Corrosion control

This research reports the consequences of mass loss estimations by utilizing of oxygen scavengers in boilers to limit the consumption rate of carbon steel tubes. The consumption rate information was chosen from the literature as function of temperature, pressure, and inhibitors level. Consumption rate increased with increasing in temperature and pressure, and diminished with inhibitor level. Hydroquinone, ascorbic acid, and ethanolamine were utilized as consumption inhibitors. The present work is focused on deciding the artificial neural network (ANN) and mathematical formulas so as to increase great expectation properties. Five scientific models and five ANN display structures were recommended. Computer aided program was utilized for building up these models. The outcomes demonstrate that the polynomial mathematical model and multi-layer discernment can precisely anticipate the deliberate information with high relationship coefficients. Multi-Layer Perceptions (MLP) 3:3-4-1:1 was the best model over than the others with higher correlation coefficient.

Considering corrosion rate during the remaining life assessment of aging pipelines is fundamental to calculate the interval between two consecutive inspections. A total of 798 internal and external corrosion defects have been detected, using the Magnetic Flux Leakage intelligent inspection tool, over 48 km of a pipeline length located in the west region of Algeria. The statistical analysis has shown that there is a strong correlation between the corrosion defect length and the corrosion defect circumferential width, with a significant correlation coefficient equal to 82.87%. A probabilistic methodology is presented for the assessment of the remaining life of a corroded pipeline transporting gas, and a finite element method (FEM) was used to assess the pipeline failure pressure. The numerical FEM modeling results were compared with the commonly used codes-models for calculating limit pressure to establish a more realistic and accurate engineering model. The reliability analysis of an API 5L X60 steel made Algerian natural gas pipeline, in service for thirty years, and exposed to active corrosion attack, is presented. The sensitivity analysis of the basic random variables within the nonlinear limit state function was carried out to bring out the relative contribution of each variable affecting the remaining life of corroded pipelines. The reliability analysis is carried out by using Breitung's formula, based on the second-order reliability method (SORM). The reliability assessment of the corroded pipeline is based on the usage of the notched failure assessment diagram (NFAD), different codes for the calculation of the failure pressure, and the numerical results using the finite element analyses (FEA) software ANSYS.

Fossil fuels are not renewable energy in addition they create massive pollution in the environment. This pollution affects air, water and the food. Because of global fossil fuel shortage and environmental pollution, solar energy utilization has developed rapidly. Solar energy is considered the energy supplied by the sun that is a renewable and clean energy. This review investigates corrosion of silver, corrosion of solar cells and ways of control corrosion process of solar cell.

Corrosion combined with fouling growth can interfere with the operation of submerged equipment, impose increased loading stresses and accelerate deterioration of marine structures, and adversely affect the performance of ships by increasing hydrodynamic drag, which necessitates the use of more power and fuel to move the ship through the water. The protection of the submerged portions of a ship's hull seems to have been long acknowledged and practiced but corrosion related failure of ship components continue to occur giving economical loss to ship owners. An enlightened approach to materials selection, protection and corrosion control is needed to minimize the risk of failures or major renewals of hull structures during the ship's expected life span. Further, Proper and cost effective corrosion protection measures are necessary to maintain the asset value of the vessel with a special emphasis on the means and methods now being adopted in international regulatory regimes to contain it. This paper addresses the causes of corrosion in ship and the way in which corrosion can be reduced or entirely eliminated in a ship by integrating both technical and non technical methods of corrosion control.

The main purpose of this research was to establish the effectiveness of the V844* corrosion inhibitor for seawater on various metallic materials: carbon steel, aluminum and copper alloy at different concentrations via colloid formation. The changes in both physical and chemical properties of seawater, including pH, total hardness, alkalinity, total dissolved solids (TDS) and conductivity at different concentrations of V844 were assessed, too. The test procedure involves dissolving the V844 corrosion inhibitor (CI) powder provided by Magna International Private Limited in seawater to obtain a stock solution of 4% V844 in seawater, which was further diluted to obtain the remaining concentrations. The analysis of parameters begun when various metal species, polished beforehand, were placed into the solutions. The analysis was observed over a period of 26 days and a total of 9 sets of readings were obtained. From our observation and ear power stations burning fossil-fuels generating acidic rains, the pH can diminish to 6.

