Corrosion Of Metallic Parts Research Articles

Corrosion of metal parts in the power plant

AbstractThe AISI 304 (X5CrNi19‐10) stainless steel is widely used for the production of various metal parts in power plants. A procedure for testing the influence of the dust from a power plant on resistance to general and pitting corrosion of the AISI 304 stainless steel is developed and performed. The quantitative (XRD method) and qualitative (Fourier–transform infrared spectroscopy [FTIR] method) composition of the dust present in the power plant is determined. Applying the Mott–Schottky method, the properties of the passive layer are analyzed, while a degree of chromium depletion of the grain boundary is determined by the electrochemical potentiokinetic reactivation method with double loop method. Values of polarization resistance (linear polarization resistance and electrochemical impedance spectroscopy methods) and the corrosion current density (polarization measurements) indicate that the stainless steel has a higher resistance to general corrosion in the dust solutions than in the etalon solution. Also, based on the measured value of the pitting potential (Epit) and the difference between the values of the pitting potential and the corrosion potential (Epit – Ecorr), it can be seen that stainless steel has a higher resistance to localized types of corrosion, such as pitting corrosion, in dust solutions than in the etalon solution.

Utilization of green inhibitors as a sustainable corrosion control method for steel in petrochemical industries: A review

Infrastructure upgrades in the energy sector are encouraged to satisfy the expanding world’s energy needs, including innovation, consumption, production, and transportation. Thus, steel has been an extensively used construction material, particularly for pipelines and oil wells. However, in their application, every step of the production cycle results in the corrosion of metal parts. One of the simplest and most active ways to inhibit steel from corroding, especially in acidic situations, is to use a corrosion inhibitor. Synthetic organic compounds have been used successfully as corrosion inhibitors in the gas and oil industry. However, their use is today restricted and controlled due to their toxicity, environmental harm, and growing concern about the preservation of ecosystems. This has necessitated the present trend of searching for and developing green inhibitors that are environmentally benign, non-toxic, biodegradable, and low in cost. Corrosion inhibitor develops a shielding layer on the metal surface. Corrosion is avoided by a thin coating that has been adsorbed on the metal surface, which keeps the metal isolated from its surroundings. Several researchers have reported on the success of green inhibitors for steel corrosion protection, particularly in acidic environments. However, the use of green inhibitors still leaves several questions about inhibitor formulation, content, and adsorption mechanisms to be answered. Therefore, based on provided experimental results and an explanation of their inhibitory action, the use of green inhibitors (especially organic inhibitors) for the prevention of pipeline steel corrosion in various grades is studied in this review. Both the identified drawback and the projected future trend have also been highlighted.

Corrosion of metal parts on satellites by iodine exposure in space

Iodine becomes increasingly popular as alternative propellant for electric propulsion (EP) systems offering several advantages over established xenon. However, iodine is also a reactive and corrosive element. Thus, a careful material selection for the EP system itself, but also for components employed on the satellite is required in the light of typical space mission durations of several years. Here, we carefully define an approach for mimicking long-term interaction of material specimens with iodine in a space environment. The space conditions cover typical iodine atmospheres (10− 1 to 10− 4 Pa), which occur in the vicinity of a satellite employing an iodine-fed EP system, and exposure times, which correspond to 10 years of mission duration. The approach is used to expose a wide range of metal specimens commonly used on spacecraft to iodine. Chemical modifications of the surfaces of the treated samples are analyzed by x-ray photoelectron spectroscopy (XPS). The elemental metals Fe, Ti, Al, and Nb chemically react with iodine, whereas the elemental metals Ni, Cr, Ta, W, and Mo are basically inert. The stainless-steel and aluminum metal alloys show the same behavior as the corresponding dominant elemental specimens, i.e., Fe and Al, respectively. Somewhat surprisingly, Cr as constituent in stainless steel reacts with iodine, in contrast to elemental Cr. Nevertheless, our studies reveal that long-term exposure to low-pressure iodine atmospheres is not critical for the macroscopic structural integrity of all tested specimens even over space mission durations of several years. The reaction with iodine is macroscopically a surface effect, which mainly affects the optical appearance.

