| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-strength cold-rolled steel sheet that has a tensile strength of 440 MPa or higher and also is excellent in workability such as bendability.SOLUTION: The high-strength cold-rolled steel sheet excellent in workability has a constitution in which, in mass%, C: 0.02% to 0.16%, Si: 0.6% or less, Mn: 0.6% or less, P: 0.05% or less, S: 0.01% or less, Al: 0.08% or less, N: 0.0080% or less, and Ti: 0.04% to 0.20%, are contained and in which the following formula (1) is satisfied, and the remainder is composed of Fe and inevitable impurities. The area ratio of the ferrite phase is 90% or greater, the average crystal grain size of the ferrite phase is 6.0 μm or less, the area ratio of the processed-ferrite to the ferrite phase is 20% or less, the average grain size of the Ti-containing carbide within the crystal grain of the ferrite phase is 10 nm or less, and the ratio of the amount of Ti present in a solid solution state to the amount of contained Ti is 10% or less. (C/12)/(Ti/48)≥1.2--(1), where the symbols of element represent the content (mass%) of the respective elements. |