This paper presents an updated review of the external corrosion and failure mechanisms of buried natural gas and oil pipelines. Various forms of external corrosion and failure mechanisms such as hydrogen-induced cracking (HIC), hydrogen embrittlement (HE), corrosion fatigue (CF), stress corrosion cracking (SCC) and microbiologically influenced corrosion (MIC) for oil and gas pipelines are thoroughly reviewed. The factors influencing external corrosion and possible forms of environment-assisted cracking (EAC) of pipeline steels in the soil are also reviewed and analyzed in depth. In addition, the existing monitoring tools for the external corrosion assessment and the models for corrosion prevention and prediction, failure occurrence, and remaining life of oil and gas pipelines, are analyzed. Moreover, the articles on external corrosion management, reliability-based models, risk-based models, and integrity assessment including machine learning and fuzzy logic approaches, are also reviewed. The conclusions and recommendations for future research in the prevention and prediction of external corrosion are presented at the end.

Hydrogen evolution and permeation occur during electroplating, corrosion, and cathodic protection. Hydrogen accumulates in areas of high stress and may reach a critical concentration, potentially causing fractures and catastrophic damage. This chapter describes hydrogen permeation and hydrogen-induced damage in metals and alloys. It also discusses hydrogen evolution kinetics, theoretical diffusion solutions, and basic hydrogen permeation models. Models are used as a diagnostic tool to determine the effectiveness of various metals and alloys as hydrogen permeation inhibitors. It then explains experimental atomic hydrogen permeation transient determination and hydrogen absorption rate constants and diffusivity evaluation into metals using case studies. Hydrogen embrittlement, hydrogen-induced cracking, hydrogen blistering, and hydrogen stress cracking are also discussed to show the relationship to hydrogen permeation and hydrogen-induced cracking mechanisms. Finally, various techniques used to prevent and control hydrogen damage of metals and alloys are described.

Anees A. Khadom 1 2 3 Your article is protected by copyright and all rights are held exclusively by Akadémiai Kiadó, Budapest, Hungary. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

The effect of urea as a corrosion inhibitor on mild steel in the present of water taken from the 2204-tank located in Al-Shaiba Crude Oil Refinery in Basrah was investigated by using potentiodynamic measurement. It is found that the inhibition efficiency (IE) and coverage ratio of urea at 1.5 g/L increase by increasing the concentration of urea until reach 99.46% and 0.994, respectively. The corrosion rate is reduced with increasing the concentration of inhibitor until 1.5g/L; however, after that the corrosion rate increases. Urea inhibitor acts as a cathodic inhibitor.

tThe inhibition of steel–copper couple galvanic corrosion in petroleum waste water solutionby Curcuma longa was studied at different temperature and different cathode to anode ratiosusing weight loss technique. Inhibition efficiency was increased with increase in inhibitorconcentration but decrease with rise in temperature. Adsorption followed the Temkinisotherm with negative values of G◦ads, suggesting a stable, and spontaneous inhibitionprocess. Mathematical equations were suggested to represent the corrosion rate data withhigh correlation coefficients. Quantum chemical parameters were calculated for inhibitor susing the AM1-SCF method to simulate the adsorption of the C. longa molecules on couple surface.

Due to lack of corrosion monitoring activities in SWGEZ, the current case study shows the ability to interpret metal loss and/or corrosion rate of 8 inches transporting line (9 km offshore line from SWGEZ P/F tied in 3.4 km onshore line and reaching SWGEZ process plant) and so on evaluation of corrosion inhibitor injection system according to injection conditions (Injection points, injection dose, inhibitor efficiency) and processing conditions (Fluid velocity, Temperature and phases).

