Decrease In Corrosion Rate Research Articles

Evaluation of Mixed Corrosion Inhibitors in Cooling Water System

The effect of mixed corrosion inhibitors in cooling system was evaluated by using carbon steel specimens and weight loss analysis. The carbon steel specimens which immersed in mixture of sodium phosphate ( Na2HPO4 ) used as corrosion inhibitor and sodium glocunate ( C6 H11 NaO7 ) as scale dispersant at different concentrations (20,40, 60, 80 ppm) and at temperature 25°C for (1-5) days. The corrosion inhibitors efficiency was calculated by using uninhibited and inhibited water to give 98.1%. The result of these investigation indicate that the corrosion rate decrease with increase the corrosion inhibitors concentration at 80 ppm and for 5 days, (i.e. corrosion rate= 0.042 gmd).

Effect of Cu on the passivity of Ti–xCu (x = 0, 3 and 5 wt%) alloy in phosphate-buffered saline solution within the framework of PDM-II

The effect of copper content on the passivity of Ti–xCu alloys in a phosphate-buffered saline electrolyte (pH 7.4), in the steady-state condition, was examined using potentiostatic polarization, electrochemical impedance spectroscopy, and Mott-Schottky analysis. The study demonstrates that the oxide layer forms on the Ti–xCu alloys surface have n-type semiconducting character, and the steady-state thickness of the oxide layer is observed linearly and depends on the applied potential. The study observations are in line with the predictions of the Point Defect Model (PDM-II), which provides a physiochemically realistic description of the oxide layer formation on Ti–xCu alloys. The observations reveal that the Cu additions result in a decrease in the charge transfer resistance and capacitances associated with the hydroxide and barrier layer, an increase in the donor density, and reduce the electrochemical resistance of the Ti–xCu alloys. The study also exhibits that the decrease in the steady-state current density after the initial addition of 3 wt% of Cu is attributed to the progressive substitution of copper on the cation sublattice of the film resulting in enhanced electrostatic interaction between the immobilized copperCuTix′, and the mobile cation interstitialsCui+, which carries the excess current over and that conveyed by oxygen vacancies Vo•• in the barrier layer. Moreover, it is also observed that over a hundred-year implant period, about 0.006 cm (0.06 mm) of Ti–3Cu alloy is predicted to lose due to steady-state corrosion in the PBS solution under the given set of conditions, it is further seen that, as the Cu amount increased from 3 wt% to 5 wt% in the Ti–xCu alloys, the steady-state corrosion rate decreases.

Corrosion behavior of Cu−Al−Mn−Zn−Zr shape memory alloy in NaCl solution

Abstract The corrosion behavior of a copper-based shape memory alloy (Cu−Al−Mn−Zn−Zr) in 3.5 wt.% NaCl solution was investigated by means of potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). At the beginning of corrosion, oxidation products formed on the surface of the shape memory alloy and constantly covered the reaction surface, resulting in the decrease of corrosion rate. After 4 d of immersion in NaCl solution, the corrosion product layer became thick and porous, leading to the increase of corrosion rate, and the corrosion reaction mechanism changed from polarization control to diffusion control. The diffusion impedance increased with increasing thickness of the oxide layer for the samples immersed in NaCl solution for 6−15 d. During the whole corrosion process, the reaction mechanism of the alloy changed and the corrosion resistance was improved continuously. The corrosion products mainly contained CuO, ZnO, Al2O3, MnO/Mn2O3, MnO2 and Al(OH)3. Transition of the corrosion products from Cu2O to CuO and Al2O3 to Al(OH)3 occurred during corrosion.

