Mass-loss Technique Research Articles

Study of the inhibitory properties of 2-((benzylthio)methyl)-1H-benzo[d]imidazole with respect to the corrosion of aluminum in a nitric acid medium

Due to its massive use, the behavior of aluminum in a 1 M nitric acid solution was studied in this work; this study which is mainly based on the inhibitory properties of 2-((benzylthio)methyl)-1H-benzo[d]imidazole (2-BTM1HBI) was carried out using the mass loss technique of temperature varying from 298 to 338 K and concentration of 10-3 mM at 5 mM. The inhibitory efficiency of 2-BTM1HBI increases with the increase of the concentration and this up to 96.09% but decreases with the increase of the temperature. The study of isotherms shows that the adsorption of the molecule studied on the surface of aluminum obeys the modified Langmuir isotherm (villamil model). The thermodynamic adsorption quantities were determined and discussed. They show that the adsorption of 2-BTM1HBI is spontaneous and exothermic with an increase in disorder. Adsorption is done in two modes: physisorption and chemsorption with a predominance of physisorption. The thermodynamic quantities of activation have shown that the dissolution process is endothermic with an increase in disorder.

Importance of the autoclave testing parameters on the initial stage of corrosion under CO2-containing geothermal environments

Autoclave corrosion testing has been used for many years; however, few have studied the effect of its shortcomings on the formation of corrosion products and corrosion behaviour. In particular, understanding of these effects under high temperature and high pressure (HTHP) is rare. In this study, we highlighted the important parameters such as heating periods, flow rates and volume-to-surface ratios influencing carbon steel corrosion in the early stages. Especially, characterisation and protection behaviour of corrosion products associated with corrosion behaviour in the heating stage under the geothermal CO2-containing environment were systematically studied via mass loss, in-situ electrochemistry and surface analysis techniques. The roles of pCO2, volume-to-surface ratio and flow rate influence the formation of the corrosion products in the early stage are also evaluated.

Furosemide drug as a corrosion inhibitor for carbon steel in 1.0 M hydrochloric acid

Furosemide (4-chloro-2-furan-2-ylmethylamino-5-sulfamoylbenzoic acid) was examined as an inhibitor for the corrosion of carbon steel (CS) in 1.0 M HCl. The investigation included mass loss (ML) and electrochemical techniques: potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The efficiency of inhibition rises with increasing Furosemide concentration and temperature. This compound follows the Temkin isotherm with good fit. The presence of varying quantities influences both anodic metal dissolution and cathodic hydrogen evolution. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) were used to detect the effect of the compound on the CS surface. The molecular inhibitory effect of Furosemide was demonstrated using quantum chemical calculations, and the molecular simulation results demonstrated the adsorption on the carbon steel surface.

Review of the Application of Gravimetric and Electrochemical Techniques to Evaluate Corrosion Mechanisms in Metal Materials

Corrosion in carbon steels is a phenomenon that causes degradation of mechanical properties; iron alloys are susceptible to corrosion. Factors such as changes in temperature, pH of the medium, and humidity accelerate the corrosion process, and the oxides formed can generate irreversible changes to the material. The evaluation of surface corrosion is necessary to be able to predict in time, to be able to provide good maintenance whether by coatings, inhibitors, or anticorrosive paints, in an opportune way, and to avoid large economic and structural losses. Gravimetric techniques such as mass loss and electrochemical techniques such as Open Circuit Potential-OCP and Electrochemical Impedance Spectroscopy-EIS, help understand the different corrosion mechanisms, simulate real conditions, and generate reproducible studies with efficiency of time and interpretation. This work shows a brief review of gravimetric and electrochemical techniques applied to the evaluation of corrosion of carbon steels.

Study of the Thermodynamic Quantities of Adsorption and Activation of Piroxicam in Copper Corrosion in a Nitric Acid Environment

The objective of this work is to assess the inhibitory efficacy of the piroxicam molecule on copper corrosion in a 1M nitric acid medium using the mass loss technique (gravimetry). The inhibition efficiency, represented as IE (%), increases with higher concentrations and temperatures. Various adsorption isotherm models (Langmuir, El-Awady, Freundlich, and Temkin) were employed to describe the interactions between the molecule and metallic copper. The Dubinin-Radushkevich isotherm, along with the Adejo-Ekwenchi isotherm, was utilized to identify the types of adsorption. Additionally, the thermodynamic adsorption and activation functions were determined and analyzed.