The purpose of this paper is to evaluate the electrochemical kinetics parameters of galvanic corrosion inhibition of the
copper alloy- steel alloy couple, exposed to cooling tower water. Polyvinyl alcohol was utilized to evaluate the inhibition
behaviour under galvanic couple conditions. Polarization technique was used to evaluate the corrosion rate data. Barnartt`s
three point method and McLaughlin method were used to evaluate the kinetics parameters. The results were compared with
the results of conventional Tafel extrapolation method.

In this research, the effect of thiosulfate ion on pitting corrosion behavior of 316 stainless steel was studied. Part I of this work deals with the influence of thiosulfate on the critical pitting temperature of 316 SS in 0.1 M chloride solution and studies the effect of this ion on the pit chemistry. Electrochemical experiments performed in absence and presence of 0.01 M thiosulfate ion revealed that thiosulfate deteriorates the CPT. Pencil electrode studies showed that thiosulfate addition decreases both saturation concentration of metal cations necessary to metal salt precipitate at the pit bottom (CS) (the value of diffusion controlled limiting current density (iLim) was decreased) and the ratio of C*/CS (where C* is the critical concentration of metal cations in pit solution essential for a pit to remain stable) while it increases the anodic dissolution rate in a simulated pit solution. Furthermore, scanning electron microscopy showed that the lacy cover formed over the pits mouth has coarser pore structure in the presence of thiosulfate ion.

The corrosion inhibition of copper–nickel alloy by benzotriazole (BTA) in 1.5 M HCl has been
investigated by weight loss and polarization techniques at different temperatures. Maximum value of inhibitor
efficiency was 99.8% at 35°C and 0.1 M inhibitor concentration, while the lower value was 86.3% at 65°C
and 0.02 M inhibitor concentration. The activation energy values were higher in presence of BTA which indi
cate that in presence of inhibitor, corrosion reaction requires more energy to occur. Two mathematical models
were used to represent the weight loss corrosion rate data with high correlation coefficients. Electrochemical
polarization measurements showed that BTA is a mixed type inhibitor.

Brine purification process of GHCL did not meet the specification of electrolyzer in the context of excess hydroxide ion (OH-). The electrolyzer, anolyte tank and dechlorination tower tank faced serious corrosion. This paper describes an innovative method adopted to meet the electrolyzer's specification of excess OH-. This method consists of an innovative HCl dosing system added to purified brine tank. After adopting this method corrosion of electrolyzer, anolyte tank and dechlorination tower tank has been decreased in a noticeable rate. Also some chemical dosings have been reduced.

The effect of dichromate ions on the corrosion behaviour of 316 stainless steel was investigated in 0.1 M NaCl solution by electrochemical measurements and electron microscopy. The results revealed that the addition of dichromate increases the resistance to pitting corrosion as the pitting corrosion does not occur in the presence of 0.05 M dichromate ions at room temperature. The mechanistic studies showed that the increase in pitting corrosion resistance in presence of Cr2 O7 2 is due to the decrease in the meta-stable pit initiation, lower kinetics of metastable pit dissolution and increase in the survival probability of the pit formation.