Microstructural and Electrochemical Characterization of Zinc Coating onto Low Carbon Steel Substrate

Ordinary steels have poor corrosion resistance in chloride medium leading to a deterioration of their longevity. The present research work focuses on the deposition and characterization of a zinc layer by dip galvanizing onto low carbon steel ASTM A283M-98 in sheet form using different characterization techniques such as optical microscopy, scanning electron microscopy (SEM) coupled to energy dispersion spectrometer (EDS), atomic force microscopy (AFM) and X-ray diffraction (XRD). Optical microscopy and X-ray diffraction analyses of the steel reveal a ferritic microstructure with the presence of a small amount of pearlite. The deposited layer is composed of four Fe–Zn intermetallic phases, namely eta (η), zeta (ζ), delta (δ), and gamma (Γ). The electrochemical study in 0.5M NaCl medium indicate an enhancement of the corrosion resistance of ASTM A283M-98 steel coated with Fe–Zn multi-phased layer, characterized by a decrease in corrosion current (Icorr = 3.36μA/cm2) and corrosion rate (Cr = 0.29mm/year) compared to the bare steel (Icorr = 12.29μA/cm2 and Cr= 0.72mm/year).

Corrosion behavior of aluminum-Fiber Glass composite fabricated through surface mechanical alloying in alkaline media

Dissolution reaction control of aluminum in 2M KOH alkaline media was achieved through surface mechanical alloying SMA with dielectric Fiber glass ‘FG’ powder. A significant decrease corrosion rate from 0.867 for blank Al to 0.0002 mm y−1 for SMA Al with FG powder previously etched after 15 min; surface mechanical attrition treatment ‘SMAT’; Formed surface metal matrix Al/FG composites layers on Al anodes have attractive electrical properties. Its analysis obtained using X-Rays Diffraction XRD, scanning electron microscopy SEM. Used three electrochemical techniques EIS, CV and PDP indicate corrosion resistance improvement in 2M KOH correspond to inhibition efficiency reaches 99.81%. Such inhibition encourage for forming efficient and safe air batteries for interesting applications using Al anodes after consecutive SMAT & SMA processing.

The Suitability of Methylene Blue Discoloration (MB Method) to Investigate the Fe0/MnO2 System

The typical time-dependent decrease of the iron corrosion rate is often difficult to consider while designing Fe0-based remediation systems. One of the most promising approaches is the amendment with manganese dioxide (Fe0/MnO2 system). The resulting system is a very complex one where characterization is challenging. The present communication uses methylene blue discoloration (MB method) to characterize the Fe0/MnO2 system. Shaken batch experiments (75 rpm) for 7 days were used. The initial MB concentration was 10 mg L−1 with the following mass loading: [MnO2] = 2.3 g L−1, [sand] = 45 g L−1, and 0 < [Fe0] (g L−1) ≤ 45. The following systems where investigated: Fe0, MnO2, sand, Fe0/MnO2, Fe0/sand, and Fe0/MnO2/sand. Results demonstrated that MB discoloration is influenced by the diffusive transport of MB from the solution to the aggregates at the bottom of the test-tubes. Results confirm the complexity of the Fe0/MnO2/sand system, while establishing that both MnO2 and sand improve the efficiency of Fe0/H2O systems in the long-term. The mechanisms of water decontamination by amending Fe0-based systems with MnO2 is demonstrated by the MB method.

Decreasing corrosion rate of clean water distribution pipes using bio-inhibitor

Iron pipes that distribute clean water to the community often experience corrosion and leakage. It causes dirt in the soil to enter the water flow and can cause health problems. Therefore, to provide good quality water to the community, it is necessary to control pipes’ corrosion. In previous research, there has been much discussed the bio-inhibitor corrosion in pipes, but very few have tested corrosion under real environmental conditions. Thus, this research aims to analyze the amount of reduction in the corrosion rate of clean water distribution pipes using real environmental conditions using bio-inhibitors. This study employed the same bio-inhibitor but different concentration variations. The inhibitor used came from lime peel waste with various concentrations of 120, 220, and 320 ppm. Corrosion rate testing used Potentiodynamic methods. The results showed that using a bio-inhibitor of 320 ppm could reduce the pipe’s corrosion rate by 90.7%. Before being given the bio-inhibitor, the corrosion rate was 34.690 mpy, and after being given the bio-inhibitor, it decreased to 3,225 mpy. This study’s results will later be useful for the community to utilize the bio-inhibitor as an alternative to controlling corrosion in pipes.

