Official Answer
Answer
While 316 stainless steel is 'marine grade,' it is still susceptible to pitting in stagnant seawater environments where chloride ions can breach the passive chromium-oxide layer. Wave springs are particularly vulnerable because the contact points between the waves and the housing create 'crevices.' These crevices lead to localized oxygen depletion, causing a breakdown of the passive film and forming an anodic cell. The failure is characterized by small, deep holes. For subsea applications, materials with a higher Pitting Resistance Equivalent Number (PREN) such as Inconel 625 or Super Duplex stainless steel are recommended.
