摘要
采用旋转挂片和SEM,EDS及IR分析研究Q235钢在海水淡化一级反渗透产水中(RO)的腐蚀速度和腐蚀产物变化规律,并利用动电位扫描、电化学阻抗法研究腐蚀过程及腐蚀反应控制步骤。结果表明,Q235钢在海水淡化一级反渗透产水中腐蚀速度在48 h内迅速增大至1.4 mm/a,其后保持稳定。锈层初期为γ-FeOOH薄层,随时间延长逐渐转为由Fe_3O_4构成的内锈层及由γ-FeOOH和α-FeOOH构成的外锈层。腐蚀过程受阴极控制,初期腐蚀阻力达到最大,其后由于大量γ-FeOOH在酸性条件下极易转化为对腐蚀反应没有阻滞作用的Fe_3O_4,腐蚀阻力迅速减小,腐蚀速度迅速增大,当Q235钢表面γ-FeOOH生成和转化达到平衡后,腐蚀阻力保持稳定,腐蚀速度也不再发生变化。
The corrosion behavior of Q235 steel in seawater reverse osmosis permeate（RO） was investigated by rotation coupon method, SEM, IR and XRD, and electrochemical tests were used for studying the control step and electrode process of corrosion reaction. Experimental results showed that the corrosion rate was speeded up in first 48 h and maintained at 1.4 mm/a afterwards. Initial rust layer was formed by a thin layer of γ-FeOOH, and with time passing by, it transformed to a double-layer structure with inner thick Fe3O4 layer and outer a-FeOOH/γ-FeOOH layer. Corrosion process was controlled by cathodic reaction, resistance of which reached peak in initial stage, then reduced rapidly because of conversion of γ-FeOOH to Fe3O4, which provided no inhibition of corrosion and caused high corrosion rate of Q235 steel. As the generation and conversion of γ-FeOOH reached equilibrium on the surface of Q235 steel, corrosion resistance and corrosion rate kept steady.
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2012年第5期412-416,共5页
Journal of Chinese Society For Corrosion and Protection
基金
中央高校基本科研业务费专项资金(20102080101000090)资助
关键词
海水淡化
一级反渗透产水
Q235
钢腐蚀
seawater desalination, reverse osmosis permeate, Q235 steel, corrosion
