Corrosion Rate Of Metal Research Articles

A numerical analysis of the mechano-electrochemical effects on localised corrosion in pipelines using a multi-physical field coupling approach

In this study, we used a multi-physics coupling approach integrating the electrochemical and solid mechanics fields to develop a three-dimensional finite element model. This model was specifically designed to investigate the effects of mechano-electrochemical (M-E) effects on pipeline corrosion. The boundary conditions for the finite element simulation were established using experimental data, enabling the model to effectively predict the corrosion potential and current density, which aligned well with the experimental findings. Subsequently, the validated model was applied to examine the M-E effects near the pipe corrosion defects, considering various depths of corrosion defects and axial strain. Our results indicate that the stress concentration at the core of the defect increases with increasing axial tensile strain and deepening corrosion. The investigation of the correlation between the corrosion potential and net current density revealed that mechanical forces significantly impact metal corrosion rates, thus influencing pipeline longevity. When the metal structure of the pipeline is deformed within the elastic deformation range, the impact of the M-E effects on corrosion is minimal. However, when a tensile strain is applied or the defect geometry induces plastic deformation at the defect site, a notable increase in the local corrosion activity is observed.

Study the Corrosion Behavior of Low Carbon Steel Weldments Immersed in Tap Water

Corrosion is one of the main sources of failure for metals and alloys, thus it is a major engineering problem. Engineers must consider the corrosion of metals in different environments when designing engineering parts. Metals tend to corrode in different media; they show different behaviors due to differences in chemical composition and the severity of the corrosive medium. In tap water, the corrosion of mild steel products is an electrochemical phenomenon that includes two reactions: the dissolving of iron (anodic) and the reduction of oxygen (cathodic). This work observes the corrosion behavior of welded low-carbon steel by Friction Welding (FW), Shielded Metal Arc Welding (SMAW) , and MIG welding techniques using immersion tests in tap water at different periods. The results revealed that while the corrosion rate of Base Metal (BM) increases, it reaches a nearly steady state in the friction-welded and SMAW-welded samples. The difference in the corrosion rate of the welded samples can be attributed to changes in the concentrations of Cl– and CaCO3 ,as well as the pH values of the corrosive mediums. Pits could be observed in the microstructure of the nugget zone for all weldments.

Effects of electrochemical corrosion on retrogressed and different reaged friction stir welded AA7075-AA6082 dissimilar welds

ABSTRACT The research is primarily to study the microstructure, tensile and electrochemical corrosion behaviour of friction stir welded AA7075-T651-AA6082-T6 dissimilar welds, subjected to retrogression and reaging at 280⁰C for 5 min followed by aging at 110⁰Cfor 1 , 5 , 10 and 24 h respectively. The AA7075-AA6082 welds were made using optimum parameters such as feed rate 80 mm/min, tool rotation speed 980 rpm, and tilt angle 2 o . The alloys of 100 × 50 × 6mm³ plates were welded with a conical tapered tool pin profile. Further, the welds were scanned for potentiodynamic polarisation with a 3.5 percentNaCl solution. Optical metallographic (OM) images were revealed to determine morphology andcorrelate with the measured corrosion rate. Here, the dissimilar friction stir weld AA7075-AA6082-aged for 5 h had an ‘Ultimate tensile strength’ (UTS) of 269.73N/mm2 due to coherent precipitates. Moreover, at 24 h, the lower tensile strength of 226.06 N/mm2 was observed, due to coarser precipitates across the AA7075-AA6082 weld cross-section. Due to over-aged coarse precipitates, the corrosion rate of 6082BM and weld metal had increased to 5.110e + 003mpy and 1.010e + 003mpy. Under other aged conditions, the corrosion rate was decreased below 0.001mpy.

