Corrosion Rate Of Iron Research Articles

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.

Application of petai peel as an iron corrosion inhibitor in sodium chloride medium

Tannin as an organic inhibitor has been proven capable as a metal inhibitor in acidic media. The purpose of this study is to test the tannin ability of the Petai peel to inhibit the iron plate in the sodium chloride solution. The inhibitory ability of tannins derived from the Petai peel will be assessed in the form of powders, concentrated extracts, and pure tannins. Corrosion rate and efficiency of inhibition as tested parameters will be calculated by doing some variations on the immersion time and inhibitor concentration. Based on the results obtained, Petai peel powder, Petai peel concentrated extracts, and tannins from Petai peels can reduce the rate of iron corrosion in sodium chloride solution, but the best inhibitors of these three forms are in the form of tannins, which can reach the lowest corrosion rate of 0.9770 mpy and inhibition efficiency up to 92.86%. The lowest corrosion rate and highest efficiency are obtained by adding tannin as much as 3 g and immersion duration for 3 days.

Corrosion Morphology and Rate of Iron and Steel in NaCl Solutions during Repeated Wet-Dry Cycling Condition

Corrosion Morphology and Rate of Iron and Steel in NaCl Solutions during Repeated Wet-Dry Cycling Condition

SIMULATION OF IRON CORROSION IN LEAD-MAGNESIUM EUTECTIC (LME) USING OXYGEN INHIBITOR

SIMULATION OF IRON CORROSION IN LEAD-MAGNESIUM EUTECTIC (LME) USING OXYGEN INHIBITOR. Lead-magnesium (Pb-Mg) is a metal that considered to have potential as a coolant raw material in the heat transfer system of nuclear reactors. However, the coolant in the form of Pb-Mg eutectic is corrosive to structured materials (eg steel cladding) used in reactors. In this research, steel material is represented by pure iron to simplify the simulation and calculation. This research aims to determine the effect of temperature on iron corrosion and the effect of adding oxygen as an inhibitor to reduce the iron corrosion rate in LME. In this study, corrosion was observed by looking at (coefficient) the diffusion of iron atoms into LME. A large iron diffusion coefficient represents high iron corrosion. To see inhibition effectivity with oxygen, the most effective oxygen concentration that can reduce the iron diffusion coefficient is searched. Simulations of iron corrosion and inhibition are performed using molecular dynamics simulation. The result of this research showed that oxygen concentration mixed into LME for effective inhibition of iron corrosion was in the range of 0.125 wt% - 0.135 wt% (for temperatures of 973K). Thus, oxygen is believed that able to inhibit iron corrosion in Pb-Mg eutectic up to 98.44%

EFFECT OF TEMPERATURE AND CONCENTRATION OF NaOH SOLUTIONS AS INHIBITORS ON IRON CORROSION RATE IN WATER MEDIA

Corrosion is a chemical phenomenon that often occurs in iron materials that are exposed or immersed in a medium either liquid or air. As a result of this corrosion is fragility and damage to the object so that the object cannot function properly. The purpose of this research is to prevent or slow down the occurrence of corrosion by adding chemicals called corrosion inhibitors which work by forming a protective layer on the surface of objects in the form of metal or iron.In this study, inhibitors were used in the form of NaOH solution with variations in the concentration of 0.1; 0.5; 1; 1.25; 1,5; 5 and 10 N are dissolved in water media and the iron immersion process is carried out at temperatures of 40, 45, and 50 °C. Soaked iron bars are measured for surface area and volume as well as weighing before and after the immersion process so that the corrosion rate is obtained with various variables used. Based on the research results obtained corrosion rate increases with increasing temperature and the addition of NaOH concentration inhibitors. Optimal temperature and concentration to inhibit the rate of iron corrosion is at an immersion temperature of 45 ° C and a concentration of 0.1 N NaOH with a corrosion rate of 0.084875 mpy.

An electrochemical analysis of acute contamination of environmental water and restoring of water quality using taro carbon

Electrochemical techniques were successfully employed to estimate contamination of water of river Buriganga, Bangladesh. A Pt–Cu electrode has been exploited to measure selective nitrate concentration, and corrosion rate of iron has been proposed to indicate relative abundance of dissolved contaminants. In order to evaluate the pollution level, water parameters of river Buriganga have been compared with those obtained from two freshwater streams named Surma and Dawki of the country. An iron strip in contact with Buriganga river water is corroded three times rapidly compared to its contact with Dawki or Surma river water indicates acute contamination of Buriganga river water. The River Buriganga is facing acute pollution from the point of high TDS (0.664–0.694 g/L), low DO (1.47–4.4 mg/L), high COD (197–218 mg/L), high ammonia (270–420 mg/L) and high nitrate concentration (107–157 mg/L). Negative ORP value (− 292 to − 310 mV) of Buriganga river water indicates that the stream contains high level reducing species. Meanwhile, positive ORP value indicates that Dawki (+ 203 to + 209 mV) and Surma (+ 184 to + 205 mV) river water contain oxidizing species. Sediment analysis shows the deposition of disintegrated organic pollutants on the bottom of the River Buriganga. Cost-effective carbon material synthesized from taro stems has been proposed to restore water parameters of filthy water system like Buriganga river.

