Weight Loss Measurements Research Articles

Corrosion behavior analysis of steel in simulated carbonated concrete pore solution based on 3D optical microscopy method

The main purpose of this study was to analyze the corrosion behavior of steel in simulated carbonated concrete pore solution (SCCPS) with the help of 3D optical microscopy method. This method was adopted to provide qualitative observation of surface with 3D information and quantitative results of defects for steel which was affected by various NaCl contents and inhibitors (inorganic inhibitor (NaNO2) and organic inhibitor (DEA(C4H11NO2)). As the NaCl contents changed during all corrosion periods, the mean pitting depths (Ra) and NaCl contents showed stronger linear relationships, and the slop values presented as the Ra added value of per wt% for different inhibitor systems were all detected to be closed to 3 μm/wt% in all linear regression models. This method provided a new angle to investigate and estimate the defect variation on steel surface, which denoted to better understand the corrosion behavior in SCCPS. Additionally, electrochemical impedance spectroscopy (EIS) and weight loss measurements were also used to verify the results of 3D optical microscopy analysis.

Identification of Bacterial Species Capable of Degrading LDPE

Abstract: The Plastic is polymeric material having capability of being molded or shaped by the application of heat and pressure. The low-density polyethylene(LDPE) is the type of plastic which is used in various purpose of our daily life. It is one of the major environmental problems because of its slow degradation rate .To control the pollution caused by low-density polyethylene, microbes are isolated from the dumping site of the Durg region of Chhattisgarh. These microbes are screened by the zone of clearance method for degradation of low-density polyethylene using PEG as substrate. The screened microbes were identified by morphological and biochemical characteristics.Nine bacterial isolates was selected for biodegradation studies.Confirmation of bacterial biodegradation of low-density polyethylene was performed by using weight loss measurement and pH change due to production of acidic product.One potential isolate were further identified through 16S rRNA sequences Alcaligenes faecalis was shown the high degradation rate of low-density polyethylene

Synthesis and Performance of a New and Simple Schiff Base Structure for Corrosion Inhibition of C38 steel in 1 M HCl Solution: Experimental Studies and DFT Investigation

In order to investigate the corrosion of carbon steel (C38) in acidic media, experimental studies (weight loss measurements, electrochemical methods, thermodynamic adsorption isotherms and field emission scanning electron microscopy coupled with energy dispersive X-ray) and computational approach were adopted to study the newly synthesized and simple Schiff base structure, namely 4-((phenylimino)methyl) phenol (PIMP) as a corrosion inhibitor for C38 steel in 1M HCl. Characterization techniques (Fourier Transform Infrared spectroscopy, mass spectrometry, proton nuclear magnetic resonance) showed that PIMP was successfully synthesized with a yield of 63%. Experimental methods (weight loss, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP)) showed that PIMP is a mixed-type inhibitor with an inhibition percentage of 91.1% under optimal conditions (7.5 mM PIMP at 30°C). These experimental results were supported by surface analysis (Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-Ray (EDX)), where PIMP molecules are adsorbed on the steel surface and form a protective barrier against aggressive ions, thereby limiting steel oxidation. The adsorption of PIMP on the carbon steel surface followed the Langmuir adsorption isotherm along with a mixture of physical and chemical adsorption, forming a complete and dense protective film on the C38 steel surface. Theoretical results using density functional theory (DFT) calculations showed that PIMP contains highly reactive centers and confirmed the experimental results obtained.

Assessment of the ability of Pseudomonas aeruginosa and Staphylococcus aureus to create biofilms during wound healing in a rat model treated with carboxymethyl cellulose/carboxymethyl chitosan hydrogel containing EDTA.

