ABSTRACT
Stainless steels provide a wide range of strengths and corrosion resistance in seawater environments. Stainless steels have negligible general thinning in seawater because of a protective, predominantly chromium oxide film that forms immediately on their surface with exposure to air. Stainless steels are used for a wide range of applications in seawater and for many different reasons. Austenitic stainless steels have a tough, ductile structure and are the commonly available and versatile type of stainless steel. Duplex stainless steels contain both austenite and ferrite in their structure in roughly 50:50 proportions. Although austenitic and duplex stainless steels are the most commonly used in marine service, other grades, including ferritic and martensitic stainless steels, are available. Passive stainless steels are toward the noble end of the galvanic series and are more noble than copper alloys, aluminium, and steel. Chlorination, in optimal doses, is favourable to the corrosion performance of stainless steels in preventing fouling and marine growths that introduce tight crevices.
