通过高压釜腐蚀实验研究了添加微量Si (0.02%)对Zr-1Nb(质量分数, %)和Zr-1Nb-0.8Sn-0.38Fe-0.1Cr 合金在400℃/10.3 MPa 过热蒸汽和360 C/18.6 MPa/0.01 mol/L LiOH 水溶液中耐腐蚀性能的影响. 利用透射电子显微镜(transmission electron microscope,TEM)观察了合金的显微组织. 结果表明: 添加微量Si 对Zr-1Nb 合金在两种水化学条件下的耐腐蚀性能影响不大; 添加微量Si会使Zr-1Nb-0.8Sn-0.38Fe-0.1Cr合金在400℃/ 10.3 MPa过热蒸汽中的耐腐蚀性能变差, 但对其在360 C/18.6 MPa/0.01 mol/L LiOH 水溶液中的耐腐蚀性能影响不大. 这说明Si 对不同的合金在不同水化学条件下耐腐蚀性能的影响规律是不同的. 在Zr-1Nb 和Zr-1Nb-0.8Sn-0.38Fe-0.1Cr 中添加0.02% Si 后分别发现了尺寸较大的Zr5Si4 第二相(second phase particles, SPPs)和Zr(Nb, Fe, Cr, Si)2 第二相, 这会对锆合金的耐腐蚀性能产生不利影响.
孙风涛1,2, 姚美意1,2, 徐龙1,2, 黄娇1,2, 张金龙1,2, 周邦新1,2
. 添加微量Si 对锆合金耐腐蚀性能的影响[J]. 上海大学学报(自然科学版), 2015
, 21(2)
: 182
-189
.
DOI: 10.3969/j.issn.1007-2861.2014.05.008
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.
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