'More layer heat treatment furnace, a heat treatment apparatus and heat treatment process'

摘要

A heat treating device, wherein, by using a multi-layer heat treating furnace (1), one layer is formed in a fluidized bed (2) formed of granular material and excellent in heat efficiency and uniformity of thermal distribution and the other layer is formed in an atmosphere layer (3) formed of gases in a free board portion at the upper part of the fluidized bed (2), the temperatures of the layers are differentiated from each other, and one portion of a workpiece as a heat-treated body is dipped in the fluidized bed (2) at a specified temperature and the other portion is exposed to the atmosphere layer (3) at a specified temperature for heat treatment, whereby desirable mechanical properties can be provided for each portion of a metal product without increasing an equipment cost.