МЕХАНИЗМ АНОДНОГО РАСТВОРЕНИЯ КОРРОЗИОННОСТОЙКИХ И КОНСТРУКЦИОННЫХ УГЛЕРОДИСТЫХ СТАЛЕЙ В УСЛОВИЯХ ЭЛЕКТРОИМПУЛЬСНОГО ПОЛИРОВАНИЯ

In this article were suggested the schemes of anode processes, taking into account the nature of metals, anion structure, pH solution of electrolyte and anode potential by electropulse polishing of corrosion- resisting and structural carbon steels.It is shown and experimentally confirmed, that under conditions of electropulse polishing of anode dissolving of metals, which are contained into corrosion-resisting and structural carbon steels, carried out according to mechanism of complex formation through a set of series and series-parallel of intermediate stages. In the 1st stage on the surface of metals adsorption complexes with participation of chemisorption molecules of water are formed. In the next stages anions of electrolyte’s solution and molecules of water take part. In final stage of dissolving on the surface of anode soluble compounds are formed, which by transition into solution into simple ions are dissociated. It is determined that by electrical-impulse polishing in dissolving of components of corrosion-resisting carbon steels the important role play chemical processes, and anode dissolving of metals take place in the field of mixed electrochemical and diffusion kinetics . Diffusion limitations appear as a result of difficult ion mass transfer through surface salt, oxide and hydro-oxide and absorption-phase coatings.Предложены схемы анодных процессов, учитывающие природу металлов, анионный состав, pH раствора электролита и анодный потенциал при электроимпульсном полировании коррозионностойких и конструкционных углеродистых сталей.Показано и экспериментально подтверждено, что в условиях электроимпульсного полирования анодное растворение металлов, входящих в состав коррозионностойких и конструкционных углеродистых сталей, происходит по механизму комплексообразования через ряд последовательных или последовательно-параллельных промежуточных стадий. На первой стадии на поверхности металлов образуются адсорбционные комплексы с участием хемосорбированных молекул воды. В последующих стадиях принимают участие анионы раствора электролита и (или) молекулы воды. На заключительной стадии растворения на поверхности анода образуются растворимые в воде соединения, которые при переходе в раствор диссоциируют на простые ионы.Установлено, что при электроимпульсном полировании в растворении компонентов коррозионностойких и конструкционных углеродистых сталей значительную роль играют химические процессы, а анодное растворение металлов происходит в области смешанной электрохимической и диффузионной кинетики. Диффузионные ограничения возникают в результате затрудненного ионного массопереноса через поверхностные солевые, оксидные и гидроксидные адсорбционно-фазовые пленки

ИССЛЕДОВАНИЕ МОРФОЛОГИИ И ХИМИЧЕСКОГО СОСТАВА ЭЛЕКТРОИМПУЛЬСНО ПОЛИРОВАННОЙ ПОВЕРХНОСТИ УГЛЕРОДИСТЫХ И КОРРОЗИОННОСТОЙКИХ СТАЛЕЙ

The paper presents results of the investigations pertaining to morphology and chemical composition of thin surface layer of structural carbon and corrosion-resistant steel after the process of electro-impulse polishing. It has been established that removal of metal being polished occurs due to anode processes on the treated surface that leads to formation of surface films that can have different nature and thicknesses.  The paper reveals that under conditions of electro-impulse polishing anodic dissolution of steel takes place with direct participation of anions of electrolyte solution.Приведены результаты исследования морфологии и химического состава тонкого поверхностного слоя конструкционных углеродистых и коррозионностойких сталей после электроимпульсного полирования. Установлено, что съем металла при полировании происходит в результате протекания на обрабатываемой поверхности анодных процессов, приводящих к формированию поверхностных пленок, которые могут иметь различную природу и толщину. В условиях электроимпульсного полирования анодное растворение сталей происходит с непосредственным участием анионов раствора электролита

ГИДРО- И ОЛЕОФОБНЫЕ ПОКРЫТИЯ НА ОСНОВЕ ПОЛИВИНИЛОВОГО СПИРТА И НАНОЧАСТИЦ ДИОКСИДА КРЕМНИЯ

The wettability of composite coatings based on polyvinyl alcohol (PVA) and silicon dioxide formed on silicon by the spin coating method from PVA colloid solutions of SiO2 nanoparticles was studied. These coatings modified with hydrolysed heptadecafluorotetrahydrodecyltrimethoxysilane are found to exhibit superhydrophobic and oleophobic properties. It was found that PVA increases the wear stability of SiO2–PVA coatings.Изучена смачиваемость композиционных покрытий на основе поливинилового спирта (ПВС) и диоксида кремния, сформированных на кремнии методом центрифугирования из коллоидов наночастиц SiO2 в ПВС. Установлено, что данные покрытия, модифицированные гидролизованным гептадекафтортетрагидродецилтриметоксисиланом, проявляют супергидрофобные и олеофобные свойства. Показано, что ПВС увеличивает стабильность покрытий SiO2–ПВС к механическому воздействию