Simulation of Ozone Concentrations Inside Co-60 Industrial Irradiator Using UV Optical Cell

ozone concentration in the Co-60 industrial irradiator is controlled by the local exhaust ventilation (LEV). if the event of a ventilation malfunction, the ozone concentration becomes increasingly sensible within the radiation chamber. Ozone (O3) is a toxic gas which can cause tract, asthma, and permanent lung damage. its detrimental effects on humans and corrosion of metal parts within the radiation chamber indicates its importance as a safety factor consideration. The motivation for this work designs a standby system to reduce the ozone concentration within the Co-60 industrial radiator. MATLAB was used to simulate the effect of ultraviolet (254 nm) absorption cells on ozone concentration and calculate the decay time. The simulation illustrated that UV absorption is linearly increasing with increasing ozone concentration. Employing a UV Cell proved to reduce ozone concentrations and their decay time with an efficiency of 99%. This may prevent or significantly reduce the discharge of ozone into the air from the workplace. so it’s recommended that’s using UV (254 nm) in the ozone concentration within the Co-60 industrial as it is cheap and efficient controlling substance.

Neural Network Based Estimation of Service Life of Different Metal Culverts in Arkansas

The Arkansas Department of Transportation (ARDOT) uses different types of metal culverts and cross-drains. Service lives of these culverts are largely influenced by the corrosion of the metals used in these culverts. Corrosion of metallic parts in any soil-water environment is governed by geochemical and electrochemical properties of the soils and waters. Many transportation agencies including ARDOT primarily focus on investigating the physical and mechanical properties of soils rather than their chemical aspects. The main objective of this study is to analyze the geotechnical and geochemical properties of soils in Arkansas to estimate the service lives of different metal pipes in different conditions. Soil resistivity values were predicted after analyzing the United States Department of Agriculture (USDA) soil survey data using neural network (NN) models. The developed NN models were trained and verified by using laboratory test results of soil samples collected from ARDOT, and survey data were obtained from the USDA. The service lives of metal culverts were then estimated based on the predicted soil properties and water quality parameters extracted from the data acquired from the Arkansas Department of Environmental Quality (ADEQ). Finally, Geographic Information System-based corrosion risk maps of three different types of metal pipes were developed based on their estimated service lives. The developed maps will help ARDOT engineers to assess the corrosion potential of the metal pipes before starting the new construction and repair projects and will allow using proper culvert materials to maximize their life spans.

The Device for Houseplants Caring

The article is devoted to the development of an automated device for plant care at home. The main factors influencing plant development are considered. A comparative analysis of existing devices was made. The growth of plants is influenced by many factors: the level of light, soil moisture, room temperature, carbon dioxide level. When plants are growing indoors, the most important thing is timely watering and access to light. The required amount of light for most plants is 12-18 hours per day. Our country is in the temperate climate zone, so we have 15 hours of light in summer, 13 hours in autumn and spring, and 9 hours in winter. The amount of light in summer is normal, in autumn and spring - within normal limits, but in winter there is a certain lack of light. The lack of natural insolation in winter leads to light starvation of houseplants and reduced intensity of photosynthesis. Therefore, the decrease of the amount of natural light is compensated by artificial light sources. Analysis of the devices on the market has shown that devices that can solve such problems exist, but there is no device with all functions simultaneously. Lighting devices illuminate on a timer, regardless of natural light. Irrigation devices are intended for industrial, not for domestic use. Existing technological solutions for home cultivation have only a warning function: sound or light, which can bring some inconvenience. Looking on these problems, a device is created to maintain the required soil moisture and the required amount of light. The control unit is based on a microcontroller that analyses the data obtained from the sensors and sends the appropriate signals to the climate control devices. The device is equipped with a soil moisture sensor, a light sensor, a real - time sensor, an LED lamp, a water pump, an LED lamp driver, and a control key of water pump. To control soil moisture, a capacitive humidity sensor is used, the advantages of it is the absence of corrosion of metal parts of the sensors that touch the ground. A light meter based on the BH1750 chip is used as a light sensor. This sensor has a wide measuring range, measuring accuracy - 1 lux, small dimensions and the ability to connect to a microcontroller via I2C interface. The DS3231 chip is used as a real-time clock that required to maintain a circadian rhythm close to the natural one for a given plant. An LED strip with red and blue LEDs is used for lighting. The ratio of blue / red LEDs depends on the stage of growth and the type of plant, but it is usually from 1/3 to 1/5. The key that controls the LED strip and the water pump are the MOS transistors. They are silent and allow you to adjust the brightness of the LED strip.

