| 摘要 |
PROBLEM TO BE SOLVED: To provide a chromate-free hot dip zinc - aluminum alloy plated steel sheet subjected to post-treatment which has excellent weldability and corrosion resistance. SOLUTION: A galvannealed layer having a composition containing, by mass, 1 to 10% Mg, 2 to 19% Al and 0.01 to 2% Si, and in which Mg and Al satisfy the inequality of Mg (mass%)+Al (mass%)<=20 mass%, and the balance Zn with inevitable impurities is formed. Further, a film containing a zirconium compound in 10 to 30 mass% as a zirconium compound and vanadium in 5 to 20 mass% as a vanadyl compound is formed at least on one side of the surface layer by 200 to 1,200 mg/m<2> as coating weight.
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