Assessment of the corrosivity of AISI 1020 steel through microbiological analyzes and the mass loss technique in a clayey soil

This search aims to evaluate the corrosivity of AISI 1020 steel in clayey soil through microbiological analyzes and the mass loss technique. Through the results obtained, according to the identification methodology of the Bergey manual, the presence of two microorganisms was verified, Acidithiobacillus thiooxidans and ferrooxidans , responsible for the biocorrosion process , in addition to filamentous fungi. The presence of these bacteria does not generate a classification for the soil, however, it is known that they can accelerate the corrosion process when in contact with a metallic structure. Regarding the mass loss rate, a criterion used to simulate the assessment of corrosivity in pipes, NACE Standard RP-07-75 was adopted, which defined the intensity of the corrosive process, obtaining as a result for the sterilized sample a value considered low, since it was free of microbial activities and any other contaminating factor, but for the sample without sterilization, the soil was classified as having severe potential. Therefore, this research sought to correlate the characteristics of the soil representative of the Amazon with a process of corrosion of buried pipes due to the presence of microorganisms, which would correspond to a microbiological corrosion. Although, in many cases, there is suspicion of the accuracy of corrosion monitoring techniques, mass loss and microbiological identification techniques were used, which had a positive result in relation to the microbiological one.

Experimental and Theoretical Assessments on Anticorrosion Performance of 2-(1H-benzimidazol-2-yl)-3-(4-hydroxyphenyl) Acrylonitrile for Copper in 1M HNO3

The present study was designed to determine the inhibition effect of 2-(1H-benzimidazol-2-yl)-3-(4-hydroxyphenyl) acrylonitrile in 1M HNO3 using a combined experimental and theoretical approach. Mass loss techniques revealed that 2-(1H-benzimidazol-2-yl)-3-(4-hydroxyphenyl) acrylonitrile inhibition efficiency is dependent on its concentration and temperature. It has been shown that the studied molecule inhibits copper corrosion by an adsorption behavior by donating and accepting electrons. Kinetic parameters have been determined and discussed. Quantum chemical parameters calculated by means of density functional theory (DFT) have shown that studied molecule reactivity is strongly related to the electronic properties, which could help to understand the molecule-metal interactions. The reactive sites have been determined by means of Fukui Functions and dual descriptor. Quantitative structure-property relationship (QSPR) model introduced in this study was used to find a set of quantum chemical parameters capable of correlating the experimental and theoretical data in order to design more suitable organic corrosion inhibitors. The theoretically obtained results were found to be consistent with the experimental data reported.

Copper corrosion inhibition in nitric acid solution by 2-(1,3-dihydrobenzimidazol-2-ylidene) -3-oxo-3-(pyridin-3-yl) propanenitrile: Gravimetric, Quantum chemical and QSPR studies

The metal corrosion threat in the metallurgical industry is becoming increasingly important. So in this work, the inhibition properties of 2-(1,3-dihydrobenzimidazol-2-ylidene)-3-oxo-3-(pyridin-3-yl) propanenitrile for copper corrosion in 1 M nitric acid medium were evaluated by mass loss technique, density functional theory (DFT) and quantitative structure-property relationship (QSPR) model. The results show that this compound was excellent anticorrosive properties with a maximum inhibition efficiency of 89.39 % for a concentration of 0.2 mM at 323 K. The inhibition efficiency increases with increasing temperature and inhibitor concentration. Adsorption isotherms reported that the molecule adsorbs on copper surface according to Langmuir isotherm. Thermodynamic adsorption and activation parameters were determined and analyzed. They revealed spontaneous adsorption and a strong interaction between the molecule and copper surface. DFT calculations at the B3LYP level with 6-31G(d,p) and 6-311G(d,p) basis set permitted to explain the electronic exchanges between molecule and copper, thus justifying the experimentally obtained inhibition efficiency values. A local reactivity study of molecules indicated that N (29) and C (7) atoms are the likely sites for nucleophilic and electrophilic attacks, respectively. In addition, QSPR model was used to correlate experimental inhibition efficiency with the descriptor parameters of the studied molecule, and it is found that the calculated inhibition efficiencies are close to experimental inhibition efficiencies. Finally, this study showed a good correlation between theoretical and experimental data.