Quantum chemical calculations, molecular dynamics simulation and experimental studies of using some azo dyes as corrosion inhibitors for iron. Part 1: Mono-azo dye derivatives
Loutfy H. Madkour a , ∗, Sava ¸s Kaya b , Cemal Kaya b , Lei Guo c
a Chemistry Department, Faculty of Science and Arts, Baljarashi, Al-Baha University, P.O. Box 1988 Al-Baha, Saudi Arabia b Cumhuriyet University, Faculty of Science, Department of Chemistry, 58140 Sivas, Turkey c School of Material & Chemical Engieering, Tongren University, Tongren 554300, PR China
This study consists of two parts. In the first part, the inhibitive performance of six mono-azo dye (MAD_ 1 –6 ) derivatives was investigated experimentally (gravimetric, thermometric, UV–visible spec- trophotometric and electrochemical potentiostatic methods) and computationally against corrosion of Fe metal in 2 M HNO 3 and 2 M NaOH solutions. Density functional theory (DFT) calculations and molec- ular dynamics simulation (MDS) approach were performed. Quantum chemical parameters such as the highest occupied molecular orbital energy ( E HOMO ), lowest unoccupied molecular orbital energy ( E LUMO ), the energy gap between E LUMO and E HOMO ( E ), dipole moment ( D ), chemical hardness ( η), softness ( σ), electronegativity ( χ), proton affinity, global electrophilicity ( ω), global nucleophilicity ( ε) and total energy (sum of electronic and zero-point energies) were calculated and discussed with the help of HF/SDD, HF/6- 311 G, HF/6-31 ++ G, B3LYP/SDD, B3LYP/6-311 G and B3LYP/6-31 ++ G methods. Polarization measurements indicate that (MAD) compounds are of mixed-type inhibitor in acidic, act mainly as cathodic in alkaline solution. Kinetic model involving binding constant ( K b ), active sites ( 1/y ) and standard free energy values of adsorption ( G o ) were compared with the parameters of equilibrium constant ( K ads ), lateral interac- tion ( f ) and ( G o ), that obtained from Frumkin adsorption isotherm model. Then, we calculated binding energies on Fe (110) surface of the inhibitors. The theoretical data obtained are in good agreement with the experimental inhibition efficiency results. ©2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

The constant growth in the area of metal phosphonate materials is exemplified with rich chemistry and a variety of applications. From the multitude of subjects related to metal phosphonates, we have decided to focus on metal phosphonate coordination polymers as corrosion inhibitors in the present Comment. A plethora of metal phosphonate organic-inorganic polymeric hybrid materials have been synthesized, structurally characterized, and evaluated for their anticorrosion properties for the protection of carbon steels. These materials are composed of a metal ion (usually Zn 2þ , Ca 2þ , Sr 2þ , Ba 2þ , etc.) and polyphosphonate ligands such as AMP (amino-tris-(methylenephosphonate) and HDTMP (hexamethylenediaminetetrakis(methylenephosphonate), or carboxyphosphonate ligands, such as PBTC (2-phosphonobutane-1,2,4-tricarboxylate) and HPAA (hydroxyphosphonoacetate). Their corrosion inhibition performance has been evaluated and some interesting conclusions are drawn relating molecular structure to inhibitory activity.

The effect of the new natural corrosion inhibitor known as an aloe vera (mannose–6– phosphate) on the corrosion inhibitor for mild steel in (1 wt. % NaCl) was investigated by using potentiodynamic polarization measurement. Obtained results revealed that this compound was very good inhibitor and behave better in NaCl solution. Polarization studies showed that the aloe vera behaves as mixed type of inhibitor for mild steel in sodium chloride solution. The inhibition efficiency reached (81.81%) at concentration of (75 µml).

Corrosion combined with fouling growth can interfere with the operation of submerged equipment, impose increased loading stresses and accelerate deterioration of marine structures, and adversely affect the performance of ships by increasing hydrodynamic drag, which necessitates the use of more power and fuel to move the ship through the water. The protection of the submerged portions of a ship's hull seems to have been long acknowledged and practiced but corrosion related failure of ship components continue to occur giving economical loss to ship owners. An enlightened approach to materials selection, protection and corrosion control is needed to minimize the risk of failures or major renewals of hull structures during the ship's expected life span. Further, Proper and cost effective corrosion protection measures are necessary to maintain the asset value of the vessel with a special emphasis on the means and methods now being adopted in international regulatory regimes to contain it. This paper addresses the causes of corrosion in ship and the way in which corrosion can be reduced or entirely eliminated in a ship by integrating both technical and non technical methods of corrosion control.

An Inconel 601 crucible containing a ternary eutectic mixture of lithium carbonate (Li 2 CO 3), potassium carbonate (K 2 CO 3) and sodium carbonate (Na 2 CO 3) was placed into a 450˚C preheated furnace to check their compatibility as storage and containment materials for Thermal Energy Storage (TES) applications. Failure was observed after around 22 hours and proved to be assisted by the diffusion of oxygen and carbide forming elements through grain boundaries. Microstructural studies showed cracks of an intergranular type resulted from the high amount of residual stress and microstructural evolution during the thermal exposure; EBSD investigations confirmed the occurrence of partial recovery leading to stress reduction in the matrix. The failure of this nickel-based superalloy crucible was concluded to be a combination of stress induced by sensitization, exposure to hot corrosive media, and cold work manufacturing besides thermal instability of the microstructure.

