Effectiveness of an Inorganic Corrosion Inhibitor in Pore Solution Containing Sodium Chloride

2014 ◽  
Vol 556-562 ◽  
pp. 158-161 ◽  
Author(s):  
Xing Guo Feng ◽  
Guang Hui Dong ◽  
Jun Yan Fan
Keyword(s):  
Weight Loss ◽  
Sodium Chloride ◽  
Corrosion Rate ◽  
Corrosion Current Density ◽  
Inhibition Efficiency ◽  
Corrosion Potential ◽  
Pore Solution ◽  
Electrochemical Measurement ◽  
Corrosion Current ◽  
Organic Inhibitor

Combining use electrochemical measurement and weight loss testing, the inhibition efficiency of an organic inhibitor was studied in a chloride contaminated solution. The results showed that the added inhibitor can enhance the corrosion potential and decreased the corrosion current density of rebar. The weight loss testing confirmed that the inhibitor reduced the corrosion rate of rebar by 80% in the chloride containing solution. Moreover, the linear polarization results are consistent with the weight loss testing, which suggests that the former is an effective method to estimate the inhibition efficiency of inhibitors.

scholarly journals Influence of Seawater Salinity on Corrosion of Austenitic Steel

2019 ◽  
Vol 26 (3) ◽  
pp. 219-225
Author(s):  
Robert Starosta
Keyword(s):  
Sodium Chloride ◽  
Corrosion Rate ◽  
Austenitic Steel ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Saturated Calomel Electrode ◽  
Corrosion Current ◽  
Seawater Salinity ◽  
Corrosion Susceptibility

Abstract Due to the paramagnetic properties and the ability to passivation, for the production of hulls of some vessels (mainly warships), corrosion-resistant (stainless) steels with austenitic structure are used. This article describes the influence of seawater salinity on selected corrosion properties of high-alloy steel X5CrNi 18-10 (304). The average salinity of the seas is taken as 3.5% content of sodium chloride. Corrosion rate of the tested material was evaluated in an aqueous solution of sodium chloride was evaluated. The NaCl concentration in corrosive solutions was 0.7%, 1.4%, 2.1%, 2.8%, 3.5%, 4.2%. Corrosion tests were performed using the potentiodynamic method. The range of electrochemical potential changes was Ecorr ±150 mV. Corrosion rate was assessed on the basis of corrosion current density measurements. Corrosion potential values against the saturated calomel electrode were also determined. Based on the obtained measurement results and non-parametric significance tests carried out, a significant influence of seawater salinity on the value of corrosion current density and corrosion potential was found. The highest value of corrosion current density (jcorr), and thus the highest corrosion rate, was recorded for 3.5% NaCl solution. In the concentration range from 0.7 to 3.5% NaCl in solution, the corrosion rate of austenitic steel increases. A further increase in salinity of electrolyte results in the inhibition of corrosion rate of steel. There is almost a full negative, linear correlation between the proportion of sodium chloride in the corrosive solution and the value of corrosion potential. Along with the rise in the salinity of seawater, increase the electrochemical activity, and thus the corrosion susceptibility, thus the corrosion susceptibility, of the austenitic steel X5CrNi 18-10 was observed.

scholarly journals Preparation and Anticorrosion of Octadecyl Trichlorosilane SAMs for Copper Surface

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Xue Shouqing ◽  
Liu Xiaohui
Keyword(s):  
Corrosion Rate ◽  
Corrosion Current Density ◽  
Inhibition Efficiency ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Copper Surface ◽  
Self Assembled Monolayer ◽  
Corrosion Medium ◽  
Octadecyl Trichlorosilane

The self-assembled monolayer (SAM) was prepared using octadecyl trichlorosilane (OTS) in distilled solution on the copper surface. The effect of inhibitor concentration on the rate of inhibition efficiency and corrosion rate in corrosion medium on copper by using polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM) was studied. The results showed that OTS SAMs exhibit the better corrosion resistance; the corrosion potential of copper OTS SAMs protection increased by about 1.02 V, while the corrosion current density decreased to 0.59 μA/cm2. The corrosion rate is minimized and flattened and can reach 9.2% while the inhibition efficiency reached 95.4%, when the corrosion inhibitor has concentration of 40 ppm.

Effect of adding rare-earth cerium on the microstructure and acid rain corrosion resistance of the ADC12 alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
LiJie Zhang ◽  
Hong Yan ◽  
YongCheng Zou ◽  
BaoBiao Yu ◽  
Zhi Hu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Acid Rain ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
The Self ◽  
Electrochemical Tests ◽  
Immersion Corrosion ◽  
Eutectic Si

Abstract The effect of adding cerium on the microstructure and acid rain corrosion resistance of the AlSi11Cu3 alloy was investigated by means of optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy. The AlSi11Cu3 alloy was doped with varying stoichiometries of cerium to generate AlSi11Cu3-xCe, where x = 0, 0.5, 1.0, and 1.5 wt.%. The results show that the α-Al, eutectic Si, and β-Al5FeSi phases in the AlSi11Cu3-1.0Ce alloy are significantly refined. Electrochemical tests demonstrated an increase in the self-corrosion potential value of the AlSi11Cu3-1.0Ce alloy from –670 mV to –628 mV relative to the untreated alloy. In addition, the AlSi11Cu3-1.0Ce alloy has the lowest corrosion current density (8.4 μA × cm–2). Immersion corrosion testing on the AlSi11Cu3-1.0Ce alloy revealed a corrosion rate of 0.71 mg × cm–2 × d–1, constituting a 72% reduction in the corrosion rate compared to the untreated alloy. These results indicate that the AlSi11Cu3-1.0Ce alloy has a high resistance to acid rain corrosion, which is the result of a refinement of the cathode phases.

