Optimization of Simulated Rust Layer of 304 Stainless Steel Occluded Cell in Ammonia Desulphurization Slurry

An occluded cell model of localized corrosion of 304 stainless steel was constructed in ammonia desulphurization slurry. The key factors of simulated rust layer in the model were optimized through the amount of ion migration in the occluded area, the pH of the solution and the corrosion rate of the inner electrode, and finally the optimal simulated rust layer was determined. The results show that the optimal simulated rust layer was based on filter paper as a carrier, a mixture of mixed iron oxide and calcium sulfate with a mass ratio of 9∶1 as a loading material, and a 0.5% (mass fraction) agar solution as a fixed molding agent. The occluded cell model with the optimal simulated rust layer could simulate well the development process of localized corrosion.