| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vehicle collision energy-absorbing member excellent in collision energy-absorbing power in the axial direction in collision. <P>SOLUTION: A vehicle collision energy-absorbing member is obtained by molding processing of a high-strength thin steel sheet which has a TS of 980 MPa or greater while an n value and the critical bend radius Rc satisfy an expression of Rc≤1.31×ln (n)+5.21. By using the high-strength thin steel sheet having the characteristics, even in a case where an TS is 980 MPa or greater, the member can be stably buckled in the axial direction to be crushed and deformed into a bellow shape in vehicle collision. The high-strength thin steel sheet to be used preferably has: a composition containing 0.14-0.30 mass% of C, 0.01-1.6 mass% of Si, 3.5-10 mass% of Mn, 0.0060 mass% or less of N and 0.01-0.10 mass% of Nb; and a structure which comprises 30-70 vol% of a ferrite phase with respect to the entire structure, the ferrite phase having an average particle size of 1.0 μm or less, and a second phase including at least 10% or more by volume ratio of a residual austenite phase with respect to the entire structure, the residual austenite phase having an average gap of 1.5 μm or less. <P>COPYRIGHT: (C)2013,JPO&INPIT |
