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The effect of temperature on the corrosion rate of iron-carbon alloys
Abstract
Temperature has a significant effect on the progress of corrosion processes on the surface of metals and alloys. The corrosion behavior of iron-carbon alloys in a 0.1 N solution of sulfuric acid at various temperatures was studied. The parameters of the corrosion rate for the investigated system «iron-carbon alloy – 0.1 N solution of sulfuric acid» at different temperatures were determined. It was found that when the temperature increases by 10 °C, the dissolution of the iron-carbon alloy accelerates by an average of 2.3 times. The values of the activation energy of the corrosion process for the investigated iron-carbon alloys are determined, which indicate that the corrosion processes in a solution of sulfuric acid proceed by an electrochemical mechanism. It is established that when the carbon content in the alloy increases, the energy of corrosion activation increases, which means that the beginning of corrosion processes on the surface of iron-carbon alloys occurs later. After the beginning of corrosion, the dissolution of metal under the influence of an aggressive environment occurs faster on the surface of alloys with a high carbon content. Large mass losses of iron-carbon alloys with a high carbon content are caused by the presence on their surface of a greater number of «iron – carbon» galvanic couples. The more such pairs, the more likely and stronger corrosion.
... For all the systems, i was a function of the C INH of PILs, where the Tafel curves displayed a lower i at 175 ppm. and the different PILs [34]. As for ΔEcorr, displacements from −14 mV to −31 mV are displayed within the ±85 mV interval and indicate that the PILs exhibited the behavior of mixed-type CIs [35]; the ΔEcorr trend toward more negative values suggests higher activity in the cationic part [Im + ] of the PILs. ...
... This behavior pattern is attributed to the adsorption of the CIs through the blocking of the metallic surface active sites [33]. From Table 3, it can be concluded that the temperature increase accelerated the dissolution of the metallic surface in the presence of H 2 SO 4 and the different PILs [34]. As for ∆E corr , displacements from −14 mV to −31 mV are displayed within the ±85 mV interval and indicate that the PILs exhibited the behavior of mixed-type CIs [35]; the ∆E corr trend toward more negative values suggests higher activity in the cationic part [Im + ] of the PILs. ...
... The IEs exhibited the following trend: [Br]. The diminution of the IEs with the T increase implies higher kinetic energy in the redox reactions and, as a consequence, the increase in the steel anodic dissolution, which provoked the desorption of the PIL molecules and less covered fraction [34,38]. The IEs of Poly[VIMC4] [Br] and Poly[VIMC2][Br] diminished in~33% with the temperature increase, which was related to the low contribution of the non-ionic blocks (acrylamide and vinylpyrrolidone) to the adsorption process. ...
In the present research work, the temperature effect on the corrosion inhibition process of API 5L X60 steel in 1 M H2SO4 by employing three vinylimidazolium poly(ionic liquid)s (PILs) was studied by means of electrochemical techniques, surface analysis and computational simulation. The results revealed that the maximal inhibition efficiency (75%) was achieved by Poly[VIMC4][Im] at 308 K and 175 ppm. The PILs showed Ecorr displacements with respect to the blank from −14 mV to −31 mV, which revealed the behavior of mixed-type corrosion inhibitors (CIs). The steel micrographs, in the presence and absence of PILs, showed less surface damage in the presence of PILs, thus confirming their inhibiting effect. The computational studies of the molecular orbitals and molecular electrostatic potential of the monomers suggested that the formation of a protecting film could be mainly due to the nitrogen and oxygen heteroatoms present in each structure.
... As the maintenance cost of corroded equipment is extremely high, it is required to take at most care to protect the equipment from corrosion [13]. Temperature is one of the key parameter contributing a significant impact on attainment of corrosion process on metal and alloy surfaces and the corrosion rates are calculated based on diffusion process [14]. ...
... A strong diffraction peak reflected in the XRD spectrum displays the disparity of intensity with respect to different diffraction angles. The highest diffraction peak observed at 2θ = 25 • with maximum intensity of 2700 counts indicates the presence of TiO 2 and PANI and this designates that vibrations of particles are high [14]. PANI-TiO 2 powder was tested using FTIR analysis as shown in Fig. 12. ...
... The particles seem to be very fine, distributed without any agglomeration as shown in Fig. 13(a). The particles of pure PANI and PANI-TiO 2 were intact and this confirms the successful synthesis [14]. The coated samples exhibited rough and thick surface morphology under scanning The corrosion inhibition studies using PANI solution with varying amounts of TiO 2 indicates that the coated layer act as a barrier to protect the metals from direct contact with oxygen, moisture and corrosive solution can be affected by varying the amount of TiO 2 in to PANI solution. ...
Oil and gas industries are the driving force of Oman’s economy and have a relatively diversified wealth among
Gulf Cooperation Council Countries. Oil pipelines play an important role in transporting oil and gas from the
wellheads to the processing facilities. Corrosion normally results in the deterioration of the pipe material with
exposure to the surrounding environment and complete control of corrosion is difficult. Corrosion in oil transmission
pipeline would be effectively addressed by introducing conventional corrosion control practices. Most of
the conventional techniques are either less effective or too expensive in controlling the deterioration rate of the
pipe materials. However, preventative measures may be taken to protect the metal surface from corrosion is a
possible way to reduce corrosion. This research work aimed to develop a novel technique utilizing Polyaniline
(PANI) and Titanium dioxide (TiO2) nanocomposites to assess its corrosion inhibition effect on mild steel. TiO2
was synthesized by sol-gel process. Polyaniline-Titanium dioxide (PANI/TiO2) nanocomposites were coated on
mild steel specimen by dip coating technique. The coated specimen was subjected to stability studies at different
environmental conditions and exposure time. The stable thin film coated specimen was employed in the
corrosion inhibition studies at various processing environments. The characteristics of TiO2 nanoparticles and
PANI-TiO2 thin films were analyzed using Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive
X-Ray analysis (EDX) and X-Ray Diffraction (XRD) and Dynamic Light scattering (DLS). Scanning Electron Microscopy
(SEM) was used to visualize the surface morphology and micro structural characteristics of the preformed
thin layer. Potentio dynamic test, Atmosphere test and Wet/Dry tests were carried out to investigate the
corrosion behaviour of coated and uncoated specimen. The study demonstrates that the Polyaniline – TiO2
composite thin films fabricated using dip coating technique with minimum film thickness could be a feasible
solution in controlling the corrosion in oil pipelines with good film stability, high durability, with a cost effective
and environmentally friendly approach.
... Most chemical and electrochemical reactions become faster as the temperature increases 9 . In this study, we suggested to study the impact of temperature on the behavior of carbon steel in 3% NaCl. ...
... It is established that when the carbon content in the alloy increases, the energy of corrosion activation increases, which means that the beginning of corrosion processes on the surface of iron-carbon alloys occurs later. 9 The corrosion behavior of E690 steel in 3.5 wt.% NaCl solution at temperatures from 20°C to 60°C was investigated using electrochemical test. The findings indicated that the corrosion rate of E690 steel increased as the temperature rose. ...
ur main motivation in this study was to review the effects of acid concentration and solution temperature on the corrosion behavior of XC48 carbon steel in acidic and saline environments. We conducted both gravimetric and electrochemical analyses to evaluate the extent of corrosion. The gravimetric study revealed interesting findings regarding the influence of acid concentration on the corrosion rate. Initially, as the acid concentration increased, the corrosion rate showed an upward trend, reaching a peak at approximately 6M (44.1%) of sulfuric acid. However, at higher concentrations, such as 10.3M (65.15%) the corrosion rate decreased to a lower value at different immersion times. A similar trend was observed with phosphoric acid, where the maximum corrosion rate occurred at around 10M (66.6%), but decreased at 14.5M (84.68%) over different immersion times. Notably, in the case of hydrochloric acid, the corrosion rate exhibited a logarithmic behavior at higher concentrations (6M, 7M, 10M), which can be attributed to the formation of passive layers. The decrease in corrosion rate at higher concentrations indicates the protective effect of these passive layers. During the electrochemical analysis, we investigated the effect of temperature and NaCl concentration on the corrosion rate. Our results indicated that the corrosion rate increased with an elevation in temperature and NaCl concentration. The maximum corrosion rate was observed within the range of 3 to 4% of NaCl. Overall, this study provides valuable insights into the corrosion behavior of XC48 carbon steel in acidic and saline environments. The gravimetric analysis highlighted the influence of acid concentration on corrosion rate, including the formation of passive layers at high concentrations. The electrochemical study demonstrated the impact of temperature and NaCl concentration on corrosion rate, with higher values observed at elevated temperatures and increased NaCl concentrations. These findings contribute to a better understanding of the corrosion mechanisms and can aid in the development of effective corrosion prevention strategies for carbon steel in similar environments
... Many factors influence corrosion, such as salinity, PH, chemical components of water, stress on structures, water pollution, fluid velocity, temperature. Among them especially temperature change impacts the rate of all chemical reactions, therefore it plays an important role in the development of corrosion processes in metal products, equipment, and structures (Dastgerdi et al., 2019;Konovalova, 2021). For example, the amount of dissolved oxygen in the water decreases as the temperature of the seawater rises, but corrosion accelerates (Schumacher, 1979). ...
