JPS6442564A - Ion carburizing furnace - Google Patents

Abstract

PURPOSE:To prevent the generation of an arc between a cathode and an anode, to prevent the consumption of the cathode, and to stabilize the ion carburization by fixing an inner cylinder made of metal and an outer cylinder made of an insulating material on the outside of the water-cooled cathode for supporting a metallic material to be treated in the title ion carburizing furnace for the metallic material, and passing a purge gas through the space formed by the cylinders. CONSTITUTION:The material 5 to be treated such as steel is supported by the cathodes 3 and 3 and set on a hearth 6 made of graphite in the ion carburizing furnace 1, a gaseous hydrocarbon such as C3H8 and CH4 is introduced from a gas supply pipe 8, a glow discharge is generated between the material 5 and the anode 2 by an electric power source 30 to implant the ionized carbon generated by the decomposition of the gaseous hydrocarbon into the surface of the steel 5, and the steel is carburized. In this case, cooling water is passed through a water pipe 12 from a water supply port 13 to cool the cathode 3, the inner cylinder 22 made of stainless steel and the outer cylinder 26 made of an insulating material are provided on the outside of the cathode 3, a nonoxidizing purge gas such as Ar is passed through a space 23 between the cathode 3 and the inner cylinder 22 and a space between the inner cylinder 22 and the outer cylinder 26 to prevent the generation of an arc discharge between the anode 2 and the cathode 3, hence the cathode 3 is not damaged by an arc, and the operation of the ion carburizing furnace is stabilized.