Application of rare earth in surface heat treatment of hot-working die steels

摘要

This paper studies a compound treatment, i. e. liquid S, N, C co-diffusing with rare earth (RE) and then oxidization, for hot-working die steels, and the effect of RE on thermal fatigue behavior of the diffused layer. XRD and SEM energy spectrum prove that trace RE element actually penetrates into the surface layer of steels. The result shows that RE can reduce the gradient of change of hardness in dif- fused layer, improve the morphology and distribution of com- pounds, and reduce the degree of surface alligator crack for thermal fatigue.