The questions of organization of cathodic protection against corrosion of pipelines laid by the «pipe in pipe» method are considered. The variants of the organization of the cathodic corrosion system for pipelines laid by this method are determined. A laboratory stand simulating a pipe-in-pipe gasket with the installation of coppersulphate electrodes of comparison of small size between the pipes has been prepared. Laboratory studies to verify the protection of the main pipeline under various schemes of organization of cathodic corrosion protection were carried out. The conditions that must be observed when laying the pipeline to ensure the operation of the cathodic protection system, the main ones are the presence of electrolyte in the medium between the pipelines, as well as the absence of direct electrical contact between the pipelines. Negative features of joint protection of both pipelines are revealed. The optimal schemes of organization of cathodic corrosion protection during pipeline laying by this method, which are schemes with the use of extended anode grounding between pipelines or schemes without cathodic protection of external pipe, are determined. Solutions are proposed to eliminate the «failure» of the protective potential in contact with the metal between the pipelines, which consists in laying an extended anode grounding and local displacement of the potential of the internal pipeline relative to the external one.

Anode groundbeds are intended for use as low-soluble elements of cathodic protection systems against corrosion of main pipelines and other underground metal structures. The classification of Anode groundbeds into deep, subsurface and extended ones indicates the features of their construction and the method of installation. At the time their application area is determined primarily by the material of the working electrode of the Anode groundbed. With the development of modern technologies, as well as the ability to purchase working elements for anodes on the world market, a large number of new Anode groundbeds from different materials have appeared. In this case, the declared technical characteristics of even the same type of materials from different manufacturers may vary greatly. This situation makes it difficult for design organizations and anti-corrosion protection specialists to select the most suitable Anode groundbeds for specific operating conditions. This article provides an analysis of the performance properties of the main materials of Anode groundbeds and, based on the limitations inherent in each material, provides the recommended area of their application. The materials such as mixed metal oxide (MMO), manganese dioxide, graphite, silicon iron alloy and magnetite are reviewed.

The protective efficiency of the volatile IFHAN-114 corrosion inhibitor (VCI) was determined by impedance spectroscopy under atmospheric corrosion of St3 steel and copper in livestock buildings containing trace amounts of carbon dioxide, ammonia and hydrogen sulfide in the regulatory allowable concentrations. A 0.1 M NaCl solution was used as the background electrolyte. The effect of the combined presence of NH3 and CO2 corrosion stimulants of metals in the air was modeled by introducing (NH4)2CO3 in concentrations of 10 and 100 mg/L into the background solution. To simulate the combined presence of NH3 and H2S in air, equivalent amounts of Na2S and NH4Cl were introduced into the background electrolyte solution to obtain (NH4)2S (10 and 100 mg/L) at specified concentrations. This resulted in the hydrolysis of NH4 + and S2- ions to form NH4OH and H2S, which are stable in the surface phase film. According to impedance spectroscopy, (NH4)2CO3 at a concentration of 10 mg/L acts as an corrosion inhibitor of steel in a 0.1 M NaCl solution, and IFKHAN-114 (nonequivalent mixture of polyaniline with benzoic acid), introduced into the solution along with this amount of ammonium carbonate, plays the role of a corrosion stimulator. However, with an increase in the concentration of ammonium carbonate, its inhibitory effect is decreased, and for IFKHAN-114, introduced along with the salt, on the contrary, is appeared. A similar pattern is observed for the copper electrode. In the presence of (NH4)2S, almost the same effect of salt and VCI is observed for steel and copper, but with some variation. A comparison of the data obtained by gravimetric tests and impedance measurements showed that in the latter case only qualitative results can be obtained, although they undoubtedly confirm the presence of the inhibitory ability of IFKHAN-114 in a chloride neutral solution.

Norbornenylmethanol was synthesized by the reaction of cyclopentadiene and allyl alcohol, on the basis of which aminomethoxy derivatives of norbornenylmethanol were synthesized in the presence of formaldehyde and secondary amines by Mannich condensation. The yield of the target products was 43-71%. On the basis of 5-morpholinomethoxymethylbicyclo[ 2.2.1]-hept-2-ene and hexylbromide (1:1) in the presence of isopropyl alcohol, its complex was obtained. The physic-chemical properties of the synthesized compounds and the resulting complex were determined, their 1% solutions in isopropyl alcohol and 5% solution of 5-morpholinomethoxymethylbicyclo[2.2.1]-hept-2-ene were prepared. Their influence on the vital activity of sulfate-reducing bacteria of the type «Desulfovibrio desulfuricans» in three concentrations (5; 50; 100 mg/L) was studied. Bactericide inhibitors used in industry – AMDOR IK-7 and AMDOR IК-10 were taken as standards. It was determined that all the synthesized compounds and the resulting complex showed high bactericidal properties, moreover, compounds obtained on the basis of cyclic secondary amines showed a higher bactericidal effect against sulfate-reducing bacteria, unlike compounds obtained on the basis of aliphatic secondary amines. Considering that these aminomethoxy derivatives of norbornenylmethanol affect bacteria at very low concentrations, they can be proposed as effective inhibitors against sulfate-reducing bacteria.

