Effect of Annealing Process on the Corrosion Resistance of Zr-0.8Sn-0.25Nb-0.35Fe-0.1Cr-0.05Ge Alloy

Abstract:

The corrosion resistance of Zr-0.8Sn-0.25Nb-0.35Fe-0.1Cr-0.05Ge alloy samples with different annealing processes has been studied in super-heated steam at 400 ℃/10.3 MPa by autoclave test. The microstructure of the samples was investigated by TEM/EDS and SEM. The results show that partial recrystallization occurs in the samples annealed at 500 ℃, and the effect of annealing time on the size of second phase particles(SPPs) is not obvious; while complete recrystallization occurs in the samples annealed at 580 ℃, as the prolongation of annealing time, the size of SPPs enlarged in Zr-0.8Sn-0.25Nb-0.35Fe-0.1Cr-0.05Ge alloy. There exist Zr(Nb,Fe,Cr)2 SPPs with a hexagonal close packed structure, tetragonal Zr3Ge and orthogonal Zr3Fe SPPs. The corrosion resistance of Zr-0.8Sn-0.25Nb-0.35Fe-0.1Cr-0.05Ge alloy in super-heated steam at 400 ℃/10.3 MPa is improved with the prolongation of annealing time and increase of annealing temperature.