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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 rate and corrosion products of Q235 steel in desalinated first-order reverse osmosis (RO) water were investigated by rotating coupons and SEM, EDS and IR analyzes. The corrosion process and corrosion of Q235 steel were studied by potentiodynamic and electrochemical impedance spectroscopy Reaction control steps. The results show that the corrosion rate of Q235 steel in desalinated first-order reverse osmosis water rapidly increases to 1.4 mm / a within 48 h and then remains stable. The initial rust layer of γ-FeOOH thin, with time gradually turned into an internal rust layer composed of Fe_3O_4 and by the outer layer of γ-FeOOH and α-FeOOH rust layer. Corrosion process is controlled by the cathode, the initial corrosion resistance reaches the maximum, then due to a large number of γ-FeOOH in acidic conditions easily transformed into the corrosion reaction without blocking the role of Fe 3 O 4, the corrosion resistance decreases rapidly, the corrosion rate increases rapidly when Q235 steel surface γ-FeOOH generation and conversion reached equilibrium, the corrosion resistance remained stable, the corrosion rate is no longer change.