... Therefore, the calculation of the rate coefficient value should be based on another formula. In previous experimental studies on different materials, an equation over the material's lost mass per unit area was used to calculate the rate coefficient value (Konovalova, 2021). ...
For the prediction of corrosion wastage on ships, field tests are commonly used. Statistical approaches based on field tests provide an average corrosion prediction rather than an explanation of corrosion characteristics. Furthermore, the models that ignore effects of environmental factors on corrosion development are unrealistic. Establishing a model that includes environmental factors, based on the segmentation of field tests, will provide a more than average approach for risk of aging ship structures assessment. In this study, a mathematical model that estimates corrosion wastage as a function of time and the working environment temperature of ships established for the ballast tanks by using segmentation of field test results.
... As for temperature, it accelerates the overall electrochemical processes. Indeed, an increase in temperature is associated with a decrease in activation energy, as well as an increase in the number of active corrosion sites [44]. However, it can also lead to the formation of corrosion products with protective properties, particularly in anoxic conditions with ferrous ions and carbonates. ...
In the context of the deep geological disposal of high-level and intermediate-level long-lived radioactive waste in France, the Callovian–Oxfordian (Cox) clay formation has been selected as a natural barrier. Thus, understanding the corrosion phenomena between the carbon steel used (API 5L X65) for the waste lining tubes and the Cox pore water, as well as its possible future evolutions, is of great importance. A controlled laboratory experiment was conducted using robust handmade API 5L X65 carbon steel electrodes in synthetic Cox pore water under equilibrium with three distinct gas atmospheres, simulating oxic, anoxic, and sulfide-rich environments at 25 °C and 80 °C, in a batch-type electrochemical cell. The experimental methodology involved linear polarization resistance (LPR) cycles, electrochemical impedance spectroscopy (EIS), and Tafel extrapolation at regular intervals over a period of 70 to 100 h to elucidate corrosion mechanisms and obtain corrosion current densities. At the same time, the fluid’s key geochemical parameters (temperature, pH, and redox potential) were monitored for temporal variation. This study, with results showing high corrosion rates under the three conditions investigated at two temperatures, underscores the importance of controlling the immediate environment of the containment materials to prevent exposure to variable conditions and to ensure that corrosion remains controlled over the long term.
... In the same time, with elevated temperatures, the mobility of ions in the electrolyte solution increases. This increased mobility allows ions to more easily reach the 316SS surface and participate in electrochemical reactions, leading to higher corrosion rates 30,31 . Moreover, at elevated temperatures, the stability of these passive films of 316SS surface can decrease, leading to a higher susceptibility to corrosion [32][33][34] . ...
This study investigates the thermodynamics, kinetics, and adsorption mechanisms of Lavender angustifolia extract (LAE) as a corrosion inhibitor for stainless steel (316SS) in desalination units. The primary aim is to evaluate the efficacy of LAE in mitigating corrosion in a 5.0 M HCl solution under dynamic conditions. High-Performance Liquid Chromatography (HPLC) analysis identified key components of the LAE extract that contribute to corrosion inhibition, including linalyl acetate (41.7%), linalool (13.6%), 1,8-cineole (8.3%), β-ocimene (6.2%), terpinen-4-ol (5.7%), lavandulyl acetate (7.5%), and camphor (4.7%). Results indicate that the inhibitory efficiency of LAE increases with concentration, peaking at 94.3% at 300 mg L⁻¹. The Freundlich adsorption isotherm model best describes the experimental adsorption data. Notably, the activation energy for corrosion increases from 7.17 kJ mol⁻¹ in the 5.0 M HCl solution to 21.65 kJ mol⁻¹ with the addition of LAE, reflecting enhanced protection. The enthalpy change (∆H*) in the presence of LAE (19.04 kJ mol⁻¹) is significantly greater than that of the extract-free solution (4.55 kJ mol⁻¹), indicating improved corrosion resistance of 316SS. Electrochemical techniques confirmed the mixed-type inhibition behavior of LAE, while UV and SEM-EDAX analyses demonstrated effective adsorption of the extract on the stainless steel surface.
... Aluminum composites have established a unique role within metal matrix composites (MMCs). Although MMCs may use diverse matrices such as titanium, magnesium, and copper, aluminum-based composites are mostly favored owing to aluminum's low density, superior corrosion resistance, and advantageous cost-to-performance ratio [10]. Titanium-based composites provide elevated strength and thermal resistance; yet, they are associated with increased prices and density [11]. ...
This study explores friction stir processing (FSP) of Al-6061 aluminum alloy reinforced with alumina nanoparticles, analyzing the effects of processing parameters—including transverse speed, rotational speed, and number of passes—on ultimate tensile strength, yield strength, natural frequencies, and damping ratios. Using a CNC milling machine, FSP was conducted at rotational speeds of 900, 1100, 1300, and 1500 rpm, with traverse speeds of 10, 15, and 20 mm/min. An advanced machine learning model, SRS-optimized long short-term memory (LSTME), was utilized to predict the properties of the processed material, achieving high R² values of 0.911 for ultimate strength, 0.951 for yield strength, 0.953 for natural frequency, and 0.985 for damping ratio. Key findings indicate that FSP improves damping characteristics and mechanical properties, with maximum damping effectiveness observed at 900 rpm across all passes. Alumina nanoparticles enhanced damping capabilities, while increased rotational speeds promoted grain refinement, resulting in a stronger, more deformation-resistant material. The LSTME model outperformed other machine learning approaches, reaching R² values between 0.965 and 0.993 in training and 0.911 to 0.987 in testing. These results demonstrate the efficacy of combining FSP with machine learning to optimize material properties for high-performance applications
... However, like pearlitic steels, U75V is also susceptible to corrosion, particularly in Thailand's tropical rainforest climate, characterized by high temperatures due and humidity levels to proximity to the metal increased risk of [2]. This sea damage due to corrosion is exacerbated by higher temperatures [3]. ...
The development of multiphase bainitic/martensitic steel aims to enhance the mechanical properties and corrosion resistance compared to traditional pearlitic steel. However, the impact of elevated temperatures on the corrosion resistance behavior of these materials cannot be overlooked. This study investigates the corrosion resistance behavior of multiphase bainitic/martensitic steel and pearlitic steel at varying temperatures. Electrochemical tests using Electrochemical Impedance Spectroscopy (EIS) and Linear Polarization (LP) in a 3.5 wt.% NaCl solution demonstrate a consistent trend: acicular bainitic steel exhibits superior corrosion resistance compared to granular bainitic steel and pearlitic steel at both room temperature and elevated temperatures. Further characterization using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) reveals that the formation of oxide layers significantly contributes to the enhanced corrosion resistance observed in these materials.
... Studies indicate that with an increase in temperature, the corrosion products on the metal surface tend to change from thick and porous corrosion product layers (Figure 4a-d) to thin and compact product layers (Figure 4e,f). This is probably because the formation and growth rates of corrosion products are enhanced at higher temperatures, resulting in denser products [44,[49][50][51]. Additionally, temperature may influence the composition and structure of corrosion products. ...
Carbon Capture, Utilization, and Storage (CCUS) technology is an emergent field with the potential for substantial CO2 emissions reduction, enabling low-carbon utilization of fossil fuels. It is widely regarded as a critical technology for combating global climate change and controlling greenhouse gas emissions. According to recent studies, China has identified CCUS as a key emissions reduction technology in climate change response and carbon neutrality objectives. Within this framework, supercritical CO2 (SC-CO2) transport pipelines are an essential means for efficient and safe transportation of CO2. Corrosion protection of pipelines enhances the efficiency and safety of CCUS technology and supports broader implementation and application. This paper reviews the current research on corrosion protection for SC-CO2 transport pipelines, discusses effect factors, compares various corrosion protection strategies, and analyzes the challenges in corrosion protection of SC-CO2 transport pipelines. It concludes with a perspective on future research and development directions in this field. This paper is dedicated to providing new research strategies for pipeline corrosion protection in CCUS technology in the future, and providing technical support for pipeline corrosion protection in CCUS industrial applications.
