| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot dip Zn-Al alloy plated steel sheet which is free from a honeycomb pattern and has a smooth surface, small spangles and excellent design characteristics, and whose plated film is excellent in workability, and to provide a method of producing the same. SOLUTION: The hot dip Zn-Al alloy plated steel sheet has a plated film which is characterized in that the plated film contains 3.5 to 10% Al, 0.01 to 0.50% Mg, and the balance being Zn and inevitable impurities, the total amount of the inevitable impurities of Pb, Sn, Cd and Bi is <=0.020%, the amount of Fe is <=0.5 g/cm2, the average diameter of the spangles is <=2.0 mm, and the orientation coefficient of Zn (00.2) face parallel to the plated face is <3.5. The steel sheet having such characteristics is produced by plating the steel sheet with a plating bath having a desired chemical composition, rapidly cooling with a cooling speed of 10 to 50 deg.C/s or subjecting the plated steel sheet to a process for spraying a zinc powder onto the plated layer, and subjecting to a post heat treatment comprising keeping at 130 to 350 deg.C for at least 10 s.
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