| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot dip Zn-Al-Mg base metal coated steel sheet having >10 to 22 mass % level of Al content in the coated layer, excellent outward appearance and high corrosion resistance. SOLUTION: This hot dip high Al-containing Zn-Al-Mg base metal coated steel sheet is characterized in that the galvanized layer of the component composition consisting by mass % of >10 to 22% Al, 1-5% Mg and further, if necessary, 0.002-0.1% Ti, 0.001-0.045% B, 0.005-0.5% Si is formed on the surface of a steel sheet and the layer has metallurical structure where [primary crystal Al phase]] coexists in the basis of [Al/Zn/Zn2Mg three component eutectic structure]. Further, Zn11Mg2 base phase in this metallurgical structure does not substantially exist in this coated steel sheet. |
