PRESS MOLDING AND ITS HIGH FREQUENCY QUENCHING METHOD AND ITS HIGH FREQUENCY QUENCHING SYSTEM

摘要

A press formed article such as a center pillar or the like for a vehiclehaving a demanded strength distribution achieved by hardening throughinduction hardening or the like, and a method and an apparatus forperforming induction hardening on the press formed article. The center pillar(10) being a press formed article has an intermediate top portion (11) whichextends in a longitudinal direction of the center pillar (10), and two bladeportions (12) which are both bent toward the same side from both sides of theintermediate top portion (11), in which hardening regions (Q) are provided onboth sides of the intermediate top portion (11), extending over theintermediate top portion (11) and the blade portions (12). These hardeningregions (Q) hardened by the induction hardening apparatus are regions in theform, widening toward the end, which continuously expands from the upperportion to the lower portion of the center pillar (10). Therefore, the ratiobetween the hardening regions and non-hardening regions changes in thelongitudinal direction of the center pillar (10), resulting in a demandedstrength distribution.