The primary objective of this study was to develop a carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCS) hydrogel containing ethylene diamine tetra acetic acid (EDTA) as the materials for wound healing. CMC and CMCS solutions were prepared with a concentration of 4% (w/v). These solutions were made using normal saline serum with a concentration of 0.5% (v/v). Additionally, EDTA with the concentrations of 0.01%, 0.05%, 0.1%, 0.5%, 1%, and 2% (w/v) was included in the prepared polymer solution. The analysis of the hydrogels revealed that they possess porous structures with interconnected pores, with average in size 88.71 ± 5.93 μm. The hydrogels exhibited a swelling capacity of up to 60% of their initial weight within 24 h, as indicated by the weight loss and swelling measurements. The antibacterial experiments showed that the formulated CMC/CMCS/EDTA 0.5% hydrogel inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, the produced hydrogels were haemocompatible and biocompatible. At the last stage, the evaluation of wound healing in the animal model demonstrated that the use of the produced hydrogels significantly improved the process of wound healing. Finally, the findings substantiated the effectiveness of the formulated hydrogels as the materials for promoting wound healing and antibacterial agents.

Isoindigo derivatives as some potential corrosion inhibitors for mild steel in hydrochloric acid solution: Synthesis, experimental and theoretical studies

This investigation synthesized two isoindigo derivatives (IIDBr-NBr and IIDBr-MBr). These derivatives were then applied as green corrosion inhibitors for mild steel in a 1 mol L−1 HCl aqueous solution. The study investigated the corrosion inhibition performance of IIDBr-NBr and IIDBr-MBr through electrochemical and weight loss (WL) measurements, as well as surface analysis (SEM, AFM and XPS). The results showed that both IIDBr-NBr and IIDBr-MBr exhibited excellent corrosion inhibition performance (inhibition efficiency of 96.27 % for IIDBr-NBr and 96.46 % for IIDBr-MBr). Quantum chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) were used to reveal the adsorption mechanisms of IIDBr-NBr and IIDBr-MBr at the steel/solution interface.

Corrosion Inhibition by Musa paradisia ca Peel Extract for SS 304 in 1 M Hydrochloric Acid Solution

Objectives: To study the corrosion inhibition of Musa paradisiaca peel (MPP) extract for stainless steel (SS) 304. Method: The corrosion rate of stainless steel was studied by weight loss measurements in a 1 M hydrochloric acid solution at different concentrations of MPP inhibitor and at various temperatures, e.g., 298 K, 303 K, and 308 K. Scanning electron microscopy (SEM) was used to study the morphology of the films created on the stainless steel surface in various immersion media at various immersion times. Both potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) examined inhibition efficiency. Langmuir adsorption isotherm studied inhibitor surface adsorption SS 304. Findings: The corrosion rate and inhibition efficiency depend on the concentration of the inhibitor and the temperature. When there is an increase in the concentration of the inhibitor, inhibition efficiency increases, e.g., at 50 mg/l concentration, 77% inhibition efficiency, and at 200 mg/l concentration, 87% inhibition efficiency at 298 K. When temperature increases, inhibition efficiency decreases, e.g., at 200 mg/l concentration, 87% at 298 K, 85% at 303 K, and 83% at 308 K. Novelty: This article provides an eco-friendly corrosion inhibitor for stainless steel 304. Musa paradisiaca peel extract inhibitor was previously used for iron, mild steel, and carbon steel but was not used for stainless steel 304 in 1 M HCl. Keywords: Corrosion, Stailess stell, Inhibitor, Acid

Relationship between ceramic additives and improved biodegradability, osseointegration, and surface roughness of Ni–Ti shape memory alloy for use in load-bearing bone site applications

