Patent ID: 6019857
Filing Date: 2000-02-01
Classification: C21D,C23C,Y02P

Abstract:
A carburized hardening process for a power transmission member provided at equal intervals on its periphery with teeth, wherein each tooth has a root part and a side part, comprising the steps of:(a) carburizing the power transmission member to form a carburized layer on each tooth of said power transmission member,(b) cooling the power transmission member and(c) surface-hardening the power transmission member by heating the tooth of the power transmission member in a manner such that the temperature at the root part is set to be higher than that at the side part so that carbides precipitated during said carburizing along a grain boundary in the carburized layer of the root part are more soluble in a parent phase than that in the carburized layer of the side part to produce a greater residual austenite volume in the carburized layer at the root part than that at the side part.