Zvirko O. The regularities of the operation degradation of oil-trunk pipelines and tanks steels under the corrosion action of oil-water medium

Dissertation covers the determination of effect of long-term exploitation of oil-trunk pipelines and tanks steels on its corrosion rate, a sensitivity to stress corrosion cracking and brittle fracture in residual water and oil-water medium and the development of effective inhibitor protection against corrosion of oil pipelines inner surfaces. It is revealed that long-term exploitation of oil-trunk pipelines and tanks steels causes essential deterioration its electrochemical characteristics, a decrease of corrosion resistance in bulk material, sensitivity to stress corrosion cracking and brittle fracture as a result of oil-water medium aggressive action. It is established that oil-water medium with phase boundary is characterized by the most corrosion activity and oil-water emulsion - by the lowest one. The important role of hydrogenation of steels in its operation degradation is shown. It became apparent by the increase of material microdefectiveness and brittle fracture resistance decrease. The inhibitor NEFGAN-1 is developed and its high effectiveness for protection against corrosion of oil pipeline inner surfaces in residual water and oil-water medium is established. It is proposed to use the inhibitor NEFGAN-1 as the effective method for interoperational protection of oil trunk-line reserve branches.