Corrosion behaviour of nickel-based alloys in seawater service systems

Over the past three decades great progress has been made in the selection o f high resistant materials to service the need of the ever-increasing corro sion problems in marine environment. Though the conventionally used austeni tic stainless steels, 316L SS appear to be reasonably corrosion resistant a nd cost-effective, they are prone to local attack such as pitting and crevi ce, due to aggressivity of the environment mainly of chloride ions and temp erature. In the present investigation, electrochemical corrosion experiment s were carried out on 316L SS, alloy 825, alloy C-276 and alloy 59 to deter mine the pitting corrosion resistance in seawater at room temperature, 50 d egrees C and at 80 degrees C. The parameters of interest recorded were the corrosion potential (E-corr) breakdown potential (E-b), the repassivation p otential (E-p).