| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel sheet having a tensile strength of≥900 MPa and having an excellent hole expansibility, and to provide its production method. SOLUTION: The high strength cold rolled thin steel sheet having an excellent hole expansibility has a composition comprising, by mass, 0.05 to 0.22% C, 0.001 to 0.8% Si, 2.0 to 3.3% Mn, 0.001 to 0.1% P, 0.0001 to 0.01% S, 0.001 to 0.2% Al, 0.0001 to 0.01% B and 0.005 to 0.3% Ti, and the balance Fe with inevitable impurities, has a tensile strength of≥1,100 MPa, and also has a hole expansion ratio of≥40%. COPYRIGHT: (C)2006,JPO&NCIPI
|
