| 摘要 |
PROBLEM TO BE SOLVED: To provide a high strength hot dip galvanized steel sheet which has improved unplating and plating adhesion on high working, and has excellent ductility, and to provide a production method therefor. SOLUTION: The high strength hot dip galvanized steel sheet has a plated layer having a composition containing 0.001 to 0.5% Al and 0.001 to 2% Mn, and containing, at need, 5 to 20% Fe, and the balance Zn with inevitable impurities. The Si content in the steel: X(%), the Mn content in the steel: Y(%), the Al content in the steel: Z(%), the Al content in the plated layer: A(%) and the Mn content in the plated layer: B(%) satisfy the following inequality (1), and the microstructure of the steel sheet consists of, by volume fraction, 70 to 97% ferrite having a mean grain diameter of <=20μm and 3 to 30% austenite and/or martensite having a mean grain diameter of <=10μm. 3-(X+Y/10+Z /3)-12.5×(A-B)>=0...(1).
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