Field underground pipelines corrosion testing and results of the first specimens lot extraction presented and discussed in this paper. The object of the investigation is underground pipeline corrosion regularities. The specimen locations were selected based on Corrosion survey reports and In-line Inspections reports. Specimens were buried close to the wall of pre-selected underground pipelines on the same depths. In every location one group of specimens were connected to the pipelines cathodic protection systems via. test-posts, the rest specimens were exposed to soil corrosion without any protection. The test conditions were controlled by means of field measurements during installation and prior to extraction, occasionally in course of exposition. Corrosion rate was measured by gravimetric method and based on maximum corrosion defect depth of specimen. Obtained results are discussed; preliminary conclusions about influence of control parameters on soil corrosion of pipe grade steels were made. The following conclusions can be made as a result of first sample party excavation. It is shown soil resistivity up to 30 Ohmв€™m represents corrosion aggressivity of soils adequately. Corrosion situation in the anticipated most dangerous pipeline sections was estimated; the results demonstrated the normative conditions of corrosion protection system. Regression plots of pipe steel corrosion rate versus cathodic protection parameters and corrosion environment conditions were attempted.В The results will be applied in Transneft regulatory documents.
1. Lisin Yu.V., Research of physical and chemical properties of steel for continuously operated pipelines and assessment of safe operational life (In Russ.), Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov, 2015, no. 4(20), pp. 18–28.
2. Mustafin T.S., Neganov D.A., Skuridin N.N. et al., Technical condition and development concept of the corrosion protection system of JSC “Transneft” facilities (In Russ.), Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov, 2015, no. 3(19), pp. 6–11.
3. Zhuk N.P., Kurs teorii korrozii i zashchity metallov (Course in the theory of corrosion and protection of metals), Moscow: Al'yans Publ., 2006, 472 p.
4. Romanoff M., Underground corrosion, NBS Circular 579, 1957.
5. Barlo T.J., Field testing the criteria for cathodic protection of buried pipelines, Washington DC: American Gas Association, 1994.
6. Leeds S.S., Cottis R.A., The influence of cathodically generated surface films on corrosion and the currently accepted criteria for cathodic protection, Corrosion-2009, Paper no. 09548, Houston, TX: NACE, 2009.
7. Sanders L., Fleury E., Fontaine S., Vasseur V., DC stray currents: Evaluation of the relevance of the risk assessment criterion proposed by the European Standard EN 50162, Part 2, European Corrosion Congress "Eurocorr-2017", paper no. 76481, Praha, Czech Republic, 2017.
8. Kop'ev I.Yu., Pushkarev A.M., Goncharov A.V., Popov V.A., Practice of inspection of anti-corrosive protection system of pipeline on railroad crossing (In Russ.), Praktika protivokorrozionnoy zashchity, 2013, no. 1(67), pp. 52–65.