Laboratory and numerical corrosion experiments impose an electric potential on the metal surface, differing from natural corrosion conditions, where corrosion typically occurs in the absence of external current sources. In this work, we present a new computational model that enables predicting corrosion under charge-conservation conditions. The metal potential, an output of the model, is allowed to change, capturing how the corrosion and cathodic reactions must produce/consume electrons at the same rates, as in natural conditions. Finite element simulations are performed over a large range of concentrations and geometric parameters. The results highlight the notable influence of the charge-conservation assumption and pioneeringly quantify corrosion rates under realistic conditions. They further show: (i) the strong coupling between the corrosion rate and the hydrogen and oxygen evolution reactions, (ii) under which circumstances corrosion pits acidify, and (iii) when corrosion is able to become self-sustained lacking oxygen.

翻译：实验室和数值腐蚀实验会对金属表面施加电位，这与自然腐蚀条件不同——自然条件下腐蚀通常发生在无外部电流源的环境中。本研究提出了一种新计算模型，能够在电荷守恒条件下预测腐蚀行为。该模型将金属电位作为输出变量，使其动态变化，从而捕捉腐蚀反应与阴极反应在自然条件下必须保持电子产生/消耗速率相等的特性。通过有限元模拟，我们在广泛的浓度与几何参数范围内进行了计算。结果凸显了电荷守恒假设的显著影响，并首次量化了真实条件下的腐蚀速率。研究进一步表明：（i）腐蚀速率与析氢反应和析氧反应之间存在强耦合效应；（ii）腐蚀坑在何种条件下会发生酸化；（iii）在缺氧环境中腐蚀何时能够实现自维持。