To provide a method for manufacturing a flange structure with which the development of crack in a material can be restrained and continuous processing having no batch treatment can be performed and the cost-reduction can be attained.
This method for manufacturing the flange structure, is to form the flange structure provided with a shaft member 31 and the flange 32 extended to the outer diameter direction from the shaft member 31. By using a blank material 35 composed of a middle carbon steel, a forming blank 36 charged in a closed forging die M is subjected to the following processes, that is; extrusion to the forward in a first process 151; preforming in a second process 152; forming processing using the closed forging die M in a third process 153; and if necessary, boring processing at the center in a forth process 154. Further, these processes are continuously performed in one die set in a warm temperature range.
KAWAMURA HIROSHI
Hideka Tanaka
Yoshiyuki Shiraishi
Kunihiko Shiromura
Tsuyoshi Kumano