| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot dip galvannealed steel sheet having improved interface adhesive strength while having formability, and to provide a method for producing a hot dip galvannealed steel sheet providing improved productivity. SOLUTION: The hot dip galvannealed steel sheet is obtained by providing the surface of a steel sheet base material with a hot dip galvannealing layer. The steel sheet base material has a chemical composition comprising, by mass,≤0.25% C, 0.030 to 0.15% Si, 0.030 to 3.0% Mn,≤0.050% P,≤0.010% S,≤0.0060% N and 0.10 to 0.80% sol.Al, and the balance Fe with inevitable impurities. The hot dip galvannealing layer comprises 8.0 to 15% Fe and 0.080 to 0.50% Al, and is further free from aηphase, and, in the interfacial debonding part between the hot dip galvannealing layer and the base material, the ratio of area interfacial debonding in the grain unit on the base material side in the steel sheet is≥5.0%. COPYRIGHT: (C)2008,JPO&INPIT
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