The Influence of Galvanic Coupling on Corrosion of Carbon Steel Coupled with Stainless Steels for Use in Concrete Structures

摘要

The judicious use of stainless steel and carbon steel in concrete structures-using stainless steel only in areas with a high risk of corrosion and carbon steel in low-risk areas-could be a viable option for reducing lifetime cost, and extending service life. However, the concern about the risk of galvanic corrosion between the two different steels has prevented this application in the field. This paper investigates the galvanic coupling behaviours of carbon steel and three different stainless steels (304LN, 316LN and 2205). The results indicate that the oxygen reduction reaction is a rate-determining step and is much lower on stainless steel than on passive carbon steel. Therefore, the galvanic coupling current between stainless steel and corroding carbon steel is lower than the coupling current between passive and corroding carbon steels. Consequently, the combination of stainless steel with carbon steel will not increase the risk of corrosion of carbon steel.