A RESEARCH FOR CORROSIVE MICROBE IN INTERNAL RUST LAYER OF CARBON STEEL IN SEAWATER

摘要

Samples of carbon steel were exposed to seawater at Yulin and Qingdao test site for 1, 3, 6, 9, 12 and 36 month. Corrosive bacteria in internal rust layers were analyzed; Modality and distribution of the bacteria was observed By SEM. Content of FeS in internal rust layers was measured. Microbiologically influenced corrosion of carbon steel in seawater was discussed. The results showed that large quantity of SRB congregate in internal rust layer of carbon steel. Heterotrophic bacteria, iron bacteria and sulfide-oxidizing bacteria more or less exist in internal rust layers. Content of FeS in internal rust layer is more than 6%. With the increase of exposure time, Content of FeS tends towards increase. Corrosion of steel below rust layer or rust tumor was mainly influenced by SRB.