Effects of CeO2 on Microstructure and Corrosion Performance of the Coatings Prepared by Pulse Micro Arc Oxidation on AZ31B Mg Alloy

2020 ◽  
Vol 20 (8) ◽  
pp. 4778-4786
Author(s):  
Lilu Qin ◽  
Jiamu Huang ◽  
Longlong Hao ◽  
Jun Su ◽  
Niu Ma ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Salt Spray ◽  
Electrochemical Measurement ◽  
Corrosion Current ◽  
Corrosion Performance ◽  
Micro Arc Oxidation ◽  
Micro Morphology

To improve corrosion performance of coatings on AZ31B magnesium alloy, the nano-CeO2 additives were included in Na2SiO3 based electrolyte during process of pulse micro arc oxidation (MAO). The MAO-CeO2 coating was successfully prepared to characterize its structure, micro morphology and composition. The XRD results indicated that MAO-CeO2 coatings were consisted of Mg2SiO4, MgSiO3, MgF2 and CeO2. The intensity of CeO2 peaks increases with increasing nano-CeO2 particles in electrolyte. The number of cracks on MAO-CeO2 coatings exhibited a V-shaped trend with increase in nano-CeO2 content. Meanwhile, the influence of nano-CeO2 on corrosion behavior of MAO-CeO2 coatings is investigated by salt spray test and electrochemical measurement. The corrosion current density of coatings presented same trend and corrosion potential is further studied. The MAO-CeO2 coatings formed in electrolyte with 10 g/L nano-CeO2 showed best corrosion performance which has the lowest corrosion current density of 0.58 nA/cm2 and the highest corrosion potential of - 1269 mVSCE.

scholarly journals Influence of Seawater Salinity on Corrosion of Hull Structural Steel

2019 ◽  
Vol 26 (2) ◽  
pp. 189-195
Author(s):  
Paweł Zagożdżon ◽  
Robert Starosta
Keyword(s):  
Sodium Chloride ◽  
Structural Steel ◽  
Current Density ◽  
Mass Fraction ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Corrosion Tests ◽  
Seawater Salinity

Abstract Hulls of ships are often made of steel, which are produced under the supervision of classification societies. Usually, the hull steel of ordinary strength category A is used for the ship's shell (the yield strength is 235 MPa and the impact strength 27 J at 20ºC). Vessels sail in sea areas with various levels of salinity and thus with different corrosiveness. The average salinity of the seas is taken as 3.5% content of sodium chloride. This article presents the results of corrosion tests of S235 JRG1 steel in an aqueous solution in which the mass fraction of sodium chloride was: 0.7%, 1.4%, 2.2%, 2.8%, 3.5% and 4.2%. Corrosion tests were performed using the potentiodynamic method. As parameters characterizing the corrosion properties of the tested steel, the corrosion current density and corrosion potential were assumed. Statistically significant influence of seawater salinity on the corrosion properties of hull structural steel of ordinary strength of category A was found. The highest value of the corrosion current density was observed in the solution containing 3.5% NaCl mass fraction was observed. In seawater with a sodium chloride content in the range of 0.7 to 3.5%, an increase in the value of the corrosion current density was observed, along with the increasing share of NaCl. In seawater with higher salinity, the corrosion rate was reduced. The corrosion potential of S235JRG1 steel decreases with the NaCl content in the corrosive solution. The susceptibility of this material to corrosion in seawater increased.

Application of Seeds from Psidium Guajava as Organic Inhibitor

2020 ◽  
Vol 867 ◽  
pp. 103-108
Author(s):  
Atria Pradityana ◽  
Subowo ◽  
Hari Subiyanto ◽  
Eddy Widiyono ◽  
Dwi Winarto Gathot
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Potentiodynamic Polarization ◽  
Inhibition Efficiency ◽  
Psidium Guajava ◽  
Test Material ◽  
Corrosive Media ◽  
Surrounding Environment ◽  
Organic Inhibitors ◽  
Organic Inhibitor

Corrosion is the process of natural changes in the nature of a material due to the influence or reaction with the surrounding environment. One way to control it is by adding inhibitors. In this study, seeds from guava (Psidium Guajava) were used as organic inhibitors. The test material used is API 5L grade B steel. For corrosive media, a solution of 1 M H2SO4 is used. In experiments used variations in the concentration of extracts 0, 2, 3, 4, 5 and 6 ml. The results of the experiments showed a decrease in the corrosion rate of API 5L grade B when there were additional inhibitors. This is supported by the experimental results of Potentiodynamic Polarization. The rate of corrosion without the presence of an inhibitor shows 75,018 mmpy whereas in the presence of 2,8845 mmpy inhibitors. Based on the calculation, the inhibition efficiency is 96.155%. This is also indicated by the results of the testing of weight loss that has been done. The efficiency shown is 90.130%.