Защитные покрытия Ленгмюра–Блоджетт на основе высших жирных кислот

The morphology and tribotechnical properties of Langmuir–Blodgett (LB) monolayers and multilayers of some fatty acids, such as nervonic (NA), cerotic (CA) and montanic acids (OCA), was investigated. It was established that the wear resistance of silicon surface coated by LB monolayer of OCA is greater by 11 and 1.3 times in comparison with the LB monomolecular films of NA and CA, respectively. The multilayer of OCA, formed by 140 layers, increases the stability of steel surface by 35 times.Исследованы морфология и трибологические свойства моно- и мультислойных пленок Ленгмюра– Блоджетт (ЛБ) на основе нервоновой (НК), церотиновой (ЦК) и монтановой кислот (МК). Установлено, что ЛБ монослой МК на поверхности кремния в 11 и 1,3 раза стабильнее мономолекулярных ЛБ пленок НК и ЦК соответственно. Мультислойное покрытие МК, состоящее из 140 слоев, в 35 раз увеличивает износоустойчивость стальной поверхности

MECHANIZM OF ANODE DISSOLVING OF CORROSION-RESISTING AND STRUCTURAL CARBON STEELS UNDER ELECTROPULSE POLISHING

In this article were suggested the schemes of anode processes, taking into account the nature of metals, anion structure, pH solution of electrolyte and anode potential by electropulse polishing of corrosion- resisting and structural carbon steels.It is shown and experimentally confirmed, that under conditions of electropulse polishing of anode dissolving of metals, which are contained into corrosion-resisting and structural carbon steels, carried out according to mechanism of complex formation through a set of series and series-parallel of intermediate stages. In the 1st stage on the surface of metals adsorption complexes with participation of chemisorption molecules of water are formed. In the next stages anions of electrolyte’s solution and molecules of water take part. In final stage of dissolving on the surface of anode soluble compounds are formed, which by transition into solution into simple ions are dissociated. It is determined that by electrical-impulse polishing in dissolving of components of corrosion-resisting carbon steels the important role play chemical processes, and anode dissolving of metals take place in the field of mixed electrochemical and diffusion kinetics . Diffusion limitations appear as a result of difficult ion mass transfer through surface salt, oxide and hydro-oxide and absorption-phase coatings

INVESTIGATIONS OF MORPHOLOGY AND CHEMICAL COMPOSITION OF ELECTRO-IMPULSE POLISHED SURFACE OF CARBON AND CORROSION-RESISTANT STEEL

The paper presents results of the investigations pertaining to morphology and chemical composition of thin surface layer of structural carbon and corrosion-resistant steel after the process of electro-impulse polishing. It has been established that removal of metal being polished occurs due to anode processes on the treated surface that leads to formation of surface films that can have different nature and thicknesses.  The paper reveals that under conditions of electro-impulse polishing anodic dissolution of steel takes place with direct participation of anions of electrolyte solution

Studying the effects of severe Aerosol Pollution of the atmosphere on the dynamics of cumulonimbus cloud charge structure by Numerical Modeling

Studied are the effects of severe aerosol pollution of the atmosphere on the parameters of a cumulonimbus cloud (including its charge structure) and on precipitation. Considered is the example of the cloud that developed on May 11, 2009 near the town of Kharagpur (India) under conditions of severe aerosol pollution of the atmosphere due to dust transport from the desert. The in situ observations of the evolution of the cumulonimbus cloud of large vertical and horizontal extent and of its electric conditions were carried out on that day. It is found that the distribution of electric charges in the cloud was characterized by inverted polarity (i.e., the main positive charge is in the bottom of the cloud and the negative one is in the upper part of the cloud that contradicts usually observed cases). Using the small-dimension numerical model conducted are numerical experiments on the simulation of aerosol effects produced on the evolution of dynamic, microphysical, and electric structure of the cloud under study, namely, the cloud development under background conditions and in case of high aerosol concentration. It is assumed that aerosol particles possess ice-forming properties. It is obtained that the dynamic, microphysical, and electric structures of the cloud are significantly transformed under the influence of high aerosol concentrations; precipitation generation also significantly intensifies; polarity in the distribution of electric charge varies that agrees with the data of in situ observations