ИССЛЕДОВАНИЕ ПРОЦЕССА ОЧИСТКИ БИОГАЗА ОТ СЕРНИСТЫХ СОЕДИНЕНИЙ С ИСПОЛЬЗОВАНИЕМ АППАРАТА ВИХРЕВОГО СЛОЯ

The use of biogas for the operation of recycling equipment in its pure form is unacceptable due to the high content of sulfur compounds (hydrogen sulfide), which leads to corrosion of metal parts of the equipment contacting with biogas and reduces its service life. The article considers various ways of cleaning biogas from sulfur compounds. (Research purpose) The research purpose is in studying the process of biogas purification from sulfur compounds by sulfonating in the vortex layer apparatus. (Materials and methods) The laboratory of bioenergetic and supercritical technologies of VIM created an experimental device of a vortex magnetic layer. Authors used information research methods, including standard analytical methods of modern system approach, processing and analysis. (Results and discussion) The amount of hydrogen sulfide in the biogas was sharply reduced and when the gas stayed in the working chamber for 5 minutes, it did not exceed 20 parts per million. The concentration of carbon dioxide decreased slightly. The water in the working chamber of the installation serves as a solvent for incoming gases, and the ferromagnetic particles, when worn out, form a fine (20-50 micrometers) iron powder, which reacts chemically with dissolved hydrogen sulfide to form iron sulfide. Fast-rotating ferromagnetic particles create a large contact surface of liquid and gas, which improves the absorption of hydrogen sulfide and carbon dioxide. (Conclusions) It is possible to purify biogas from sulfur compounds by sulfonating in the vortex layer apparatus. The article proposes a method for improving the cleaning process by increasing the pressure and reducing the temperature of water in the working chamber of the vortex layer apparatus.

Corrosion Susceptibility of Austenitic Stainless Steels in Direct Carbon Fuel Cell

The direct carbon fuel cell (DCFC) is a future energy technology which is an efficient process for electrical energy generation from carbon-based sources. This technology has an extremely high theoretical efficiency due to favourable thermodynamics of the electro-oxidation reactions in the process. However, several technical challenges exist which must be addressed before the technology can be commercialized. One of the challenges is the corrosion of metal parts in the cell which limits the service life of the unit. In recent year, research on the development of new alloys and surface engineering have been done to address the corrosion issues in molten carbonate fuel cells. However, the literature on the corrosion behaviour of metals in a slurry system (coal + carbonate) is limited. Austenitic stainless steels are known for their high temperature corrosion resistance and excellent mechanical properties. In this work, the corrosion susceptibility of two types of austenitic stainless steels, i.e. 316L (16 wt.% Cr and 10wt. % Ni) and 235 MA (21 wt.% Cr and 11 wt.% Ni) were compared for fuel cell tank body application. The corrosion behaviour of the two stainless steels were evaluated in a slurry, which contained 20 wt% coal and 80 wt% ternary-eutectic (Li2CO3: 43.5 mol%, Na2CO3: 31.5 mol%, and K2CO3: 25.0 mol%), with nitrogen as a sweep gas at 800⁰C was examined for a 30-day period. The results indicate that the weight gain (due to corrosion product build-up) for both the stainless steels was marginal after 7 day exposure, i.e., 0.4% and 0.5% for 316L and 253 MA, respectively. However, after 30 days exposure, the weight gain increased to 0.98% for 316L, whereas for 253MA the weight gain remained at ~ 0.5%. Thus, the study suggest that 235 MA stainless steel is superior to 316L stainless steel in the coal-carbonate slurry environment. The corrosion mechanisms of the stainless steels will be discussed in the presentation.