... This discrepancy is attributed to the electrochemical reaction induced by the "iron-carbon" galvanic couples, which enhances the corrosion of iron in the pots. Generally, iron pots with higher carbon content tend to have more "iron-carbon" galvanic couples, thereby increasing the electrochemical reaction (Konovalova, 2021). The carbon content of CIPs ranges from 2.5% to 4%, while that of RIPs is less than 0.02%. ...
The World Health Organization (WHO) has identified the use of iron cookware as a potential strategy for alleviating iron deficiency anaemia (IDA) and emphasises the need for action-oriented research in this area. In response to this need, our study systematically investigated the patterns of iron release from various types of cookware under different cooking conditions. Among these, nitrided iron pots (NIPs), the most widely used cookware, were selected for the development of kinetic models to predict iron release efficiently across a range of cooking temperatures and pH levels in food materials. Our results demonstrated that iron release from the pots was significantly influenced by cooking conditions such as the type of cookware, cooking temperatures, cooking times, types of acidic substances, and the pH of the cooking environment. Specifically, higher temperatures, longer cooking times, lower pH levels, and the presence of acetic acid were found to maximise iron release into food. We developed a series of kinetic models—Iron Release-Temperature Models (I, II, and III) and Iron Release-pH Models (IV, V, and VI)—to predict iron release from NIPs. The temperature models are applicable for cooking food with a pH of 5.00–6.00 within a temperature range of 50–100 °C, while the pH models are designed for food with a pH of 3.00–6.00 at boiling temperatures. Validation experiments confirmed the relative accuracy of these models. Additionally, when comparing the predicted iron release with the Recommended Nutrient Intake (RNI) guidelines, the findings support the efficacy of iron pots as a viable method for iron supplementation.
... It can be caused by the different surface roughness of aluminum duralumin [13]. Other things that also cause differences in the corrosion rate are NaCl solubility, water pH, and the presence of impurities [14]. ...
... However, the estimated life on this table is very conservative as this failure is due to corrosion. According to [12,13,14], even with corrosion, its effect may be uniform as pitting corrosion may occur. It may also happen that the neater handles corrosion promoting solutions, in which case the life expectancy will be much shorter. ...
The corrosion behaviour of copper as a solar collector material was adequately simulated in tests in a solar water heating system. The weight loss technique of corrosion determination was used under exposure conditions ranging from slightly acidic to alkaline. Uniform corrosion was observed and corrosion rates; calculated estimates of the life of a typical collector made of copper were evaluated and found to be below 0.0254 mmpy and the subsequent evaluation of the life of a 3mm thick pipe shows lives of over a hundred years under the varying exposure conditions. A significant fact is that uniform corrosion took place over the period of the test.
... Based on the interaction, corrosion rate increases as TDS concentration or temperature increases. Temperature appears to have a significant effect on corrosion processes on metal and alloy surfaces (Konovalova 2021). The interaction of pH and time on corrosion rate is shown in Fig. 7e. ...
This study is focused on the modelling of the composite effect of corrosion factors using Design Expert 13 software on the corrosion rate in the water distribution network of Patna (Bihar), India. A total of nine variables, including pH, temperature, total dissolved solid (TDS), alkalinity, calcium hardness, chloride, sulphate, dissolved oxygen (DO) and time, were considered for modelling. The physicochemical parameters were determined through regular monitoring of water samples. The corrosion rate was determined by the direct monitoring of water distribution pipes using adjustments of seven GI coupons for 45, 90, 135, 180, 225, 270 and 315 days. Modelling was performed for various corrosion factors using the low-level and high-level experimental ranges. Nine of the corrosion factors, i.e. pH, temperature, TDS, alkalinity, calcium hardness, chloride, sulphate, DO and time, were considered in this study. The data used for low-level and high-level range were 7.28, 23, 430, 115, 24, 18, 10.94, 3.5 and 0 and 7.86, 28, 704, 284, 180, 98, 38.7, 6.8 and 315, respectively. Using the Box-Behnken design (BBD), 160 runs were conducted, including ten replicates at the central point of each block. The results of ANOVA indicate that the values of R2, adjusted R2 and predicted R2 are 0.9714, 0.9507 and 0.8941, respectively. The value of R2 (0.9714) was close to 1, which indicates a good fit. The adequate precision was found to be 30.8442, indicating a good signal. The coefficient of variance discusses reproducibility, and in this case, it was 9.90%. On the basis of the ANOVA result, the quadratic model is well-fitted and can be accepted as a suitable model. A total of seven parameters, such as chloride, sulphate, hardness, alkalinity, pH, calcium and hardness, were used for the design of the experimental corrosion rate (CR). Corrosion rate as observed by direct monitoring of the water distribution system was 1.37, 3.08, 1.90, 1.38, 1.09, 2.05 and 1.45 MPY for 45, 90, 135, 180, 225, 270 and 315 days, respectively. These individual CR versus synthetic aqueous solutions were used to validate the interaction of the response surface. It was observed that the trend of individual corrosion rates in synthetic aqueous solutions and the interaction of composite variables with corrosion rates in a quadratic model of response surfaces were clearly correlated.
... Cheng et al. [19] According to the obtained results ( Figure 4, Table 5), the temperature of 50 • C was manifested as a significant factor reducing the corrosion resistance. It was also documented by the authors of [22,28,[33][34][35][36]. Under this temperature conditions chemical surface treatment for removal of the high-temperature oxides (Figure 4, SP 50 specimen) did not prevent the passivity lose and the active dissolution with high corrosion current density took place. ...
Corrosion resistance of sensitized austenitic stainless steel (SS) in chloride environments is currently the subject of numerous studies. Most of them are focused on neutral chloride solutions at room temperature and the experiments are carried out on ground stainless steels surfaces. This paper deals with the corrosion behavior of sensitized AISI 304 stainless steel in acid 1 M chloride solution (pH = 1.1) at the temperatures of 20 ± 3 °C and 50 °C. The specimens after sensitization are tested as covered by high-temperature surface oxides (“heat tinted”), and also after their chemical removal to assess the impact of the surface state on corrosion resistance. Potentiodynamic polarization (PP) and exposure immersion test are used as the independent corrosion tests. Microstructure before/after exposure immersion test is evaluated by optical microscopy (OM) and SEM. The results obtained showed that sensitization significantly conditions corrosion regardless of the removal of high-temperature oxides, and the elevated temperature mainly acts as its accelerating factor.
... The reac-tion activity of thiourea and polyepoxysuccinic acid decreased when the temperature continued to increase. So, the temperature has a substantial effect on the development of corrosion processes [38]. The effect of different pH values on corrosion inhibition performance for PESA and CNS-PESA is shown in Figure 10(b). ...
In this paper, thiourea-modified polyepoxysuccinic acid (CNS-PESA) was synthesized and used as a corrosion and scale inhibitor for the circulating cooling water system of the factory. Polyepoxysuccinic acid (PESA) has been widely used in industrial water treatment due to its good corrosion inhibition and scale inhibition performance. It also acts as a reliable material for dispersion of iron oxide, good biodegradation efficiency, and phosphorus-free content. The scale inhibition performance for calcium carbonate and calcium phosphate scale with corrosion inhibition performance using different inhibitor concentrations, temperatures, pH, and calcium ion concentration on scale inhibition efficiency were studied. The scanning electron microscope (SEM) analysis on the scale and corrosion of carbon steel with two methods as GB/T 18175-2000 “Measurement of inhibitors in water treatment: rotation coupon method” and electrochemical method for CNS-PESA and PESA were utilized. Compared to using CNS-PESA and PESA for calcium carbonate and calcium phosphate, the scale inhibition rates were increased by 6% and 18.7%, and the corrosion inhibition rate increased by 22.4%. The scale inhibition efficiency of CNS-PESA is best when the calcium ion concentration is less than or equal to 350 mg/L. Moreover, the thiourea-modified polyepoxysuccinic acid (CNS-PESA) was phosphorus-free corrosion and scale inhibitor and minimizes environmental pollution problems.
... In low temperature water chemistry, the effect of temperature on the corrosion behavior of the alloy is mainly reflected in increasing the activation energy and promoting the occurrence of J o u r n a l P r e -p r o o f chemical reaction to accelerate metal dissolution [166]. Temperature has larger influence on the corrosion rate in a gas environment compared with water vapor [167]. ...