To make metallic biomaterial implants acceptable for use in bone replacement applications, this research aimed to identify a potential means of improving the poor wear resistance of implants as well as their limited osseointegration capability and rapid biodegradation. In this regard, mechanical alloying was used to make a nickel-titanium (Ni–Ti) shape memory alloy with increasing amounts of hardystonite (HT) and niobium carbide (NbC). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to examine the phase composition and microstructure of the sintered samples. To test osseointegration and biodegradation, samples were immersed in simulated body fluid (SBF). They were then analyzed using SEM, weight loss measurements, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The SEM pictures indicated that increasing HT and NbC helped build apatite layers on their surfaces, anticipating successful osseointegration if utilized as bone implants. ICP findings showed that HT and NbC significantly reduced Ni2+ ion release, preventing tissue damage. In contrast to electrical conductivity, these ceramics improved the compressive strength and microhardness of the examined samples. The improvement in their strength was 10.81, 27.02, 21.62, and 31.89 %. SEM results confirmed the role of ceramic materials to enhance the wear resistance of the tested samples. Based on these findings, the prepared nanocomposites achieved the main goal of this study.

Evaluating the corrosion inhibition efficiency of 5-(4-pyridyl)-3- mercapto-1,2,4-triazole for mild steel in HCl: insights from weight loss measurements and DFT calculations

Evaluating the corrosion inhibition efficiency of 5-(4-pyridyl)-3- mercapto-1,2,4-triazole for mild steel in HCl: insights from weight loss measurements and DFT calculations

Gravimetric and electrochemical evaluation of environmentally novel nanopyrazole derivatives for 304 SS in acidic solution: AFM, SEM/EDX, contact angle, and DFT/MDs simulations

Influence of two novel corrosion inhibitors of bis(chromeno[4,3‐c]pyrazol‐4‐oxo‐2‐yl)phosphineoxide (CPO) and bis(4‐formyl‐3‐phenyl‐1H‐pyrazol‐1‐yl)phosphineoxide (FPO) on the localized corrosion protection of 304 stainless steel (304 SS) in a 1.0 M HCl solution was investigated at different concentrations (10−13−10−5 M) and at different temperatures (298–343 K). Weight loss and electrochemical measurements indicated that the pyrazole derivatives are efficient inhibitors for corrosion of 304 SS, and the inhibition efficiency was increased with inhibitor concentrations up to 73.18 and 98.50 % for CPO and FPO, respectively. Langmuir adsorption isotherm was found to be the more fitted model for the adsorption process description with mixed adsorption mechanisms. UV–visible and XRD measurements showed the formation of a protective film formed by corrosion inhibitors. The scanning electron microscope (SEM) images, energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and static contact angle measurement corroborated the protection provided by CPO and FPO inhibitors on the surface of 304 SS immersed in a 1.0 M HCl solution. FPO exhibits antibacterial activity, and CPO has antifungal activity. The relationships between the corrosion protection performance of the pyrazole derivatives, their structural properties, and the adsorption type were determined by density functional theory (DFT), natural bond orbital (NBO), and molecular dynamics (MD), which confirmed that FPO has a higher corrosion protection efficiency than CPO. The theoretical parameters were in good agreement with the experimental results.

Study on the corrosion inhibition properties of some quinoline derivatives as acidizing corrosion inhibitors for steel

In this paper, four quinoline quaternary ammonium salts were synthesized using quaternization reaction, which were benzyl quinolion (BQL), naphthylmethyl quinolinium chloride (NQL), benzyl-8-hydroxy quinolinium chloride (BHQ) and naphthylmethyl 8-hydroxy quinolinium chloride (NHQ). The corrosion inhibition properties of the quinoline derivatives as corrosion inhibitors on P110 steel in 20% HCl solution at 60°C at different concentrations were investigated by weight loss and electrochemical measurements. The results showed that as the concentration of corrosion inhibitor increases, the corrosion rate decreased and the inhibition efficiency improved. Among various corrosion inhibitors at the same concentration, their inhibition efficiencies can be ranked from lowest to highest as follows: QL(quinoline)<8-HQ(8-hydroxyquinoline)<BQL<BHQ<NQL<NHQ. The inhibitors synthesized from 1-chloromethyl naphthalene, NQL and NHQ, exhibited excellent inhibition property, in which the inhibition efficiencies reached to 99.8% and 99.9% even with concentration of 0.1%. It also demonstrated the adsorption of all inhibitors on the steel surface followed Langmuir adsorption isotherms, in which QL and 8-QH exhibited as physical adsorption, BQL and BHQ exhibited as mixed adsorption and NQL and NHQ exhibited as chemical adsorption. The inhibition mechanism of inhibitors was also investigated with scanning electron microscopy (SEM), quantum chemical analyses and molecular dynamics simulations, which proved BHQ and NHQ can facilitate an increase in electron cloud density on the benzene ring, thereby enhancing corrosion inhibition performance.

