Patent ID: 11939640
Assignee: JFE STEEL CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 1:
2. The method of claim 1, the method comprising:
hot rolling a steel material of the composition of claim 1, wherein the composition further comprises, in mass %, one or more selected from Cu in an amount of 0.50% or less, Ni in an amount of 0.50% or less, B in an amount of 0.01% or less, and a total of 0.005% or less of Ca and/or REM, under the conditions where a rolling reduction of a final pass of finish rolling is 12% or more, a rolling reduction of a preceding pass of the final pass is 15% or more, and a finisher delivery temperature is 850 to 950° C.;
subjecting the steel after the hot rolling to first cooling in which the steel is cooled to a cooling stop temperature at a first average cooling rate of 50° C./s or more, the cooling stop temperature being 750° C. or less;
subjecting the steel after the first cooling to second cooling in which the steel is cooled to a coiling temperature at a second average cooling rate of 5° C./s or more and less than 50° C./s; and
coiling the steel after the second cooling at a coiling temperature of 650° C. or less.