The Crevice corrosion tests were performed on UNS S31603, UNS S31703, UNS S31726, UNS S31254, UNS N08904, UNS N625, UNS N825 and UNS N276 was investigated in seawater and neutral brine solution using a multiple crevice washer assembly. PTFE multiple-crevice washers were bolted to both sides of the test specimens with PTFE bolts and nuts. The specimens were exposed to seawater flowing at a rate of 100 L/h for periods of 3000 h and 6000 h. Duplicate specimens were immersed in a plexiglass cell containing the flowing seawater at a temperature of 30°C. The results showed that all the tested coupons were susceptible to some degree of crevice corrosion attack. However, the stainless steels were the most severely affected. The degree of
crevice corrosion attack for the nickel base alloys decreased as the percentage of molybdenum content in the alloys increased. Destruction of the passive layer by the concentration of chloride or acidity and reduction of hydrogen ions at the crevices is believed to be the cause of the crevice attack.
Keywords: crevice corrosion, seawater, reverse osmosis, stainless steels, nickel alloys.