| 摘要 |
PURPOSE:To obtain the titled cold rolled steel sheet without using a slight amt. of additive elements by subjecting a steel slab which is specified in the contents of C and Mn and is controlled in the contents of N and solAl to finish rolling, cold rolling and continuous annealing under prescribed conditions. CONSTITUTION:The steel which is so incorporated with C and Mn as to satisfy the formula and is controlled to 0.001-0.004wt% N and 0.01-0.1% solAl is made into a slab. The slab is heated to 1,100-1,250 deg.C and is subjected to finish rolling at >=900 deg.C finishing temp., then to cold rolling and continuous annealing, by which the extra low carbon aluminum killed cold rolled steel sheet is obtd. The steel sheet having excellent characteristics among the non-aging cold rolled steel sheets for ultra deep drawing having >=about 48% elongation, >=about 1.6 r value, <=about 0.6 DELTAr, and <=about 3kg/mm<2> aging index (A, I) is thus obtd.
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