Electrochemical Study of Iron Deposit in Acid Media for Its Recovery from Spent Pickling Baths Regeneration

Electrochemical technologies for the regeneration of spent pickling baths are feasible since they allow simultaneous metal deposition and acid production in the same process unit. In this work, the effect of Fe2+ concentrations on the electrochemical iron deposition from model spent pickling baths is analyzed by voltammetry switching potentials, Tafel plots and spectrum-electrochemistry studies. The analysis showed that the electrodeposition rate and potential decreased as Fe2+ concentration increased. Moreover, at higher Fe2+ concentrations, a decrease on the hydrogen evolution reaction was observed. Moreover, chemical Fe dissolution is present at all concentrations studied, due to the high corrosion rate of iron at low pH of the model bath. Thermodynamic diagrams and electrochemical tests coupled to UV-Vis analysis demonstrated the presence of iron sulfate complexes suggesting that iron deposit is conducted by an inner sphere layer mechanism.

In Vitro Corrosion Behavior of Biodegradable Iron Foams with Polymeric Coating.

Research in the field of biodegradable metallic scaffolds has advanced during the last decades. Resorbable implants based on iron have become an attractive alternative to the temporary devices made of inert metals. Overcoming an insufficient corrosion rate of pure iron, though, still remains a problem. In our work, we have prepared iron foams and coated them with three different concentrations of polyethyleneimine (PEI) to increase their corrosion rates. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FT-IR), and Raman spectroscopy were used for characterization of the polymer coating. The corrosion behavior of the powder-metallurgically prepared samples was evaluated electrochemically using an anodic polarization method. A 12 weeks long in vitro degradation study in Hanks’ solution at 37 °C was also performed. Surface morphology, corrosion behavior, and degradation rates of the open-cell foams were studied and discussed. The use of PEI coating led to an increase in the corrosion rates of the cellular material. The sample with the highest concentration of PEI film showed the most rapid corrosion in the environment of simulated body fluids.

Koroziona svojstva laserski čišćenih površina na artefaktu od gvožđa

Nd:YAG laser was used for cleaning surfaces of cultural heritage iron artefacts covered with corrosion products. The corrosion products were removed without damaging the base material. Three different electrochemical techniques were used for the determination of the corrosion rate of mechanically prepared iron, laser-cleaned iron and laser-cleaned iron with Paraloid B44 coating. The morphology of the tested surfaces was analysed by SEM. The linear polarization resistance technique, electrochemical impedance spectroscopy and linear sweep voltammetry have shown that the corrosion rate of the laser-cleaned iron is approximately 50 % higher than the corrosion rate of the mechanically prepared iron. Electrochemical impedance spectroscopy has shown that the pore resistance of the Paraloid coating on the laser-cleaned iron sample decreases at the beginning of the test and remains approximately constant after this period. At the beginning of the test, the charge transfer resistance value is constant and then decreases rapidly i.e. the corrosion rate of the iron in the Paraloid coating pores increases with time. During the linear sweep voltammetry test of the iron sample with Paraloid coating, it was noticed that the anodic polarisation curve shows an unusual shape at the potentials more positive than - 0.5 V.

Electrochemical And Metallurgical Behaviour Of Ductile Iron In Acidic, Basic And Saline Environments

