硝酸根离子对U-0.79Ti合金腐蚀行为的抑制作用  

Inhibitive Effect of NO3-on the Corrosion Behavior of U-0.79wt%Ti Alloy in Na Cl Solution

作　　者：蔡定洲[1] 陈向林[1] 吴昊曦 王铭 杨善丽[1] 桑格[1] 李英儒 Cai Dingzhou;Chen Xianglin;Wu Haoxi;Wang Ming;Yang Shanli;Sang Ge;Li Yingru(Materials Institution,China Academy of Engineering Physics,Mianyang 621700,China)

机构地区：[1]中国工程物理研究院材料研究所,四川绵阳621700

出　　处：《稀有金属材料与工程》2020年第1期101-108,共8页Rare Metal Materials and Engineering

基　　金：Science and Technology Development Foundation of China Academy of Engineering Physics(2015B0301063);Initiative Scientific Research Program of Materials Institute,CAEP(TP02201704);Sichuan Science and Technology Development Foundation for Young Scientists(2017JQ0050)。

摘　　要：采用电化学方法研究了硝酸根离子(NO3-)对U-0.79Ti合金在0.01mol/LNa Cl溶液中腐蚀的抑制作用。实验证明,NO3-对U-0.79Ti合金在含氯离子(Cl-)溶液中的腐蚀具有抑制作用,且与NO3-浓度密切相关。当NO3-与Cl-浓度比大于0.1时,NO3-能够有效抑制U-0.79Ti合金点蚀的发生;而低于这个比例时,NO3-对U-0.79Ti合金的腐蚀行为几乎无影响。从电化学过程来看,加入NO3-能够降低浓差极化并增大极限扩散电流密度。同时,NO3-能够降低氧化膜的阳极活性溶解速度,提高U-0.79Ti合金的点蚀电位。表面划痕实验则表明,NO3-的抑制作用很可能缘于其优先于Cl-在表面缺陷处吸附,阻碍了Cl-的点蚀成核。The inhibitive effect of NO3-on the corrosion behavior of U-0.79 wt%Ti alloy in 0.01 mol/L Na Cl solution was studied by electrochemical methods.The results show that NO3-ions possess inhibitive effect on the corrosion of U-0.79 wt%Ti alloy in the solution containing Cl-ions,which has a close relationship with the concentration of NO3-.When the concentration ratio of NO3-and Cl-exceeds 0.1,NO3-could inhibit the appearance of the pitting on U-0.79 wt%Ti alloy effectively;however,when the ratio is less than 0.1,NO3-shows hardly any inhibitive effect on the corrosion behavior of U-0.79 wt%Ti alloy.In the viewpoint of electrochemical process,the NO3-could increase the open circuit potential(OCP)of the alloy and lower the concentration polarization;meanwhile,it could increase the limited diffusion current density.At the same time,NO3-could also lower the rate of active anode dissolution,and increase the pitting corrosion potential of U-0.79 wt%Ti alloy.The surface scratches experiments show that the inhibitive effect of NO3-may root from that the NO3-ions have precedence over Cl-ions in being absorbed at the surface defects,which would inhibit the nucleation of pitting corrosion.

关 键 词：铀钛合金 硝酸根 抑制作用 腐蚀 

分 类 号：TG178[金属学及工艺—金属表面处理]