To provide a method for softening an aluminum or aluminum alloy member, by which a work-hardened part of the workpiece made of aluminum or aluminum alloy can be locally and efficiently softened, and the workpiece suitable for partial softening.
The workpiece 2 made of aluminum or aluminum alloy has an outer flange 22, inner flange or a flange at its end. The outer flange 22, the inner flange or the flange is bent with a radius of curvature with respect to a base 20. In the outer flange 22, the inner flange or the flange, the length l from a bent part 22 to the tip is ≥1 mm, and the radius of curvature R at the bent part 22 corresponds to ≥1/3 of the thickness t of the base 20. By applying electric current to an induction heating coil 1 disposed close to the workpiece 2, the workpiece 2 is locally softened by induction heating, particularly at the arc-like bent part 22.
COPYRIGHT: (C)2011,JPO&INPIT
Yoshihaya Imamura
Kazushige Horiguchi