Increase in rust resistance of farm vehicles at storage due to use of new protective lubricant

Innovative development of agro-industrial complex assumes not only perfecting of the existing technical means and technologies of mechanization of agriculture, but also creation new devices, which meet modern requirements. The key part in manufacturing of the village products is assigned to its hardware. Particular importance has the smooth operation of farm vehicles. Because of seasonal nature of work in the agrarian sector the important place is taken by storage of vehicles, which usually happens at the open areas. The objective of the study was to expand the ability to increase the corrosion resistance of metal parts of agricultural machines when stored in open areas through the use of new additives. The use of used engine oils of autotractor engines; the saponified tall pitch - the waste formed by production of paper and cardboard. This problem is achieved by the fact that the proposed lubricant containing used engine oil, emulsifier, additive and water contains saponified tall pitch as an emulsifier, nitric acid as an additive in the following ratio, wt.%: Used engine oil - 20-40; saponified tall pitch - 2,0-4,0; nitric acid - 0,15-0,45; water is the rest Tests have confirmed that the use of a lubricant of this composition eliminates the corrosion of metal parts of agricultural machinery when stored in open areas due to high adhesion. This lubricant doesn’t demand heating. The use of used motor oils eliminates the use of expensive oil-based petroleum compounds for lubricants.

Long-Term Safety of Intraperitoneal Radio Transmitter Implants in Brown Bears (Ursus arctos).

Intraperitoneal radio transmitters have been widely used in free-ranging wild mammals, but there are no long-term studies on their biocompatibility or technical stability within the abdominal cavity of animals. Possible negative health effects may bias results from ecological studies on instrumented animals and raise concerns over animal welfare issues. The aim of this study was to evaluate the long-term technical stability and pathological effects of Telonics intraperitoneal very high frequency (VHF) radio transmitters in brown bears (Ursus arctos). We instrumented 305 individual bears with intraperitoneal VHF radio transmitters during a 19-year period. We surgically removed devices that had been in bears for 1–9 years and collected transmitters from animals that died 1–13 years after implantation. We took biopsies for histopathology from tissue encapsulating implants in live bears. Retrieved transmitters underwent a technical inspection. Of the 125 transmitters removed from live bears, 66 were free-floating in the peritoneal cavity [a mean (SD) of 3.8 (1.5) years after implantation], whereas 59 were encapsulated in the greater omentum [4.0 (1.8) years after implantation]. Histopathology of biopsies of the 1–15 mm thick capsules in 33 individuals showed that it consisted of organized layers of connective tissue. In one third of the bears, the inner part of the capsule was characterized by a foreign body reaction. We inspected 68 implants that had been in bears for 3.9 (2.4) years. The batteries had short-circuited four (5.9%) of these devices. This resulted in the death of two animals 10 and 13 years after implantation. In two other bears that underwent surgery, we found the short-circuited devices to be fully encapsulated within the peritoneal cavity 5 and 6 years after implantation. A significant proportion of the other 64 inspected implants showed serious technical problems, such as corrosion of metal parts or the batteries (50%), detachment of the end cap (11.8%), and erosion (7.4%) or melting (5.9%) of the wax coating. We conclude that the wax coating of the transmitters was not biocompatible, that the technical quality of the devices was poor, and that these implants should not be used in brown bears.

Numerical prediction of gas migration properties in Callovo‐Oxfordian (COx) argillite using morpho‐mathematical operations

SummaryThe feasibility study of long‐term radioactive waste storage in low‐permeable rocks has been performed by considering various damage and failure scenarios. This study aims at the numerical investigation of gas (mainly produced by corrosion of metallic parts) migration properties through the low‐permeable formation of Callovo‐Oxfordian argillite. Traditional methods, based on macroscopic approaches or homogeneous transport properties, are inappropriate to analyze this issue at the mesoscopic/microscopic scale. In this study, realistic porous space morphologies are constructed through union of excursions of random fields considering different experimental pore size distributions. Afterwards, purely geometric analysis of pore space is conducted by morpho‐mathematical operations for the purpose of the extraction of preferential gas transport pathways and the prediction of the gas entry pressure, the gas breakthrough pressure, and the following imbibition process.