The safety of nuclear power plants has put forward new requirements for the corrosion resistance of fuel cladding with the advancement of industrialization. FeCrAl alloys are expected to be a substitute for Zircaloy. This work summarizes the corrosion of Zircaloy and presents a comprehensive review on the corrosion behavior of FeCrAl alloys including oxidation kinetics, corrosion processes and influencing factors in nuclear reactors. Corrosion performance of Zircaloy in nuclear water chemistry is definite while influencing mechanisms of relevant parameters (e.g. coolant pH) are still unclear. A small change of LiOH concentration may cause contrary effect on corrosion behavior. Different from Zircaloy cladding, FeCrAl cladding shows various kinetics in corrosive environments. A single, duplex or triple oxide layer is all possibly observed. Specific corrosion behavior depends on the properties of water chemistry and chemical reactions of main alloying elements. Developing challenges and prospects of FeCrAl alloys are concluded to expand its commercial scale in nuclear fuel cladding. For successful commercial application of FeCrAl cladding, a systematic evaluation considering corrosion resistance and other properties (e.g., mechanical strength, thermal hydraulic characteristics and neutron economy) is required.
The corrosion behavior of copper in aerobic deep geological repository (DGR) environment was investigated with respect to environmental factors (pH, chloride, and temperature) using electrochemical tests, surface analyses, response surface methodology (RSM), and corrosion simulation. A regression model describing the relationships between environmental factors and copper corrosion rate was developed using RSM. The corrosion rate of copper increased with increasing temperature and chloride ion concentration. Among the environmental factors, temperature had the most significant effect on the copper corrosion rate, while pH had little effect. This is attributed to chloride ions being the main reactive species in copper corrosion, with diffusion of reactive species and reaction rates increasing with temperature. The RSM results were consistent with the initial stage results of the corrosion simulation for the DGR environment. However, as time progressed, the corrosion simulation results indicated that only the effect of temperature was significant on the copper corrosion rate. This is due to the depletion of reactive species on the copper surface caused by their slow diffusion in the DGR environment. At this stage, the depletion of the oxygen as the oxidizing agent has the most significant effect. In conclusion, the RSM results effectively predict the corrosion rate of copper based on the environmental factors in the early stage of the DGR environment. However, the corrosion simulation revealed that the influence of environmental factors on the copper corrosion rate changes with immersion time. This study provides valuable insights into predicting copper corrosion in aerobic DGR environment.
To enhance sustainability and resilience against climate change in infrastructure, a quantitative evaluation of both environmental impact and cost is important within a life cycle framework. Climate change effects can lead performance deterioration in bridge components during their operational phase, highlighting the necessity for a risk-based evaluation process aligned with maintenance strategies. This study employs a two-phase life cycle assessments (LCA) framework. First, risk assessments are conducted to evaluate the impact of climate change on steel plate girder bridges and prestressed concrete (PSC) girder bridges under identical structural conditions. The reduction in flexural strength of steel plate girders and PSC girders due to changes in environmental variables such as temperature and relative humidity, induced by various climate change scenarios, was evaluated analytically. Subsequently, life cycle environmental impact and cost assessments were performed, including maintenance outcomes derived from risk assessments. The findings revealed that the environmental impact and cost could increase by approximately 12.4% when climate change is considered, compared to scenarios where it is not taken into account. Sensitivity analyses were performed to identify the key factors influencing environmental impact and cost. The analysis determined that the frequency of preventive maintenance, the recycling rate, and environmental cost coefficient weight in the life cycle assessment significantly affected the results.
The oil and gas sector play a significant role in the Sultanate of Oman’s economic growth and contribute major revenue. Corrosion is a global concern and that strongly affects the industrial sectors. The corrosion problems in oil pipelines would be successfully resolved by means of novel control techniques. This research focused on the fabrication of Graphene oxide (GO) - Cadmium sulphide (CdS) nanocomposite for controlling corrosion in mild steel specimen. Graphene oxide was synthesized from Alovera extract by carbonization process. GO - CdS nanocomposite was prepared and deposited on a mild steel pipe by self-assembly technique. The coated material was used for stability studies at varying pH conditions and exposure period followed by corrosion studies. The testing methods adopted are Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Energy Dispersive X-Ray analysis (EDX), and Fourier Transform Infrared Spectroscopy (FTIR). Wet/Dry test and Atmosphere tests were conducted to examine the performance of coating material towards corrosion. The atomic force microscope (AFM) operated in non-contact mode was used to study surface topology of the coated specimen. From the outcome of the corrosion studies, it was established that the GO- CdS Nano composites thin film acted as an ecofriendly corrosion inhibitor to enhance the lifespan of the mild steel pipe. This novel research is aligned with the United Nations Sustainability Goals (UNSD - 9: Industry, Innovation and Infrastructure & UNSDG 12 – Responsible consumption and production) and Oman vision 2040. The results from the study validates that the GO - CdS thin films coated on mild steel pipe could be a viable solution to corrosion issues in oil pipelines owing to their good film stability, minimum film thickness, high durability, and ecofriendly approach.
The increasing demand for corrosion prevention strategies that are both effective and sustainable is part of the research the background. Nonionic surfactants offer a potential replacement for traditional corrosion inhibitors. These surfactants are well-known for their low toxicity and biodegradability. The research involved conducting experimental tests (such as weight loss, polarization and impedance spectroscopy) and theoretical computations to investigate the role of nonionic surfactant (polyoxyethylene (7) tribenzyl phenyl ether) (PETPE) in controlling the corrosion of mild steel in hydrochloric acid (1.0 M HCl) environment. The results of the study demonstrated that PETPE exhibited significant corrosion inhibition properties for mild steel in HCl solution. The inhibition efficiency of PETPE was found to increase with increasing PETPE concentration. PETPE is an excellent corrosion inhibitor because it significantly reduces the rate of corrosion, as seen by the notable inhibition efficiency result (95.4%) at a relatively low dose of PETPE (100 ppm). Thermodynamic studies were used to discuss the fundamental mechanisms that control PETPE-acid interactions. The adsorption process followed Langmuir adsorption isotherm, indicating a monolayer adsorption of the PETPE on the mild surface. Theoretical computations confirm the strong inhibition behavior of PETPE. The innovative feature of this research is its comprehensive strategy, which integrates experimental studies and theoretical simulations to evaluate the impact of PETPE on the corrosion control of mild steel in hydrochloric acid. The combined effort has the ability to supply valuable knowledge into the mechanisms of corrosion that will lead to the establishment of powerful corrosion control strategies.
In this study, we investigated the electrochemical properties and lifespan of the NiCr (NiCr 8020) sensor wire of a resistance leaking detection (LD) system to detect pipe corrosion and leakage in an actual district heating (DH) system. The temperature and applied stress of the sensor wire during the actual operation of the resistance LD system of the DH system were derived through simulations and calculations. The anodic dissolution of the sensor wire was accelerated with the increased temperature and the applied current. The corrosion type changed from localized corrosion, such as pitting, to uniform corrosion. The applied stress caused ductile fracture of the thinned sensor wire by anodic dissolution. In conclusion, we confirmed that in the resistance LD system of a DH system, where current and stress are applied at high temperatures, the sensor wire becomes thin due to the anodic dissolution and subsequent ductile fracture. In addition, the lifespan of the sensor wire was derived according to the resistance level measured in the resistance LD system of the DH system. Our findings contribute to preventing failure and improving the reliability of the resistance LD systems of DH systems.
A sealed container for the geological disposal of spent nuclear fuel and vitrified high-level waste is the only component of a deep geological repository that provides complete containment of radionuclides. As such, attention is focused on its lifetime. The lifetime of the container is influenced by material degradation processes during disposal and is typically of the order of several millennia and, for some container materials, up to one million years. Designing, manufacturing, and predicting the performance of containers over such long periods requires an in-depth understanding of their material properties, fabrication processes, and degradation mechanisms. Scientific and technological progress can improve both the performance of containers and the robustness of lifetime predictions. Optimization of these aspects is of primary importance for many national radioactive waste disposal programs. In this article, the state of the art of complex coupled degradation processes, as well as the optimization potential of novel container materials, is presented. Furthermore, the existing tools allowing the prediction of long-term barrier integrity are discussed.
Purpose
This study aims to investigate the corrosion behavior of stir-cast hybrid aluminum composite reinforced with CeO 2 and graphene nanoplatelets (GNPs) nanoparticulates used as cylinder liner material in the engines (automotive, aerospace and aircraft industries).
Design/methodology/approach
The composites were prepared using the stir-casting technique, and their microstructure and corrosion behavior was evaluated using scanning electron microscopy (SEM) and potentiodynamic polarization test, respectively.