Pipeline Integrity Assessment has remained key to both the Regulators and Operators in the Oil and Gas Industry.

Whilst the regulators have over the years watched for conformance to stated regulatory standards, various Operators are cut between regulating OPEX whilst also ensuring Integrity.

We as Integrity professionals are thus saddled with finding a middle ground for obeying the Government Regulation alongside ensuring the continuous integrity of fixed assets.

Syntheses and structures of alkaline earth metal ions and EDTMP, ethylenediamine-tetrakis(methylenephosphonate), are reported. The isostructural Ca 2+ and Sr 2+ analogs have 1D topologies, with EDTMP acting as both chelating and bridging ligand. The M-EDTMP compounds act as Fe-oxide removers from corroded surfaces.

Present work studied the high temperature corrosion inhibition rate of steel in
different concentration ratios of MgO, to corrosive fuel ash in temperature range 600 – 900
o C and time range 10 – 40 h. Weight loss technique was used to evaluate the corrosion rate
values. Corrosive environment was collected locally from boilers of Northern Baghdad
Power Plant Station. Analysis focused on determining optimum mathematical equation and
ANN architecture in order to gain good prediction results. Three mathematical equations
and five ANN architectures were recommended. Computer aided program was used for
developing these models. Results show that polynomial mathematical equation and MPL
are able to perfectly forecast corrosion data with high correlation coefficients.

The inhibition of the corrosion of mild steel in hydrochloric acid solutions by 4-amino-5-phenyl-4H-
1,2,4-trizole-3-thiol (APTT) inhibitor was studied using weight loss technique. Basic kinetic parameters
of the corrosion inhibition process were obtained by reaction kinetic equations. Rustles show that the
inhibition increases with increasing of inhibitor concentration. Kinetic calculations show that the
maximum value of time for which the corrosion rate increases twice the initial one, while time for which
the mass of the sample subjected to corrosion decreases twice the initial one were at 8  104 Mof APTT.
The dynamics were described by an exponential kinetic equation of self-accelerating reactions in the
absence of inhibitor and by an equation of a zero order in its presence.

In the present part of study, the effect of thiosulfate ion on pitting corrosion of AISI 316 stainless steel in 0.1 M NaCl solution was investigated. In order to elucidate the effect of thiosulfate on pitting corrosion, the metastable pitting has been studied in more details. The results showed that the thiosulfate addition increased susceptibility to pit initiation and increased the dissolution kinetics of metastable growing pits in a fashion that facilitates the transition from metastability to stability. Consequently, the pitting potential of the stainless steel was decreased in the presence of thiosulfate ion.

A series of metal-phosphonate organic-inorganic polymeric hybrid materials are synthesized, structurally characterized, and evaluated for their anticorrosion properties for the protection of carbon steels. These materials are Zn-AMP (where AMP ) amino-tris(methylenephosphonate)), Zn-HDTMP (where HDTMP ) hexamethylenediamine-tetrakis(methylenephosphonate)), and Ca-PBTC (where PBTC ) 2-phosphonobutane-1,2,4-tricarboxylate)). Their structures are described and compared. Their corrosion inhibition performances are also compared, and some interesting conclusions are drawn that relate molecular structure to inhibitory activity.

The common failures mechanisms of boiler components at elevated temperatures and monitoring techniques used in power plants to detect damaging or failures are generally well described in literature. Despite of different classification concerning the principal failure mechanisms of boiler thermal power plant components, it is necessary to emphasize that essential difference between these classification does not exist. Concerning the different failures mechanisms it is obvious that the most of them are completely explained and clear in physical sense of process but some of them are not still so explicit. Therefore, until today there is a great interest to investigate the failures of power plant boiler components especially having in mind the all peculiarities of particular events. This efforts are necessary while a full assessment of the failure mechanism(s) is required to prevent further failures due to the same causes. The numerous case studies presented in this paper were done as a...

