The effect of vacancy on the microstructure of the ferritic steel with a nominal composition of Fe–14Cr–3W–0.4Ti–0.4Y2O3 was investigated. By using the resistivity measurements, the vacancy formation enthalpy of the alloy was calculated to be 1.11eV, which was lower than that of α-Fe. The Ti–Y–O nanoclusters in the alloy were responsible for stabilizing the vacancies. The hardness of the steel increased with the heat treating temperature. The hardening mechanism in the ferrite matrix could be attributed to the interaction between dislocations and vacancies or vacancy clusters.

Formation of Vacancies in a Nanocluster-Strengthened Ferritic Steel. F.Liu, Y.Liu, D.Liu, Y.Wang, D.Zhao, L.Zhang: Materials Letters, 2011, 65[2], 253-5