Role of phosphorus as micro alloying element and its effect on corrosion characteristics of steel rebars in concrete environment

This communication reports the effect of phosphorus (P) added in micro concentration range in steel on kinetics, mechanism and growth of passive film in contact of chloride contaminated concrete. Electrochemical impedance spectroscopy, direct-current polarization, mass loss and Raman spectroscopic techniques were used to arrive at the findings. The results showed that an intentional addition of P in steel (0.064%) makes it more prone to uniform and localized corrosion (about 1.1 and 1.7 times) than the steel having low phosphorus (< 0.016%, present as tramp element) exposed under wet/dry conditions in simulated pore solution added with chloride and in the absence of this ion. A similar effect is also noted for the rebars embedded in mortars. Identification of corrosion products formed on steel rebars surface by Raman spectroscopy reveals thermodynamically stable maghemite and goethite phases on the surface of low P content steel. Unstable phase of lepidocrocite is recorded on the surface of higher phosphorus steel rebars. The findings are discussed with experimental evidence and taking clues from the published literature to arrive at plausible mechanism for this behaviour.

Chemical, Electrochemical, and Surface Morphological Studies of the Corrosion Behavior of the AZ31 Alloy in Simulated Body Fluid: Effect of NaOH and H2O2 Surface Pretreatments on the Corrosion Resistance Property.

Magnesium and its alloys have attracted attention for biomedical implant materials in dental and orthopedic applications because of their biodegradability and similar properties to human bones. The very high rate of degradation in the physiological systems is, however, a major setback to their utilization. Chemical modification is one of the approaches adopted to enhance the corrosion resistance property of Mg and its alloys. In this work, NaOH and H2O2 were used as a pretreatment procedure to improve the corrosion resistance of the AZ31 Mg alloy in simulated body fluid (SBF). Advanced techniques such as dynamic electrochemical impedance spectroscopy (dynamic-EIS), atomic force microscopy, and optical profilometry were used in addition to the classical mass loss, hydrogen evolution, EIS, and polarization techniques to study the corrosion resistance property of the alloy in SBF for 30 h. Results obtained show that the surface treatment significantly enhanced the corrosion resistance property of the alloy. From dynamic-EIS at 30 h, the charge transfer resistance of the untreated AZ31 Mg alloy is 432.6 Ω cm2, whereas 822.7 and 2617.3 Ω cm2 are recorded for NaOH- and H2O2-treated surfaces, respectively. H2O2 is a better treatment reagent than NaOH. The mechanism of corrosion of both untreated and treated samples in the studied corrosive medium has been discussed.

Statistical and Artificial Neural Network Analysis for Corrosion of Mild Steel in Hydrochloric Acid in Presence of Eco-Friendly Inhibitor

In present work, the inhibition performance of the Portulaca Grandiflora Leaf Extract (PGL), as environmental-friendly corrosion inhibitor, for low-carbon steel in 0.5 M hydrochloric acid solution at variable inhibitor concentrations and temperatures is evaluated by mass loss technique. The dependent variable was corrosion rate, while the independent variables were inhibitor concentration and temperatures. Several mathematical and artificial neural network (ANN) models have been suggested. A computer aided program is used during regression and estimation processes. Several models were used. Polynomial – individual effect, polynomial – interaction effect, linear effect, exponential growth, and piecewise regression models were estimated. Results show that the Piecewise regression model was the best one with high correlation coefficient (R2) equal to 0.9994. For ANN studies, Linear Model (LM), Radial Basis Function (RBF), and Multi-Layer Perceptron (MLP) were evaluated. The data were divided into training and testing. MLP of two inputs, multi-hidden layers, and one output (2:2-8-1:1) was the highly accurate artificial neural network model ANN with a high correlation coefficient (R2=0.9826). The effect of temperature was lower than the effect of PGL concentration as shown by mathematical and ANN analysis.

