PRESS-FORMING METHOD

摘要

A current density changing portion is formed in a heating process on an upper base side with respect to a center portion of a flat metal plate in a direction of current flow, by passing current from a lower base side to the upper base side of the flat metal plate which is rectangular when viewed from above. As a result, a quenchable portion is formed on the upper base side with respect to the center portion of the flat metal plate in the direction of current flow, and a non-quenchable portion is formed on the lower base side with respect to the center portion of the flat metal plate in the direction of current flow. The flat metal plate is press-formed after the heating process, so a complex die cooling structure is not necessary during press-forming, which enables the die cost to be reduced.