| 摘要 |
PURPOSE:To inexpensively and efficiently produce a cold rolled steel sheet having excellent deep drawability by subjecting the steel sheet to cold rolling in a manner as to attain >=40% cumulative cold rolling rate, then to quick heating and softening annealing by heaters provided between rolling stands. CONSTITUTION:The quick heaters 2 are disposed at plural points between the rolling stands of a continuous cold rolling device consisting of the plural stands and the softening quick heater 3 is disposed on the outlet side of the final stand. The hot rolled strip is cold rolled to attain >=40% cumulative cold cold rolling rate in the case of cold rolling the hot rolled steel strip having >=2.0mm and <=12.0mm sheet thickness. The cold rolled steel sheet is thereafter heated quickly to the temp. above the recrystallization temp. by the quick heaters 2 disposed between the rolling stands. The steel sheet is then subjected to the softening annealing by the softening quick heater 3 on the outlet side of the final stand, by which the cold rolled steel sheet having the excellent deep drawability is economically produced.
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