Objectives The service life of the shipboard equipment will be seriously affected in the harsh corrosive environment of seawater. Therefore, it can effectively reduce the equipment damages due to corrosion by understanding corrosion mechanism and predicting corrosion.
Methods Lattice Boltzmann (LBM) corrosion model can be used to describe multiphase multicomponent flow and transmission, electrochemical reaction and metal steady pitting process. Based on this model, a numerical study is conducted to simulate a single corrosion pit on a metal surface immersed in the liquid corrosive environment; the effects of corrosion reaction rate, corrosion solution diffusion coefficient and corrosion product diffusion coefficient on the degree of corrosion are analyzed.
Results Morphological changes of the pit on the metal surface can be obtained by the numerical simulation. The numerical results show that, the pitting corrosion will be deeper because of the electrochemical corrosion system of large cathode and small anode formed by passivation film and metal matrix during the steady corrosion process of the single pit on the metal surface; the primary pitting hole will produce secondary pitting hole at the bottom. A conclusion obtained by changing the factors in the model is that, the degree of corrosion increases as the corrosion reaction rate increases, increases as the diffusion coefficient of the reactant components increases, and decreases as the corrosion product diffusion coefficient increases.
Conclusions The similar corrosion morphology of the real metal can be simulated through this corrosion model.
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