| 摘要 |
PROBLEM TO BE SOLVED: To produce a high strength steel sheet with a sheet thickness of <=20 mm having high impact absorbing energy. SOLUTION: This thin high strength steel sheet with a sheet thickness of <=20 mm having high impact absorbing energy has chemical components containing, by weight, 0.03 to 0.1% C, 1.0 to 2.0% Mn, 0.01 to 0.1% Nb, 0.005 to 0.02% Ti and 0.001 to 0.006% N, containing 0.5% Si, 0.02% P, 0.003% S, 0.06% Al and <=0.005% O, and the balance iron with inevitable impurities, and rolled texture satisfying the inequality (1): log [I/I0 100}×I/I0 111}]<=0.5...(1). I: the plane strength obtained by X-ray diffraction as for this steel, I0: the plane strength obtained by the X-ray diffraction for a sample having random crystal orientation, I/I0 hkl}: the ratio between the plane intensity I of the lattice plane hkl} of ferrite and the plane intensity I0 of the lattice plane hkl} of ferrite, where the measured plane in the X-ray diffraction is the one parallel to the rolling face at a position of 1/4 thickness in the sheet thickness direction.
|
