Affiliation:
1. State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing (USTB) Beijing 100083 China
Abstract
FeCrAl alloy is considered a promising material for light water reactor fuel cladding due to its excellent elevated temperature oxidation resistance and radiation performance. The effects of 0.21 wt% Nb or 0.23 wt% La additions on the microstructure, second phase, yield strength and toughness of FeCrAl alloy are studied. The morphology and number fraction of inclusions in FeCrAl alloys are analyzed. The addition of 0.21 wt% Nb in FeCrAl alloy promotes the precipitation of nanoscale (Fe,Cr)2(Nb,Ti) Laves phase and refining grain size. The addition of La‐modified Al2O3 and MgO·Al2O3 inclusions to La2O3 and LaS, and La2O3 is favorable to promote the heterogeneous nucleation of α‐Fe. The fracture mode of the FeCrAl alloy with 0.21 wt% Nb or 0.23 wt% La transitions from dimple fracture and quasi‐cleavage fracture to dimple fracture, in comparison with Nb‐free or La‐free FeCrAl alloy. Nb and La additions improve the yield strength and toughness of FeCrAl alloy. The addition of Nb exhibits a more pronounced strengthening effect on FeCrAl alloy compared with the addition of La.
Funder
Innovative Research Group Project of the National Natural Science Foundation of China