The cartographic image of space is represented by a mosaic of halos of the characteristics of the natural framework. The recognition of the characteristics is become an urgent task of any environmental management, both for the purpose of protecting objects and preventing damage from damaging factors such as corrosion. Any natural-technogenic complex is an interconnected functioning paragenetic geosystem, namely, “natural framework – technogenic constructions – heat capacity – wind flow – humidity-biological effect – chemical reactions (corrosion) – cartographic image”. A city is a functioning anthropogenically transformed geosystem in which flows or corridors are involved, barriers are formed that repel and attract flows, and a thermal cushion is formed at different heights. The dynamics, mechanism, factors and patterns of development of dangerous natural and technologically natural processes, the forecast of their development to ensure environmental safety is carried out by “technologies at a glance” or technologies of the geographical industry, built on the principle of recognition or indication. The basis of the methodology is the provision on the city breeze, a phenomenon that causes the compensating movement of air flows in the surface layers of the atmosphere from the outskirts of the city to the center along the corridors for air movement, such as, river valleys, ravine-beam network, radial transport and engineering communications (railway, highways, power lines). The principle of thermogradient, as the driving force of air exchange in a metropolis, becomes the main indicator of determining the paths in the geo-ecological framework on the territory’s photo portrait: an aerial photograph, map, photograph, which forms the basis of “technologies at a glance”.

The corrosion rate of the inner surface of the tanks in contact with the natural vapor-gas phase of the tanks can reach 3 mm/year. On the surface of the metal simultaneously occur two corrosion reactions, namely, the first with the formation of iron oxides and hydroxides, the second - with the formation of sulfide compounds. The resulting corrosive deposits are pyrophoric ones and cause spontaneous combustion of the tanks. Replacement of the natural vapor-gas phase with a mixture of N2 + O2 (nitrogen protection) with an O2 content of not more than 7 vol.% leads to a decrease in the corrosion rate by more than 2 orders of magnitude and is up to 0.013…0.015 mm/year. Continuous operation of nitrogen system provides fire and explosion safety operation of the tanks as a result of the termination of the formation of pyrite. In tanks, steel corrodes by an electrochemical mechanism, since the thickness of the moisture film on their walls (105…106 monolayers) is commensurate with the thickness of the diffusion layer at the steel – electrolyte solution interface.

Influence of sodium hypophosphite admixture to electrolyte for deposition of Ni-W alloy on the coating composition, morphology, structure and microhardness is investigated. Antisymbatic dependence of tungsten and phosphorus content in Ni-W and Ni-W-P alloys on the sodium hypophosphite concentration in the electrolyte is observed, namely, at higher sodium hypophosphite concentration in the electrolyte solution the coatings are become poorer in tungsten whereas phosphorus content is increased. Phosphorus incorporation into the alloy leads to globular morphology of the surface of coatings. The minimal roughness was obtained at high hypophosphite concentrations in the electrolyte (7.5 and 10 g/L). As-deposited Ni-W and Ni-W-P alloys possess nanocrystalline structure manifested in broad X-ray diffraction peaks. Addition of 2.5…5 g/L of hypophosphite markedly weakens Ni reflections (200) and (220), the (111) peaks becomes broader. In addition, a Ni3P phase is appeared in the coatings. Thermal treatment in vacuum at 400 °С induces growth of nickel crystallites. Microhardness of as-deposited coatings is weakly dependent on sodium hypophosphite concentration in the electrolyte and is in the range 3.8…4.2 GPa. Thermal treatment of Ni-W-P alloys at 400 °С during 1 h increases microhardness up to 5.9…8.8 GPa

The effect is studied of addition of hydrophilic aluminum oxide and hydrophobic polytetrafluoroethylene on the morphology and chemical composition of zinc coatings from acidic electrolytes. Inclusion of hydrophobic polytetrafluoroethylene particles into zinc coatings from acidic zinc electrolytes in the absence of any surfactants is more facilitated than that of hydrophilic aluminum oxide particles of various dispersion and phase composition. The formation of composite electrochemical Zn-Al2O3 and Zn-polytetrafluoroethylene coatings is determined by the state of the surface of the growing zinc deposit (its comparative hydrophobicity) that facilitates the adhesion of hydrophobic polytetrafluoroethylene particles. Addition of aluminum oxide particles into the electrolyte causes no fundamental changes in the overall surface morphology of the zinc deposits. However, a relatively large number of inclusions of aggregates of nanosized aluminum oxide particles are observed over the entire coating surface. The concentration of aluminum oxide inclusions in Zn-Al2O3 composite coatings reaches 5...7 wt.%. The surface of Zn-polytetrafluoroethylene deposit is represented by globules. The total polytetrafluoroethylene content in the obtained composite coatings reaches 30 wt.%. An increased oxygen content is found in such coatings. It is probably explained by formation of a relatively larger amount of surface zinc oxide due to the significant development of the surface morphology of the deposits.