| 摘要 |
The present invention relates to a coated steel sheet having a hot-dip galvanized layer on a surface of a steel sheet of a composition consisting of not less than 0.1 mass% and under 3 mass% of Al, optionally (i) one or two kinds selected from not less than 0.1 mass% of Si and not less than 0.5 mass% of Mn, and further optionally 0.0005 to 0.25 mass% of C and/or 0.001 to 0.20 mass% of P, or (ii) 0.03 to 0.25 mass% of C, 0.001 to 1.0 mass% of Si, 0.5 to 3.0 mass% of Mn, and 0.001 to 0.10 mass% of P; and further optionally 0.0001 to 0.01 mass% of S; not more than 0.15 mass% of Ti, not more than 1.0 mass% of Cr, 0.001 to 0.005 mass% of B; and/or one or two kinds selected from 0.01 to 1.0 mass% of Mo and 0.005 to 0.2 mass% of Nb; or the group consisting of 0.01 to 0.5 mass% Cu, 0.01 to 1.0 mass% Ni, and 0.01 to 1.0 mass% Mo; wherein the balance being Fe and unavoidable impurities; and wherein Oxide of Al exists in said matrix right under said surface of said steel sheet. Furthermore, the present invention provides a method for manufacturing said coated steel sheet, wherein said method comprises steps of heating and holding the steel slab, hot rolling the slab and hot dip galvanizing the steel sheet. |
