Marine applications require construction material to resist harsh environments, but yet must be economical to produce and buy. Alloys such as UNS N06686 or UNS N10276 exhibit excellent corrosion resistance, but at a high price. Other alloys, like those in the 6% molybdenum superaustenitic stainless steel (6%Mo SS) family are more economical, but sacrifice much of the corrosion resistance of the higher alloyed materials. Thus, an alloy that could approach the corrosion resistance of UNS N10276, but with a price near the 6%Mo SS alloys would satisfy both of the requirements for marine service. To meet these requirements, a new superaustenitic stainless steel with enhanced corrosion resistance to both general and localized environments has been developed. Corrosion rates for this new alloy and competitive alloys in seawater, in chloride environments, and other applications relevant to marine service are discussed.
Keywords: superaustenitic stainless steel, corrosion, new alloy, mechanical properties, seawater, stress corrosion cracking, nitrogen, sigma phase, pitting, crevice corrosion