Effect of glass fibre sizing on the interfacial properties of composites produced using in-situ polymerised Polyamide-6 transfer moulding

The fibre-matrix interfacial properties of glass-fibre/polyamide-6 (GF/PA-6) composites produced by thermoplastic resin transfer moulding (TP-RTM) were investigated. Two different fibre sizings were compared, a specially-developed novel reactive fibre sizing and a standard silane glass fibre sizing. Scanning electron microscopy, atomic force microscopy and a number of mass-loss techniques were employed to study the form, distribution, quantity and degradation temperature of the fibre sizings. Activated PA-6 monomer precursor materials with viscosities of ∼10 mPa s were injected into the glass-fibre fabrics, contained between heated press platens, and polymerisation occurred in-situ within several minutes. Glass-fabric laminates with fibre volume fractions of ∼53% and low void content were produced at a pressure of ∼4 bar, with the low viscosity of the monomer negating the need for expensive high-pressure injection. Similar quality between the laminates was demonstrated by measuring density, thickness, fibre volume fraction, void content and fibre bundle distribution. Transverse mechanical properties of the composites reinforced with the novel reactive sizing were 20–28% higher than those with the standard fibre sizings, demonstrating improved fibre-matrix interfacial properties. Average mode I fracture toughness was also measured to be 10–30% higher than with the standard fibre sizing. Scanning electron microscopy and 3D depth composition were used to investigate fracture surfaces and determine the surface roughness. The novel reactive fibre sizing resulted in improved fibre-matrix adhesion and improved fracture toughness.

In-situ surface wear assessment using a bearing area curve technique

ABSTRACT Wear during running-in of rolling contact occurs at the surface asperities level and cannot be assessed using a conventional mass loss technique due to the very small changes. The purpose of this paper is to propose an in-situ wear volume measurement using the BAC technique. The experimental work is conducted in-situ and a fixed datum is set as a reference to avoid measurement errors. The wear volume measurement using a proposed BAC technique is in good agreement with the asperities profile-based technique with a small error of 1.67%. The relocation at 90% of BAC is unnecessary as it causes a measurement error of 4.67%. Therefore, the assumption that no change in the asperity valleys beyond 90% of BAC is inaccurate and may lead to error in the wear volume assessment. This study provides a validation of the BAC technique that has been used extensively in wear volume measurement.

Lead Corrosion and Corrosivity Classification in Archives, Museums, and Churches.

Sixteen localities were involved in a broad study, resulting in the classification of the indoor corrosivity of metals considered in the ISO 11844 standard, especially lead. Recently, lead has been added to the standard as a metal specifically sensitive to volatile organic compounds such as acetic acid. Data on one-year exposure in museum depositories and exhibition spaces, archives, libraries, and churches show that the currently valid lead corrosivity categories are not correctly defined. The obtained data allowed for the proposal of new realistic ranges of indoor corrosivity categories for lead. The exposure program was also used to validate techniques for determining the corrosion degradation of metal coupons. Mass increase and mass loss techniques were supplemented with the galvanostatic reduction technique and the measurement of color changes. The study identified the limitations of the mass gain method. Not only is the galvanostatic reduction technique applicable for silver and copper coupons, but the build-up of reducible lead corrosion products depends on air corrosivity. CIELab color-change measurement has proven to be a simple and easy-to-apply method for monitoring the corrosivity of indoor atmospheres with regard to lead. A more reliable response is provided by the determination of color change after 3 months of exposure rather than after one year.

Corrosion Protection of CNTs/CNFs Modified Cement Mortars

The aim of this study is to examine the performance of nano additives in two different sets of mortar specimens armed with reinforcing steel rebars. In particular, three sets of reinforced concrete cylinders with additives of 0.1% wt of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) have been exposed to a solution of 3.5% NaCl, and further examined for the impact of nano-modification on corrosion performance. The anti-corrosive performance of these additives was investigated through linear polarization technique (LPR), mass loss and mercury porosimetry technique (MIP). From the investigation results, it is found that the addition of CNTs/CNFs causes lower steel corrosion, whereas the pore structure of concrete with CNTs/CNFs can significantly reduce the mass loss rate and the relative permeability.

