scholarly journals Effect of Conducting Polyaniline/Graphene Nanosheet Content on the Corrosion Behavior of Zinc-Rich Epoxy Primers in 3.5% NaCl Solution

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 850 ◽  
Author(s):  
Yanhua Lei ◽  
Zhichao Qiu ◽  
Jiurong Liu ◽  
Dongdong Li ◽  
Ning Tan ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Potential Versus ◽  
Electrochemical Impedance ◽  
Graphene Nanosheet ◽  
Protective Properties ◽  
Free Corrosion Potential ◽  
Conducting Polyaniline ◽  
Sacrificial Cathodic Protection

The corrosion behavior of zinc-rich epoxy primers or paints (ZRPs) with different conducting polyaniline-grafted graphene (PANI/Gr) contents was investigated. Conductivity of the formed PANI/Gr nanosheets was significantly improved by employing the Gr as the inner template to synthesize the PANI. The protective properties and electrochemical behavior of coatings with artificial defects were investigated by monitoring the free corrosion potential versus time and by using localized electrochemical impedance spectroscopy (LEIS). A synergetic enhancement of the physical barrier role of the coating and the zinc sacrificial cathodic protection was achieved in the case of ZRP including PANI/Gr nanosheets. In addition, the ZRP mixed with the PANI/Gr at a content of 0.6% exhibited the best anticorrosion performance across the range of investigated PANI/Gr contents.

Influence of sulfate reducing bacteria on the cupronickel corrosion

2014 ◽  
Vol 61 (6) ◽  
pp. 395-401
Author(s):  
Liu Kecheng ◽  
Liu Xia ◽  
Long Xiao ◽  
Wei Jiaqiang ◽  
Hu Mengsha ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Sulfate Reducing Bacteria ◽  
Free Corrosion Potential ◽  
Content Type ◽  
Linear Polarization Resistance ◽  
Sulfate Reducing ◽  
Reducing Bacteria

Purpose – The purpose of this study is to explore the influence of the sulfate reducing bacteria (SRB) on the corrosion of cupronickel. Design/methodology/approach – Tests monitoring the change in free corrosion potential, linear polarization resistance and electrochemical impedance spectroscopy and examination using the scanning electron microscope and energy spectrum analysis were used to investigate the corrosion behavior of cupronickel in blank medium and in media inoculated with SRB to explore the influence of the SRB on the corrosion behavior of cupronickel alloy. Findings – The results show that SRB can destroy the surface oxide film of cupronickel and significantly reduce the free corrosion potential and polarization resistance of the cupronickel, causing the cupronickel to corrode significantly. Originality/value – SRB are widely found in the water supply system and is one of the important factors inducing microbial corrosion. This paper verified that SRB promote cupronickel corrosion and explored the influence and mechanism of attack.

Hot Corrosion of Nimonic 105 in Sodium Sulfate-Sodium Chloride Melts

CORROSION ◽  
1981 ◽  
Vol 37 (7) ◽  
pp. 392-407 ◽  
Author(s):  
C. A. C. Sequeira ◽  
M. G. Hocking
Keyword(s):  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Analytical Methods ◽  
Sodium Sulfate ◽  
Hot Corrosion ◽  
Corrosion Potential ◽  
Free Corrosion Potential ◽  
Chloride Melts ◽  
Ni Alloy ◽  
Potential Decay

Abstract The corrosion behavior of Nimonic 105 in molten Na2SO4, NaCl, and mixtures of these two salts, at 900 C, in laboratory air and under O2 + SO2/SO3 atmospheres has been evaluated by potentiodynamic, potential decay, and free corrosion potential measurements. In addition, the corrosion products were examined using several electron-optical techniques, and by other analytical methods. Pure Na2SO4 in air did not seem to be very corrosive towards Nimonic 105. Addition of NaCl to the molten Na2SO4 resulted in increased dissolution of Nimonic 105, which was in general nonuniform, alloy constituents nickel and cobalt dissolving more than others. Evidence of internal attack and enhancement of dissolution of the Ni alloy by SO3 was significant only when the corrosion conditions were prolonged. In pure NaCl, catastrophic corrosion occurs, which has been attributed to the depletion, dissolution, and vaporization of some alloy species.

scholarly journals Influence of the Alkaline Reserve of Chloride-Contaminated Mortars on the 6-Year Corrosion Behavior of Corrugated UNS S32304 and S32001 Stainless Steels

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 686 ◽  
Author(s):  
Asunción Bautista ◽  
Francisco Velasco ◽  
Manuel Torres-Carrasco
Keyword(s):  
Corrosion Behavior ◽  
Stainless Steels ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Duplex Microstructure ◽  
Testing Period ◽  
Alkaline Reserve ◽  
Eis Measurements ◽  
High Chloride ◽  
Chloride Concentrations

