Biocorrosive activity analysis of the oil pipeline soil in the Khanty-Mansiysk Autonomous Region of Ugra and the Krasnodar Territory of the Russian Federation

Influence of Phase Composition of Steel on a Damage Rate from Bio-Corrosion

“…Hydrogen tends to concentrate in the zone of local maximum three-axis damages which is, for example, at some distance from crack top. In a similar way when pitting the anode sites fixed at the bottom of a time in the protective film formed by a layer of products of corrosion can be points of concentration of hydrogen where its partial pressure can be very big [14].…”

“…Now there is no uniform theory opening the mechanism of participation of the sulfate-reducing bacteria and other microorganisms in the course of corrosion of metals. The contribution of bacteria to corrosion is explained by one or several of the following mechanisms: a) direct impact on the speed of anode or cathode reaction of corrosion process; b) creation of the corrosion environment due to formation of metabolism products (the theory of corrosion metabolites), aggressive in relation to metal; c) establishment of conditions of growth and reproduction at which concentration galvanopara or couples of differentiated aeration are created; d) biogenous acceleration of the corrosion and mechanical phenomena: hydrogen saturations and embrittlements of the main gas pipelines (SCC or a stress corrosion) protected by electrochemical protection which are statically loaded steels and their sulphidic cracking in serovodorodsoderzhashchy environments, internal rill corrosion of oil-field pipelines, corrosion cracking energized [11,14,16]. Up to 80% of corrosion equipment failures from high-strength by steel it is connected with activity of the sulfate-reducing bacteria due to sulphidic cracking (SSC) -a special case of hydrogen embrittlement in serovodorodsoderzhashchy environments, hydrogen cracking (HIC) and the hydrogen cracking (SOHIC) focused by tension.…”