Analysis of the use of paint coatings to protect the hull from corrosion

The most common and reliable method of protecting a ship’s hull from corrosion is paint coatings. Paint coatings can be used to paint products of any size. In case of complete or partial destruction, the paintwork can be easily restored by tinting or completely repainting the surface. Paints and varnishes are easily combined with other methods of corrosion protection. The use of paint coatings is more economical in comparison with other types of corrosion protection. Therefore, it is currently the most common method of protecting ship hulls. In order to determine the quality, the experimental studies of various paints and varnishes were carried out. Experimental prototypes were made. The effect of low temperatures and the effect of an impending water flow on paint and coatings were considered. The main conclusions were drawn from the results of the experiments. For long-term protection from the external environment, it is necessary that the coating film should maintain high adhesion to the surface maintain continuous, have minimal water absorption, devoid of pores and be solid. Samples with a two-layer and three-layer coating of Jotun paint have the best adhesion. Satisfactory results were also obtained on samples with a three-layer coating of XC-436 enamel and with a two-layer coating of stone red.

The inhibitory properties of ion-modified zeolite for priming paint coatings

The anticorrosion environmentally friendly pigments based on synthetic zeolite for paint coatings were obtained by liquid-phase ion exchange method. Zeolite was modified with zinc, calcium and manganese ions. The corrosion resistance of 09G2C steel in 0.1% NaCl solution and in suspensions of modified zeolite was investigated by potentiodynamic polarization method. It was shown that the use of zeolite modified with cations of divalent metals contributes to the reduction of corrosion currents. It was found that the zeolite modified with zinc cations exhibits the most anticorrosion effect relative to 09G2C steel, as indicated by the values of corrosion currents (which are ~2 times smaller than in the non-inhibited solution) and the results of electrochemical impedance spectroscopy. The surface morphology of 09G2S steel after exposure to the inhibited media was determined by scanning electron microscopy. Protection mechanism of the modified zeolite was suggested.

The Comparative Analysis of the Coatings Deposited on the Automotive Parts by the Cataphoresis Method

The paper presents preliminary research focused on the determination of the influence of surface preparation on the quality of the paint coating obtained by the cataphoresis method (KTL). The tests were carried out on steel parts used in the construction of trailers and truck bodies. The first research group consisted of cold-rolled and chemically cleaned parts, the second group were mechanically cleaned with abrasive blasting. In order to determine the influence of surface treatment on the corrosion resistance of the tested coatings, besides a corrosion test, roughness measurements were also carried out. Tests were performed on the crude surface and after coating deposition. Moreover, tests were supplemented by measuring the thickness of the coating using the magnetic induction method and the hardness with the use micro and nano hardness testers. Measurements of the tribological parameters under dry friction conditions were performed using a T11 tester. The corrosion resistance of the applied coatings was determined in a salt spray test. The obtained results were compared to those that were determined for different zinc coatings. It has been shown that the method of base steel surface preparation affects every measured parameter and property of tested paint coatings. The quality of the coating deposited on the steel base after chemical cleaning is much better than the one applied to the sandblasted surface. The measured corrosion resistance of the tested paint coatings is only greater than the corrosion resistance of the lamellar zinc coating. The other zinc coatings (galvanic, hot-dip, sherardized) show corrosion resistance by an order of magnitude higher.

A Systematic Review of HPM Energy Absorbers for Building Applications

A modern weapon, high power microwave (HPM) pulses, can have a profound effect on the quality of functioning of society as the use of this weapon can result in damage to or destruction of electronic equipment and computer and telecommunications systems, both military and civilian. Protection against the energy of HPM pulses can be achieved in two basic ways: by using radiation-absorbent materials (RAM) or artificial electromagnetic (EM) structures. If the object to be protected is a building, protection based on RAM is used. Hence, this literature review focuses on the possibilities of using HPM energy absorbers in building products and structures. Attention is concentrated on four basic types of elements: claddings, concrete and mortar, small-sized elements (bricks, hollow masonry units), and paint coatings. In each of the categories, examples of HPM radiation absorbers having a high potential to be combined with basic construction materials are given on the basis of the literature on the subject.

LASER ABLATION OF PAINT COATINGS IN INDUSTRY

A comparison is made between the laser and sandblasting methods for removing paint from industrial facilities. The advantages of laser ablation are discussed. The possibilities of laser paint removal systems - stationary and moving - are shown. The main factors influencing the laser ablation process and the indicators that determine the quality of the obtained surface are systematized. Researchers' publications on this technological process are analyzed.

