氢氟酸-硝酸体系中TC4钛合金的腐蚀行为

本文探讨了氢氟酸-硝酸体系中TCA钛合金的腐蚀速率和腐蚀过程中的吸氢量，并利用电化学测试方法研究了TCA钛合金在这种体系中的腐蚀行为。研究结果表明，腐蚀速率随氢氟酸浓度和温度的增加而增大，而随硝酸浓度的增加先增大后降低。TCA钛合金在氢氟酸．硝酸体系中吸氢量较小，吸氢量随硝酸浓度的增加而减少。在只含有氢氟酸的腐蚀溶液中。极化曲线呈现活化特征，加入硝酸后，极化曲线出现明显的活化-钝化转变特征，硝酸浓度继续增大到一定值后，极化曲线呈现自钝化倾向，钝化膜的稳定性增加。腐蚀过程中硝酸能够促进钛合金表面钝化和抑制氢的生成。

Corrosion Behavior of TC4 Titanium Alloy in HF-HNO3 System

The corrosion rate and hydrogen absorption of TCA titanium alloy in HF-HNO3 system were investigated. Meanwhile corrosion behavior was studied in HF-HNO3 system by use of electrochemical method. The results show that the corrosion rate increased with the HF concentration and temperature increasing. However, when the concentration of HNO3 gradually increased, the corrosion rate initially rose and then decreased. Hydrogen absorption capacity of TCA titanium alloy was lower in HF-HNO3 system. The HNO3 content was higher. The hydrogen absorption capacity was lower. In the solution containing HF single, active characteristics occurred in the polarization curve, after HNO3 was added to HF solution, obvious active-passive transition characteristics could be seen in the polarization curve. When the concentration of HNO3 reached the threshold value, the polarization curve showed the self-passivation trend and the stability of passive film improved. During the corrosion process, HNO3 could promote the surface passivation and inhibit hydrogen formation.