This research work presents the comparative study of the effect of some selected environments on the corrosion characteristics and accompanying changes in microstructure on ductile iron. In this study, the atmospheric corrosion of ductile cast iron immersed in acidic (2M H2SO4), basic (2M NaOH) and saline (3.5% NaCl) environments, which represents the major atmospheric environments in which metals are mostly subjected to while in service. The corrosion characteristics of ductile iron have been determined by current potential curves. To determine the corrosion rates, the anodic and cathodic Tafel regions extrapolating to corrosion potentials were used. The individual corrosion rates of ductile iron were evaluated for a time period of 600 seconds, 1mv/s scan rate and Tafel plot range of -250mv to 250mv. Each sample were dimensioned, polished, pickled in dilute HCL and rinsed with distill water, degreased with acetone followed by drying and then mounted for the potential dynamic tests. The results obtained reveal that corrosion of DI in 2M H2SO4 is (0.25699 mmpy), 2M NaOH is (0.025955 mmpy), 3.5% NaCl is (0.10396 mmpy) and distill water is (2.6447e-05 mmpy). The results obtained showed that corrosion rate in decreasing order is 2M H2SO4, 3.5% NaCL, 2M NaOH and lastly as expected distil water. The corrosion product morphologies of the DI showed the nodular matrix was gradually covered up as the corrosion rate increased. This work is important reference point for the corrosion effectiveness of ductile iron in major atmospheric conditions.

Online monitoring and control of drinking water corrosion potential at a full-scale plant

Abstract To mitigate pipe and water quality degradation in distribution, treatment targets were established to continuously control the corrosion potential of drinking water towards cement, lead and iron materials at a 225 MLD surface water treatment plant. Indicators were identified to estimate the corrosion potential of water for each of the 3 materials: the Langelier Saturation Index (LSI) for cement, pH for lead and a novel corrosion index for iron. Linear Polarization Resistance (LPR) probes equipped with cast iron and lead electrodes provided direct and continuous measurements of actual lead and iron corrosion rates for finished water. Corrosion control was achieved by adjustments to caustic soda doses. The set-point for finished water pH was determined with a site-specific algorithm using online values for temperature, pH, and conductivity as surrogate for calcium and alkalinity. Over the 7 months of implementation, measured iron corrosion rates were maintained well below the established threshold of 50 μm/year. Lead corrosion rates varied from 20 to 40 μm/year with higher levels occurring when pH dropped below 7.5. The full-scale experience validated a treatment strategy and demonstrated the feasibility of using LPR probes for online monitoring of corrosion potential on drinking water matrices.

Corrosion Mitigation of Gray Cast Iron and Aluminum in NaOH Using Water Hyacinth (Eichhornia crassipes) Plant Extract

This research focused on the corrosion behavior of gray cast iron and aluminum in alkaline medium (0.5 M NaOH) with and without inhibitor (water hyacinth Eichhornia crassipes extract) of varying concentrations of 5%, 10%, 15%, 20% and 25%. The corrosion rates of the metal samples were investigated using the weight loss and electrochemical methods alongside the formulation of a dispersant using readily available chemicals to develop a colloidal solution of the extract produced by hot water digestion of the water hyacinth plant leaves. The metallography tests of control samples as well as the most and least corroded samples were carried out using Optical Microscope (OM). The results revealed that the aluminum resulted in minimum corrosion rate of 0.000483 mg/mm2/yr with inhibitor efficiency of 98.93% obtained for sample A5 (25% extract from water hyacinth) while for the gray cast iron, a minimum corrosion rate of -4.4E-05 mg/mm2/yr with inhibitor efficiency of 566.6% obtained for sample C3 (15% extract from water hyacinth). The electrochemical result of aluminum showed increase in corrosion potential from -1.494 VAg/AgCl to -1.482 V Ag/AgCl and that of gray cast iron from -0.5436 VAg/AgCl to -0.2839 VAg/AgCl upon increase in inhibitor concentration. Therefore, the use of water hyacinth (Eichhornia crassipes)extract reduced the corrosion or dissolution rate of gray cast iron and aluminum in (NaOH) sodium hydroxide medium.

Peculiarities of Corrosion of a Zinc Coating in Neutral Media in the Presence of Inhibitors Based on Benzotriazole, Cyclohexylamine, and Morpholine

