Electrochemical Studies of Crevice Corrosion Rates on Stainless Steels

A crevice corrosion cell was designed to utilize electrochemical techniques for the quantitative determination of crevice corrosion rates in three commerical austenitic stainless steels, AISI 304, 316L, and UHB 904L. Studies were conducted on Teflon/metal crevices exposed to 1 M NaCl at 22 and 55 C. Crevice corrosion current, electrochemical potential, and pH could be monitored. In addition, the area and location of each crevice corrosion site was determined in order that the data could be evaluated in terms of both the crevice corrosion current density (i) and potential (E) at the local site. These data were compared with anodic polarization studies in simulated crevice solutions. The study demonstrated the superiority of 904L; the interplay of i, E, and local solution chemistry upon crevice corrosion behavior; and allowed discussion of general guidelines for industrial monitoring of crevice corrosion.