mn, 0.05% by mass or less (excluding 0%) of P, 0.05% by mass or less (excluding 0%) of S, 0.005 to 0.1% Al and 0.015 by mass or less (excluding 0%) of N with the balance comprising ion and inevitable impurities. The hot dipped galvanized steel sheet or the alloyed hot-dip galvanized steel sheet is also characterized in that the metallic structure thereof contains bainite as a matrix structure, and the area ratio of ferrite is 3 to 20% and the area ratio of martensite is 10 to 35% relative the entire structure. |
