| 摘要 |
PROBLEM TO BE SOLVED: To provide a high strength thin steel sheet having excellent impact resistance, and in which the static and dynamic difference of tensile strength is wide. SOLUTION: A hot rolled steel sheet or a cold rolled steel sheet having a componential composition containing, by mass, 2 to 20% Ti,≤0.1% C≤3.0% Si,≤5.0% Mn,≤0.04% P,≤0.01% S,≤5.0% Al and≤0.01% N, and the balance Fe with inevitable impurities is annealed at≥600°C for≥1 sec so as to produce a thin steel sheet having a metallic structure composed of ferrite and an intermetallic compound including Fe and Ti with the average particle diameter of≥0.1μm by 5 to 80% in area ratio, and having a tensile strength TS of≥440 MPa, and in which the static and dynamic difference of the tensile strength is≥180 MPa. COPYRIGHT: (C)2011,JPO&INPIT |