Fabrication of Protective Organic Layer Using Schiff-Base Metal Complex Responsible for Excellent Corrosion Performance: Experimental and Theoretical Perspectives.

The effectiveness of a copper(II) complex with a Schiff base derived from 2-amino-4-phenyl-5-methylthiazole and salicylaldehyde (APMS) as a corrosion inhibitor for XC18 steel in an HCl solution was investigated. Experimental findings indicated a slight negative correlation between inhibition efficiencies in 1 M HCl and temperature but a positive correlation with both inhibitor concentration and immersion time, respectively. The weight loss measurement revealed that APMS achieved a maximum inhibition rate of 92.07% at 303 K. A fitting analysis demonstrated that APMS adheres to the Langmuir adsorption isotherm. The electrochemical results revealed an enhanced inhibitive performance of APMS, with the efficiency increasing as concentrations increased, ultimately reaching a peak of 94.47% at 5 × 10-3 mol L-1. Potentiodynamic polarization measurements revealed that APMS acted as a mixed-type inhibitor without affecting the corrosion mechanism. Scanning electron microscopy investigations of the metal surfaces corroborated the presence of an adsorbed organic layer. Advanced theoretical calculations utilizing density functional theory and first-principles density-functional tight-binding were conducted to gain insights into the behavior of APMS on the metal surface. APMS derives its advantages from crucial inter- and intramolecular interactions, resulting in the formation of a resilient adsorption layer, in line with the experimental findings. It is found that the presence of the APMS-based inhibitor exhibits a significant synergistic corrosion inhibition effect. The current study offers a design direction for enhancing the structural characteristics of Schiff base metal complexes, laying the groundwork for multifunctional frameworks to minimize corrosion rates with considerations for real-world use and cost-efficiency. The ability to replace harmful, expensive constituents with sustainable, and cost-effective organic alternatives represents a significant outcome of this study.

Optimization and Predictive Modelling of Gravimetric Corrosion Characteristic of Irvingia Gabonensis Leaves Extracts as Anti Corrosion Inhibitor of Mild Steel in HCl Solution

 In this research, the optimization and predictive modeling of gravimetric corrosion characteristics of Irvingia gabonensis leaf extracts (IGLE) as an anti-corrosion inhibitor of mild steel in hydrochloric acid were investigated. Design expert software version 11 were used to analyze the corrosion inhibition-related process characteristics, such as inhibition efficiency, corrosion rate, and weight loss, and their relationships. An effort were made to obtain the optimal conditions for these corrosion inhibition-related process characteristics. Weight loss measurement and design methodology were used for the evaluation of the inhibition efficiency of IGLE for mild steel in HCl. The corrosion inhibition process variables were optimized and predictive regression models were developed using Box-Behnken tool of the Response Surface Methodology (RSM). The findings showed that there were a good fit between the model predictions and the experimental results. The quadratic models developed were significant with P value less than 0.05.  The research established an inhibition efficiency of 88.9%, a corrosion rate of 0.143mm/yr, and a weight loss of 0.02 g, which were obtained at the optimum conditions of an extract concentration of 0.6 g/L, an immersion time of 16 hrs, and a temperature of 298K.Therefore, the models were considered ideal for prediction with a confidence level of 95%, and the optimal combination is suitable for the corrosion inhibition process design. Hence these models can be recommended for applications such as oil well acidizing and pickling pipelines.

