贫铀表面钛镀层的抗腐蚀性能研究

Anti-corrosion Performance of Titanium Deposit on Depleted Uranium Surface

利用电化学测试技术、扫描电镜(SEM)及X射线能谱(EDS)对贫铀表面钛镀层的抗腐蚀性能进行了研究。结果表明:在50μg/gCl-的KCl溶液中,钛镀层的腐蚀电位远高于贫铀的腐蚀电位,钛镀层对贫铀是阴极性镀层,对贫铀的保护是基于其对腐蚀介质的物理屏障作用;贫铀表面完整钛镀层的极化电阻和电化学阻抗幅值远大于贫铀,腐蚀电流远小于贫铀,完整钛镀层对贫铀具有良好的抗腐蚀保护作用;贫铀表面钛镀层的腐蚀特征为局部腐蚀,由孔蚀向电偶腐蚀转变;破坏的钛镀层将加速铀基体的腐蚀。

Anti-corrosion performance of titanium deposit on depleted uranium surface was studied by electrochemical technology, scanning electron microscope （SEM） and X-ray energy dispersive spectroscope （EDS）. The results indicate that in 50 μg/g Cl^-1 potassium chloride solution, corrosion potential of titanium deposit is much higher than that of depleted uranium. Titanium coating is cathodic deposit to depleted uranium. Protection of titanium coating to depleted uranium depends on physical barrier to corrosive medium. The intact titanium deposit on depleted uranium surface has much higher polarization resistance, greater magnitude of electrochemical impedance and much lower corrosion current than that of depleted uranium. The intact titanium coating has excellent anti-corrosion and protection effect to depleted uranium substrate. Corrosion characteristic of the titanium deposit on depleted uranium surface is typical local corrosion and changes from pit corrosion to galvanic corrosion. The damaged titanium coating will accelerate the corrosion of depleted uranium substrate