On the surface of the melting spelter - aluminum alloy plated steel sheet and that production mannered

摘要

PROBLEM TO BE SOLVED: To provide a hot dip zinc-aluminum alloy plated steel sheet improved in the workability of the conventional zinc-aluminum alloy plated steel sheet.;SOLUTION: In this steel sheet, the surface of the steel sheet is provided with a plated layer having a composition containing, by mass, 3 to 18% Al, 2.1 to 10% Mg and Si by 1 to 50% of the Mg content, if required, containing ≤1% Fe, and the balance Zn with unavoidable impurities, and further, the plated layer is incorporated with Si-based substances with an area of ≥100 μm2 by 6×103 pieces per the unit cross-sectional area of the plated layer. If required, the surface of the plated layer is coated with an inorganic oxide film or an organic resin film as well. In the method for producing the hot dip zinc-aluminum alloy plated steel sheet, the plating bath temperature is controlled to 480°C, and, after plating, cooling is continuously performed at a cooling rate of ≥10°C/s, by which the plated layer is incorporated with Si-based substances of ≥100 μm2 by ≤6×103 pieces per the unit cross-sectional area of the plated layer.;COPYRIGHT: (C)2001,JPO