An Innovative Specimen for Mg Corrosion Studies

2011 ◽  
Vol 690 ◽  
pp. 365-368 ◽  
Author(s):  
Zhi Ming Shi ◽  
Andrej Atrens
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
High Purity ◽  
Crevice Corrosion ◽  
Corrosion Current Density ◽  
Cathodic Polarization ◽  
Corrosion Current ◽  
Polarization Curves ◽  
Corrosion Rates ◽  
Corrosion Studies

Plug-in specimens enable measurement of reliable Mg polarization curves. Cathodic polarization curves were measured for high purity Mg in 3.5% NaCl saturated with Mg(OH)2using (i) mounted specimens and (ii) plug-in specimens. Polarization curves yielded the corrosion current densityicorrand the corresponding corrosion ratePi, which was compared with corrosion rates evaluated from hydrogen evolution,PH, and weight loss,PW. Mounted specimens producePivalues three times larger than plug-in specimens, due to crevice corrosion in the mounted specimens. Plug-in specimens had no crevice and allow simultaneous measurement ofPHandPi. Piwas less thanPHand indicated an apparent valence of 1.45 in support of the existence of the uni-positive Mg+ion.

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

scholarly journals Microstructure of Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn Alloys

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Wenzheng Chen ◽  
Wenlong Zhang ◽  
Dongyan Ding ◽  
Daihong Xiao
Keyword(s):  
Mechanical Properties ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Aging Treatment ◽  
Corrosion Current ◽  
Homogenization Temperature ◽  
Tafel Polarization ◽  
Al2cu Phase ◽  
Different Temperatures ◽  
Microstructural Optimization

Microstructural optimization of Al-Li alloys plays a key role in the adjustment of mechanical properties as well as corrosion behavior. In this work, Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn alloy was homogenized at different temperatures and holding times, followed by aging treatment. The microstructure and composition of the homogenized alloys and aged alloys were investigated. There were Al7Cu4Li phase, Al3Li phase, and Al2CuLi phases in the homogenized alloys. The Al7Cu4Li phase was dissolved with an increase in homogenization temperature and holding time. Al2Cu phase and Al2CuLi phase coarsened during the homogenization process. The alloy homogenized at 515 °C for 20 h was subjected to a two-stage aging treatment. Peak-age alloy, which had gone through age treatment at 120 °C for 4 h and 180 °C for 6 h, was mainly composed of α-Al, Al20Cu2Mn3, Al2CuLi, Al2Cu, and Al3Li phases. Tafel polarization of the peak-age alloys revealed the corrosion potential and corrosion current density to be −779 mV and 2.979 μA/cm2, respectively. The over-age alloy had a more positive corrosion potential of −658 mV but presented a higher corrosion current of 6.929 μA/cm2.

scholarly journals Corrosion behaviour of an AlZnSnSrGa alloy in aqueous solutions of NaCl and Na2So4

2000 ◽  
Vol 65 (1) ◽  
pp. 73-81
Author(s):  
P. Zivkovic ◽  
J. Pjescic ◽  
S. Mentus
Keyword(s):  
Corrosion Rate ◽  
Aqueous Solutions ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Behaviour ◽  
Base Material ◽  
Corrosion Current ◽  
Open Circuit ◽  
Base Metals ◽  
Aluminium Plant

The alloy composed of Al(95.53%), Zn(2.85%), Sn(0.515%), Ga(0.1%) and Sr(0.009%), with the weight percents in the parentheses, was prepared by melting, using Al(99.84%), a product of the Aluminium Plant-Podgorica, as the base material. The corrosion behaviour of this alloy was tested in relation to the behaviour of the base metals, by both open curcuit potential and polarization resistance methods, in aqueous solutions of both NaCl and Na2SO4, the concentration of which varied within the range 0.00051 - 0.51 mol dm -3. Over the whole salt concentration ranges, the corrosion parameters indicate that the corrosion rate of the alloy is significantly higher than the rate of the base material. For instance, for the concentration range 0.00051 - 0.51 mol dm -3 , the stationary open circuit potentials, related to SCE, in NaCl solutions were - 1.200 to - 1.460 V for the alloy and - 0.693 to - 0.920 V for Al, while in Na2SO4 solutions, the stationary open circuit potentials were - 1.190 to - 1.465V for the alloy and - 0.780 to - 0.860V for Al. At the same time, the corrosion current density in NaCl solutions varied within 11-89 mA cm -2 for the alloy and 0.35 - 0.80 for Al, while in Na2SO4 solutions it amounted to 5.7.52 mA cm -2 for the alloy and 0.28 - 0.88 mA cm -2 for Al.

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