用循环伏安法研究钼酸盐对软钢的缓蚀作用

把软钢加工成旋转圆盘电极,用循环伏安法,研究软钢在去空气和空气饱和的中性低硬度水中钼酸盐的缓蚀性能,以及钼酸盐与亚硝酸盐的协同效应。通过测定点蚀电位再钝化电位和点蚀临界氯离子浓度等参数来评定体系的抗点蚀性能。实验结果表明:钼酸盐比亚硝酸盐对软钢有更好的抗点蚀性能。亚硝酸盐有利于钝化;而钼酸盐有利于再钝化。当它们结合使用时,由于性能的相互补偿,产生很好的协同效应。旋转环盘电极的研究表明,钼酸盐改善再钝化性能是由于形成铁的不溶性钼酸盐化合物所致。

Study on Corrosion Inhibition of Mild Steel with Molybdate Using Cyclic Voltammetry

The effect of molybdate on corrosion inhibition of mild steel add the syner-gistic corrosion inhibition of mild st(?)el with molybdate and nitrite together in deaerated andaerated low hardness water (pH=7) were investigated separately by cyclic voltammetry. The rotating disk electrode (mild steel) was used in these studies. By determinations of pitting potentials, repassive potentials and pitting critical concentrations of Cl-, the resistance to pi-tting corrosion was evaluated. The results indicated that the resistance to pitting corrosion of mild steel inhibited by molybdate is better than by nitrite. Nitrite is favourable to passi-vation; while molybdate is favourable to repassivation. When they are used together, good synergism was-observed, complementing each other in their properties. Studies on cyclic voltammetry of rotating ring-disk eletrode indicated that molybdate improved the repassiveproperty by forming an insoluble molybdate compound.