| 摘要 |
PROBLEM TO BE SOLVED: To improve the absorbing effect of shock energy without causing an increase of the number of part items and an increase of mass. SOLUTION: This center pillar 12 is formed with an extruded material of an aluminum alloy, and the vehicle lower portion (lower section) 12E from the nearly center section 12D in the longitudinal direction is applied with a T4 heat treatment, i.e., ordinary temperature aging, after the solution treatment of the aluminum alloy to form a portion having large elongation against a load. The vehicle upper portion (upper section) 12F from the nearly center section 12D in the longitudinal direction of the center pillar 12 is applied with a T6 heat treatment, i.e., artificial aging, after the solution treatment of the aluminum alloy to form a portion having small elongation against a load.
|
