| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel thin-sheet for press with a tensile strength of a 380-540 MPa grade, and a manufacturing method therefor. SOLUTION: The steel sheet for press comprises 0.0005-0.01% C, 0.6-1.8% Si, 0.1-2% Mn, 0.1% or less P, and 0.03% or less S, and the balance Fe with unavoidable impurities, wherein a volume rate of polygonal ferrite is 90% or more, an average particle diameter of ferrite is 50μm or more but 200μm or less, and an elongation rate of the ferrite particle is 2 or less. The method for manufacturing the steel sheet for press comprises roughing rolling a slab having the above composition, subsequently completing a finish rolling in a temperature region of the Ar<SB>3</SB>transformation temperature +20°C or higher, and then winding it at 600°C or higher. COPYRIGHT: (C)2003,JPO
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