中文摘要：

用静态高压釜腐蚀实验研究了添加0.05%-0.3%（质量分数）Bi对Zr-1Nb合金在400℃/10.3 MPa过热蒸汽中耐腐蚀性能的影响;用SEM观察了腐蚀140 d的氧化膜显微组织。结果表明：随着Bi含量的增加,Zr-1Nb-XBi合金的耐腐蚀性能逐渐提高。说明添加Bi可以改善Zr-1Nb合金的耐腐蚀性能。氧化膜显微组织观察表明,Bi的添加使氧化膜内表面起伏程度变小,断口上等轴晶与柱状晶的界面附近孔隙和微裂纹减少。这说明Bi的添加可以有效延缓氧化膜的显微组织演化过程,从而提高了合金的耐腐蚀性能。

英文摘要：

The effect of Bi contents（0.05 wt%~0.3 wt%） on the corrosion resistance of Zr-1Nb was investigated in superheated steam at 400 oC and 10.3 MPa by autoclave tests. The microstructures of the oxide film formed on the alloys corroded for 140 d were observed by SEM. Results show that the corrosion resistance of Zr-1Nb-Xbi alloy is improved gradually with the increasing of Bi content. The microstructure observation of oxide films shows that the Bi addition makes the inner surface of oxide films smoother, and decreases the amount of pores and micro-cracks near the boundaries of equiaxed grains and columnar grains. This indicates that Bi can slow down the oxide micro-structure evolution, thereby improving the corrosion resistance of Zr-1Nb alloy.