| 摘要 |
<p>PURPOSE:To manufacture a cold rolled steel sheet having high form ability by using electrolytic iron having extremely high purity as a raw material and executing cold rolling and annealing. CONSTITUTION:Electrolytic iron with high purity contg., by weight, <0.002% C, <0.05% Mn, <0.01% Al, <0.002% N and <0.007% O is used as stock, which is subjected to cold rolling at >=10% draft to work into a sheet material and is thereafter subjected to softening at 550 to 800 deg.C. The cold rolled steel sheet having high formability in which the {111} texture in the sheet plane of the annealed sheet is exceedingly developed and the strength ratio {I111/I100} in the resistance to randomness between the {111} plane having high correlation with F value and the {100} plane is regulated to >=100 because of the reduction of the sheet plane {100} as well as excellent in workability of >=58% total elongation and >=2.5F value can be obtd.</p> |
