| 摘要 |
PROBLEM TO BE SOLVED: To suppress nucleation and granular growth in the orientation in which the plane anisotropy of (r) value at the time of recrystallization annealing is made remarkable by adding Mg to steel, specifying the componental compsn. and specifying the size and distribution of Mg and Ti oxides and multiple oxides in the steel sheet. SOLUTION: This steel sheet has a compsn. contg., by mass, 0.01 to 0.06% C, 0.005 to 0.5% Si, 0.01 to 2.0% Mn, 0.01 to 0.10% P, <=0.02% S, <=0.004% Al, 0.0001 to 0.01% Mg, 0.001 to 0.01% O, 0.001 to 0.01% N, 0.005 to 0.1% Ti, and the balance Fe. The steel contg. Mg and Ti oxides and/or multiple oxides by 0.005 to 0.1μaverage grain size and by 40 to 1000 pieces/mm<2> face density is obtd. In this way, the steel sheet in which the degree of the anisotropy of (r) value (dr=rmax -rmin ) is <=0.2 which causing no problems as to the height of earing after forming in practice can be produced without deteriorating the balance of strength and ductility.
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