| 摘要 |
There is provided a high-strength galvanized steel sheet having a TS of ‰¥ 590 MPa that has a high YR and a high BH and has excellent unifomity of mechanical characterisitics, particularly high strength and elongation uniformity in a coil formed thereof in order to improve crashworthiness and a method for manufacturing the high-strength galvanized steel sheet. The high-strength galvanized steel sheet comprising, on a mass percent basis, C: more than 0.060% and 0.13% or less, Si: 0.01% or more and 0.7% or less, Mn: 1.0% or more and 3.0% or less, P: 0.005% or more and 0.100% or less, S: 0.010% or less, sol.Al: 0.005% or more and 0.100% or less, N: 0.0100% or less, Nb: 0.005% or more and 0.10% or less, Ti: 0.03% or more and 0.15% or less, and the balance comprising Fe and incidental impurities, satisfying the relationship of (Nb/93 + Ti*/48)/(C/12) > 0.08 (wherein Ti* = Ti - (48/14)N - (48/32)S). The high-strength galvanized steel sheet has a structure including ferrite and martensite. The ferrite has an average grain diameter of 15 µm or less and an area percentage of 80% or more. The martensite has an area percentage of 1% or more and 15% or less. |
