| 摘要 |
PROBLEM TO BE SOLVED: To provide a high strength galvanized steel sheet consisting of components having not positively expensive alloy elements, and excellent in processability with excellent extension and extension flange property and having tensile strength of 900 MPa or more.SOLUTION: There is provided a high strength galvanized steel sheet having a component composition containing, by mass%, C:0.16 to 0.24%, Si:0.8 to 1.8%, Mn:1.0 to 3.0%, P:0.020% or less, S:0.0040% or less, Al:0.01 to 0.1%, N:0.01% or less, Ca:0.0001 to 0.0020% and the balance Fe with inevitable impurities, and having the area ratio of total of a ferrite phase and a bainite phase to the whole structure of 30 to 70%, the area ratio of a tempered martensite to the whole structure of 20 to 40%, the area ratio of the retained austenite phase to the whole structure of 10 to 20%, and the area ratio of the martensite phase to the whole structure of 2 to 20%. |