Hot-Spot Stress Analyses of a T-Shaped Tubular Joint Subjected to Uniform, Grooving and Non-uniform Corrosion

The study aims to investigate the impact of uniform, grooving and non-uniform corrosion degradation on the hot-spot stresses of a T-shaped tubular joint using the finite element method. The through-thickness linearization method is employed to estimate the hot-spot stresses, allowing a more reasonable consideration of the effect of grooving corrosion and non-unform corrosion. The grooving corrosion degradation is modelled assuming that the corrosion rate of the weld metal is 1.4 times that of the base metal. The non-uniform corrosion is modelled by moving the nodes around the weld by a random distance along the direction perpendicular to the surface. The random distances are generated based on the surface roughness parameter Ra. The results indicate that the stress concentration factor (SCF) increases with the uniform corrosion depth. The grooving corroded tubular joint results in a higher SCF than those of the corresponding uniformly corroded tubular joint. The non-uniform corrosion can lead to SCF deviations from the SCF of the uniformly corroded tubular joint. The SCF deviation at the critical region follows the normal distribution, and its standard deviation increases with Ra.

A predictive model for corrosion of carbon steel exposed to organic acids: Theory and validation in formic, azelaic and citric acid

Organic acids can severely corrode metals, despite rarely reaching particularly low pH values. The mechanisms underlying the corrosion process in the presence of organic acids can be different and more complex with respect to the ones in the presence of strong acids. Since organic acids are commonly found in several industrial environments, they pose a serious threat that needs to be carefully addressed and investigated. Throughout the years, many research efforts have been put towards predictive modeling of corrosion. The Tafel-Piontelli model aims at becoming a universal and versatile model for acidic corrosion, able to adapt to different situations and predict corrosion rates of active metals exposed to all kinds of acidic environments. The model foundations are grounded in the principles of the corrosion process, regulated by the Tafel law. The efficacy of the model was tested on carbon steel samples immersed in solutions of weak acids with increasing proticity — formic, azelaic, and citric acid — at temperatures ranging from 20°C to 60°C and pH values from 3 to 4. The validation analysis was conducted using two primary tests: mass loss tests to assess corrosion rates and potentiodynamic polarization tests to determine the kinetic parameters of the cathodic and anodic reactions involved in the corrosion process. The results from the experiments are promising, confirming and extending the predictive capabilities of the model to the case of organic acids. These findings have broad implications for improving safety and durability in industrial applications where organic acids are prevalent, highlighting the model’s potential to significantly enhance preventive strategies and material selection.

A study of pomegranate peel extract effect on corrosion inhibition performance on aluminum in HNO3 solution

Green corrosion inhibitors have an important role in reducing the corrosion rate of metals and the effects of toxic chemicals in the environment. In this study, the inhibition effect of pomegranate peel extract (PPE) with concentration of 0.5, 1, 1.5, 2, 2.5 and 3 g/L on the aluminum 1050 alloy corrosion behavior in the nitric acid solution investigates using the weight loss, electrochemical techniques, scanning electron microscope (SEM), atomic force microscope (AFM), contact angle images, gas chromatography-mass spectrometer (GC-MS) analysis, fourier transform Infrared spectroscopy (FTIR) and ultraviolet radiation (UV-IR). And, the (UV-IR), (GC-MS), and FTIR results confirm the presence of many organic compounds (Containing the N, S, and O atoms), which are responsible for inhibitor performance and absorption phenomena. Meanwhile, the electrochemical impedance results (EIS) indicate that the double layer capacity decreases and the corrosion resistance (Corrosion current density (icorr) from 0.128 to 0.009 mA/cm2) increases with the increase of the inhibitor concentration (The inhibition efficiency increased with increasing the inhibitor concentration from % 54.29 to the % 92.58 at (1–3 g/L). In addition, the corrosion current density decreases with the increase of the inhibitor concentration using the potentiodynamic polarization (PDP) test. However, the corrosion rate enhances with increasing the temperature. From the other hand, quantum chemical (QC) calculation and molecular dynamics (MD) simulation perform to investigate the theory of the adsorption mechanism. According to these studies, the adsorption of PPE on the aluminum 1050 alloy surface is agreement with the langmuir isotherm and as a result it is a mixed-type inhibitor. In final the SEM and AFM results show that the corrosion rate of the aluminum 1050 alloy surface is significantly reduced after the addition of the inhibitor to the corrosive environment. Furthermore, the contact angle image shows that the inhibited aluminum surface has a hydrophobic property in an aqueous solution. And, the QC calculation and MD simulation clarify well the thin layer formation due to the good adsorption of inhibitor (PPE) on the surface of aluminum 1050 alloy in the nitric acid solution, theoretically. It is concluded that PPE will inhibit the surface of aluminum against the corrosion agents in acidic environment and can use as a green inhibitor.

