| 摘要 |
PURPOSE:To provide satisfactory drawability and suitability to chemical conversion treatment by restricting the amount of Ti in a Ti added steel to a range in which the suitability to chemical conversion treatment is not deteriorated and by reducing the amount of Al to improve the anisotropy of r-value. CONSTITUTION:A slab consisting of, by weight, <=0.005% C, 0.03-0.5% Mn, <=0.02% Al, <=0.003% N, <=0.03% Ti and the balance Fe is used. In the composition, the amount of Ti satisfies 0<=C*<=60ppm (C* is calculated by the formula). The slab is hot rolled as usual, coiled at 650-750 deg.C, pickled, cold rolled and continuously annealed. The annealing includes soaking at a temp. between the recrstallization temp. and the Ac3 point. In this way, a cold rolled steel sheet having small anisotropy of r-value and superior suitability to chemical conversion treatment is obtd.
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