| 摘要 |
PROBLEM TO BE SOLVED: To obtain a steel sheet uniform in the sheet thickness and having high (r) value with high productivity at a low cost by subjecting a steel slab having a specified compsn. composed of C, Si, Mn, P, S, Al, N, Ti, Nb and Fe to specified lubricating hot rolling with a specified work roll and thereafter executing recrystallizing treatment. SOLUTION: Te slab of a steel having a compsn. contg. one more kinds among, by mass, <=0.01% C, <=2.0% Si, <=3.0% Mn, <=0.2% P, <=0.05% S, 0.005 to 0.1% Al, <=0.01% N, 0.001 to 0.2% Ti and 0.001 to 0.2% Nb, furthermore contg. 0.0001 to 0.005% B and moreover contg. 0.01 to 1.5% Cu is hot-rolled. At this time, in at least one pass of the finish rolling, rolling is executed at less than the Ar3 transformation point at a draft of >=50% while lubricating oil of <450 mm<2> /S 40 deg.C viscosity is fed at 0.2 to 10 ml/m<2> water injection with a work roll having >=0.05μm center line average roughness Ra. This hot rolled sheet is subjected to recrystallizing treatment in a coiling stage or an annealing stage to obtain a hot rolled steel sheet for deep drawing excellent in the uniformity of the sheet thickness.
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