General corrosion is the main form of corrosion likely to affect carbon steels in an anoxic and near neutral environment such as encountered in the context of long term storage of steel canisters in a deep geological repository. This paper aims at studying the influence of the electrical and geometrical properties of a siderite corrosion product layers (CPL) formed in such conditions on its stability and on its subsequent protective properties against corrosion. A 1-D numerical model describing general corrosion under a porous conductive CPL and accounting for chemical evolution in the electrolyte is presented. It is demonstrated that a conductive layer with a cathodic activity increases the corrosion rate and the Fe^{2 +} ions concentration. Otherwise, a conductive layer leads to high saturation levels of siderite and high pH values within the CPL and consequently to a stabilization of the CPL. It is shown also that the stability of the CPL is promoted when it is initially thick and/or when it has a low porosity.

中文翻译：

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一维多孔电极模型，用于预测导电腐蚀产物层下的腐蚀速率

全面腐蚀是腐蚀的主要形式，腐蚀可能会在缺氧和接近中性的环境中影响碳钢，例如在深层地质处置库中长期储存钢罐的情况下所遇到的腐蚀。本文旨在研究在这种条件下形成的菱铁矿腐蚀产物层（CPL）的电学和几何特性对其稳定性及其随后的腐蚀防护性能的影响。提出了一种一维数值模型，该模型描述了多孔导电CPL下的一般腐蚀并解释了电解液中的化学演化。结果表明，具有阴极活性的导电层可提高腐蚀速率和Fe ^{2 +}离子浓度。否则，导电层会导致CPL内的菱铁矿饱和度高和pH值高，从而导致CPL稳定。还显示出，当CPL最初很厚和/或具有低孔隙率时，CPL的稳定性得到提高。