钛在硫酸中的阳极保护及腐蚀行为研究

Study of Anodic Protection and Corrosion Properties of Titanium in Sulphur Acid

利用阳极保护技术研究了钛在不同温度、浓度硫酸中的腐蚀行为。测定了阳极极化曲线并据此分析出钝化区和保护电位值,监测钛在这些电位下进行以168 h为1周期的腐蚀行为。结果表明,无论硫酸介质处于静态还是动态,钛在温度低于90℃、40 wt%H_2SO_4及温度低于60℃、70 wt%H_2SO_4中均能应用阳极保护来防止腐蚀,其中静态腐蚀率更低。XPS分析表明阳极氧化膜由TiO_2及2种中间氧化物组成,其腐蚀率随氧化膜中TiO_2含量而变化。

By applying the anodic protection technique, corrosion behaviours of titanium in sulphur acid of different concentrations at different temperatures are studied in this paper. Based on the relevant anodic polarization curves obtained by potentiodynamic technique, the safe passive zone and the protection potentials were analized and established. The titanium specimens were held at these potentials and the corrosion behaviours were monitored over a 168 hour-period. The results reveal that corrosion can be controlled to an acceptable degree by applying anode in 40 wt% H_2SO_4, lower than 90 ℃ and 70 wt% H_2SO_4, lower than 60 ℃ , no matter H_2SO_4 is static or dynamic, but the corrosion rate is lower when it is static. XPS analysis indicate the anodic oxides are composed of TiO_2 and 2 other intermediate oxides, the corrossion rate of which changes with TiO_2 content in the oxide film.