Steel sheet, method of manufacturing same, crown cap, and drawing and redrawing (DRD) can
Provided is a steel sheet having sufficient formability and strength even after sheet metal thinning, the steel sheet including: a chemical composition containing, by mass %, C: more than 0.0060% and not more than 0.012%, Si: 0.02% or less, Mn: 0.10% or more and 0.60% or less, P: 0.020% or less, S: 0.020% or less, Al: 0.01% or more and 0.07% or less, and N: 0.0080% or more and 0.0200% or less, with the balance being Fe and inevitable impurities, in which a dislocation density at a depth position of ½ of a sheet thickness from a surface of the steel sheet is 2.0×10 14 /m 2 or more and 1.0×10 15 /m 2 or less.
1. A steel sheet comprising:
a chemical composition containing, by mass %,
C: more than 0.006% and not more than 0.012%,
Si: 0.02% or less,
Mn: 0.10% or more and 0.60% or less,
P: 0.020% or less,
S: 0.020% or less,
Al: 0.01% or more and 0.07% or less, and
N: 0.0080% or more and 0.0200% or less,
with the balance being Fe and inevitable impurities; wherein
a dislocation density at a depth position of ½ of a sheet thickness from a surface of the steel sheet is 2.0×10 14 /m 2 or more and 1.0×10 15 /m 2 or less.
2. The steel sheet according to claim 1 , having a thickness of 0.20 mm or less.
3. A crown cap made of the steel sheet as recited in claim 1 .
4. A DRD can made of the steel sheet as recited in claim 1 .
5. A method of manufacturing the steel sheet as recited in claim 1 , comprising:
a hot rolling step of heating a steel raw material at 1200° C. or higher, finish rolling the steel raw material to obtain a hot rolled sheet, and then coiling the hot rolled sheet within a temperature range of 670° C. or lower;
a pickling step of pickling the hot rolled sheet after the hot rolling step;
a primary cold rolling step of cold rolling the hot rolled sheet after the pickling step to obtain a cold rolled sheet;
an annealing step of annealing the cold rolled sheet after the primary cold rolling step in a temperature range of 650° C. to 750° C. to obtain an annealed sheet; and
a secondary cold rolling step of cold rolling the annealed sheet after the annealing step, with a rolling reduction of 10% or more and 30% or less and an average tension of 98 MPa or more between cold rolling stands in a rolling apparatus having at least two cold rolling stands.
6. A crown cap made of the steel sheet as recited in claim 2 .
7. A DRD can made of the steel sheet as recited in claim 2 .
8. A method of manufacturing the steel sheet as recited in claim 2 , comprising:
a hot rolling step of heating a steel raw material at 1200° C. or higher, finish rolling the steel raw material to obtain a hot rolled sheet, and then coiling the hot rolled sheet within a temperature range of 670° C. or lower;
a pickling step of pickling the hot rolled sheet after the hot rolling step;
a primary cold rolling step of cold rolling the hot rolled sheet after the pickling step to obtain a cold rolled sheet;
an annealing step of annealing the cold rolled sheet after the primary cold rolling step in a temperature range of 650° C. to 750° C. to obtain an annealed sheet; and
a secondary cold rolling step of cold rolling the annealed sheet after the annealing step, with a rolling reduction of 10% or more and 30% or less and an average tension of 98 MPa or more between cold rolling stands in a rolling apparatus having at least two cold rolling stands.