Improved corrosion resistance of dental Ti50Zr alloy with (TiZr)N coating in fluoridated acidic artificial saliva

The electrochemical corrosion behavior of the dental Ti50Zr alloy with and without nanocrystalline (TiZr)N coating was comparatively investigated in artificial saliva solutions with different pH values and fluoride ion concentrations. The chemical stability of the passive films on the coated and non-coated Ti50Zr alloy was evaluated by calculating passive film thickness. The chemical compositions and valence structures of the passive films were analyzed by X-ray photoelectron spectroscopy (XPS). The results show that the (TiZr)N-coated alloy displays distinctly decreased corrosion rate and increased impedance compared with Ti50Zr alloy in non-fluoridated and fluoridated acidic solutions. Particularly, in the solution of pH = 3.9 and 0.15% NaF-containing, the corrosion protection efficiency of (TiZr)N coating reaches 90%. The excellent corrosion resistance of the coated alloy is attributed to that the nanocrystallines in (TiZr)N coating decreases micropores and crack defects, which strongly impedes the corrosive ions diffusion and electrode process at Ti substrate/coating interface. Meanwhile, (TiZr)N coating shows good passivation behavior in acidic solution and active–passive transition behavior in fluoridated acidic solution. The coated Ti50Zr alloy with high chemical stability has potential application prospect for dental implants.

Mechanical Characterization Studies of Aluminium Alloy 7075 Based Nanocomposites

In the present study, addition of nano silicon carbide particulates (nSiCp) in the matrix of aluminium alloy 7075 (AA7075) in different weight proportions (0 %, 0.5 %, 1 %, 1.5 %, 2 % and 2.5 %) are done by means of ultrasonic cavitation assisted stir casting technique. The distribution of reinforcing elements was visualized using Field Emission Scanning Electron Microscope (FESEM) image, which reveals that uniform distribution is possible with 1.5 % of nSiCp addition after which agglomeration of nanoparticles is observed. It is observed that with 1.5 % addition of nSiCp mechanical properties gets enhanced, after which it gets reduced. Compared with as cast alloy, tensile strength is improved by 188.17 % and micro-hardness by 48.58 % with a reduction in % elongation by 48.57 % and increase in impact strength by 73.17 % decrease in corrosion rate by 39.44 % is achieved with 1.5 % nSiCp addition with AA7075. Wear resistance tends to improve by 25 % with an increase in the coefficient of friction by 14.18 % with 1.5 % addition of nSiCp. With higher addition of nSiCp above 1.5 %, properties tend to lower due to clustering of nSiCp, which eventually lowers the surface area of nSiCp.

New green inhibitor of Olax subscorpioidea root for J55 carbon steel corrosion in 15% HCl: theoretical, electrochemical, and surface morphological investigation

The corrosion inhibition performance of Olax subscorpioidea (OS) root extract on J55 carbon steel corrosion in acidizing solution stimulated with 15% HCl was studied using weight loss and electrochemical techniques as well as surface morphological study. The weight loss study showed a decrease in corrosion rate and an increase in inhibition efficiency by increasing the OS concentration. Potentiodynamic polarization measurements indicated that the OS extract is a mixed-type corrosion inhibitor but predominantly of anodic type. Electrochemical impedance spectroscopy (EIS) studies revealed that the introduction of OS in the 15% HCl solution increases the charge transfer resistance and simultaneously decreases the double-layer capacitance, enhancing an adsorbed film formation on the steel surface. Maximum inhibition efficiency of 89.7% was obtained with EIS study in the presence of 2.0 g/L of extract. The Fourier-transform infrared spectroscopy (FTIR) results indicated that the mechanism of inhibition is an absorption process through the functional groups present in OS molecules. The adsorption of OS onto the J55 steel surface followed the Langmuir adsorption model. Scanning electron microscopy (SEM), energy-dispersive X-ray spectra (EDS) analysis, and atomic force microscopy (AFM) confirm the formation of an adsorbed protective film of the OS molecules on the J55 steel surface. Quantum chemical calculations performed by density functional theory (DFT) on the major phytochemicals present in the OS root extract supported the experimental results and explained the adsorption behavior of the extracts.

