Influence of macroscopic defects on the corrosion behavior of U-0.79 wt%Ti alloy in sodium chloride solution
Influence of macroscopic defects on the corrosion behavior of U-0.79 wt%Ti alloy in sodium chloride solution
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影响%20of%20宏观%20缺陷%20on%20the%20腐蚀%20行为%20of%20U-0.79%20wt%Ti%20合金%20in%20钠%20氯化物%20溶液
DOI：
10.1039/c7cp06697j
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发表时间：
2018
影响因子：
3.3
通讯作者：
Li Yingru
中科院分区：
文献类型：
--
作者：
Cai Dingzhou;Wang Ming;Ren Yiming;Yang Shanli;Sang Ge;Li Yingru
低钛含量的铀合金因其优异的力学性能和耐腐蚀性能而受到广泛关注。本文采用传统的电化学测试技术和新型扫描电化学复合探针（SECP）研究了宏观缺陷对U-0.79 wt%Ti（记为U-Ti）合金在0.01 M NaCl溶液中腐蚀行为的影响。结果表明，由于宏观缺陷的存在，合金表面会迅速发生点蚀。此外，宏观缺陷导致腐蚀电位和极化电阻下降，腐蚀电流密度增加。此外，使用复合探针在同一区域内检测电位和pH值分布。结果表明，宏观缺陷周围区域成为腐蚀活跃区，其电位差（相对于合金表面平均电位）显著高于无宏观缺陷处，而pH值分布则相反。此外，垂直方向（Z）电位在活动点和非活动点的分布明显不同。这可能是由于合金表面活性点和非活性点之间的电场分布和电极反应类型不同所致。
Uranium alloys containing a low concentration of titanium have received wide attention due to their greatly enhanced corrosion resistance and outstanding mechanical performances. Herein, we investigated the effect of macroscopic defects on the corrosion behavior of U–0.79 wt%Ti (denoted as U–Ti) alloy in 0.01 M NaCl solution using traditional electrochemical testing technologies and a novel scanning electrochemical composite probe (SECP). The results demonstrate that pitting corrosion occurs rapidly on the alloy surface due to macroscopic defects. Moreover, macroscopic defects led to a decrease in corrosion potential and polarization resistance, and an increase in corrosion current density. Furthermore, the potential and pH value distributions were detected in the same region using the composite probe. The results show that the region around the macroscopic defects become corrosion-active positions and the potential difference (vs. the average potential of the alloy surface) in this area is significantly higher than that at positions without macroscopic defects, while the opposite was observed for the pH value distribution. In addition, the distribution of the vertical direction (Z) potential at the active point was clearly different from that at the inactive point. A possible reason for this could lie in the difference in the electric field distribution and electrode reaction type between the active point and inactive point on the alloy surface.