METHOD OF COOLING HOT FORGED PART, APPARATUS THEREFOR, AND PROCESS FOR PRODUCING HOT FORGED PART

摘要

In the production of a shaft part with flange portion by hot forging of steel as a material, there is provided a hot forged part wherein good cold workability has been imparted to its flange portion and high fatigue strength has been imparted to a boundary area between the flange portion and its shaft portion. In the cooling of a hot forged part with flange portion and shaft portion, during or after the hot forging for the hot forged part, the hot forged part is supported with the axial direction of the shaft portion set in the vertical direction and a refrigerant is locally blown against a boundary area between the flange portion and the shaft portion from the inferior side of the flange portion.