The influence of domestic nitrogen-containing corrosion inhibitors of the VNKh-L type on corrosion regularities of a zinc coating on steel in neutral media is investigated. This work is aimed at studying the surface structure of a corroding zinc coating, as well as the influence of conditions simulating the degradation of inhibitors during real operation on their protective properties. Mechanical activation in a ball planetary mill is used to simulate the deformation and thermal operational conditions of inhibitors. Corrosion of a zinc coating on steel is carried out in a sulfate–chloride medium simulating atmospheric corrosion and in a borate buffer solution. The concentration of inhibitors in the corrosion media was 0.2 wt %. The morphology of a corroded surface of a zinc coating is studied using a Philips SEM-515 scanning electron microscope (at an accelerating voltage of 10 kV) with an X-ray microprobe. Studies of the corrosion rate of zinc coating on St 08 are carried out by the indirect measurement of corrosion resistance with the help of a MONIKOR-1 corrosion meter. A borate buffer solution (Na2B4O7 + H3BO3, pH 6.6) and a solution simulating atmospheric corrosion (NaCl + Na2SO4, pH 6.0) are used as corrosion media. The corrosion rate of samples in corrosive media without an inhibitor is accepted 1. The exposure time of each sample in corrosive media is 3 h. The chemical composition of corrosion products is studied by the mirror reflection in the IR range. The IR spectra of the metal plate surface are recorded using an FSM-1202 IR Fourier spectrometer in a wavelength range of 450–4000 cm–1 with a resolution of 2 cm–1 and an accumulation of 100 scans. To record the reflection spectra, a mirror-reflection attachment with a 10° angle of incidence is used. The corrosion rate of zinc coating in sulfate–chloride and solvent media in the presence of inhibitors based on benzotriazole and cyclohexylamine is practically not decreased when compared with the corrosion rate in the same media without inhibitors. The addition of both initial and mechanically activated inhibitors based on morpholine and benzotriazole to the corrosion medium decreases the corrosion rate of iron when compared with the corrosion in the same media without inhibitors. The pitting corrosion of a zinc coating is observed in the presence of initial and mechanically activated inhibitors of both types in studied corrosion media. Herewith, the pitting depth is smaller than the zinc-coating thickness under these conditions.

Peculiarities of zinc coating corrosion in neutral environments with inhibitors based on benzotriazole, cyclohexylamine and morpholine

The influence of domestic VNKh-L type nitrogen-containing corrosion inhibitors on the corrosion patterns of zinc coating on steel in a neutral environment was investigated. The paper aims to study the structure of the corroding zinc coating surface, as well as the influence of conditions simulating the degradation of inhibitors under actual application conditions on their protective properties. Mechanical activation in a ball planetary mill was used to simulate the thermal and deformation conditions of inhibitors. Zinc coating corrosion on steel was carried out in a sulfate-chloride environment simulating atmospheric corrosion and in borate buffer solution. The concentration of inhibitors in corrosion environments was 0,2 wt.%. The corroded surface morphology of the zinc coating was studied using the Philips SEM-515 scanning electron microscope (at an accelerating voltage of 10 kV) with an X-ray micro probe. Studies of the zinc coating corrosion rate on St 08 were carried out by the indirect measurement of corrosion resistance using the MONIKOR-1 corrosion meter. Borate buffer solution (Na2B4O7 + H3BO3, pH = 6,6) and the solution simulating atmospheric corrosion (NaCl + + Na2SO4, pH = 6,0) were used as corrosive environments. The corrosion rate of samples in corrosive environments without inhibitors was taken as 1. Exposure time of each sample in corrosive environments was 3 h. The chemical composition of corrosion products was studied by mirror reflection in the IR range. The IR spectra of metal plate surfaces were recorded on the FSM-1202 IR Fourier spectrometer in a wavelength range of 450–4000 cm–1 with a resolution of 2 cm–1 and an accumulation of 100 scans. A mirror reflection attachment with a 10° angle of incidence was used to obtain reflection spectra. The zinc coating corrosion rate in sulfate-chloride and borate environments in the presence of inhibitors based on benzotriazole and cyclohexylamine was virtually not reduced compared to the corrosion rate in the same environments without inhibitors. When both initial and mechanically activated inhibitors based on morpholine and benzotriazole are added to the corrosion environment, the iron corrosion rate decreases compared to the corrosion rate in the same environments without inhibitors. In the presence of initial and mechanically activated inhibitors of both groups, pitting corrosion of the zinc coating in the studied corrosion environments is observed. At the same time, the pitting depth under corrosion conditions is less than the zinc coating thickness.

The Influence of Relative Humidity and Intrinsic Chloride on Post-excavation Corrosion Rates of Archaeological Wrought Iron

ABSTRACTThis study examined the impact of relative humidity (RH) on the corrosion rate of 129 archaeological iron nails from two sites. Oxygen consumption of individual nails in controlled RH was used as a corrosion rate proxy to deliver quantitative data on corrosion rate as a function of RH. This was negligible at 20% RH, slow up to 40% RH for both sites, and increased rapidly at 60% RH for Roman nails from Caerleon (Wales) and at 70% RH for medieval nails from Billingsgate (London). The nails were digested and their chloride content was determined and related to their oxygen consumption at specific RH values. While a generic pattern of corrosion as a function of chloride was identified, for any single concentration of chloride corrosion rate was not predictable. Desiccation is in common use to control post-excavation corrosion of archaeological iron; quantifying how differing levels of desiccation changed corrosion rate provided a scaled tool for identifying corrosion risk, estimating object longevity, and calculating cost benefit for storage options.

