| 摘要 |
A high-strength galvanized steel sheet that has TS ‰¥ 440 MPa, average r-value ‰¥ 1.2, and » ‰¥ 80%, and has excellent deep drawability and stretch flangeability, and a method for manufacturing the high-strength galvanized steel sheet are proposed. The high-strength galvanized steel sheet contains C: 0.010% or more and 0.06% or less, Si: more than 0.5% and 1.5% or less, Mn: 1.0% or more and 3.0% or less, P: 0.005% or more and 0.1% or less, S: 0.01% or less, sol.Al: 0.005% or more and 0.5% or less, N: 0.01% or less, Nb: 0.010% or more and 0.090% or less, and Ti: 0.015% or more and 0.15% or less, on a mass percent basis. The Nb and C contents of the steel satisfy the relation of (Nb/93)/(C/12) < 0.20. C* satisfies 0.005 ‰¤ C* ‰¤ 0.025. Ferrite constitutes 70% by area ratio or more of the steel sheet. Martensite constitutes 3% by area ratio or more of the steel sheet. C* = C - (12/93)Nb - (12/48){Ti - (48/14)N}, wherein C, Nb, Ti, and N denote the C, Nb, Ti, and N contents of the steel. |
