Temperature dependence of strengthening mechanisms in the nanostructured ferritic alloy 14YWT: Part II—Mechanistic models and predictions

The temperature dependence of strengthening mechanisms in the nanocluster-strengthened 14YWT alloy was investigated to elucidate the relative significance of contributing mechanisms in different temperature ranges. This study was also aimed at providing the prediction capability of yield strength for the nanostructured ferritic alloys over a wide range of temperature. The four major strengthening mechanisms: the Peierls stress, grain boundary strengthening, direct nanocluster strengthening, and dislocation forest hardening, were taken into account in the calculation, and their roles and characteristics in different temperature ranges were extensively discussed. The results indicated that the contribution of grain boundary strengthening to total strengthening was the most significant component. Yield strength calculation was made by combining all the strengthening components and the results were compared with the experimental data. Further, the validation of the proposed approach was attempted by applying to the yield strength of other alloys.