Numerical Simulation of Transient Crevice Corrosion of Metal Pipeline under Coating

A two-dimensional mathematical model was established, which fully considered the effects of mass transfer process, potential gradient change and electrical neutrality principle of the solution in crevice. The changing law of the oxygen concentration, pH, ion concentration and conductivity of the solution in the crevice under transient conditions were analyzed by numerical simulation method. The results show that the oxygen concentration of solution decreased rapidly with the extension of time. The pH of solution peaked at 15 mm from the crevice mouth and gradually stabilized with the extension of time. The conductivity of solution increased with the extension of time, and decreased with the increase of the crevice depth. The evaluation error between simulation results and test results was 1.8%.