Investigation of corrosion behaviour of iron in four different organic acids

The corrosion behaviour of iron in four different organic acid have been investigated using weight loss method. The acids used includes succinic, formic, maleic and citric acid. The results of the corrosion rates of iron in C 4 H 4 O 4 , C 4 H 6 O 4 , HCOOH and C 6 H 8 O 7 are 1.125, 1.100, 0.800 and 0.500 mg cm -2 h -1 respectively. The rate of corrosion increases with increasing concentration of acid and with increase in temperature. The study shows that the rate of corrosion follows the order of reactivity C 4 H 4 O 4 > C 4 H 6 O 4 > HCOOH > C 6 H 8 O 7 . Keyword : Iron, weight loss, corrosion rate.

Relationship between concentration of hydrogen sulfide and corrosion rate of cast iron in sewer environment

Relationship between concentration of hydrogen sulfide and corrosion rate of cast iron in sewer environment

Sensitivity Analyses for Modeling Evolving Reactivity of Granular Iron for the Treatment of Trichloroethylene

To better predict long-term performance of a remediation system, parameters of a numerical model should be constrained with care by calibrating with reliable experimental data. This study conducted sensitivity analyses for model parameters, which were shown to represent reasonably well the observed geochemical behaviors for the column experiments that evaluated evolving reactivity of granular iron for the treatment of trichloroethylene (TCE) resulting from precipitation of secondary minerals. The particular model parameters tested include iron corrosion rate, aragonite and Fe2(OH)2CO3 precipitation rates, and proportionality constants for each mineral. For sensitivity analyses, a specific parameter was systematically changed, while other parameters were fixed at the values for the base case. The ranges of parameters tested were determined based on the previous modeling study. The results showed that the most important and sensitive model parameters were secondary mineral precipitation rates. Also, not only absolute precipitation rate for each mineral but also relative precipitation rates among different minerals were important for system performance. With help of sensitivity analysis, the numerical model can be used as a predictive tool for designing an iron permeable reactive barrier (PRB) and can provide implications for the long-term changes in reactivity and permeability of the system.

Mechanism of Acceleration of Iron Corrosion by a Polylactide Coating.

Strong and biodegradable materials are key to the development of next-generation medical devices for interventional treatment. Biodegradable polymers such as polylactide (PLA) have controllable degradation profiles, but their mechanical strength is much weaker than some metallic materials such as iron; on the other hand, tuning the corrosion rate of iron to a proper time range for biomedical applications has always been a challenge. Very recently, we have achieved a complete corrosion of iron stent in vivo within the clinically required time frame by combining a PLA coating, which provides a new biomaterial type for the next-generation biodegradable coronary stents termed as a metal-polymer composite stent. The underlying mechanism of accelerating iron corrosion by a PLA coating remains an open fundamental topic. Herein, we investigated the corrosion mechanism of an iron sheet under a PLA coating in the biomimetic in vitro condition. The Pourbaix diagram (potential vs pH) was calculated to present the thermodynamic driving force of iron corrosion in the biomimetic aqueous medium. Electrochemical methods were applied to track the dynamic corrosion process and inspect various potential cues influencing iron corrosion. The present work reveals that acceleration of iron corrosion by the PLA coating arises mainly from decreasing the local pH owing to PLA hydrolysis and from alleviating the deposition of the passivation layer by the polymer coating.

Discussion on the relationship between iron content and corrosion rate in production fluid of oil wells

To provide an economical and practical technique for the application of on-line corrosion monitoring technology in oil production system, in this paper, the iron content was measured by a water quality multi-parameter tester and corrosion rate was determined by the weight loss method. Then, the quantitative relationship between the iron ion and corrosion rate could be found. On this foundation, in order to correctly describe the corrosion in the wellbore of oil wells, according to SY/T0026-1999 water corrosion test method standards, a mathematical relational expression between iron ion content and corrosion rate in oil wells production fluid was established. In order to verify the reliability of relational expression, the iron content in the produced fluid of 17 wells corrosion conditions before and after adding medicine were measured on the spot. Then, the relational expression entered the field application. The results show that there was the positive correlation between the iron ion and corrosion rate. The error of the calculated corrosion rate of 17 wells in the field was less than 26% compared with the measured corrosion rate. The mathematical relational expression had good effect in J45-62 well. It could reflect the corrosion trend of well bore. Thus, through the internet+ technology, the on-line monitoring system for remote corrosion could be established, and corrosion trend of wellbore pipelines could be predicted with the help of nerve net algorithm.