The Effect of Addition Organic Inhibitor Bintaro Fruit Extract (Cerbera Manghas) to Inhibition Eficiency and Corrosion Rate on JIS G3131 Steel in 0,1 M H2so4 Environment

Currently, the oil and gas processing industry has increased quite well. The oil and gas processing industry uses shelters such as tanks for storing and processing fluids. The type of tank must be adapted to the fluid characteristics contained insite it to reduce the possibility of damage such as corrosion. In the process of oil refinement, there is always corrosion in the tank. This happen caused by contact between sulfuric acid (H2SO4) used to remove impurities with steel in the tank. So it needs a good corrosion handling to overcome the problem. In this study, organic inhibitors from Bintaro fruits (Cerbera manghas) will be used to reduce corrosion on surface JIS G3131 steel. The antioxidant compound content of extract was confirmed using 2,2-difenil-1-pikrilhidrazil (DPPH) and Fourier Transform Infra Red (FTIR) testing. Observation of corrosion rate on JIS G3131 steel and inhibition efficiency is studied through weight loss method and (Open Circuit Potential) OCP measurement. From this research we obtained IC50 value of DPPH testing equal to 126,7882 ppm which shows the antioxidant activity is medium. Through the FTIR test it is indicated that the Bintaro fruit contain the coumarin compound. The result of weight loss and OCP test on JIS G3131 steel is known that the addition of 200 ppm fruit extract with 720 hours of soaking is the best optimization result which can decrease corrosion rate up to 22,767 mm/year with the efficiency of 25,249% inhibitor.

Structure and electrochemical behaviour of composite Pb-nano ZnO in sulfuric acid solution for different temperature

Lead is one of the important materials used as an electrode for batter application. With a good performance at the lowest price possible, using lead as an active material for lead-acid battery still high even though the fact that lead waste is very dangerous for the environment. Lead must be optimized to reduce lead waste with adding new material to the lead for the electrode. For this research lead and nano zinc oxide became a composite Pb-Nano ZnO and this composite tested into sulfuric acid solution with various solution temperature 10°C, 25°C, and 40°C. The structure and electrochemical behaviour were analysed with X-Ray Diffraction (XRD) and Potentiostat (LSV and CV) respectively. Detected phase from the spectrum shows lead phase with cubic FCC crystal structure. Linear Sweep Voltammetry and Cyclic Voltammetry test used to see is the composite can be used as an electrode for a battery and is the performance different than lead electrode. The result shows that the composite is electrochemically reversible and corrosion rate decrease when nano ZnO added with lowest corrosion rate 0.011852 mm/year in ZnO 20% wt composition on temperature variation 10°C.

PH Effect of Natural Gas Hydrate on X80 Steel Solid-Liquid Phase Scouring Corrosion.

In order to solve the problem of pipeline erosion–corrosion under acidic conditions with different CO2 contents of natural gas hydrate (NGH), the influence of different pH values on the erosion corrosion of X80 steel under dynamic conditions was studied. The erosion and corrosion behavior of X80 pipeline steel in multiphase flow (0.5% sand + 3% NaCl aqueous solution) at different pH was studied by rotating a cylindrical electrode apparatus combined with the electrochemical method in this paper. By analyzing the electrochemical impedance spectroscopy of the Tafel curve, the results showed that under dynamic solid–liquid two-phase conditions, with the decrease of the pH value, the self-corrosion potential of X80 steel samples was positively shifted, and the corrosion current density showed a trend of gradually increase. When the pH value is 2.0–3.0, the ac impedance spectrum of X80 steel samples shows a reactance arc in the high-frequency region and an inductive reactance arc in the low-frequency region. With the increase of the pH value, the radius of the capacitance and resistance arc of the impedance spectrogram increases gradually, and the time of the Bode spectrogram is “half peak” in the low-frequency region. As the time constant increases, the impedance decreases and the phase angle decreases; the overall polarization resistance Rp on the surface increased gradually and the corrosion rate decreased significantly. Therefore, the pH value of the content of NGH with different CO2 contents has obvious influence on the solid–liquid two-phase erosion corrosion of X80 steel. With the increase of the pH value, the corrosion resistance of X80 steel increases, the corrosion rate decreases, and the corrosion strength decreases.

