This work aims to develop environmentally friendly silane coating reinforced with a hybrid pigment to protect mild steel against corrosion in a saline environment. Fourier-transform infrared (FT-IR) ...spectroscopy, contact angle (CA) measurement, field emission scanning electron microscopy (FE-SEM), and energy dispersive spectroscopy (EDS) were used to study the coating structure and its protective mechanisms. The presence of hybrid pigment led to the conversion of more Si–OH groups into Si–O–Si groups during condensation process increasing the cross-linking density of silane; the enhanced cross-linking yields the coating with lower defects and stronger adhesion to substrate and so improved barrier and anti-corrosion properties. The EIS test showed that the charge transfer resistance (Rct) for the sample coated with hybrid sol-gel silane increases up to 40 % for all immersion times after the incorporation of the hybrid pigment into the coating matrix. The polarization test showed that the corrosion current density (icorr) value decreases from 1.40 to 0.56 μA/cm2 after 120 h of exposure to the saline solution when the hybrid pigment is added to the coating matrix. These results demonstrate the inhibitive action of the hybrid pigment enhancing the protective performance of the sol-gel silane coating.
Display omitted
•TiN/Ti, ZrN/Ti, ZrC/Ti samples were grown using the PLD technique at room temperature.•The corrosion resistance of TiN/Ti, ZrN/Ti, ZrC/Ti samples was measured by linear sweep ...voltametry and electrochemical impedance spectroscopy.•After 32 days of immersion in simulated body fluid, ZrN and ZrC layers have assured a good protection of Ti substrate against corrosion.
Thin films of TiN, ZrC, and ZrN were deposited at room temperature on highly polished Ti and Si samples using the pulsed laser deposition technique. Grazing incidence X-ray diffraction investigations showed that films were nanocrystalline, with grain sizes from 5 to 12nm and under compression. Simulations of X-ray reflectivity curves acquired from the samples indicated that the deposited layers were dense and smooth. Electrochemical tests performed in simulated body fluid showed that the deposited coatings significantly improved the corrosion resistance of Ti samples. The comparative study found out that the best sample was ZrN/Ti, its corrosion current after 32 days immersion in simulated body fluids being half of that measured for the bare Ti sample and in the same time almost unchanged from the initial value.
The paper aims to characterize film-forming materials from the microstructural, mechanical point of view for the assessment of the elasticity and flexibility of films, and from the chemical point of ...view, to determine their resistance to various chemicals, distilled water, 3% hydrochloric acid and 3% sodium hydroxide and their behaviour at corrosion in saline mist. It aims to develop a coating technology with film-forming materials for protection against corrosion.
This paper presents a method for the formation of composite-polymer-containing coatings on MA8 Mg alloy by plasma electrolytic oxidation (PEO), followed by the deposition of a fluoropolymer from an ...aqueous suspension of superdispersed polytetrafluoroethylene. The Scanning Electron Microscope(SEM), Energy Dispersive Spectroscopy(EDS), and X-ray Diffraction(XRD) analyses established morphological features as well as elemental and phase composition of composite coatings. The fact that the pores are filled with a fluoropolymer has been experimentally confirmed. An assessment of the corrosion properties of formed composite coatings revealed a decrease in the corrosion current density by more than four orders of magnitude in comparison with the base PEO layer. The highest resistance to the damaging effects of a corrosive environment, according to the results of long-term exposure tests, was demonstrated by coatings after three treatments with polytetrafluoroethylene. The obtained polymer-containing coatings have antifriction properties, reducing the wear of the coatings by more than 27-fold in comparison with the base PEO layer. It was revealed that composite coatings have superhydrophobic properties: the value of the contact angle reaches 154°, and the hysteresis of the contact angle is less than 10°.
This paper presents the methodology developed for underwater measurements using electrochemical impedance spectroscopy (EIS) technique, aimed at determining the resistance of an epoxy coating applied ...in seawater to the legs of an oil production platform. Performing such underwater tests in an offshore environment was technically challenging. The results of measurements obtained on the platform were confronted with comparative results obtained in the laboratory, where the properties of the coating applied in water collected from the Baltic Sea (thickness, hardness, adhesion, and electrical resistance) were examined. This made it possible to conclude about the correctness of the paint coating application by divers on the legs of the platform. The single-layer epoxy coating applied by brush to the platform legs had a resistance above 10 kΩ∙cm2 and thus met the assumed minimum resistance of the protective coating cooperating with cathodic protection as the anti-corrosion protection system of the platform legs. The synergy of these two technologies ensures full protection of offshore structures against corrosion. Measurements of the potential of the platform legs confirmed this. Before painting, the potential value at a depth of 0–15 m was 310 ÷ 320 mV versus the zinc reference electrode, while after painting the potential value decreased to 220 ÷ 240 mV, which means that the effect of full cathodic protection was achieved and the platform legs were protected from corrosion. The developed methodology for underwater EIS measurements on the high seas can be applied to any underwater metal structure to assess the quality of protective coatings.