Insights of 2-(Benzoxazol-2-ylthio)-N-(4-phenyl-5-phenylazo-thiazol-2-yl)-acetamide as a novel corrosion inhibitor for J55 carbon steel in hydrochloric acid: Experimental, Spectroscopic analysis, and theoretical studies

The inhibitory efficacy of 2-(Benzoxazol-2-ylthio)-N-(4-phenyl-5-phenylazo-thiazol-2-yl)-acetamide (BNP) was systematically explored through weight loss measurements, potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS), in relation to the corrosion mitigation of J55 carbon steel (J55CS) within hydrochloric acid (HCl) environments. This research employs a combination of experimental techniques, including gravimetric analysis, electrochemical tests, and theoretical considerations. It has been determined that BNP has an inhibitory effect on the corrosion of J55CS in strong HCl, reaching 91.8% at 18 × 10−6 M at 298 K. The inhibitory efficiency displays a notable enhancement as the concentration of the BNP is elevated within the range of 3–18 × 10−6 M. Conversely, the IE% experiences a raised when the temperature is raised. This augmentation can be attributed to the inherent ability of BNP to facilitate the formation of inhibitory films on the surface of J55CS. An analysis of Tafel plots reveals that the BNP adheres to a mixed-type inhibitor. The adsorption of BNP obeyed the Temkin adsorption isotherm. The investigated isotherm plots revealed that the adsorption process for BNP on the metal surface was endothermic, spontaneous, and chemical adsorption. Theoretical modeling [density functional theory (DFT) and Monte Carlo (MC)] revealed the correlation between the BNP molecular chemical structure and its anticorrosive property.

Influence of Galvanized Steel on Kombucha Fermentation: Weight Loss Measurements, Scanning Electron Microscopy Analysis, Corrosion Activity, and Phytochemical Study

This study aimed to investigate the influence of galvanized steel coupons on black tea kombucha fermentation. As a secondary objective, the corrosion activity of the fermented medium at different stages of fermentation was investigated. The results revealed significant interactions among microorganisms, the metal, and the fermented medium. On one hand, mass loss measurement, scanning electron microscopy (SEM) analysis, and released zinc and iron ion analysis showed the deterioration of galvanized steel coupons. On the other hand, HPLC-RI analysis showed that the presence of steel coupons improved the kinetics of fermentation. The chemical composition and bioactivity of kombucha were also influenced by the presence of galvanized steel. The results showed the detection of eleven phenolic compounds by HPLC-DAD, including trihydroxyethylrutin, methyl 3,5-dihydroxybenzoate, and ethyl 4-hydroxy-3-cinamate, which were found only in kombucha in the presence of galvanized steel (K+GS). In addition, a total of 53 volatile compounds were detected by GC-MS before and after derivatization, including eleven constituents identified for the first time in K+GS. Concerning antioxidant activity, a higher percentage of inhibition against the DPPH radical was attributed to the ethyl acetate extract found in K+GS (IC50 = 8.6 µg/mL), which could suggest the formation of inhibitors. However, according to the electrochemical findings, the corrosion current density increased threefold during the fermentation process compared to acidified black tea, indicating that corrosion activity was promoted in the kombucha medium and suggesting several competing phenomena between corrosion and inhibition.

Inhibition of mild steel corrosion by 4-[(benzylidene)-amino]-antipyrine

The inhibition effect of 4-[(benzylidene)-amino]-antipyrine (BAAP) on corrosion behaviour of mild steel in 1 M HCl solution was studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. Polarization measurements indicate that BAAP acts as mixed type of inhibitor. The adsorption of BAAP on the mild steel surface follows Langmuir adsorption isotherm model. The thermodynamic parameters governing the adsorption process were determined and discussed. Also, quantum chemical parameters were calculated to provide further insight into the mechanism of inhibition action of BAAP.