Potentiostatic oscillations of current and surface structure in a 3D cellular automaton model of metal passivation

Some recently obtained data from simulations in our 3D cellular automaton model on metal passivation are presented and discussed. The model is a non-equilibrium heterogeneous Ising-like model with moving boundary due to metal depletion by corrosion. The mobile particles representing metal oxide are produced in corrosion events. They bind to the metal surface and to each other with short range interaction. They diffuse by random walk with asymmetric exclusion and disappear in the bulk solution.The results of this paper are obtained in potentiostatic conditions. In our model, this amounts to a fixed bare metal corrosion rate. The results include current transients and surface snapshots at a number of moments of time. We define several other dynamic variables. Their transients allow us to construct phase portraits, to identify the bare metal surface area and the oxide layer thickness as the essential variables for the oscillations. The first of those is equivalent to current density by model construction. The second plays a peculiar role in periodic current spiking, as discussed in the text.

Semi-Quantitative Categorization Method for the Corrosion Behavior of Metals Based on Immersion Test

Corrosion processes are complex in nature and their studies have become an interdisciplinary research field, combining fundamental sciences and engineering. As the quantification of corrosion processes is affected by many variables, standard guidelines to study such phenomena had been developed, such as ASME and ISO, and are broadly used in industry and academics. They describe methods to perform immersion test experiments and to quantify the corrosion rates of metals exposed to corrosive environments, but do not provide any guidelines for post-exposure analysis of the as-obtained corroded samples, which might provide useful information to understand the underlying physicochemical mechanisms of corrosion. This knowledge is useful for selecting optimal construction materials and developing corrosion prevention strategies. In this work, a semi-quantitative categorization method of the corrosion behavior of metals exposed to a corrosive medium based on their mass loss and aspect is presented. For each category, the mathematical aspects of gravimetric measurements of mass change rate and the analytical techniques that can be used for the characterization of materials are discussed. The following method does not intend to replace industrial standards, but to expand them in order to maximize the amount of information that can be extracted from immersion tests.

КОРРОЗИОННО-МЕХАНИЧЕСКАЯ УСТАЛОСТЬ: ПРОБЛЕМЫ ПРОГНОЗИРОВАНИЯ. ЧАСТЬ 3. МЕХАНИЗМЫ КОРРОЗИОННО-МЕХАНИЧЕСКОЙ УСТАЛОСТИ

Corrosion is one of the main electrochemical processes that damage metal materials. The combination of cyclic stresses and a corrosive environment causes wear-fatigue damage, called corrosion-mechanical fatigue. The paper investigates the problem of predicting this type of corrosion-fatigue damage, which occurs in almost all branches of technology, especially in the chemical, oil, metallurgical industries, transport. The work consists of several parts. In the first part a technique for estimating the fatigue limit in a given corrosive environment (direct effect) is developed. The second part analyzes the reverse effect, i.e. the effect of acting stresses on the corrosion rate of metals and alloys, and proposes a method for predicting corrosion-erosion damage with the reverse effect based on the energy criterion. The third part discusses the mechanisms of corrosion-mechanical fatigue with direct and reverse effects taking into account the interacting phenomena of adsorption, hydrogen and corrosion fatigue itself. The concept of diffuse effect of multiple shear, oxidation, transfer is introduced as a complex type of damage in corrosion-mechanical fatigue.

