CONTINUOUS VACUUM CARBURIZING FURNACE

PROBLEM TO BE SOLVED: To adequately adjust a carburized depth and a carbon amount on a surface while inhibiting the formation of cementite, in a continuous vacuum carburizing furnace for continuously carrying out the step of heating a treating material, subjecting the treating material to carburization/diffusion treatment in a reduced pressure, and then lowering the temperature of the treating material. SOLUTION: This carburizing furnace comprises a heating chamber 11 for heating the treating material 1 under atmospheric pressure; a first controlling room 12 in which the pressure is decreased from atmospheric pressure to a reduced pressure, after the treating material has been introduced therein from the heating chamber; a carburization/diffusion chamber 13 for accommodating the several treating materials introduced from the first controlling room, and repeating carburization and diffusion for them two or more times under the reduced pressure; a second controlling room 14 in which the pressure is increased from the reduced pressure to atmospheric pressure, after the treated material in the carburization/diffusion chamber has been introduced therein; a temperature-lowering chamber 14 for lowering the temperature of the treated material introduced from the second controlling chamber; and shutters 16a to 16d which are installed between neighboring chambers, and are opened and closed only when the treating materials move between neighboring chambers. COPYRIGHT: (C)2005,JPO&NCIPI