| 摘要 |
PROBLEM TO BE SOLVED: To provide a galvannealed steel sheet excellent in the stickiness, particularly, the chipping resistance, and the producing method thereof. SOLUTION: The galvannealed steel sheet has a phase having the thickness of >=10% of the thickness of the galvannealed layer on the interface between the galvannealed layer and the steel sheet, desirably, Al concn. in the most upper surface on the galvannealed layer is made to <=5 times of the average Al concn. in the galvannealed layer. This producing method is executed to an alloying treatment of the galvanized steel sheet at 550-850 deg.C, and after cooling to <=200 deg.C, this steel sheet is brought into contact with alkali-solution.
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