| 摘要 |
<p>A galvannealed steel sheet includes: a steel sheet; a galvannealed layer which is formed on at least one surface of the steel sheet and includes an amount equal to or more than 0.05 mass% and equal to or less than 0.5 mass% of Al, an amount equal to or more than 6 mass% and equal to or less than 12 mass% of Fe, and the balance composed of Zn and inevitable impurities; and a composite oxide layer of Mn, Zn, and P which is formed on the surface of the galvannealed layer, includes an amount equal to or more than 0.1 mg/m2 and equal to or less than 100 mg/m2 of Mn, an amount equal to or more than 1 mg/m2 and equal to or less than 100 mg/m2 of P, and Zn, and has the P/Mn ratio of equal to or higher than 0.3 and equal to or lower than 50. The galvannealed layer includes a flat portion having an area ratio of equal to or higher than 10% and equal to or lower than 70% and a rough portion which is at a position closer to the steel sheet than the flat portion at the interface of the galvannealed layer and the composite oxide layer. The composite oxide layer of Mn, Zn, and P contains an amorphous compound.</p> |