Anticorrosive Properties of Green Silver Nanoparticles to Prevent Microbiologically Influenced Corrosion on Copper in the Marine Environment

Microbiologically influenced corrosion is a global problem especially materials used in marine engineering. In that respect, inhibitors are widely used to control fouling and corrosion in marine systems. Most techniques used in inhibitor production are expensive and considered hazardous to the ecosystem. Therefore, scientists are motivated to explore natsural and green products as potent corrosion inhibitors especially in nano size. In this study, antibacterial and anticorrosive properties of green silver nanoparticles (AgNPs) were studied through weight loss, electrochemical characterization, and surface analysis techniques. The corrosion of copper (Cu) in artificial seawater (ASW), Halomonas variabilis (H. variabilis) NOSK, and H. variabilis + AgNPs was monitored using electrochemical measurements like open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization curves. AgNPs showed excellent antibacterial activity against pathogenic microorganisms. Electrochemical studies demonstrate a noticeable decrease in OCP and current density in ASW containing H. variabilis + AgNPs compared to both ASW and ASW inoculated with bacterium, which confirmed the decrease of corrosion rate of copper. Furthermore, the obtained voltammograms show that the silver nanoparticles were adsorbed on the copper electrode surface from the corrosion solution. Thus, the results prove that the novel idea of green silver nanoparticles acts as an anticorrosive film in the marine environment.

Role of rare earth elements on the improvement of corrosion resistance of micro-alloyed steels in 3.5 wt.% NaCl solution

The effects of rare earth (RE) addition on the corrosion behavior of micro-alloyed steels in 3.5 wt.% NaCl solution were investigated elaborately through electrochemical tests and material characterization analyses. Results showed that the corrosion rate decreased after addition of RE elements. The RE elements did not alter the pitting nucleation mechanism, while the sensitivity of pitting propagation was reduced by decreasing the pitting density and pitting depth. In the long-term corrosion, preferential precipitation of RE corrosion products promoted the formation of protective rust layers and accelerated the co-deposition of these layers, which probably be favorable for the formation of compact rust layers. Moreover, the RE addition reduced the surface electrochemical activity and the adsorption tendency of Cl− on the metal surface. As a consequence, the resistance of electrochemical reactions (represented by Rp values in EIS tests) increased, resulting in a decrease of corrosion rate by RE addition.

Anti-Corrosive Behavior of the Seed Extract of Amomum sabulatum

An aqueous extract of Amomum sabulatum seeds was evaluated for anticorrosive effects on mild steel in the presence of HCl. Weight loss measurements were taken to determine the corrosion rate and inhibition efficiency at various concentrations. With the increasing concentrations of plant extract, the results showed an improvement in inhibition efficiency and a decrease in corrosion rate. In the presence of 1500 ppm concentration of plant extract, it has an inhibition efficiency of 82.08 % at 303 K. The scanning electron microscope was used to examine the surface, which proves that while the extract was there, a protective layer formed on the metal surface.

Evaluation of the Influence of Alumina Nano-Particle Size and Weight Composition on the Corrosion Resistance of Monolithc Aa1070 Aluminium

Corrosion resistance of AA1070 aluminum alloy (AA1070) was compared to AA1070 reinforced with alumina at weight composition (wt. %) of 5% and 10%, and grain size of 150 nm and 600 nm. Potentiodynamic polarization and open circuit potential analysis were employed in 0.0125 M H2SO4, 3.5% NaCl and 0.0125 M H2SO4-3.5% NaCl solutions. Data showed 0.0125 M H2SO4-3.5% NaCl solution was the most deleterious with peak corrosion rate value of 6.682 mm/y while 3.5% NaCl solution was the weakest with peak value of 0.084 mm/y. AA1070 at 5% wt. % and 150 nm particle size generally displayed the highest corrosion rate. However, visible decrease in corrosion rate occurred with increase in alumina weight fraction and particle size due to growth of the protective oxide on the composite and reduction of discontinuities. Cathodic and anodic reaction mechanisms significantly differs with respect to the electrolyte. Anodic reaction mechanism appeared under activation control in the sulphate-chloride and chloride solution, compared to cathodic reaction mechanism in the sulphate and sulphate-chloride solutions. Significant anodic degradation reaction was prevalent on the anodic polarization plot in the sulphate solution. Plots from open circuit potential analysis shows the composites and monolithic Al were the most thermodynamically stable in H2SO4 solution. In the sulphate-chloride solution, significant potential transients coupled with high corrosion tendency are conspicuous. The plot showed chaotic thermodynamic behaviour active passive transition behaviour of the passive film.

