钝化304不锈钢在弱碱性含氯介质中的点蚀机理

Pitting Mechanism of Passive 304 Stainless Steel in Weakly Basic Media Containing Chlorion

摘要: 采用交流阻抗技术研究了钝化304不锈钢在pH8.4,H₃BO₃(0.2Mol/t-Na₂B₄O₇(0.05mol/1)及pH9.2,Na₂B₄O₇(0.05mol/l)的含氯介质中的点蚀行为;提出了点蚀的反应机理及发展阶段的界面等效电路模型,并认为在点蚀的发生和发展阶段都可能有复合物(MOHCl)及其进一步的吸附产物(MOHCl-Cl_n^-)_ad形成。

Abstract: The pitting behavior of passive 304 stainless steel in pH8.4, H₃BO₃ (0.2mol/l)-Na₂B₄O₇ (0.05mol/l) and pH9.2, Na₂B₄O₇ (0.05mol/l) solutions containing chlorion has been investigated using impedance technique. The possible reaction mechanism as well as the corresponding equivalent circuit model is presented. It is proposed that an intermediate complex (MOHCl) and its further adsorbed product (MOHCl-Cl_n^-)ads will form during pit initiation and propagation stages.