During the past 15 years of R&D program in seawater desalination at KISR, many metals and alloys have been studied for their corrosion behavior. Stainless steels, nickel-base alloys, titanium among the groups of alloys that were evaluated. Linear polarization, cyclic polarization, open-circuit potential, impedance spectroscopy, crevice corrosion and erosion corrosion were some of the major techniques and tests used to evaluate the candidate materials for this program. Tests indicated that austenitic stainless steel UNS S31603 and UNS S31703 were the least favored to be used in the construction of seawater reverse osmosis units.