Exploring sustainable corrosion inhibition of copper in saline environment: An examination of hydroquinazolinones via experimental and ab initio DFT simulations

Copper's potential in various applications is constrained due to environmental degradation, particularly in high-salinity environments, representing a sustainability concern. Herein, two novel hydroquinazolinones, namely 1-((4-hydroxynaphthalen-1-yl)methyl)-2-phenyl-2,3-dihydroquinazolin-4(1H)-one (DQ-H) and 1-((4-hydroxynaphthalen-1-yl)methyl)-2-(p-tolyl)-2,3-dihydroquinazolin-4(1H)-one (DQ-CH3), were analyzed for their ability to inhibit copper corrosion in a 3.5 % NaCl solution. The compounds, characterized by 1H and 13C NMR, were evaluated via potentiodynamic polarization curves, electrochemical impedance spectroscopy, and weight loss measurements. Comprehensive analyses utilizing scanning electron microscopy, Fourier Transform Infrared, and UV–vis spectroscopy have revealed insights into the surface morphology and the interactive nature of inhibitor molecules with the copper surface. Our findings highlight the formation of a strong, sustainable inhibitor film on the copper surface due to the addition of hydroquinazolinones, thereby exhibiting an enhanced polarization resistance and decreased double-layer capacitance. Both DQ-H and DQ-CH3 demonstrated a considerable inhibition effect, with efficiencies of 92 % and 94 % respectively, illustrating their potential for sustainable copper protection. Electrochemical impedance spectroscopy (EIS) results indicated a significant increase in polarization resistance from 605.7 (blank) to 9403 and 12861 Ω cm2, after the addition of DQ-H and DQ-CH3, respectively. Furthermore, the adsorption attributes of the compounds on the Cu(111) surface were examined using first-principles density functional theory simulation, revealing several covalent bonds formation. Our work aims to contribute to sustainability efforts in materials science by offering a corrosion-protective solution that is less harmful to the environment and more efficient in preserving copper's durability, particularly in saline environments.

Effect of tabebuia heterophylla plant leaves extract on corrosion protection of low carbon steel in 1M HCl medium: Electrochemical, quantum chemical and surface characterization studies.

In the current study the chemical constituents of Tabebuia heterophylla plant leaves extract (THLE) evaluated as corrosion inhibitor for low carbon steel (LCS) in 1 M HCl. The major component present in plant extract was Hexadecanoic acid 2-hydroxy-1-(hydroxymethyl) ethyl ester confirmed by Gas Chromatography with Mass spectroscopic (GC-MS) analysis. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarisation (PDP) and weight loss measurements were used to evaluate the THLE ability to protect low-carbon steel surface against corrosion in 1M HCl medium. The maximum inhibition efficiency reported as 95.45%, 93.99% and 94.79% by weight loss measurements, EIS and PDP methods respectively. In the prolongation of the work, the entropy of adsorption (Δ Sa*), enthalpy of adsorption (Δ Ha*), Gibbs free energy of adsorption (Δ Ga*), and activation energy (Ea) of the reaction were calculated. In absence of inhibitor, the Ea value was found to be minimum 49.38 kJ/mol whereas for optimum concentration of THLE it was found to be 77.2 kJ/mol implies more energy is required to undergo corrosion. The surface morphological observation from Scanning Electron Microscope (SEM), Atomic Force Microscopic (AFM) and Contact angle explored the effective adsorption of THLE. AFM values revealed that average surface roughness (Ra) value of LCS is high (188.08), where as in the presence of THLE, Ra values significantly reduced to minimum value of 37.226. Further chemical interactions between THLE and the low-carbon steel surface as well as inhibitory mechanism were further elucidated by theoretical simulations such as Density Functional Theory (DFT) calculations and Molecular dynamics (MD) simulations.

