Patent ID: 11898230
Assignee: JFE STEEL CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 2:
3. A method for manufacturing a high-strength steel sheet, the method comprising: a continuous annealing step of, under a condition where a dew point in a temperature region of 750° C. or more is −35° C. or less, holding a cold rolled steel sheet having the chemical composition according to claim 1 at an annealing temperature of 840° C. or more for 180 seconds or more and cooling the cold rolled steel sheet at a cooling start temperature of 740° C. or more and at an average cooling rate of 100° C./s or more through a temperature region from the cooling start temperature to 150° C.; and
an overaging treatment step of, after the continuous annealing step, performing reheating as necessary and performing holding in a temperature region of 150 to 260° C. for 30 to 1500 seconds.