A study on corrosion inhibition of Carbon steel in well water by Oxalis corniculata L. Leaves extract

The objectives of this work was to analyze the corrosion inhibition of CS (CS) in well water by an ethanolic extract of Oxalis corniculata L. In the presence and absence of inhibitor the corrosion inhibition was analyzed using weight loss study, polarization study, Electrochemical Impedance Spectroscopy. Weight loss method showed that corrosion rate decreases and inhibition efficiency increase with increasing concentration of binary inhibitor system. The polarization study showed that the presence of OC-Zn2+ system has reduced the corrosion of CS in well water. EIS study revealed that the presence of inhibitors remarkably increased the charge transfer resistance of CS in well water. FT-IR measurements were also performed to analyze the nature of protective film formed on the CS surface. SEM investigation of CS surface revealed that corrosion prevention by adsorption of Oxalis corniculata extract and its active principle on CS surface. AFM studies showed the inhibitor molecules is adsorbed over the metal surface.

Influence of Temperature on Wax Deposit on Corrosion of Crude Oil Pipeline

The paper aims to study the effect of temperature on wax deposition on corrosion of crude oil pipeline at different flow rate with time. The waxy crude oil sample is pumped into the design and fabricated experimental flow-loop set up under different operating conditions. The effect of temperature on corrosion at different flow rate of wax deposition during the corrosion inhibition were studied at flow rate of 10.21, 20.37, 30.45, 40.28 and 50.70 L/min and time at 3, 6, 9, 12, 15 and 18 min while keeping temperature constant for each of the experimental run at 15, 20, 25, 30 and 35°C, to determine the corrosion rate against time. The results showed that at flow rate of 10.21 L/min and time 18 min at constant temperature of 15°C, the corrosion rate is 0.11 mpy. At flow rate of 10.21 L/min and time 18 min at constant temperature of 20°C, the corrosion rate is 0.08 mpy. At flow rate of 10.21 L/min and time 18 min at constant temperature of 25°C, the, corrosion rate is 0.12 mpy. Based on the results, a significant reduction of corrosion rates and excellent corrosion protection is achieved while others provided only moderate or negligible protection to the crude oil pipeline. However, the wax layer becomes thicker with time, if the temperature stays below the WAT for extended period of time and can in the long run, cause partial or total blockage of the pipe. Hence, as the deposition of the paraffin wax increases the corrosion rate decrease. The paraffin wax film presence on the surface promotes a significant reduction of general corrosion rates on the pipeline, although localized corrosion was observed due to loss of integrity of the paraffin layer. It means that deposition of paraffin wax inhibit corrosion and also give protection to the pipeline layer. Finally, due to the long chain paraffin layer being physically removed from the surface most of the corrosion protection has been lost during the periods of increased flow rate or temperature.

Corrosion inhibition of carbon steel in hydrochloric acid: Elucidating the performance of an imidazoline-based surfactant

A combination of electrochemical measurement and interface analysis have been applied to characterise the interaction of OMID, an exemplar imidazoline-based corrosion inhibitor, with carbon steel in 1 M hydrochloric acid. Corrosion inhibition efficiency data indicate that excellent performance is achieved well below the critical micelle concentration. High resolution X-ray photoelectron spectra demonstrate that, as the corrosion rate decreases, the interface evolves towards one comprising OMID bound to film-free carbon steel. This latter result provides key input for those researchers attempting to predict corrosion inhibitor functionality through atomic scale interfacial modelling, and so identify next generation chemistries.