| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel sheet superior in formability for three pieces necked cans. SOLUTION: This steel sheet has a steel composition of, by mass%, 0.01-0.1% C, 0.1-1.0% Mn, 0.02-0.15% Al, 0.001-0.012% N, and the balance Fe with unavoidable impurities, a Lankford value r in a vertical direction of the can, of 1.5 or less, t×r of 0.15 or more (where t is sheet thickness (mm)), YP<SB>20</SB>/YPo of 1.20 or more, which is a ratio of yield strength before and after receiving predistortion in the vertical direction of the can, where YP<SB>20</SB>is yield strength when having received the predistortion equivalent to a reduction rate of 20% for sheet thickness, and YPo is yield strength before receiving the predistortion, and further the number of inclusions with a length of 0.4 mm or longer in the circumferential direction of the can, of 6×10<SP>-4</SP>/m<SP>2</SP>or less. COPYRIGHT: (C)2003,JPO
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