Corrosion inhibition studies on mild steel in HCl by a newly synthesized benzil monohydrazone based Schiff base

The corrosion inhibition effect of newly formulated Schiff base 2-((E)-((E)-2-hydrazone-1, 2-diphenylethylidene) amino phenol) (HDAP) ligand L derived from Benzil monohydrazone and 2-Aminophenol on mild steel in 1 ​M HCl was examined. Electrochemical (Tafel and EIS) and mass loss techniques were employed to evaluate its corrosion protection efficiency. The inhibition efficiency (η %) was elevated with raise in concentration of compound L.Maximum inhibition efficiency of 94.18% was obtained at 0.01 ​M concentration of HDAP from Tafel polarisation curve. From electrochemical impedance (EIS) studies, it was confirmed that increase in concentration of HDAP led to enhancement of the charge transfer resistance. Both physical and chemical types of adsorptions were observed for the Schiff base via π-bonding electrons which obey Langmuir adsorption isotherm. The SEM picture revealed development of a thin layer on metallic surface. Quantum chemical evaluations were conducted to find out the mechanism of corrosion retardation power of HDAP.

Inhibition Effect of Atenolol on Copper Corrosion in 1M HNO3: Experimental Study and DFT

Atenolol was examined as a copper corrosion inhibitor in 1M nitric acid solution using the mass loss technique and quantum chemical studies, based on density functional theory (DFT) at the B3LYP level with the base 6-311G (d,p). The inhibitory efficiency of the molecule increases with increasing concentration and temperature. The adsorption of the molecule on the copper surface follows the modified Langmuir model. The thermodynamic quantities of adsorption and activation were determined and discussed. The calculated quantum chemical parameters related to the inhibition efficiency are the energy of the highest occupied molecular orbital E(HOMO), the energy of the lowest unoccupied molecular orbital E(LUMO), the HOMO-LUMO energy gap, the hardness (η), softness (S), dipole moment (μ), electron affinity (A), ionization energy (I), absolute electronegativity (χ),absolute electronegativity (χ), fraction (ΔN) of electrons transferred from Atenolol to copper and electrophilicity index(ω). The local reactivity was analyzed through the condensed Fukui function and condensed softness indices to determine the nucleophilic and electrophilic attack sites. There is good agreement between the experimental and theoretical results.

Fagonia arabica extract as a safe‐environment green corrosion inhibitor for Cu in HNO3 solution

AbstractThe effect of Fagonia arabica as corrosion inhibitor for Cu in nitric acid solution was studied utilizing mass loss technique, potentiodynamic polarization measurement, electrochemical impedance spectroscopy method, and scanning electron microscopy (SEM); the inhibition efficiency was found to increase with increase in the concentration of inhibitor; the inhibitive effect of this inhibitor was explained based on adsorption metal surface, the adsorption effect follows Flory‐Huggins adsorption isotherm. The corrosion rate was calculated; the results revealed that F. arabica has good inhibition effect on Cu. The surface morphology of Cu metal was examined by employing various techniques such as atomic force microscopy (AFM) and SEM. The AFM results observed greater inhibition efficiency of F. arabica for Cu dissolution in the acid corrosive environment. The parameters for the corrosion procedure have also been determined and discussed.

Evaluation of inhibitive performance of Allamanda cathartica leaves extract as a green corrosion inhibitor on mild steel in acid medium

Thecorrosion mitigationof mild steel in 1.0 M H2SO4acid solution by Allamanda cathartica leaves extract was investigated at different temperatures by mass loss technique. The inhibition efficiency was measured using electrochemical studies such as potentio-dynamic polarization technique and impedance measurements. Adsorption, thermodynamic and kinetic parameters were calculated in this work. Adsorption studies showed that the phytochemical constituents present in the inhibitor adsorbed on the metal surface. The spectrochemical studies and morphological studies confirms the formation of protective layer on mild steel in corrosive medium. The contact angle method predicted the hydrophobic nature of the mild steel in the presence of inhibitor. This research work showed that Allamanda cathartica leaves extract act as a best eco-friendly inhibitor on mild steel in acid medium.

Achieving a high corrosion resistant and high strength magnesium alloy using multi directional forging

An attempt was made to develop a corrosion-resistant, high-strength Mg alloy using multi-directional forging (MDF). An extruded alloy as well as pure Mg was MDFed at temperatures between 220 and 340 °C with 40 °C intervals. Grains, second phase distribution, and Volta-potential difference between second phases and matrix were measured. Moreover, tensile and compression tests were used to assess mechanical properties. The corrosion behavior was characterized using electrochemical, hydrogen evolution, and mass loss techniques. A corrosion-resistant Mg alloy with a corrosion rate less than even high purity Mg obtained which has not been previously reported for a light Mg alloy. It was found that the lowest corrosion rate can be obtained for the alloy MDFed at 300 °C.