A numerical model for corrosion pit propagation under mechanical loading is presented. The level set method is used for corrosion front tracking and also enables the domain to be split into a solid and a pit domain. In the pit the diffusion of atoms originating from the dissolution process occurring at the pit front is simulated. The model is capable of automatically capturing lacy cover formation due to the inclusion of activation control, diffusion control, and passivation. In the solid static equilibrium is solved to obtain strains and stresses. A parameter, dependent on the signs of the plastic strain increment and the back stress, is introduced to define the influence of plasticity on the corrosion rate. The model is used to study pit growth under electrochemical and mechanical loading. Under activation control combined with an elastic material response, pits propagate faster under constant loading than under cyclic loading. When plastic deformation occurs, cyclic loading can significantly increase the pit growth rate. Increasing the cyclic load frequency results in faster propagation due to kinematic hardening. Under diffusion control, mechanical loading does not influence the pit growth rate, given that the salt layer leading to diffusion control remains intact.

中文翻译：

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应力相关腐蚀坑传播的水平集模型

建立了机械载荷作用下腐蚀坑扩展的数值模型。水平集方法用于腐蚀前沿跟踪，还可以将区域分为实心区域和凹坑区域。在凹坑中，模拟了由于发生在凹坑前沿的溶解过程而导致的原子扩散。由于包含激活控制，扩散控制和钝化，该模型能够自动捕获花边覆盖物的形成。在固体中，静态平衡得以解决以获得应变和应力。引入一个取决于塑性应变增量和背应力的参数，以定义塑性对腐蚀速率的影响。该模型用于研究在电化学和机械载荷下的凹坑生长。在激活控制和弹性材料响应的结合下，凹坑在恒定载荷下的传播比循环载荷下的传播快。当发生塑性变形时，循环载荷可以显着提高凹坑的生长速度。由于运动硬化，增加循环负载频率会导致更快的传播。在扩散控制下，由于导致扩散控制的盐层保持完好，因此机械载荷不会影响凹坑的生长速率。