【摘要】 采用循环伏安法研究了X70钢在NaHCO3 /Na2 CO3 溶液中的阳极反应过程 ,探讨了HCO-3 浓度变化对氧化过程的影响 ,用X -射线衍射和红外光谱分析证实钢表面预钝化膜的双层结构和组成更多还原

【Abstract】 The influence of concentration of HCO-₃ ions was discussed by comparison of cyclic voltammetric behaviors of X70 steel in solutions of different concentrations of HCO-₃ ions.A prepassive film was formed with the presence of HCO-₃ ions.The stability of prepassive film was reduced with increasing of HCO-₃ ions.The formation of Fe（Ⅱ） species governed the electrochemical behavior of prepassive process.HCO-₃ ions appeared to play the dominant role in the initial dissolution of Fe.The structure of prepassive film was confirmed by XRD and IR.The film had double-layer structure.Fe（OH）₂ as the composition of inner layer deduced with the increasing of concentration of HCO-₃ ions,while FeCO₃ on the outer layer increased.更多还原