Corrosion Overview Corrosion and Galvanic Compatibility
Corrosion and Galvanic Compatibility Knowledge
General corrosion involving water and steel generally results from chemical action where the steel surface oxidizes, forming iron oxide (rust). Many of the systems and components in the plant are made from iron.
Some standard methods associated with material selection that protect against general corrosion include:The use of corrosion-resistant materials such as stainless steel and nickel, chromium, and molybdenum alloys. (Keep in mind that the corrosion is electrochemical by nature, and the corrosion resistance of the stainless steels results from surface oxide films that interfere with the electrochemical process.)
The use of protective coatings such as paints and epoxies.
The application of metallic and nonmetallic coatings or linings to the surface which protects against corrosion, but allows the material to retain its structural strength (for example, a carbon steel pressure vessel with stainless steel cladding as a liner).