Interaction of marine organisms on localized corrosion of 316L stainless steel in Dalian seawater

Abstract

Purpose The purpose of this paper is to study the interaction of main marine organisms on localized corrosion of 316L stainless steel in the Dalian Sea area. Design/methodology/approach The steel plate was immersed in the Dalian Sea area for nine months to observe the biofouling and localized corrosion. The local potential distribution on the steel plate covered by marine organisms was measured. The local electrochemical measurements were performed to facilitate understanding the interfacial status under different biofouling conditions. The local surface morphologies and corrosion products were characterized. Findings The localized corrosion of stainless steel is mainly induced by the attachment of barnacles on the steel. The mussels have no influence on the localized corrosion. The cover of sea squirts could mitigate the localized corrosion induced by barnacles. Both crevice corrosion and pitting corrosion were found beneath the barnacle without the covering of sea squirts. The pitting damage was more serious than the crevice corrosion in the Dalian Sea area. The probing of sulfur element indicates that the potential growth of sulfate-reducing bacteria at barnacle center. Originality/value The above findings revealed that the interaction of marine organisms has significant influences on the localized corrosion of stainless steel. The influences of macro-fouling and micro-fouling on localized corrosion are discussed.