Production manner null of the Cr content steel sheet which is superior in processability and

摘要

PURPOSE: To produce the cold rolled steel sheet having a high Lankford value by subjecting steel products contg. a specific ratio of Cr to hot rolling to end a finish pass in a γ single phase region and coiling the rolled steel products at a high temp., then subjecting the steel products to cold rolling and finish annealing. ;CONSTITUTION: The steel products formed by balancing the compsn. between the ratio of the Cr incorporated at 5 to 11wt.% therein and the ratio of other elements in such a manner that the perfect transformation to the γ single phase arises when heated to 1100 to 1300°C are subjected to the hot rolling to end the finish pass in the γ single phase region and are then subjected to the cold rolling and finish annealing after the coiling at a high temp. Since the structure after the hot rolling is made into the finely grained ferrite structure, the generation of the macro-cast structure generated at the time of smelting of the steel products and the band-like structure derived therefrom is suppressed. The cold rolled steel sheet which has the high Lankford value and is suitable for a high degree of working, such as deep drawing, is obtd.;COPYRIGHT: (C)1993,JPO&Japio