| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a galvannealed steel sheet excellent in adhesion strength. <P>SOLUTION: The galvannealed steel sheet has a plating layer 2 comprising, by mass, 7-15% Fe, 0.01-1% Al and the balance being Zn and unavoidable impurities on a surface of a steel sheet 1 comprising 0.05-0.50% C, 0.01-3.0% Mn, at least one chosen from ≤3.0% Si, ≤2.0% Al and ≤2.0% Cr, provided that Mn+Si+Al+Cr is ≥0.4%, and the balance being Fe and unavoidable impurities. Here, (x) the steel sheet side of the plating layer is a Zn-Fe alloy phase including (x1) at least one chosen from oxides of Mn, Si, Al and Cr and/or (x2) at least one composite oxide comprising at least two chosen from Mn, Si, Al and Cr, and (y) a surface layer of the plating layer 2 is a Zn-Fe alloy phase containing a ζ phase free of the oxide and/or the composite oxide. <P>COPYRIGHT: (C)2013,JPO&INPIT |