Analysis of the long-term hydraulic-gas transient in the central zone of a deep clay repository

Abstract In the Andra repository concept, a large amount of hydrogen gas will be generated through radiolysis of water and corrosion of metal parts from the infrastructure and the packages containing radioactive waste. The fate of the gas could have a significant impact on the rate of resaturation of the porous media, and needs to be accounted for in order to make accurate predictions of the long-term evolution of the repository. The central zone of the repository consists of a 4.5-km-long network of galleries which connect the storage zones with the surface through three shafts. These shafts, which will be backfilled and sealed after closure, will have a key role in gas and water exchange between the repository and the overlying aquifer. The aim of this work was to describe the evolution in time of both the water and gas flows in the central zone up to the end of the hydraulic-gas transient. The issue was addressed by means of numerical simulations. The simulations produced local predictions of flow rates and pressures, water saturation and amounts of dissolved gas. The results were analysed to determine how water and gas flows combine in the central zone, when the saturation of the seal will be complete, when the free gas will reach the overlying aquifer, and when the saturation of the central zone will be complete.

In vivo biostability of polyether polyurethanes with fluoropolymer and polyethylene oxide surface modifying endgroups; resistance to metal ion oxidation

Polyether polyurethanes are subject to oxidation catalyzed by, and through direct (redox) reaction with transition metal ions (metal ion oxidation, MIO). The source of the ions is corrosion of metallic parts within an implanted device. A Shore 80A polyether polyurethane was modified with fluoropolymer (E80AF) or polyethylene oxide (E80AP) surface modifying end groups (SME). The SME migrates to the surface to form a covalently bonded monolayer, while maintaining the bulk properties of the polyurethane. In vitro tests in H(2)O(2) solution indicated that both SME's accelerated MIO. Tubing samples containing cobalt mandrels were implanted in the subcutis of rabbits for up to 2 years. In vivo, E80AF significantly slowed the rate of visible degradation, but did not prevent MIO. E80AP had virtually identical visual performance to the unmodified control in vivo. Infrared spectroscopy and molecular weight correlated well with visual appearance. When cracks were seen, polyether soft segment oxidation was occurring. Both E80AP and the control developed severe loss of molecular weight in vivo. The changes were much less severe for E80AF. Thus, contrary to in vitro test results, the PEO SME had no effect at all on MIO resistance, while the fluoropolymer SME produced a significant improvement in biostability.

In vivobiostability of shore 55D polyether polyurethanes with and without fluoropolymer surface modifying endgroups

Polyether polyurethanes are subject to autooxidation and environmental stress cracking (ESC) because of interactions with lysosomal oxygen-free radicals. Oxidation can also be catalyzed by and caused by direct (redox) reaction with transition metal ions (metal ion oxidation, MIO). The source of the ions is corrosion of metallic parts within an implanted device. A previous study on a Shore 80A polyether polyurethane modified with fluoropolymer surface modifying end groups demonstrated improved biostability over unmodified controls. We predicted that this could be extrapolated to the inherently more biostable Shore 55D version (E55DF). While it is difficult to demonstrate significant biodegradation in the harder polymers within a reasonable time frame, we did see excellent biologic autooxidation and ESC resistance for both E55DF and its unmodified Shore 55D (P55D) control. E55DF was slightly, but significantly more resistant to MIO than P55D. This was particularly evident in molecular weight distributions with P55D exhibiting a large decrease in number average molecular weight compared to no change for E55DF. Both were markedly superior to the softer Shore 80A control. It does appear that one can extrapolate accelerated in vivo biostability results with the softer polymers to their harder analogues.

