An Electrochemical Study of the Action of Industrial Organic Additives on Microbial (SRB-induced) Corrosion of Steel in Aqueous Salt Media

摘要

Corrosion processes with a hydrogen depolarising cathodic reaction occur widely in chemical and metalworking industries, oil and gas production, mining, marine, rail and road transport etc. The hydrogen arrives at the metal surface as adatoms and leaves the surface after recombination into molecules. However, some of the hydrogen adatoms may be absorbed by the subsurface layer of metal. This hydrogen absorption by steel in corrosion processes results in considerable loss of mechanical properties of the metal. In this work the absorption of hydrogen by corroded steel was studied with the aid of an anodic dissolution technique. This permits the hydrogen content in steel to be obtained as a function of depth in the metal. Hydrogen absorption by steel with a cold worked ferritic-pearlitic structure produced considerable decay of mechanical properties of steel (testing by torsion twisting of wire samples with dia. 1.0 mm from C-Mn steels). It is found that the integral hydrogen content of steel is dependent on the corrosion rate and quantity of bacterial cells in the corrosion medium. The integral hydrogen content of the steel subsurface layers was less in specimens, corroded in aqueous salt medium containing sulfate reducing bacteria if organic substances with inhibitive action were present.