Wear of hulls and hull structures of Russian NAVY auxiliary vessels

В статье рассматривается вопрос износа связей корпусных конструкций судов атомно-технологического обслуживания военно-морского флота, транспортирующих жидкие радиоактивные отходы. Как известно, определение технического состояния корпуса судна является основным параметром установления их пригодности к дальнейшей эксплуатации. Авторами были проанализированы исследования влияние гамма-облучения на лакокрасочные покрытия и установлено, что такое воздействие приводит к изменению основных характеристик лакокрасочных покрытий, вследствие чего наступает их отслаивание от поверхности корпусных конструкций. В связи с тем, что ускоренное разрушение лакокрасочных покрытий влечет за собой более раннее коррозионное разрушение корпусных конструкций, авторами настоящей работы проводилось изучение скоростей изнашивания корпусных конструкций, подверженных воздействию ионизирующего облучению, так и не подверженных агрессивному воздействию груза для судов атомно-технологического обслуживания и сопоставление их с известными данными скоростей изнашивания для конструкций гражданских судов. Результаты выполненного авторами исследования могут быть использованы в научно-обоснованном прогнозировании сроков службы и определении технического состояния корпусов судов атомно-технологического обслуживания. This article considers issues, related to wear of hulls and hull structures of Russian NAVY auxiliary vessels, used for transportation of liquid radioactive wastes. As is known, assessment of ship hull state is the main criteria of ship readiness for further exploitation. The authors analyzed surveys related to influence of gamma-irradiation on paint coatings and revealed alteration of their main characteristics followed by stripping from the ship hull. Since accelerated destruction of paint coatings leads to early corrosion damage of hull structures, the authors analyzed wear rate of nuclear-servicing vessels hulls exposed and non-exposed to nuclear radiation and compared it with known wear rates of civil vessels hulls. The obtained results may be used for scientifically-based forecasting of ship service life and assessment of technical state of nuclear-servicing vessels.

Assessment of stability of varnish-and-paint coatings on polymer composite material components to ultraviolet radiation effect

The results of accelerated climatic test of protective and decorative properties of varnish-and-paint coatings deposited on polymer composite material samples by different technologies to the ultraviolet radiation effect (GOST 9.401—2018) are presented. Assessment of the protective and decorative properties of varnish-and-paint coatings was carried out according to the procedures in GOST 9.407—2015, measurement of coating adhesion was performed according to the procedures in GOST 31149—2014 (ISO 2409:2013).

Protection of Steel Structures with Paint Coatings in the Context of Environmental Pollution

The article presents important problems occurring in the operation of large-size steel structures protected by paint coatings. In our atmospheric conditions, corrosion of steel structures cannot be avoided, even with the use of protective coatings. The problem of environmental pollution with corrosion products and exfoliated paint then appears. When designing corrosion protection, durability of protection is assumed based on environmental corrosivity categories, but in practice degradation of paint coatings can occur much faster. The problem of premature peeling of paint results, among other things, from its faulty application and use. Steel structure repairs are usually carried out comprehensively, and new protection requires the removal of damaged coatings, mainly by sanding. As a result of the mechanical action of the abrasive material, old paints and corrosion products are removed, which results in a very large amount of waste that settles on the adjacent area. Due to the age of paint removed, this waste often contains compounds such as lead, chromium or zinc, which pose a real threat to the natural environment around the renovated buildings. In the article, based on the observations carried out directly on the exemplary structures in renovation, the actual scope of the waste emission was determined. This is a contribution to further spectrometric studies to determine the exact area of contamination and to identify heavy metals in the waste arising from the renovation of steel structures with paint coatings.

On the Issue of Laser Selective Removal of Paint Coating from a Sample of Metal Plating of Aircraft Gliders

In this paper the temperature fields in the zone of processing of paint coatings by laser radiation of a sample of the metal skin of aircraft gliders with selective (layer-by-layer) removal are researched. The performed theoretical studies and numerical calculations made it possible to carry out practical tests and develop conditions under which the physical effect of laser energy causes minimal damage to the alloys and composites of the sample, as well as to assess the effect of the laser on the properties of materials used in the aerospace industry. The obtained results are reflected in the technology of laser selective removal of paint coatings from metal and composite skin of aircraft gliders.