HARDENING METHOD OF SURFACE USING CARBIDES

摘要

PURPOSE: A method for hardening the surface of wearing resistant components by using carbides is provided, to overcome the inhibition of carburizing due to the Cr oxide formation and allow the soot to be removed easily. CONSTITUTION: The method comprises the steps of heating a carburizing furnace at 850-1050 deg.C, supplying the hydrocarbon gas such as methane, propane and butane or the mixture gas of hydrocarbon gas and carbon dioxide into the furnace and degrading the gases to forming 1.0-4.0 % carbon potential atmosphere, and carburizing alloy steel containing carbide-forming elements such as Cr or Mo to form 20-80 % carbide layer; quenching it; and tempering it. Preferably ammonia gas is supplied into the furnace in the carburizing step.