Cathodic Protection of Stainless Steels and other Corrosion Resistant Alloys

摘要

By now it is common knowledge that stainless steels ranging from UNS S31600 up to 6% Molybdenum stainless steels and (super)duplex stainless steels do not always resist seawater. Even for fresh natural water it is well known that 2% Molybdenum stainless steels such as UNS S31600 may fail if aggressive biofilms can develop. Seawater resistant copper alloys, such as UNS C70600 and UNS C63000 may fail due to high flow effects. Improper chlorination can cause damage to all above-mentioned alloys. And last but not least, these corrosion resistant alloys (CRA's) can cause galvanic corrosion to nearby steel constructions, or suffer galvanic corrosion if contacted to nearby noble behaving metals such as Titanium. This paper describes cathodic protection options for protecting stainless steels and other CRA's against localized corrosion and for elimination of galvanic corrosion. The subject 'Anodic Protection' will be discussed as well.