| 摘要 |
PROBLEM TO BE SOLVED: To provide a cold-rolled steel sheet which has excellent formability and shape fixability, and an a method for producing the same. SOLUTION: The cold-rolled steel sheet has a composition comprising, by mass, 0.0010 to 0.0030% C,≤0.05% Si, 0.1 to 0.5% Mn,≤0.05% P,≤0.02% S, 0.02 to 0.10% Al, 0.0010 to 0.0050% N and 0.010 to 0.035% Nb, and in which the Al content and the N content satisfy the relation in the inequality (1), and the balance Fe with inevitable impurities. The cold-rolled steel sheet has a structure essentially consisting of ferrite grains with the average grain size of 8 to 20μm, and in which the area ratio in the sheet surface of the ferrite grains within 15°from ä211} is controlled to≥50%: [%Al]/[%N]≥10 (1); wherein the [%M] denotes the content (mass%) of the M element. COPYRIGHT: (C)2011,JPO&INPIT
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