The durability of two lean corrugated duplex stainless steel (UNS S32304 and S32001) bars manufactured for concrete reinforcement was studied in four different corrosive conditions. These duplex stainless steels are more economical than the most traditional, well-known duplex grade steels (UNS S32205). The research was carried out in mortar samples for six years. In half of the samples, the alkaline reserve had been previously decreased, and their pH was slightly below 12, while in the other half, the pH close to the bars remained as-manufactured. Moreover, there were samples with modified and non-modified alkaline reserve where chlorides had been previously added to the mortar which were exposed to high relative humidity. In other samples—which were partially immersed in 3.5% NaCl—the chlorides entered through the mortar by natural diffusion. The electrochemical behavior of the reinforcements in these conditions was periodically monitored through corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) measurements during the whole testing period. The samples were anodically polarized at the end of the exposure. The results prove that the decrease in the alkaline reserve of the mortars can affect the corrosion behavior of the studied lean duplex in environments with high chloride concentrations. The duplex microstructure of the reinforcements makes it so that the corrosion proceeds by selective attack of the phases.

Role of Mn addition on the general corrosion and pitting corrosion behavior of 13Cr stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jun He ◽  
Lin Chen ◽  
Yanjing Su
Keyword(s):  
Stainless Steel ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Alkaline Solutions ◽  
General Corrosion ◽  
Content Type ◽  
X Ray ◽  
Product Film

Purpose The purpose of this study is to elucidate the effect of Mn addition on the corrosion behavior of stainless steel. Design/methodology/approach Chronoamperometry, quasi-steady-state polarization and electrochemical impedance spectroscopy were used to investigate the corrosion behavior of Mn added A13Cr-HS sample and original S13Cr samples. In addition, the corrosion product film was characterized by a field emission scanning electron microscope equipped with energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. Findings The A13Cr-HS sample with 8 wt.% Mn addition maintained good general corrosion resistance in both acidic and alkaline solutions compared to the original S13Cr sample. Additionally, the A13Cr-HS sample had good pitting resistance in an alkaline solution containing Cl−, but a weaker resistance in an acidic solution. Originality/value The influence of Mn addition on the formation mechanism of the passive film was systematically analyzed.

Study on the Corrosion Behavior of Two Kinds of Tubing at Different Temperatures

2011 ◽  
Vol 314-316 ◽  
pp. 1335-1341
Author(s):  
Xue Hui Zhao ◽  
Yan Han ◽  
Fa Gen Li ◽  
Zhen Quan Bai ◽  
Bin Wei
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Xrd Analysis ◽  
Tafel Polarization ◽  
Corrosion Rates ◽  
Two Samples ◽  
Different Temperatures

Aimed at the problem of sulfur-resistant corrosion in environment with carbon dioxide(CO2)and trace amounts of hydrogen sulfide (H2S), Tafel polarization curves and electrochemical impedance spectroscopy techniques were employed to study the electrochemistry corrosion behavior of two kinds of 80S(A and B) at different temperatures. The methods of weight-loss，scanning electron microscope and X-ray diffraction (XRD) analysis were used to study on the corrosion behavior of the sulfur-resistant tubes, including electrochemical impedance spectroscopy , average corrosion rates and the corrosion morphologies. The results showed that the corrosion potential and corrosion rates (CR) of two samples were different with the changing of the test temperatures. With the increase of the temperature, the corrosion potential decreased, and the corrosion rates increased, but decreased at 120°C. The corrosion-resistant of A80S was slightly superior to the B80S. The serious pitting corrosion and the maximum average CR occurred at 90°C. The XRD analysis suggested that the main corrosion products were FeS.

Electrochemical corrosion study of Pb-free solders

2006 ◽  
Vol 21 (1) ◽  
pp. 62-70 ◽  
Author(s):  
B.Y. Wu ◽  
Y.C. Chan ◽  
M.O. Alam ◽  
W. Jillek
Keyword(s):  
Acid Solution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Linear Polarization Resistance ◽  
Eis Measurements

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.

scholarly journals The effect of tantalum addition on the corrosion behavior of W-xTa alloys in 1 M NaOH solution

BIBECHANA ◽  
2013 ◽  
Vol 10 ◽  
pp. 1-8
Author(s):  
Susil Baral ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Corrosion Resistant ◽  
Corrosion Rates ◽  
Nanocrystalline And Amorphous ◽  
Naoh Solution ◽  
Tungsten Metal ◽  
Sputter Deposited