Corrosion of anode current collectors in molten carbonate fuel cells

Corrosion of metallic parts is one of the life-time limiting factors in the molten carbonate fuel cell. In the reducing environment at the anode side of the cell, the corrosion agent is water. As anode current collector, a widely used material is nickel clad on stainless steel since nickel is stable in anode environment, but a cheaper material is desired to reduce the cost of the fuel cell stack. When using the material as current collector one important factor is a low resistance of the oxide layer formed between the electrode and the current collector in order not to decrease the cell efficiency. In this study, some candidates for anode current collectors have been tested in single cell molten carbonate fuel cells and the resistance of the oxide layer has been measured. Afterwards, the current collector was analysed in scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). The results show that the resistances of the formed oxide layers give a small potential drop compared to that of the cathode current collector.

In vivo biostability of polysiloxane polyether polyurethanes: Resistance to metal ion oxidation

Polyether polyurethanes are subject to oxidation catalyzed by and through direct (redox) reaction with transition metal ions (cobalt), released by corrosion of metallic parts in an implanted device. Replacing part of the polyether with polysiloxane appears to reduce susceptibility to metal ion oxidation (MIO). In vitro studies indicated that polyurethanes containing 20-35% polysiloxane (PS-20 and PS-35) are about optimum. We implanted tubing samples containing cobalt mandrels in the subcutis of rabbits for periods up to 2 years. After 2 years, only traces of microscopic cracks were seen on half the PS-35 samples, PS-20 significantly delayed MIO, while the polysiloxane-free control was very severely degraded. Infrared spectroscopy established that polyether soft segment oxidation was occurring in PS-20. We could not directly evaluate oxidation in PS-35 because siloxane bands mask the aliphatic ether. Indirect FTIR evidence suggests that there is very slight polyether oxidation that develops early, and then seems to stabilize. The molecular weight of degraded PS-20 decreased. That of microcracked PS-35 decreased negligibly while that of undamaged PS-35 increased slightly after 2-year in vivo. The polysiloxane-free control was profoundly degraded. PS-20 has much improved MIO resistance, while that for PS-35 is highly MIO resistant compared with its polysiloxane-free control.

Technical noteBiological corrosion of metallic parts in underground irrigation system: study of alternative materials

<i>Technical note</i>Biological corrosion of metallic parts in underground irrigation system: study of alternative materials

Corrosion Commentary

‘Antifreeze’ gets the cold shoulder. Antifreeze must surely be one of the best‐known terms in motoring circles. Why, then, is it being dropped by BSI in favour of the more bureaucratic‐sounding ‘engine coolant concentrate’? The reason is simple: the word ‘antifreeze’ is no longer an accurate description of the immensely useful and versatile products that are being manufactured to the new British Standard BS 6580 Specification for corrosion, inhibiting engine coolant concentrate (‘antifreeze’). They will certainly prevent cracked blocks, damaged hoses, radiators and water pumps as in the past. But to satisfy BS 6580 they must also inhibit corrosion of metal parts in the engine and cooling system, and reduce the risk of the coolant boiling as well as freezing.

The Control of Slime Build-up in X-ray Processing Units

Although most X-ray workers must be familiar with accumulations of slime in the water jackets and washing tanks of X-ray processing units, this problem is seldom given the serious consideration it deserves. Perhaps it is because the possible harmful effects of such a build-up are not sufficiently appreciated, and it is the aim of this article to discuss these and to draw attention to the various chemical agents that may be used for the control of slime growth in water systems. The importance of film quality cannot be over-emphasised and it can well be seen that a wet radiograph making contact with slime deposits from the wall of the tank could result in smears and streaks over the surface of the film. These may only be seen when the film is dried. The slime deposit also acts as an insulator retarding very considerably the transfer of heat from the water jacket to the solutions. Another less obvious effect is the accelerated corrosion of metal parts caused by local cell action. This effect may be demonstra...

STEAM TURBINE LUBRICATION

This invention relates to steam turbine lubrication; and it is particularly concerned with a method of preventing the corrosion of metal parts of steam turbines lubricated by a highly refined petroleum oil containing a phenolic antioxidant, wherein a minute amount of a higher fatty acid is...