CONSTRAINED HARDENING APPARATUS AND HEAT TREATMENT APPARATUS

摘要

This invention provides a constrained hardening apparatus for hardening a rod type special member, which is liable to be bent during the hardening thereof, while preventing the same member from being deformed. In a set of metal mold in which the contact surfaces of adjacent mold members are in an engaged condition, the inner side of the metal mold consists of a plurality of projecting portions and recessed portions which have free ends the shape of which is in agreement with that of a material to be hardened, and hardening liquid ejection ports are provided in these recessed portions. Since the material is not pressed while it is soft, i.e., when the cooling of the material is started, deformation, such as flattening does not occur on even a hollow material, such as a pipe.