The role of tantalum addition on the corrosion behavior of the sputter-deposited nanocrystalline and amorphous W-xTa (x=8-77) alloys was studied in 1 M NaOH solution open to air at 25°C using corrosion tests and electrochemical measurements. Tungsten and tantalum metals act synergistically in enhancing the corrosion resistant properties of the W-xTa alloys and hence addition of 23 at% or more tantalum to the alloys were found to be effective to lower the corrosion rate of the alloys than those of alloy-constituting tungsten and tantalum elements. The corrosion rates of the W-xTa alloys containing 23-77 at% tantalum are nearly two orders of magnitude lower than that of tungsten and even slightly lower than that of tantalum in 1 M NaOH. Addition of tantalum metal in W-xTa alloys is effective for ennoblement of the open circuit corrosion potential of the tungsten metal in 1 M NaOH solution 25°C.DOI: http://dx.doi.org/10.3126/bibechana.v10i0.8363 BIBECHANA 10 (2014) 1-8

Electrodeposited Ni/Al2O3 Composite Coating on NdFeB Permanent Magnets

2008 ◽  
Vol 373-374 ◽  
pp. 232-235 ◽  
Author(s):  
Hui Zhang ◽  
Yong Wei Song ◽  
Zhen Lun Song
Keyword(s):  
Electron Microscopy ◽  
Composite Coating ◽  
Permanent Magnets ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Free Corrosion Potential ◽  
Al2o3 Composite ◽  
Nickel Electrolyte ◽  
Scanning Electron ◽  
Better Than

NdFeB permanent magnets are highly susceptible to corrosion in various environments. A new composite coating electrodeposited on NdFeB magnets was investigated in this paper. The Ni matrix film was firstly electrodeposited on NdFeB surface from watts nickel electrolyte, and then Ni/Al2O3 composite coating was successively electrodeposited on the Ni film. The microstructures of electrodeposited Ni coating and Ni/Al2O3 composite coating were observed by scanning electron microscopy (SEM). The corrosion behavior of Ni coating and Ni/Al2O3 composite coating in 3.5wt% NaC1 solution was studied by polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the Ni coating and Ni/Al2O3 composite coating could both provide adequate protection to NdFeB substrate. But the free corrosion potential of Ni/Al2O3 composite coating was more positive and the passivation region was more obvious when compared with Ni coating. Meantime, the capacitance loop diameter of Ni/Al2O3 composite coating was significantly larger than that of Ni coating ,which suggested that the anticorrosion resistance of Ni/Al2O3 composite coating was better than electroplated Ni coating.

COMPARATIVE STUDY OF CORROSION BEHAVIOR FOR PLASMA NITRIDED 1045 CARBON STEEL WITH AND WITHOUT PRETREATMENT OF SAND BLASTING

2018 ◽  
Vol 25 (01) ◽  
pp. 1850036 ◽  
Author(s):  
SHIJING LU ◽  
XIAOBING ZHAO ◽  
BIN MIAO ◽  
LU SONG ◽  
KUNXIA WEI ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Plasma Nitriding ◽  
Corrosion Current ◽  
Compound Layer ◽  
Frequency Region ◽  
Sand Blasting ◽  
Soaking Test

A pretreatment of sand blasting with the duration of 15[Formula: see text]min was carried out prior to plasma nitriding for 1045 carbon steel in this study. The corrosion behavior was evaluated by means of electrochemical polarization, electrochemical impedance spectroscopy (EIS) and soaking test, and compared with that without pretreatment of sand blasting. The results show that the pretreatment of sand blasting can significantly enhance the corrosion resistance, the corrosion potential shift to the noble direction, with higher corrosion potential of [Formula: see text][Formula: see text]mV and lower corrosion current of 0.0853[Formula: see text][Formula: see text]A/cm2, and exhibit larger diameter, higher phase angle and wider frequency region, there exists no corrosion pit after soaking test, and the corrosion rate is decreased from 0.0387[Formula: see text]g/mm2 to 0.01341[Formula: see text]g/mm2, only 1/3 comparing with that of sample without pretreatment of sand blasting. The enhancement mechanism of corrosion behavior is mainly ascribed to the excellent protection from the thicker and denser compound layer with higher amount of [Formula: see text]-Fe[Formula: see text]N.

Investigation on Fe3Al Corrosion Behavior in Simulating Marine Biofilm Environment

2008 ◽  
Vol 47-50 ◽  
pp. 177-180
Author(s):  
Xue Ting Chang ◽  
Yan Sheng Yin ◽  
Tao Wang ◽  
Cheng Wei Yin ◽  
Sha Cheng ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Calcium Alginate ◽  
Chloride Solution ◽  
Sodium Sulfide ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Natural Structure ◽  
Structure And Property ◽  
Calcium Alginate Gel ◽  
Bacteria Culture

In terms with the natural structure and property of microbe film, microbe film was simulated by Calcium Alginate gel Acetic acid, manganese dioxide, sodium sulfide were added separately into sodium chloride solution to simulate different bacteria culture systems. The corrosion behavior of Fe3Al was characterized based on the analysis of open circle potential, polarization curves, and electrochemical impedance. The corrosion potential of simulating SRB was 0.6V negative-moved in comparison with that of the other two bacteria. The results indicate that Fe3Al electrodes were much easier eroded by SRB environment.

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