Findings
The results showed that the addition of CeO 2 and GNPs improved the corrosion resistance of the composites, and the optimal combination of these two nanoparticles was found to be 3 wt.% CeO 2 and 3 wt.% GNPs. The enhanced corrosion resistance was attributed to the formation of a protective layer on the surface of the composite, as well as the effective dispersion and uniform distribution of nanoparticles in the matrix. The 0.031362 was noted as the lowest corrosion rate (mmpy) and was noticed in 94% Al-6061 alloy + (3 Wt.% CeO 2 + 3 Wt.% GNPs) sample at room temperature and at elevated temperatures; the corrosion rate (mmpy) was observed as 0.0601 and 0.0636 at 45 °C and 75 °C, respectively.
Originality/value
In the vast majority of the published research publications, either cerium oxide or graphene nanoplatelets were utilized as a single reinforcement or in conjunction with other types of reinforcement such as alumina, silicon carbide, carbon nano-tubes, tungsten carbide, etc., but on the combination of the CeO 2 and GNPs as reinforcements have very less literatures with 2 wt.% each only. The prepared hybrid aluminum composite (reinforcing 1 wt.% to 3 wt.% in Al-6061 alloy) was considered for replacing the cylinder liner material in the piston-cylinder arrangement of engines.
Corrosion is a process of destroying metals (alloys) under the chemical or electrochemical action of the environment. A valuable method to improve the corrosion resistance of metals and alloys working under extreme environments based on protecting the metal substrate with different ceramic materials has been proposed. Experiments were performed by Electron Beam – Physical Vapor Deposition (EB-PVD), for deposition of multi-thin oxide layers of the type: Al2O3 / ZrO2 doped with Y2O3 / La2Zr2O7 / ZrO2 doped with Ce2O3, on 316L stainless steel laminated sheet substrates. The influence of multi-layer oxide coatings on the corrosion of 316L stainless steel was studied by electrochemical corrosion experiments (linear polarization) in NaCl solution of different concentrations (from 0.06M to 0.6M). To highlight the microstructural aspects on the elec-trochemically corroded samples, scanning electron microscopy (SEM) analyses were performed. The coating adhesion was evaluated by scratch test. Complex multi-layer oxide coatings improve the corrosion resistance of stainless steel in dilute NaCl electrolyte solutions (0.06M and 0.2M). In contrast, for more concentrated NaCl solutions (0.4M and 0.6M), these thin multi-layer oxide coatings are more susceptible to corrosion than simple alumina coatings which have higher po-larization resistance and lower corrosion rates.
High-pressure injection molding is an important industrial process, which requires a precise cooling stage. In this work, we analyzed the reasons for the corrosion failure of the cooling circuit of molds in the molding plant. The cooling circuit was inspected visually and collected samples were further analyzed in a laboratory using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The main problems were an improper selection of the antibacterial agent and materials of the cooling circuit. Based on the performed analyses, a possible mechanism of the corrosion attack was proposed and recommendations to decrease the number of corrosion-related failures and services were formulated.
The Galfan coating (Zn-5%Al-RE) is widely used in high strength steel wires, which are commonly adopted in the construction of modern civil structures. The present research aims at the macroscopic and microscopic corrosion features, and the time-dependent probabilistic corrosion models of Galfan coating. To achieve these goals, accelerated corrosion experiments are conducted. The field emission scanning electron microscope and the three-dimensional surface morphometer are employed to observe the corrosive surface morphology. It is found that the macroscopic corrosion feature and the microscopic corrosion feature of Galfan coating can be divided into four stages and three stages, respectively. The increasing of average uniform corrosion depth of Galfan coating shows a parabolic law with the extension of exposure period. The dynamic generalized extreme value distribution is more suitable than other distributions in establishing the time-dependent probabilistic corrosion model of Galfan coating, and the block maximum pitting factor can be described by Gumbel distribution. Both the location parameter and scale parameter of the proposed model decrease exponentially with the extension of exposure period. In the last, an application method of the proposed model is provided by solving the problem of exposure period conversion.
In an acidic red soil environment, the corrosion mechanism of X80 steel may be closely related to the pH value and oxygen content, but it has not yet formed a systematic understanding. In this paper, the coupling effects of pH and dissolved oxygen on the corrosion behavior and mechanism of X80 steel in an acidic soil simulated solution were further analyzed by electrochemical methods and three-dimensional video microscope. Results showed that the hydrogen reduction reaction was almost the only cathode process in the anoxic and low pH system, and small and dense pits were present on the electrode surface. pH value increased, the pits decreased, but the size of pits increased. In the oxygen-adequate system, oxygen-consuming (OC) corrosion preferentially occurred, and a protective corrosion product layer (including FeOOH, Fe3O4, etc.) might be formed accordingly, but the proportion of hydrogen evolution (HE) increased and the product layer had defects at a low pH environment. The specific corrosion mechanism of X80 steel in an acidic soil simulated solution is described in the relevant models.
The paper considers the main types of corrosion taking into account the direction of corrosion processes. The main parameters of metal building structures corrosion and factors that have a significant influence on these parameters are taken into account, which can influence the increase of such structures longevity. One of the main factors of corrosion rate determining is the humidity of air and dust deposited on surface from atmosphere at production emissions.
There appear to be two main growth mechanisms for graphite in cast iron i) Coupled eutectic growth forms of gray irons which are classical growth modes of simultaneous parallel growth of graphite and austenite, not reliant on a bifilm mechanism. These are necessarily fine structures as a result of their control by the rate of diffusion of carbon in the liquid. These structures are well understood. (ii) Uncoupled eutectic mechanisms which appear to be much less well understood, including (a) growth of graphite on silica bifilm substrates floating freely in the melt, forming such structures as A-type graphite flakes. This prediction appears to have now been confirmed by direct observation. The transition to (b) nodular morphology occurs by Mg eliminating the silica bifilms by an exchange reaction. In this way the substrates for flake growth are instantly removed, and graphite can now wrap completely around nuclei, thereby growing as a nodule. Graphite structures in heavy sections such as chunky graphite may now be understandable in terms of the reorganisation by flotation of bifilms and/or nuclei.
This paper considers the factors influencing the formation and development of stress corrosion defects detected during the inspection and overhaul of the main gas pipeline section. The surveyed gas pipeline is made of large diameter steel pipes made by controlled rolling, produced by various companies, with the predominance of pipes produced by the Khartsyzsk Pipe Plant (KhPP). The correlation between the geometric parameters of defects is described, which makes it possible to estimate the depth of cracks by external parameters. Mechanical tests by cyclic loading of samples containing cracks, based on the site operation data for the last 11 years, showed no crack growth in the absence of a corrosive medium. Micro-X-ray spectral analysis of metal and corrosion products showed no trace of the influence of hydrogen sulphide and nonmetallic inclusions (sulphides) on the development process of SCC. According to the results of the research, the process of development of stress corrosion on the main gas pipelines located in the European part of the Russian Federation is described. The organization operating the gas pipeline is recommended to take into consideration the results of this work during drawing up their repair plan.
Deterioration of buried metal pipes due to corrosive soil environment is a major issue worlwide. Although failures of buried pipe due to corrosive soil is an old problem, yet such failures are still uncontrollable even with the application of advanced corrosion protection technologies. Therefore, understanding factors causing corrosion of buried pipes is necessary. This article reviews factors causing corrosion of buried pipes in soils. Factors include moisture content, soil resistivity, pH, dissolved oxygen, temperature and microbial activity. Moreover, we discuss the influence of manufacturing method and the comparison of corrosion behaviour of cast iron, ductile and mild steel pipes. We found that corrosion rate of pipes increases with moisture contents up to the critical moisture value. Although pH affects corrosion, there is no relationship between corrosion and pH and the corrosion rates of buried pipes are inversely proportional to soil resistivity. Soils containing more organic matter show high resistivity. Dissolved oxygen in soil develops differential cell which accelerates corrosion of metallic pipe. Different types of bacteria present in soil develop biofilms on metallic pipes, which deteriorates pipes with time.
The paper concerns the problem of evaluation of stationarity of carbon steel corrosion in 1M HCl. Comparison of corrosion rate with addition of corrosion inhibitor to the reference measurement is the most often used way of evaluating inhibitor efficiency. Such an approach is valid only if corrosion rate is a stationary process. Two complementary techniques were used simultaneously: volumetric analysis of evolved hydrogen and instantaneous impedance spectroscopy monitoring. Changes of the electrode surface area and chemical composition have a major impact on the dynamics of both cathodic and anodic processes. On the base obtained results, authors claim that the stationarity of the process determined most often on the base of corrosion potential is ineffective and insufficient.