Inhibition impact of major active ingredients of Jordanian Peganum harmala on the corrosion rate of Cu, Fe and Al metals

Inhibition impact of major active ingredients of Jordanian Peganum harmala on the corrosion rate of Cu, Fe and Al metals

Experimental teaching design of weightlessness method to determine the corrosion rate of metal

Abstract When exposed to corrosive environments, metals, which are relatively common industrial materials, undergo serious corrosion, leading to significant economic losses. Therefore, studying the corrosion rate of metals in their early stages holds great pedagogical significance. This study employs a standard specimen of 20# steel as an experimental object, designing the experimental teaching of metal corrosion rate under varying temperatures, PH levels, and hydrated salt materials. The weightlessness method determines the overall corrosion rate of the metal, while the electrochemical method determines the localized corrosion rate of the metal. When the experimental temperature is 80℃ and 100℃, the corrosion rate of 20# steel is the largest; both are 0.00800g·m−2·d−1, and the charge transfer resistance increases gradually when the temperature is −20℃~5℃, and decreases gradually when the temperature is 5℃~100℃. The corrosion rate of the metal did not change much at pH=7 and 8, and the corrosion rate reached 0.688 mm/a, and the impedance curve polarization resistance Rp was the smallest when pH=5, and its corrosion resistance was poor under acidic conditions. The average corrosion rates in MgSO4·7H2O, and CaCl2·6H2O and Ba(OH)2·8H2O were 0.0030g/m−2h−1, 0.0018g/m−2h−1, and 0.0050 g/m−2h−1, respectively. Teaching experiments were used to carry out the present study. The study aims to let students experience the process of metal corrosion through teaching experiments and better help them solve cognitive difficulties in metal corrosion.

Corrosion inhibition of extracts from the expired traditional Chinese patent medicines for Q235 carbon steel in hydrochloric acid

During the COVID-19 epidemic, traditional Chinese patent medicine played a significant role in treatment and prevention. However, excessive production of medicines will face serious disposal problems once they are expired, and how to achieve safe and efficient utilization of resources becomes another challenge. In this study, the diverse organic components of traditional Chinese patent medicine-YanReQing Granules (YGE) have been extracted and enriched using a low-temperature extraction method, and the main compositions have been analyzed by liquid chromatography-mass spectrometry (LC-MS). The inhibition performance of YGE for Q235 steel in 0.1 mol L−1 HCl solution was evaluated by various methods. The results indicated that the corrosion rate of metal decreased significantly with the addition of YGE, and the corrosion potential shifted positively as the increase of cathodic and anodic Tafel slopes, indicating that the YGE belongs to a mixed type of corrosion inhibitor with the simultaneously inhibition on cathode and anode. The inhibition efficiency of YGE increased gradually with the more additive amounts, and exceeded 99% calculated by the fitting current density in polarization curves. The active ingredients in YGE are mainly composed of hydroxyl and carbon-based aromatic hydrocarbons, which are easily protonated in hydrochloric acid solution and carry a positive charge, and then adsorb at the metal interface electrostatically to form a shielding layer. Moreover, the theoretical calculations have confirmed that the chemical adsorption can be achieved between the polar atoms and metal to enhance the protective layer ultimately.

Understanding the corrosion of Mg alloys in in vitro urinary tract conditions: A step forward towards a biodegradable metallic ureteral stent

Ureteral stents play a fundamental role in modern time urology. However, following the deployment, stent-related symptoms are frequent and affect patient health and quality of life. Using biodegradable metals as ureteral stent materials have emerged as a promising strategy, mainly due to the improved radial force and slower degradation rate expected. Therefore, this study aimed to characterize different biodegradable metals in urinary tract environment to understand their propensity for future utilization as base materials for ureteral stents. The corrosion of 5 Mg alloys – AZ31, Mg-1Zn, Mg-1Y, pure Mg, and Mg-4Ag – under simulated urinary tract conditions was accessed. The corrosion layer of the different alloys presented common elements, such as Mg(OH)2, MgO, and phosphate-containing products, but slight variations in their chemical compositions were detected. The corrosion rate of the different metals varied, which was expected given the differences in the corrosion layers. On top of this, the findings of this study highlighted the significant differences in the samples' corrosion and corrosion layers when in stagnant and flowing conditions. With the results of this study, we concluded that Mg-1Zn and Mg-4Ag presented a higher propensity for localized corrosion, probably due to a less protective corrosion layer; Mg-4Ag corroded faster than all the other four alloys, and Mg-1Y stood out due to its distinct corrosion pattern, that showed to be more homogeneous than all the other four samples, making this one more attractive for the future studies on biodegradable metals.

