Key Issues Related to Corrosion Protection of Brackish Water and Seawater Bearing Components in Cooling Water Systems

Stainless steel components in cooling water systems, using brackish- or seawater as cooling medium, are potentially vulnerable to corrosion. In many cases such corrosion issues are mainly ascribed to Microbially Influenced Corrosion (MIC). Within the scope of a study, field tests were performed in different environments (Swedish East Coast, Swedish West Coast, mouth of the river Elbe in Germany). In some cases even such materials, that are assumed to be resistant, have been affected by corrosion. However, based on the outcomes of the field tests, it can be concluded, that all results, where corrosion occurred, are explainable by environmentally assisted chloride induced corrosion. Crevice conditions produced from consolidated biofilms on component surfaces or from sludge deposits, most probably support the initiation and the progress of this kind of corrosion. Based on the test results, practical recommendations are derived, as how to prevent corrosion in brackish- or seawater environments.