| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-tensile-strength hot-dip galvannealed steel sheet superior in powdering resistance by controlling a form of an interface between a plated metal and a base metal, in a Si-containing steel which has been difficult to have both of adequate surface quality and workability with a conventional technology. SOLUTION: The hot-dip galvannealed steel sheet has a hot-dip galvannealed layer on the surface of a steel sheet. The steel sheet includes 0.0001-0.05% Bi in a steel sheet including 0.03-0.20% C, 0.03-3.0% Mn, 0.1-2.5% Si, 0.01% or less sol. S, 0.1% or less P, 1.0% or less Al and 0.01% or less N; thereby can control a penetration depth of zinc and a zinc-iron alloy to 10 μm or less in the depth direction from the interface between the hot-dip galvannealed layer and the base metal, toward the steel sheet side; and enhances the powdering resistance, the adhesiveness of the plated layer and the surface quality. COPYRIGHT: (C)2011,JPO&INPIT |
