Bssed on a previously published computerized model of crevice corrosion initiation, propagation and repassivation for Fe-Ni-Cr-Mo alloys in chloride solutions, a simpler model of crevice corrosion propagation is proposed. The model is deseribed with the use of simple algebraic equations, developed from integral equations for the voltage drop along the passive and active parts of the crevice. The validity of the algebraic equations is to some extent verified with the use of the computerized model. The algebraic equations provide a direct insight into the importanceof the various parameters for the propagation process. The mast important geometric parameter for the total corrosion current is observed to be the average crevice gap in the corroding area, while the original crevice gap in the passive region near the crevice mouth has no influence.The model also predicts the time to repassivation to be proportional to the square of the total crevice depth. The influence of the external potential and the type of stainless steel is briefly discussed.
Keywords: Stinks steels, seawater, crevice corrosion,model.