Impact of the Underground Metal Construction Cover Layer on the Cathode Protection Efficiency

[摘要] This paper presents the most probable mechanism of cover layer formation on the metal communication surfaces which are located in soil or sea water under the action of cathode protection as well as its basic properties. Basing on this analysis and data obtained during practical exploitation of the cathode protection systems the estimation of cathode protection efficiency variation in dc circuit was obtained. It was performed by estimation of both variation of cover layer electrical conductivity, and decrease of shielding current. It has been discovered that this efficiency grows with an increase of specific resistance of cover layer on the protected metal construction surface and connected with this decrease of specific shielding current density.

[发布机构] Peter the Great St. Petersburg Polytechnic University Saint Petersburg, Polytechnicheskaya, 29, 195251, Russia^1

[关键词] Cathode protection;Construction surfaces;Cover layers;Electrical conductivity;Shielding current density;Shielding currents;Specific resistances;Underground metal