The effectiveness of using Tilia cordata extract as a green corrosion inhibitor for carbon steel in 1 M hydrochloric acid solutions was demonstrated by employing some chemical and electrochemical techniques. The surface morphology of C-steel specimens was examined. The results showed that Tilia cordata has corrosion inhibition characteristics with efficiency of 96% as the concentration of Tilia cordata extract increased to 300 mg L−1. Charge transfer resistance (Rct) value increases while both the capacitance of the double layer (Cdl) and corrosion current (icorr) values decrease with increasing the extract concentration. The effect of temperature was studied in the range 30–60 °C. Some thermodynamic parameters were calculated and discussed. The adsorption of extract on the C-steel surface was found to obey Langmuir adsorption isotherm. Polarization results showed that the investigated extract acts as mixed type inhibitor. All the different used techniques gave similar results
In this article authors set out a principle of pitting corrosion protection, suggested a new class of multilayer materials with high corrosion resistance. They substantiated the choice of the layers for the multilayer material designed for exploitation in oxidizing and non-oxidizing environment. The sphere of application of the multilayer materials was defined.
The term corrosion covers a wide variety of types of surface attack and mechanism. Broadly, these may be subdivided into two categories, those associated mainly with the metal and those with the environment. In this second paper, typical cases of localized corrosion are outlined and are illustrated by examples. Available strategies for corrosion protection are reviewed and methods of prevention are concisely considered.
Flow accelerated corrosion (FAC) of carbon steels in water has been a concern in nuclear power production for over 40 years. Many theoretical models or empirical approaches have been developed to predict the possible occurrence, position, and rate of FAC. There are a number of parameters, which need to be incorporated into any model. Firstly there is a measure defining the hydrodynamic severity of the flow; this is usually the mass transfer rate. The development of roughness due to FAC and its effect on mass transfer need to be considered. Then most critically there is the derived or assumed functional relationship between the chosen hydrodynamic parameter and the rate of FAC. Environmental parameters that are required, at the relevant temperature and pH, are the solubility of magnetite and the diffusion coefficient of the relevant iron species. The chromium content of the steel is the most important material factor.
An overview of the corrosion of metals is given. Corrosion damage and possible methods to mitigate the effects are considered. The origins of corrosion processes are discussed taking into account different types of corrosion and the connections between environment and metal properties are highlighted. Several methods to prevent and mitigate corrosion are presented and a number of case studies serve to highlight the importance of corrosion in practice.
Structural and chemical attributes of amorphous and nanocrystalline metals, which affect their corrosion behaviour are outlined. Effects of the fraction of intercrystalline regions, diffusivity, chemical homogeneity / heterogeneity and local ordering are indicated. These features can lead to higher or lower corrosion resistance as compared to coarse-grained counterparts, depending on the nature of tested metal and corrosive environment. Contributions of these factors are represented by two examples of passive behavior of nanocrystalline metals and amorphous Ni-P alloys.
There has been considerable interest in the properties of nanocrystalline materials over the last decade. Such materials include metals and alloys with a crystal size within the order of 1 to 100 nm. The interest arises due to the substantial differences in electrical, optical and magnetic properties and also due to their high adsorption capability and chemical reactivity compared to their larger grained counterparts. In this paper, the corrosion of nanocrystalline metals and alloys is investigated and compared to the corrosion of microcrystalline materials having a similar composition. The focus is on the corrosion of nickel, copper, cobalt and iron alloys. Key aspects of different corrosion behaviour such grain boundaries and size are identified.
En la última década ha habido un gran interes en las propiedades de materiales nanocristalinos. Estos materiales incluyen metales y aleaciones con un tamaño de cristal del orden de 1 a 100 nm. El interes por estos materiales es debido a las grandes diferencias en cuanto a sus propiedades electricas, opticas y magneticas, asi como a su alta capacidad de adsorción y reactividad química en relación a los mismos materiales con tamaños de grano mayores. En este trabajo se ha investigado y comparado la corrosión de materiales nano y microcristalinos de similar composición química. Principalmente se ha centrado en la corrosión de metales tales como niquel, cobre, cobalto y aleaciones de hierro. Se ha comprobado que los diferentes comportamientos frente al proceso de corrosión están intimamente ligados con los bordes de grano y el tamaño de dichos granos.
This study investigates the variation of sulphuric acid concentration, temperature, and time towards the corrosion rate of saramet using response surfacemethod. Method used in this study is true experimental research. Sarametis material which is included into type of austenitic stainless steel which contains high amount of silicon. Starting at these past 2 years, the material has been widely used.This research used weight loss method. It has been found that minimum corrosion rate is achieved at concentration combination of 89.49% in 3.682 hoursandat temperature of 106,8 °C. From the variation combination, it is seen that the low concentration will decrease ion mobility corrossive ion from saramet.The long period of exposure supports the forming of passive layer which prevent the corrosive ions gets into the steel surface. As a result, corrosion rate decreases. At high temperature, steel which has high silicon content will be stable in terms of its atomic bound which therefore makes it posses high corrosion resistance.
The present study examines the effect of alkaloids extract from Siparuna guianensis leaves and stems on corrosion of C38 steel in 0.1 M HCl using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization technique and Raman spectroscopy. The protection efficiency is better with stems alkaloids extract. The inhibition was assumed to occur via adsorption of inhibitor molecules on the metal surface. The influence of stems alkaloids extract concentration on corrosion of low carbon steel in 0.1 M HCl was studied. The inhibition efficiency obtained from impedance and polarization measurements was in a good agreement and was found to increase with increasing concentration of alkaloids extract up to 50 mg/L for stems extract. The adsorption of the extract on the low carbon steel surface obeys the Langmuir adsorption.
Lower carat gold alloys, specifically 9 carat gold alloys, containing less than 40 % gold, and alloying additions of silver, copper and zinc, are commonly used in many jewellery applications, to offset high costs and poor mechanical properties associated with pure gold. While gold is considered to be chemically inert, the presence of active alloying additions raises concerns about certain forms of corrosion, particularly selective dissolution of these alloys. The purpose of this study was to systematically study the corrosion behaviour of a series of quaternary gold–silver–copper–zinc alloys using dc potentiodynamic scanning in saline (3.5 % NaCl) environment. Full anodic/cathodic scans were conducted to determine the overall corrosion characteristics of the alloy, followed by selective anodic scans and subsequent morphological and compositional analysis of the alloy surface and corroding media to determine the extent of selective dissolution. Varying degrees of selective dissolution and associated corrosion rates were observed after anodic polarisation in 3.5 % NaCl, depending on the alloy composition. The corrosion behaviour of the alloys was determined by the extent of anodic reactions which induce (1) formation of oxide scales on the alloy surface and or (2) dissolution of Zn and Cu species. In general, the improved corrosion characteristics of alloy #3 was attributed to the composition of Zn/Cu in the alloy and thus favourable microstructure promoting the formation of protective oxide/chloride scales and reducing the extent of Cu and Zn dissolution.
The role of chloride ions in the pitting corrosion of some Al–Si alloys was investigated by chemical, polarization and EIS measurements, as well as SEM studies. Differences in corrosion rates of pure aluminium and the alloys are discussed. The capacitive behaviour of the oxide covered surface is replaced by resistive behaviour as immersion time increases in HCl solutions. At neutral pH corrosion currents increase then decrease with chloride ion concentrations. Pitting by chloride ions initiates more readily in acidic media.
Purpose
The purpose of this paper is to obtain the environmental factor, which has the greatest effect on the corrosion rate of Q235 carbon steel under thin electrolyte layer, and to analyze the effect of this factor on the corrosion morphology, corrosion products and polarization process of Q235 carbon steel.
Design/methodology/approach
An electrochemical device, which can be used under thin electrolyte layer is designed to measure the corrosion current in different environments. Response surface methodology (RSM) is introduced to analyze the effect of environmental factors on corrosion rate. Scanning electron microscope (SEM) and X-ray diffraction (XRD) technique are used to analyze the results. The Tafel slopes of anode and cathode in different humidity and solution are calculated by least square method.
Findings
The three environmental factors are ranked according to importance, namely, humidity, temperature and chloride ion deposition rate. In a high humidity environment, the relative content of α -FeOOH in the corrosion product is high and the relative content of β -FeOOH is low. The higher the humidity, the lower the degree of anodic blockage, whereas the degree of cathodic blockage is independent of humidity. The above experiments confirm the effectiveness and efficiency of the device, indicating it can be used for the screening of corrosive environmental factors.
Originality/value
In this paper, an electrochemical device under thin film is designed, which can simulate atmospheric corrosion well. Subsequent SEM and XRD confirmed the reliability of the data measured by this device. The introduction of a scientific RSM can overcome the limitations of orthogonal experiments and more specifically and intuitively analyze the effects of environmental factors on corrosion rates.