This paper describes the development and operation of a small parts coating device in an electrophoretic manner. The cataphoretic coating process is nowadays highly desirable and generates a ...continuous coating against corrosion. The aim of the research is to find solutions or innovations to coat small parts in bulk. Small parts are inserted inside the device and painted in a cataphoretic manner. Painting is based on rotary device and random contact between small parts and cathode.
Zaštita čeličnih elemenata bitan je proces u proizvodnji čeličnih konstrukcija. U svrhu zaštite od pojave korozije i vanjskog utjecaja okoline, sve čelične konstrukcije potrebno je zaštititi na ...adekvatan način. Kvaliteta antikorozivne zaštite jedan je od osnovnih uvjeta za osiguranje dugotrajnosti konstrukcije te se dobro izvedenom zaštitom produljuje njezin uporabni vijek. Tehnologija nanošenja zaštite primjenom premaza zahtjevan je proces koji traži dobro poznavanje svih koraka u zaštiti konstrukcije, od odabira sustava premaza, pripreme površine do sušenja. U radu je opisana antikorozivna zaštita čeličnih konstrukcija primjenom zaštitnih premaza, kako odabrati odgovarajući sustav premaza, šta utječe na njegov odabir, kako pripremiti površinu koja se zaštićuje te koji sustavi premaza se koriste ovisno o kategoriji atmosferske korozivnosti.
Protection of steel elements is vital in steel construction manufacturing. In order to prevent corrosion and adverse influence from the surroundings, all steel structures need to be adequately protected. One of the key elements in securing the structure durability is the quality of protection coating, which - if applied properly, prolongates structure’s expected usage. Coating technology is a process, which requires knowledge of all necessary steps of structure protection process, from surface prepping to choosing the coating system and lastly, drying. This paper describes anticorrosive protection coating systems for steel structures by focusing on key elements for selecting the adequate coating system, as well as the covering surface preparation process, depending on atmospheric corrosivity class.
Selection of information was conducted to streamline the theoretical provisions and develop practical recommendations for determining the economic losses of gas transportation companies from ...accidents and failures on gas transmission pipelines, caused, in particular, by corrosion damage to a pipeline. The classification of losses due to the influence of corrosion on the linear part of gas transmission pipelines was considered. It was clarified that the structure of losses of gas transportation enterprises from corrosion during the operation of the linear part of gas transmission pipelines includes the cost of protecting the elements of structures from corrosion; losses from corrosion of metals. It was proved that the size of economic losses from accidents and failures on gas transmission pipelines to a large extent depends on the quality of the anti-corrosion protection system (measures, methods, ways and means of control), and also on observance of the rules of safe operation. The method of calculating economic losses, caused by accidents and failures on gas pipelines (taking into account the cost of compensation for losses from environmental pollution) is proposed, which takes into account the approach of neural networks and has advantages over the existing ones, as it characterizes: nonlinear quality criterion; the influence of energy characteristics of the interphase layers and aggressive agents on the corrosion processes in metal; nonlinear character of the monitoring system. On the basis of neural networks, a method of controlling the parameters, characterizing the technical state of steel structures in the oil and gas industry was developed, taking into account the nonlinear model for optimizing information and financial flows. The approach of neural networks can reduce errors in estimating the parameters of a nonlinear model that describes the system for monitoring underground pipelines.
About concrete and reinforced concrete corrosion Mirsayapov, Ilshat; Yakupov, Samat; Hassoun, Majd
IOP conference series. Materials Science and Engineering,
07/2020, Letnik:
890, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This review article provides general information about reinforced concrete corrosion and types of corrosion. The most dangerous consequence of corrosion processes in reinforced concrete is a decrease ...in the load-bearing capacity of the structure. Corrosion of reinforcing steel is one of the most common damages to reinforced concrete structures. The most dangerous type of rebar corrosion is chloride corrosion, since at a certain concentration of chlorides, the concrete immediately loses its protective properties in relation to the rebar, the corrosion develops locally and deep into the rod, leading to significant losses of its cross-section, often without visible damage to the concrete surface. Types of corrosion: physical corrosion, chemical corrosion, leaching corrosion, magnesian corrosion, carbon dioxide corrosion, sulphate corrosion, hydrogen sulfide corrosion, biological corrosion, electrochemical and electroosmotic corrosion, the destruction of cement stone. The article provides an overview of the mechanism of reinforcement corrosion, its initiation, progress and factors that expedite the process of reinforcement corrosion. Once the reinforcement corrosion is initiated, it shortens the service life of the structures by cracks initiation, propagation and subsequently spalling of the cover concrete due to expansion of corrosion steel. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation.
The article presents the working procedure for the camera of artificial climate type 2 X-5655-PAGE of the company «MONTAGNE». Accelerated corrosion tests in the camera make it possible to determine ...the ability of finished supplied products to maintain theirs properties during transportation, processing, long-term storage, as well as additional research tests in the conditions of artificial aging at the consumer, to develop methods of corrosion protection and improve the quality and competitiveness of products.
PDF
