| 摘要 |
PROBLEM TO BE SOLVED: To provide a plated steel sheet for hot-press use which is suitable for uses, such as automobile body structural parts, undercarriage parts, chassis and further various reinforcing parts, owing to its excellent toughness in the form of a formed member after hardening and also superior hardenability and corrosion resistance. SOLUTION: The plated steel sheet for hot-press use has a plating film on the surface of a steel sheet. The steel sheet has a steel composition consisting of 0.09 to 0.50% C,≤2.0% Si, 0.8 to 3.5% Mn,≤0.10% P,≤0.05% S,≤0.1% Al,≤0.01% N, 0.005 to 0.20% Nb and the balance Fe with impurities and also has a steel structure consisting of, by area ratio, 30 to 97% polygonal ferrite, 0 to <20% bainite and the balance pearlite. The average grain size of the polygonal ferrite is 2 to 25μm. Further, the surface roughness Ra of the plated steel sheet is 0.4 to 2.2μm. COPYRIGHT: (C)2007,JPO&INPIT
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