scholarly journals Anticorrosion Behaviour of Rhizophora mangle L. Bark-Extract on Concrete Steel-Rebar in Saline/Marine Simulating-Environment

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Joshua Olusegun Okeniyi ◽  
Jacob Olumuyiwa Ikotun ◽  
Esther Titilayo Akinlabi ◽  
Elizabeth Toyin Okeniyi
Keyword(s):  
Corrosion Rate ◽  
Corrosion Protection ◽  
Plant Extract ◽  
Corrosion Potential ◽  
Rhizophora Mangle ◽  
Corrosion Current ◽  
Positive Control ◽  
Bark Extract ◽  
Steel Rebar ◽  
Mathematical Correlation

This paper investigates anticorrosion behaviour of the bark-extract from Rhizophora mangle L. on steel-rebar in concrete slabs in 3.5% NaCl medium of immersion (for simulating saline/marine environment). Corrosion-rate, corrosion-current, and corrosion-potential were measured from the NaCl-immersed steel-reinforced concrete cast with admixture of different plant-extract concentrations and from positive control concrete immersed in distilled water. Analyses indicate excellent mathematical-correlation between the corrosion-rate, concentration of the bark-extract admixture, and electrochemical noise-resistance (ratio of the corrosion-potential standard deviation to that of corrosion-current). The 0.4667% Rhizophora mangle L. bark-extract admixture exhibited optimal corrosion-inhibition performance, η = 99.08±0.11% (experimental) or η = 97.89±0.24% (correlation), which outperformed the positive control specimens, experimentally. Both experimental and correlated results followed Langmuir adsorption isotherm which suggests prevalent physisorption mechanism by the plant-extract on the reinforcing-steel corrosion-protection. These findings support Rhizophora mangle L. bark-extract suitability for corrosion-protection of steel-rebar in concrete structure designed for immersion in the saline/marine environmental medium.

Preparation and Corrosion Protection Effect of Electroactive Polyurethane Containing Amino-Capped Aniline Trimer

2010 ◽  
Vol 123-125 ◽  
pp. 1255-1258
Author(s):  
Chih Wei Peng ◽  
Jui Ming Yeh
Keyword(s):  
Corrosion Protection ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Passive Layer ◽  
Visible Absorption ◽  
Protection Effect ◽  
Reversible Redox ◽  
Cold Rolled ◽  
Uv Visible

Electroactive polyurethane (EPU) containing conjugated segments of electroactive amino-capped aniline trimer (ACAT) has been successfully synthesized and characterized through Fourier-Transformation infrared and UV–visible absorption spectroscopy. Subsequently, electroactivity (i.e., redox capability) of as-prepared EPU was investigated by electrochemical cyclic voltammetry (CV) studies. It was noticed that the as-prepared EPU exhibited reversible redox capability was found to reveal better corrosion protection effect on cold-rolled steel (CRS) electrodes than that of non-electroactive polyurethane based on a series of electrochemical measurements such as corrosion potential, polarization resistance, corrosion current and electrochemical impedance spectroscopy (EIS) studies in 5 wt-% NaCl electrolyte. This significant enhancement of corrosion protection on CRS electrodes as compared to non-electroactive polyurethane might be probably ascribed to the redox catalytic property of as-prepared EPU coatings inducing the formation of passive layer of metal oxide, as evidenced by the SEM and ESCA studies.

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.

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.

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.

High corrosion resistant ZrC films synthesized by ion-beamassisted deposition

1999 ◽  
Vol 14 (2) ◽  
pp. 615-618 ◽  
Author(s):  
Xiao-Ming He ◽  
Li Shu ◽  
Hai-Bo Li ◽  
Duan Weng
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Ion Beam ◽  
High Hardness ◽  
Corrosion Current ◽  
Experimental Results ◽  
Corrosion Resistant ◽  
Ion Beam Assisted Deposition

ZrC films with high hardness were deposited on A3 steel by ion-beam-assisted deposition and had a corrosion rate more than two orders less and a corrosion potential 0.19 V greater than those of the bare A3 steel. The corrosion current of ZrC films was 10 times less and the polarization resistance at least 7.82 times higher than those of both Teflon and ZrN films, respectively. The experimental results confirmed that ZrC films notably enhanced the corrosion resistance of steels.

The Influence of Different Gas Welding Flame on Corrosion Behavior of the Carbon Steel’s Heat Affected Zone in Seawater

2015 ◽  
Vol 1120-1121 ◽  
pp. 1059-1063
Author(s):  
Cai Xiang Gu ◽  
Guang Wei Liu ◽  
Yu Dong Xu
Keyword(s):  
Corrosion Rate ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Heat Affected Zone ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Electroanalytical Chemistry ◽  
Microstructure Observation ◽  
Weight Loss Method ◽  
Loss Method

The influence of different flame of gas welding on corrosion behavior of the carbon steel’s heat affected zone in seawater were studied by the weight-loss method, electroanalytical chemistry method and surface and microstructure observation. The result indicate that when gas welding the carbon steel, the corrosion rate of the heat affected zone under the influence of mild carbonizing flame is 0.1252[g／(m2•h)], in contrast, the corrosion rate of that under the influence of neutral flame is 0.1025[g／(m2•h)]; the order of corrosion current shows as follows: Imild carbonizing flame>Ineutral flame>Ibase metal; the order of measured corrosion potential as follows: Ebase metal>Eneutral flame>Emild carbonizing flame. Compared with the base metal, the heat effected zone are more likely to corrosion, corrosion resistance of the sample under mild carbon flame are the worse.

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.

scholarly journals Study on mechanism of differential concentration corrosion

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bin Liu ◽  
Yingwei Liu
Keyword(s):  
Corrosion Rate ◽  
Oxygen Concentration ◽  
Corrosion Potential ◽  
Pipe Wall ◽  
Corrosion Current ◽  
Two Dimensional ◽  
Low Oxygen ◽  
Concentration Difference ◽  
Seawater Environment ◽  
Low Oxygen Concentration

Abstract The pipeline easily gets corroded in a seawater environment. The oxygen in the seawater is one of major parameters causing the corrosion. In practice, the corrosion due to the oxygen concentration difference, i.e. differential concentration corrosion (DCC), cannot be avoided. However, a one-dimensional DCC model cannot satisfactorily predict the corrosion because the oxygen distribution near the pipe wall is two-dimensional. In this regard, a two-dimensional DCC model was proposed in this study to numerically investigate the distribution of corrosion potential and current in the ionic conductive layer near the pipe wall as well as the overall corrosion current. The results show that DCC plays a significant role in determining the corrosion potential and current. Without considering DCC, a large corrosion potential and current exist at the location with high oxygen concentration near the pipe wall, whereas the occurrence of the low corrosion potential and current corresponds to the location with low oxygen concentration. However, as DCC is considered, at the location with high corrosion potential, cathodic polarization was produced and the corrosion rate decreases; at the location with low corrosion potential, anodic polarization was produced and the corrosion rate increases. In general, the corrosion potential can be homogenized in terms of DCC.

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