Numerical Simulation of Crevice Corrosion of Stainless Steel-Titanium in NaCl Solution

A multiphysics model based on the finite element method was adopted, emphasizing a deeper insight into the rarely studied crevice corrosion behavior of stainless steel and titanium overlapping. The model takes into account damage due to corrosion inside the crevice, different species transportation, local electrochemical reactions, homogeneous reactions in the electrolyte, and formation of a corrosion product and its influence on electrochemical reaction. The simulation results show that the location of the greatest attack for stainless steel is at the crevice opening; this finding is consistent with the IR drop theory. The potential increases gradually from the tip to the opening of the crevice, and the current changes smoothly following a sharp rise at the opening. The minimum and maximum values of pH and Cl- concentration are both in the middle and opening of the crevice. The influence of the crevice size on corrosion is also discussed in detail.