| 摘要 |
This invention provides a high strength galvanized steel sheet having a TS of 590 MPa or more and excellent processability, and a method for manufacturing the same. The component composition contains, by mass%, C: 0.05% to 0.30, Si: 0.7% to 2.7%, Mn: 0.5% to 2.80, P: 0.1% or lower, S: 0.01% or lower, Al: 0.1% or lower, and N: 0.008% or lower, and the balance: Fe or inevitable impurities. A microstructure contains, in terms of area ratio, ferrite phases: 30% to 90%, bainite phases: 3% to 30%, and martensite phases: 5% to 40%, in which, among the martensite phases, martensite phases having an aspect ratio of 3 or more are present in a proportion of 30% or more. Preferably, retained austenite phases are contained in a proportion of 2% or more in terms of volume fraction and the average crystal grain diameter of the retained austenite phases is 2.0 µm or lower. |
