| 摘要 |
PROBLEM TO BE SOLVED: To provide a cold rolled ferritic stainless steel sheet combining excellent ductility and workability with prominent ridging resistance and having outstanding surface quality after forming, and its manufacturing method. SOLUTION: A steel stock, having a composition containing, by mass, 0.01-0.12% C, 0.01-0.12% N, 11-18% Cr and <=0.03% Al, is hot rolled, subjected to preliminary rolling consisting of cold or warm rolling at 2-15% draft, and further subjected to hot rolled plate annealing consisting of long time holding and slow cooling to provide a structure having <=5 grain extension degree (e) in the sheet-thickness section parallel to a rolling direction, followed by cold rolling and finish annealing. By this method, the structure, in which the aspect ratio A of coarse-grained colonies as aggregates where coarse grains continue in the rolling direction is regulated to <=5 in the sheet-thickness section parallel to the rolling direction, can be formed. Moreover, it is preferable to regulate the FDT at hot rolling to <=850 deg.C for further improvement in press workability.
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