Preventing crystallization at high concentrated 2-amino-2-methyl-1-propanol for energy-saving CO2 capture

2-amino-2-methyl-1-propanol (AMP) combines the advantages of the faster reaction rate of primary/secondary amines and the high absorption capacity of tertiary amines, making it a highly promising alternative to monoethanolamine (MEA). However, at high AMP concentrations, the absorption products are prone to solid crystallization, resulting in unstable operation of the carbon capture system. In this work, by adding a small amount of diethylenetriamine (DETA) to AMP, the crystallization of reaction products can be effectively controlled and AMP-DETA absorbent possesses a high absorption rate, low regeneration energy, and low metal corrosion rate. Wetted-wall column tests were performed to comprehensively evaluate the mass transfer kinetics and the effect of crucial conditions, and the diffusion coefficient, gas–liquid mass transfer coefficient, enhancement factor, and mass transfer resistance distribution were obtained. The effect of the addition of DETA on the solubility of HCO3− was verified. DETA carbamate was more likely to form intermolecular hydrogen bonds with HCO3−, thus reducing the formation of dimeric or multichain macromolecules between HCO3− molecules through hydrogen bonds and inhibiting the crystallization of high concentration HCO3−. HCO3− can accelerate the desorption rate by participating in the deprotonation of protonation amines. The results demonstrated that the average regeneration energy of the AMP–DETA absorption system was reduced by 21.2 % relative to that of 5 M MEA, and its metal corrosion rate was 0.07 mm/a, which was only 7.9 % of MEA under the same conditions. The results contribute to the industrial application of AMP–DETA.

Mango extract behavior as a potent corrosion inhibitor against simulated chloride-contaminated concrete pore solution; coupled experimental and computer modeling studies

Plants extracts are nominated as reliable green sources among all classes of effective materials for metals' corrosion mitigation in various aggressive media. Herein, Mango extract was announced as a potential candidate for declining the corrosion rate of mild steel in the simulated concrete pore solution (CPS). With aiding polarization and EIS tests, the mechanism and anti-corrosion performance of the inhibitor were investigated. Surface studies were also performed for studying the inhibitors' impact on the metal surface morphology after immersion in CPS. Besides, Quantum chemistry and atomistic simulations are covered to clarify the mechanism of protection on an atomic scale. The electrochemical claims represented the mixed type inhibition and slight anodic inhibition dominancy. 2 wt.% Mango extract could diminish metal corrosion rate in the harsh CPS by around 98% index. Also, molecular simulations (Monte Carlo, MC and Molecular Dynamics, MD) represented the spontaneous absorption of the complexed heavy molecules (coordination compounds of extract molecules and inorganic cations) owing to the negative adsorption energy. Additionally, the electronic-scale quantum chemistry modeling illustrated that the adsorption of complexes mainly happened through their electron-rich sites.

Effect of SAW electrode wire preheating current on its melting rate and weldment properties of HSLA steel joint

ABSTRACT Weld strength and quality are mostly affected by process parameters, which, in turn, influence the mechanical properties of weld metal and heat affected zone. In this research work, effect of electrode wire preheating on different responses including electrode wire melting rate, wire and plate melting efficiency, width of heat affected zone, microhardness, and corrosion rate of weld metal was studied. The experiments were carried out to accumulate the response data using the optimisation techniques. Then, the quadratic mathematical models were developed and checked the significance using the tests such as ANOVA, F-test and lack of fit. The preheat current is found to be the most contributing parameter, which efficiently enhanced the wire melting rate, wire melting efficiency and microhardness of weld metal whereas reduced the plate melting efficiency, heat affected zone (HAZ) width and corrosion rate. In addition, micrographs and micro-hardness results also confirmed the significant influence of preheat current.