The present work investigates the corrosion behavior of bronze materials under thin electrolyte layers (TELs) in a simulated atmospheric environment containing formic and acetic acid by electrochemical measurements as well as surface characterization. The results show that the corrosion of bronze under TEL is significantly faster than that in the bulk solution, and the corrosion rate of bronze is the highest when the thickness of TEL is about 100 μm. Formic acid is observed to be more corrosive than acetic acid. Copper formate and copper acetate hydrate appear in the corrosion products formed on the surface of bronze, suggesting that the organic acid participates in the corrosion process of bronze materials in the simulated atmospheric environment. In a simulated solution of the atmospheric environment, both formic acid and acetic acid can corrode bronze material, which is positively correlated with the concentration of the organic acid. The study found that there may be a critical thickness of 100 μm, where the corrosion rate is the highest.
Localized corrosion of stainless steel affects seriously the erformance of these materials in service. In this paper, the design of experiment (DOE) is used to study the influence of temperature, pH and chloride concentration on the pitting and crevice corrosion of UNS S30403 stainless steel. DOE approach enables to reduce the number of tests (potentiodynamic polarization) necessary to study the effect of several parameters on the passivity breakdown potential. The use of DOE provided a regression equation that was analyzed by comparison with laboratory results. Among all these parameters, the temperature has the most significant effect on pitting corrosion resistance.
In order to protect oil industry borehole equipment and the product transport system from corrosion, and also to improve oil recovery in highly viscous oil deposits a new reagent is developed based on acidol, technical-grade isopropyl alcohol, and technical-grade phosphatide. Laboratory studies show that the reagent reduces the oil dynamic viscosity by a factor of 2.9, and is also effective as an inhibitor (the degree of overall corrosion protection is 94–96 %), while the protective effect of general corrosion is 94–96 %. Industrial testing shows that as a results of action of the reagent in the bottom-hole formation zone oil production increases on average by 22 %, and the degree of protection from overall corrosion is 90 %. Measurements also show a reduction in flow pressure in product transport pipelines 20 % from 0.12 to 0.096 MPa.
This paper studies the effects of relative humidity, temperature, sulphur dioxide, and chlorides on the short-term corrosion behavior in the dynamic environment. A multi-parameter method is developed to characterize the statistical distributions of the environmental factors with high accuracy. The results suggest that TOW (time-of-wetness) should be replaced by temperature and relative humidity distributions. A corrosion model which is combined with physical and empirical knowledge of corrosion is presented and gives more accurate corrosion estimation than using the mean values of the environmental factors and fitting them independently. It is also demonstrated that relative humidity is the most influential factor on corrosion and temperature is secondary. The nonlinearity of their accelerating effects on corrosion rate are remarkable and should be considered in the daily dynamic environment. Sulphur dioxide and chlorides are important accelerating variables and their nonlinear accelerating effects are less significant.
Based on standpoints of the surface physics, fracture mechanics and electrochemistry, a mathematical model of the physical and chemical processes near the crack tip of a metal under mechanical loads in aqueous electrolyte solutions is developed. Calculations of the energy and electrochemical characteristics are performed for the steel 20 in the 3% solution of sodium chloride. Parameters of the Tafel-type relationship between the anode current and the difference of electrode potentials are analysed. Well-known Kaeshe expression for the current density on the juvenile surface of a crack bottom is generalized both by linear approximation of the dependence of corrosion current density on surface energy of plastic deformation of the metal and with accounting for increase of mechanical tensile stress up to yield limit. © 2018 G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine. All Rights Reserved.
The attainment of a clean surface prior to the application of any subsequent treatment or coating is essential, whether this subsequent operation is electroplating, anodizing, chemical treatment, or organic coating (painting). It is to a very large extent true that problems of early failure in all kinds of metal finishing, particularly painting, are traceable to incorrect or insufficient surface preparation. This article briefly outlines common methods of surface preparation used throughout the surface finishing industries.
This study presents microstructural investigations of graphite precipitates found in cast irons. Binary Fe-C, Fe-C-Sb and Fe-C-Ce alloys containing different graphite morphologies (flake and spheroidal) were produced and compared to commercial irons in an attempt to rationalize the effect of Sb and Ce on graphite growth. The extensive use of transmission electron microscopy (mainly electron diffraction and high resolution lattice fringe imaging) enabled further understanding of graphite growth mechanisms. It was found that the inner structure of graphite precipitates consists of growth blocks stacked upon each other, for all investigated morphologies. This suggests that graphite crystals develop mainly by a 2D nucleation and growth mechanism, and that the final shape of the precipitates is associated to the occurrence of crystallographic defects in the graphite lattice (such as twins, misorientations and rotations) during growth.
Simulation of the influence exercised by the main test factors (humidity, temperature, and aggressive components of the atmosphere) on the corrosion of metal materials was performed with the purpose to develop methods for corrosion testing of materials, junctions, and products in order to estimate the performance level of devices under all climatic operating conditions. Theoretical values of the acceleration coefficients were obtained for each test factor. Values of the test parameters were calculated, namely, concentrations of aggressive substances in a test chamber. Taking into account the earlier work on simulation of the influence of aggressive components in the industrial atmosphere on metal materials in a salt spray chamber, the concentrations of test solutions were calculated.
The effect of oxide-metallic films on the structure and properties of enamel coatings for steel articles is examined. The properties of enamel coatings are determined using metal-oxide films: chemical resistance to different media, adhesion of the coating to steel, and resistance to abrasion. It is concluded that the films developed have a positive effect on the properties of enamel coatings.
The effect of the degree of plastic deformation on the mechanical properties of structural low-carbon sheet steels and their welded joints at different temperatures is studied.
The results of an increase of wear and corrosion resistance of the working surfaces of transfer press molds by means of the development and use of the microarc oxidation method are given. The protective coatings obtained enabled an increase their service life mainly within the most stressed area of the junction (closing area) and its sharp edges. Taking into account the processes occurring in the transfer press molds, the best properties of the coating and their operation modes are specified. The laboratory tests of coatings for bending, compression with shear, wear and thermal resistance, as well as tests on the structure of the transfer press mold in full-scale production proved their safe operation over 105 cycles without any damage.
The electrochemical behaviour and corrosion resistance of glassy Fe68.6Ni28.2Mn3.2 (at%) specimens were studied in different concentrations of HCl solutions. The results indicated that the corrosion rate increased with increasing concentration of the HCl solutions. Electrochemical impedance spectroscopy results were analysed by fitting the experimental data to an equivalent circuit using the ZSim Demo program, and suitable equivalent circuit models were determined. The results obtained from the impedance and polarization measurements are in good agreement. The thermodynamic parameters were evaluated for the corrosion process and discussed.
To investigate the influence of chromium content on corrosion characteristics of weathering steels, the electrochemical measurements were performed on the steels containing 0–9% Cr (wt.%) in NaHSO3 aqueous solution. The results indicated that the open circuit potential of these steels shifted to the positive direction remarkably, because the additions of Cr improved the passivation capability of the steels. The corrosion current density of the steels containing more than 7% Cr (wt.%) decreased significantly after pre-rusted treatment, implying the corrosion resistance could be enhanced by the formation of protective goethite rust layer.
The comparative analysis of phase formation on the iron surface in aqueous medium in the presence and absence of iron–carbon (coke) galvanic contact was carried out. The role of galvanic contact in phase formation processes was determined. It was shown that, in the presence of galvanic contact almost complete oxidation of iron ions on the surface of an iron half-element and a rather efficient stationary formation of dispersed phases serving as sorbents of heavy metals from solutions take place. The effect of anionic composition of solution on the parameters of phase formation was studied. It was established that maximal amount of iron–oxygen-containing phases is formed in zinc chloride solution. The presence of sulfate and nitrate ions in solution decreased significantly the rate of phase formation in iron–carbon galvanic contact.
The effect of heat treatment on the corrosion behaviour of binary Al–Fe alloys containing iron at levels between 0.04 and 0.42wt.% was investigated by electrochemical measurements in both acidic and alkaline chloride solutions. Comparing solution heat-treated and quenched materials with samples that had been subsequently annealed to promote precipitation of Al3Fe intermetallic particles, it was found that annealing increases both the cathodic and anodic reactivity. The increased cathodic reactivity is believed to be directly related to the increased available surface area of the iron-containing intermetallic particles acting as preferential sites for oxygen reduction and hydrogen evolution. These particles also act as pit initiation sites. Heat treatment also causes depletion in the solute content of the matrix, increasing its anodic reactivity. When breakdown occurs, crystallographic pits are formed with {100} facets, and are observed to contain numerous intermetallic particles. Fine facetted filaments also radiate out from the periphery of pits. The results demonstrate that the corrosion of aluminium is thus influenced by the presence of low levels of iron, which is one of the main impurities, and its electrochemical behaviour can be controlled by heat treatment.