Dried algae as potential functional ingredient in fresh cheese

AbstractAlgae have attracted the attention of researchers and consumers due to their health‐promoting bioactive compounds. In addition, the high content of polysaccharides may confer important technological properties when included in foods with high moisture content, such as fresh cheese. In this study, two dried algae species—Fucus spiralis and Petalonia binghamiae, were added to fresh cheese to improve its functional properties. Syneresis was evaluated by water holding capacity (WHC) and measurement of weight loss of the cheeses during storage at 4°C. Cheeses were also analysed for antioxidant activity, composition, and organoleptic properties. The addition of dried seaweed significantly reduced the weight loss of fresh cheese during storage (p &lt; 0.05), which is normally associated with a loss of sensory properties. A significant increase (p &lt; 0.05) in antioxidant activity was also observed in the cheeses with the addition of both algae. Except for the cheese with the addition of F. spiralis (1 g/100 g), the chemical composition did not change (p &gt; 0.05) when the algae were added to the cheeses. Cheese with the addition of dried F. spiralis showed the best results in the sensory tests, consumer preference, and purchase intention.

Arachis hypogaea’s concentration effect on AISI 1020 carbon steel for corrosion protection

The effects of inhibitor concentration on the corrosion rate and inhibition efficiency of AISI 1020 steel in an acidic and alkaline environment were investigated by means of weight loss measurement at an interval of 7 days and 14 days. To carry out this investigation, the Arachis hypogaea hull was extracted and concentrated in various weight percentages. The inhibition efficiency increased with the increased concentrations of AISI 1020 steel that were immersed in acidic and alkaline solution in the absence and presence of varying inhibitor concentrations of Arachis hypogaea hull extracts. The corrosion behavior, including the corrosion rate, is meticulously characterized through the corrosion rate analysis. The results showed that there is an increase in inhibition efficiency with an increase in inhibitor concentration and that there is a decrease in inhibition efficiency with an increase in immersion time. The organic inhibitor (Arachis hypogaea hull) produced the best inhibition efficiency of 96.4% at a 30% concentration. From the result obtained, Arachis hypogaea hull extracts revealed that it is best suited for inhibition of corrosion of mild steel in both acidic and alkaline environments. The goal of this research paper is to develop a comprehensive understanding of the corrosion inhibition and adsorption mechanisms associated with the implementation of the Arachis hypogaea hull as a natural corrosion inhibitor.

Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

Marked changes in temperature, pH, dissolved oxygen (DO) content, and nutrient content typically occur in marine thermoclines, which are key factors that affect the corrosion of metals. Offshore platforms require marine metals to be exposed to deep-sea environments and thus increase their penetration into the marine thermocline. This study investigates the galvanic corrosion of E690 steel in a marine thermocline using a simulated marine thermocline (SMT). Specifically, the corrosion of E690 steel was analyzed using the wire beam electrode (WBE) technique, linear polarization (LP), corrosion morphology, and weight loss measurement. Results indicated that the SMT had a stable multilayer structure, and the variations in temperature, DO, pH, and nutrient concentration in the SMT were similar to those in the natural marine thermocline. There were two forms of E690 steel corrosion in the SMT: galvanic corrosion and seawater corrosion. The corrosion rate of seawater corrosion was influenced by the DO concentration. Galvanic corrosion occurred after the intrusion of E690 steel into the marine thermocline. The driver of galvanic corrosion was the difference values for Ecorrs of E690 steel at various depths of the marine thermocline. The Ecorr of E690 steel was influenced by the temperature, pH, and DO of the seawater, in the following order: DO &gt;&gt; T &gt; pH. The continuous reduction in Ecorr with depth contributed to large-scale galvanic corrosion, and the oscillation variation in Ecorr with depth was the reason for small-scale galvanic corrosion. The primary anodic regions of galvanic corrosion were located in the area with the fastest temperature variation in the thermocline, and the position of the anodic regions rose with time. The anodic regions gradually expanded with time. The proportion of galvanic corrosion in the average corrosion rate could increase up to approximately 80% in the stable anodic region. There were many hemispherical corrosion pits on the surface of the single electrodes that were at the depths of 75 cm, 105 cm, and 135 cm. These single electrodes comprised a long-term, sustainable anodic region of galvanic corrosion.