H2S腐蚀产物界面性能对管线钢氢渗透动力学行为的影响机理及规律

In wet H2S environment, when sulfur iron corrosion products exist on metal surface, the hydrogen permeating kinetic behavior would be controlled by the kinetic behavior of the metal surface corrosion; and the corrosion of metals, which covered by a corrosion films often depends on the density of the films and interfacial properties between the metal and the films. Therefore, the cyclic voltammetry method is emplyed to rapidly produce H2S corrosion product film "on site" with different chemical composition and microstructure in the surface of pipeline steel, and the changing rules of semiconductor properties, ion selective permeation, membrane / solution interface electrochemical properties, hydrogen permeation current, diffusion hydrogen content and so on will be studied "in situ", in order to reveal the dependency releationship of H2S corrosion interface properties on pH value, and establish a micro physical model of the interface reaction of H2S corrosion product film and solution and matrix, and illustrate the effect mechanism and regularity of the interfacial properties of H2S corrosion products on the rate controlling step of hydrogen permeation. These results could provide the theoretical basis for revealing essentially the relationship of H2S corrosion products and HIC susceptibility of pipeline steel, provide data support for corrosion prevention measures in the H2S environment.

在湿H2S环境中，金属表面有硫铁腐蚀产物存在时，氢在金属中的渗透动力学行为被金属表面的腐蚀动力学行为控制，而膜下基体金属的腐蚀动力学行为往往取决于这层膜的致密度及界面性能。为此，本项目拟采用循环伏安方法在管线钢表面"现场"快速生成不同化学成分和组织结构的H2S腐蚀产物膜，"原位"研究腐蚀产物膜致密度、半导体性能、离子渗透选择性、膜/溶液界面电化学性能、膜下氢渗透电流、膜下扩散氢含量等的变化规律，揭示H2S腐蚀产物界面性能与H2S分压 、pH值的依存关系，建立管线钢基体/H2S腐蚀产物膜/溶液界面反应的微观物理模型，阐明H2S腐蚀产物的界面性能对氢渗透动力学速控步骤的影响机理及规律。为从本质上揭示H2S腐蚀产物与HIC敏感性关系提供理论依据，为管线钢在H2S环境中防腐蚀措施的制定提供数据支持。

在湿H2S环境中，金属表面不可避免会生成硫铁腐蚀产物，有硫铁腐蚀产物存在时，氢在金属中的渗透动力学行为被金属表面的腐蚀动力学行为控制，而膜下基体金属的腐蚀动力学行为往往取决于这层膜的致密度及界面性能。为此，本项目采用循环伏安方法在管线钢表面“现场”快速生成不同化学成分和组织结构的H2S腐蚀产物膜，“原位”研究了腐蚀产物膜致密度、离子渗透选择性、膜/溶液界面电化学性能、膜下氢渗透电流等的变化规律，揭示了H2S腐蚀产物界面性能与H2S分压 、pH值的依存关系，建立了管线钢基体/H2S腐蚀产物膜/溶液界面反应的微观物理模型，阐明了H2S腐蚀产物的界面性能对氢渗透动力学速控步骤的影响机理及规律。本项目的研究结果为从本质上揭示H2S腐蚀产物与HIC敏感性关系提供了理论依据，为管线钢在H2S环境中防腐蚀措施的制定提供了数据支持。