Page 1. Gordana M. Bakić Teaching Assistant Vera M. Šijački Žeravčić Professor Miloš B. Đukić Teaching Assistant University of Belgrade Faculty of Mechanical Engineering Biljana M. Anđelić Professor University of Kragujevac Technical Faculty of Čačak ...

The polarization resistance (Rp) of inhibition of copper-nickel alloy corrosion by
Tetraethylenepentamine (TEPA), in 5% HCl has been investigated by polarization
technique at different temperatures and different inhibitor concentrations. The data of
over potential as a function of current densities were used to analyze the polarization
curves by suggesting a mathematical model taking into account the effect of mass
transfer on activation process. The value of surface converge θ was also obtained; the
maximum value was 0.69 at 35 oC and 0.08 M TEPA, while the lower value was 0.3 at 55
oC 0.01 M TEPA.

The effect of inhibitor concentration and temperature on the corrosion process of copper–nickel alloy in
presence of naphthylamine (NA) and phenylenediamine (PDA) in 5% HCl has been investigated by weight
loss technique. Maximum value of inhibitor efficiency was 85.6% for NA at 35 8C and 0.085 M inhibitor
concentration, while the lower value was 1% at 55 8C and 0.01 M in the presence of PDA. Two
mathematical models were used to represent the corrosion rate data: second order polynomial model
and exponential model. Non-linear regression analysis shows that the first model was better than the
second model with high correlation coefficient.

Inhibition of corrosion of nickel-aluminum bronze alloy (NAB) by use of 4-amino-5-phenyl-4H-1,2,4-triazole-3-thiol (APTT) was investigated by monitoring weight loss and open-circuit potentials (OCP), and by use of electrochemical impedance spectroscopy (EIS). Quantum chemical data were calculated by use of the density functional theory (DFT) model. Results showed that APTT inhibits corrosion of NAB alloy fairly well. The efficiency of inhibition increases with increasing concentration of APTT, and adsorption of the inhibitor obeys the Langmuir adsorption isotherm model. Negative values of adsorption free energy indicate chemical adsorption is spontaneous. The theoretical study showed that sulfur and nitrogen atoms (S, N7 and N8) were the reactive sites.

In this work we have developed a decision support system that can determine corrosion and project the time for corrosion growth maintenance using probabilistic modelling approach. Historical data of the atmospheric industrial environment conditions for five years on three metals- zinc, iron and steel with known thicknesses were used. The environmental conditions included precipitation, wind speed, sulphur dioxide, relative humidity and temperature. For the five-year period, the percentiles of corrosion in the environment were determined to be from 63.1% to 69%. The corrosion rates of Zinc, iron and steel were 0.92µm/year,0.9µm/year and 0.51µm/year respectively. At the end of the first year the expected time to initiate corrosion growth maintenance actions for zinc, iron and steel were 9 years, 10 years and 14 years in that order. The probable contributions of each of the environmental factors to the corrosiveness of the environment were determined.

""The variables influencing corrosion of three metals (galvanised steel, stainless steel, brass) usable for a manure nutrient probe were examined, identifying the best material for field applications. The nutrients in 18 liquid manures were then estimated through the voltage drop between the terminals of a prototype probe.

Response Surface Modelling gave the regression functions relating each investigated response only to the statistically-significant factors.

After 168 h in the manure, it was determined that: stainless steel was the most suitable material for very close electrodes (mass: −1.8% at 15 mm), brass can be used with any inter-electrode distance (mass: −13.0% maximum at 35 mm).

The prototype probe gave reliable estimates (R2 ⩾ 0.744) of Ntot, Namm, Ptot, Ktot when dry matter and temperature were also accounted for in the regression analysis. Not considering dry matter but just electronically-detectable quantities (temperature, voltage drop), the estimates were only reliable (R2 ⩾ 0.656) above 20 °C.""