Journal of Shanghai University(Natural Science Edition) ›› 2015, Vol. 21 ›› Issue (2): 182-189.doi: 10.3969/j.issn.1007-2861.2014.05.008

• Metallurgical Materials • Previous Articles     Next Articles

Effect of adding dilute Si on corrosion resistance of zirconium alloys

SUN Feng-tao1,2, YAO Mei-yi1,2, XU Long1,2, HUANG Jiao1,2,ZHANG Jin-long1,2, ZHOU Bang-xin1,2   

  1. (1. Institute of Materials, Shanghai University, Shanghai 200072, China; 2. Laboratory for Microstructures, Shanghai University, Shanghai 200444, China)
  • Received:2015-01-25 Online:2015-04-29 Published:2015-04-29

Abstract: The effect of adding dilute Si(0.02%) on the corrosion resistance of Zr-1Nb and Zr-1Nb-0.8Sn-0.38Fe-0.1Cr alloys was investigated in super-heated steam at 400 C/ 10.3 MPa and in lithiated water with 0.01 mol/L LiOH at 360℃/18.6 MPa by autoclave tests. The microstructure of the alloys was investigated with transmission electron microscope (TEM) and energy dispersive spectrometer (EDS). No obvious difference was found in the corrosion resistance of the Zr-1Nb and Zr-1Nb-0.02Si alloys in the two corrosion conditions, respectively. In the case of Zr-1Nb-0.8Sn-0.38Fe-0.1Cr alloy, the corrosion resistance decreased due to the addition of Si in super-heated steam at 400 C. However,addition of Si had little effect on corrosion resistance in lithiated water with 0.01 mol/L LiOH at 360 ℃/18.6 MPa. It meant that the influence of Si addition on the corrosion resistance was related to the compositions of alloys and water chemistries. Zr5Si4 second phase particles (SPPs) were observed in Zr-1Nb-0.02Si alloy, while Zr(Nb,Fe,Cr,Si)2 SPPs were observed in Zr-1Nb-0.8Sn-0.38Fe-0.1Cr-0.02Si alloy. Compared to SPPs in Zr-1Nb and Zr-1Nb-0.8Sn-0.38Fe-0.1Cr alloys, Zr5Si4 and Zr(Nb,Fe,Cr,Si)2 SPPs are coarse. Different effects of Si addition on the corrosion resistance of the alloys are related to the SPPs.

Key words: corrosion resistance, microstructure, Si, zirconium alloy

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