| 摘要 |
PROBLEM TO BE SOLVED: To provide a high strength steel sheet for extra-thin-walled can, having high formability capable of satisfactorily meeting the recent demand for complicated can design, also having superior uniform deformability, and further excellent in appearance free from the occurrence of surface roughing and stretcher strain. SOLUTION: The steel sheet has a composition which contains, by weight, 0.04-0.08% C, 0.3-0.6% Mn, 0.02-0.20% Al, <=0.003% Ntotal, and <=0.005% B and in which the value of [Ntotal-(NasAlN+NasBN)] is regulated to <=0.002 wt.%, where Ntotal, NasAlN, and NasBN represent the total amount of N, the amount of N in the form of AlN, and the amount of N in the form of BN, respectively. Moreover, average carbide spacing is 5 to 30μm and crystalline grain size is No. 10 to 13, and further, the average r-value in all directions in a sheet surface is <=1.3 and the difference between the maximum r-value and the minimum r-valve is <=0.4. This steel sheet can be produced by subjecting a steel plate, after hot rolling or further forced cooling, to coiling at <650 deg.C coiling temperature, to air cooling for 10 to 60 min, to water cooling, and to cold rolling and then applying continuous annealing to the resultant steel sheet at a temperature between the recrystallization temperature and 800 deg.C.
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