Hydrogen sulfide (H2S) can either accelerate or inhibit corrosion of iron under different experimental conditions. What H2S has done to both the anodic iron dissolution and cathodic hydrogen evolution, in most cases, is to have a strong acceleration effect, causing iron to be seriously corroded in acidic medium, but H2S can also have a strong inhibition on the iron corrosion under certain special conditions where H2S concentration is below 0.04 mmol dm−3, pH value of electrolyte solution is within 3–5 and the immersion time of the clectrode is over 2 h. The inhibition effect of H2S on the iron corrosion is attributed to formation of ferrous sulfide (FeS) protective film on the electrode surface. Moreover, the structure and composition of the protective film is closely related to H2S concentration, pH of solutions and the immersion time of iron. Accordingly, the influence of the three factors on the inhibition effect is investigated in this paper by means of AC impedance technology together with the potentiostatic steady-state polarization. A probable reaction mechanism is proposed to interpret theoretically how H2S inhibits the corrosion of iron.
General relations between the chemical composition of two components of one-phase alloys and their electrochemical properties in the active and passive states are discussed. The influence of alloying elements on the kinetics of anodic and cathodic reactions controlling the rate of the corrosion processes in aqueous solutions and the behaviour of alloys which corrode with the formation of solid corrosion products under atmospheric conditions is reviewed.RésuméDiscussion des relations entre la composition chimique des alliages monophasés à deux composants et leurs propriétés electrochimiques en états actif et passif. II est traité de plus de l'influence des éléments alliés sur la cinétique des réactions anodiques et cathodiques qui régissent la vitesse de la corrosion en solutions aqueuses. On examine le compartement des alliages quise corrodent avec formation de produits de corrosion solides en milieu atmosphérique.ZusammenfassungEs werden die allgemeinen Abhängigkeiten zwischen der chemischen Zusammensetzung von einphasigen binären Legierungen und deren elektrochemischen Eigenschaften im aktiven und passiven Zustand diskutiert. Der Einfluss von Legierungselementen auf die Kinetik von anodischen und kathodischen Reaktionen, die die Geschwindigkeit der Korrosionsprozesse in wässerigen Lösungen regulieren, wird zu Betracht genommen. Das Benehmen von Legierungen bei der Korrosion im aktiven Zustand mit dem Entstehen von festen Korrosionsprodukten unter atmospherischen Bedingungen wird beurteilt.PeфepaтOбcyждaютcя oбщиe oтнoшeния мeждy xимичecким cocтaвoм двyxкoмпoнeнтныx oднoфaэoвыx cплaвoв и иx элeктpoxимичecкими cвoйcтвaми в aктивнoм и пaccивнoм cocтoянии. Pacмaтpивaeтcя влияниe кoмпoнeнтoв cплaвoв нa кинeтикy aнoдныx и кaтoдныx peaкций, oпpeдeляющиx cкopocть кoppoэиoнныx пpoцeccoв в вoдныx pacтвopax. Paэбиpaeтcя пoвeдeниe cплaвoв пpи кppoэии в aктивнoм cocтoянии c oбpaэoвaниeм твepдыx пpoдyктoв кoppoэии в aтмocфepныx ycлoвияx.
A reliable method of predicting the thickness loss of weathering steel due to corrosion is currently unavailable. Corrosion loss depends significantly on the service life of the structure, the corrosive nature of the environment, and the alloy content of the steel. Therefore, a prediction method accounting for these factors should be possible. Models showing the effects of five alloying elements (copper, nickel. chromium, silicon, and phosphorus) on thickness loss in three environments (rural, industrial, and marine) are provided in this paper based on a comprehensive database. The models result in correlation coefficients higher than 0.95. The effects of the alloying elements indicated by the models show that failure to properly account for the alloying elements can yield as much as 20% error in thickness loss. The model can be integrated with existing service life models to forecast a thickness loss estimate for a required design life.
1.
An investigation was made into the effect of temperature on the rate of corrosion and kinetics of the electrode processes for copper, iron, nickel, magnesium, and zinc in 1.0 N NaCl, 1.0 N NaCl + + 0.1 N HCl, 1.0 N NaCl + 0.1 N NaOH, and 1.0 N NaCl + 0.1 N KMnO4.
2.
Confirmation was found for our previous conclusion [12]; the variation of the rate of a corrosion process with change in temperature is due primarily to change in the factor controlling the given corrosion process.
3.
Investigation of the kinetics of the cathodic reduction of oxygen at platinum in 1.0 N NaCl showed that with rise in temperature the overvoltage for ionization of oxygen diminishes, on the average, by 2.8 my per degree.
Localized corrosion processes of passive metals are almost always initiated at local heterogeneities of the substrate material.
In the case of stainless steels MnS inclusions are of primary importance. Increasing the temperature strongly accelerates
the pitting. Detailed large-scale and microelectrochemical investigations show that this is mainly caused by an enhanced anodic
dissolution facilitating stable pit growth and retarding repassivation. Activation of new inclusions, remaining inactive at
lower temperature, may also occur but are of minor importance.
This paper approaches the study of metal anodic dissolution process controlled by mass transfer. The theoretical study of this process under rotating disc conditions leads to a mathematical model that allows to calculate the mass transfer coefficient of ionic species formed at the anode. The mathematical model was experimentally verified. In this way there were employed aqueous solutions of sulphuric acid and copper sulphate (0.025 M CuSO 4 + 1.7 M H2SO4; 0.05 M CuSO4 + 1.4 M H2SO4; 0.075 M CuSO4 +1.75 M H 2SO4), and copper anodes. Based on the measured anodic polarization curves, current-limiting densities, mass transfer coefficients and anodic dissolution rates were determined. The obtained results show that the suggested mathematical model verifies well the experimental data corresponding to relatively low values of the anode rotational speed.
This paper approaches the study of metal anodic dissolution process controlled by mass transfer. The theoretical study of this process under rotating disc conditions leads to a mathematical model that allows to calculate the mass transfer coefficient of ionic species formed at the anode. The mathematical model was experimentally verified. In this way there were employed aqueous solutions of sulphuric acid and copper sulphate (0.025 M CuSO 4 + 1.7 M H2SO4; 0.05 M CuSO4 + 1.4 M H2SO4; 0.075 M CuSO4 +1.75 M H 2SO4), and copper anodes. Based on the measured anodic polarization curves, current-limiting densities, mass transfer coefficients and anodic dissolution rates were determined. The obtained results show that the suggested mathematical model verifies well the experimental data corresponding to relatively low values of the anode rotational speed.
The types of anode and cathode reactions commonly found in corrosion by aqueous media are described, and the combination of these reactions in corroding and in passivated systems is discussed.
The principal ways in which corrosion rates are increased or decreased are classified and discussed, as follows: anodic attack and cathodic protection; anodic passivation or protection and cathodic activation; anodic inhibition and stimulation; cathodic inhibition and stimulation; resistance inhibition.
The importance of the use of electrochemical and other theoretical principles in the practice of corrosion and protection is emphasised.
This paper examines the temperature dependence of component hazard rate for the cases of log-normal and Weibull failure-time distributions and shows that the common belief that the temperature variation of component failure rate follows the Arrhenius rule can be substantially in error. Although most failures in present-day equipment are not due to defective components, the paper also examines the temperature dependence of equipment rate of occurrence of failure having a power-law or negative exponential variation with time for the temperature range where the majority of failures are due to rate processes obeying the Arrhenius equation. The consequences of a Gaussian distribution of failure-mechanism activation energy in a device population are also considered.
Although the temperature dependence of failure rate can be very high, in most situations it is much less than that of the Arrhenius acceleration factor. It is very improbable that the temperature dependence of component failure rate can be meaningfully modelled for reliability prediction purposes or for the purpose of optimizing thermal design component layout.
Attention is drawn to the invalidity of determining the failure activation energy from the average failure rates in accelerated high-temperature time-terminated life tests.
The development of the theoretical and experimental basis of
accelerated atmospheric corrosion testing (ACT) of metals, whole
machines and/or their components are discussed in this paper. It is
apparent that current techniques for ACT should be improved. One
approach, to establish the necessary environmental conditions for ACT on
various products, is determine the range of metallic corrosion based
upon the periodical wettings with KCl solution and drying process of a
film of moisture, temperature and humidity in test chamber. An equation
was created to describe one range of test chamber parameters for
calculating the quantity of metallic corrosion as a function of these
parameters. The experimental results were confirmed by checking the
related statistics. The test demonstrated that the corrosive destruction
of mobile machinery is dependent upon temperature, humidity, chemical
and mechanical pollution, vibration and mechanical wear
Surface pretreatment
- Higgins