| 摘要 |
PURPOSE:To prevent the deformation of ferrous parts with progression of bainite transformation in, for example, an austemper treatment by stopping the supply of fluidizing gas in a heat treatment in a fluidized bed furnace and heat treating the ferrous parts in the state of restraining the same with the fluid particles fixed conversely by evacuation. CONSTITUTION:The 1st valve 7 is beforehand opened to supply air from the lower part of a flow dividing plate 3 so that the fluidizing particles held at a bainite forming temp. are kept suspended and fluidized. The ferrous part imposed on a tray 12 is transferred in this state from a high temp. heating furnace to a fluidized bed furnace 1, and is placed on a tray support base 4. The tray 12 is opened with many holes like with the base 4. The ferrous part is quickly cooled from the austenite treatment temp. to the bainite forming temp. by contacting with the fluidized bed particles. The supply of air into the furnace body 2 is immediately stopped and the top surface of the fluidizing particles is covered with a cover 13, then a vacuum pump 10 is run to evacuate the inside of the furnace body 2 to detain the cover 13 downward and to restrain the fluidizing particles whereby the conversion to bainite of the ferrous part is completed. |
