The role of acetic acid or H+ in initiating crevice corrosion of N80 carbon steel in CO2-saturated NaCl solution

The role of acetic acid (HAc) or H+ in initiating the crevice corrosion of N80 carbon steel in CO2-saturated NaCl solution was studied by weight loss and electrochemical measurements. It is demonstrated that crevice corrosion could be initiated by the concentration difference either HAc or H+ between outside and inside the crevice. The corrosion rate inside the crevice becomes higher than that outside the crevice and the total corrosion rate inside and outside the crevice decreases after connection. Crevice corrosion is more severe in the solution with HAc than that in the solution with H2SO4 at the same pH value.