Corrosion of Brass Fishing Vessel Propeller in Artificial Seawater

The propeller was an important component in the fishing vessels marine propulsion system. Brass was widely used as a fishing vessel propeller. Brass was chosen because it has good mechanical properties and good corrosion resistance. The content of seawater in Indonesia has levels of 3% – 3.5% NaCl. In addition to the level of Ion Cl-, environmental factors can affect corrosion rate of material or metal. The environmental factors that affect the corrosion rate are the level of salinity, pH, DO, temperature and TDS. The objective of the present work was to explain the corrosion rate of brass in artificial seawater in Indonesia with exposure time. The material used for research is fishing vessel propeller commercial in Indonesia market. Measurement of the corrosion rate of brass used the principle of weight loss according to ASTM G31-72 (2004). During the corrosion test, the artificial seawater solution was tested for its pH and salinity quality over time of immersion. The result of immersion brass in the artificial seawater shows that the corrosion rate decreases in 1-to-10-days exposure time due to the increase in salinity levels above 30‰. While the results of exposure time immersion above 15 days tends to increase the corrosion rate due to a decrease in pH level. pH level of seawater depends on the environmental conditions and tends not to change significantly.
 Keyword: Artificial Seawater, Brass, Corrosion Rat, pH, Salinity.

Research on pitting corrosion characteristics of X90 steel based on acoustic emission and electrochemistry methods

The X90 pipeline steel pipe is expectedto become the standard steel in future pipeline construction due to its high transmission efficiency and lower cost. However, little study has been conducted on corrosion on-line monitoring of X90 steel. To investigate the pitting development of X90 steel, a combined electrochemical device and acoustic emission (AE) system was set up in this work. The results reveal that the pitting process can be divided into three stages: activation response and passive film rupture, and corrosion pit propagation, and pitting reaction. In addition, the corrosion rate of metal is quite high during the activation reaction and passivation film rupture stage, and the characteristic parameters of the AE signal are very large. In the frequency domain, the frequency range is mostly centered between 100 and 200 kHz, with a peak frequency of about 150 kHz. The corrosion pit propagation stage is the transition stage from metal oxidation to metal pitting reaction. The activity of the signal is low, and the characteristic signal is diminished, and the frequency domain characteristics are comparable to the preceding stage. The signal activity rises, the total signal intensity increases, and several signals exceeding 55 dB arise during the pitting response stage.

Corrosion Performance of Welded Joints for E40 Marine Steel

Marine steel requires excellent toughness and corrosion resistance in a low-temperature seawater environment. In this study, corrosion tests on E40 steel were performed, including electrochemical testing of the weld metal and heat-affected zone, dynamic corrosion testing in a simulated seawater environment, and the analysis and comparison of results obtained using different methods. The corrosion resistance of E40 was determined by measuring the saturation current density of the anodic dissolution of the steel in a corrosive medium by an electrochemical method. Under laboratory conditions, the corrosion resistance was investigated under simulated seawater. The results showed that regions with uneven microhardness corresponded to the inhomogeneity of the corrosion potential, with measured fluctuations of up to 40 mV. Nanoscale corrosive–aggressive non-metallic inclusions served as a substrate for the deposition of titanium and niobium carbonitrides, thereby weakening the corrosion resistance. The corrosion rate of the base metal was 1.16–1.64 mm/year, which was slightly higher than that of the heat-affected zone. The influence of deposition on the corrosion performance of welded joints under different deoxygenation processes was studied, and the deposition composition was controlled by a deoxygenation process to improve the corrosion resistance of the steel plate.

(Keynote) Parameterize Important Factors for Li Metal Batteries: Cycle Life, Calendar Life and Reactivity

The lithium (Li) metal anode is essential for next-generation high-energy-density lithium metal batteries. The calendar life and reactivity (safety) are equally important to cycle stability for the real application of Li metal anode in different devices. Our recent studies have identified that preventing Li dendrite growth by stacking pressure could improve cycle life by consuming less electrolyte and preventing inactive Li0 accumulation. A similar conclusion is obtained in the study of electrodepositing Li metal anode calendar life and reactivity (safety), in which the porosity of the deposited Li dominates the Li metal corrosion rate and reactivity. The larger the porosity of deposited Li, the faster the corrosion rate/higher reactivity will be. Moreover, all cell components must be considered when it comes to the reactivity (safety) of Li metal batteries because components may react with each other. Our results revealed that dense Li metal anode owns similar reactivity as lithiated graphite/ Li-Si alloy. All results facilitate lithium metal battery design and manufacturing.