scholarly journals Corrosion Behavior of SA508 Coupled with and without Magnetite in EDTA-Based Solutions

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 377 ◽  
Author(s):  
Yeong-Ho Son ◽  
Soon-Hyeok Jeon ◽  
Geun Song ◽  
Jong Lee ◽  
Do Hur
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Solution Temperature ◽  
Chemical Cleaning ◽  
Galvanic Coupling ◽  
Positive Direction ◽  
Edta Concentration

The effects of magnetite on the corrosion behavior of SA508 were studied in 10% and 20% EDTA-based chemical cleaning solutions at 93 °C and 121 °C using electrochemical and immersion tests. SA508 was the anode of the galvanic pair between SA508 and magnetite. The galvanic coupling shifted the mixed corrosion potential of SA508 in the positive direction and thus increased its corrosion rate. The increase of the EDTA concentration and solution temperature led to an increase in the extent of the galvanic effect.

Corrosion Behavior of Amorphous Co69Fe4.5Cr1.5Si10B15 Alloy

CORROSION ◽  
2010 ◽  
Vol 66 (11) ◽  
pp. 116002-116002-4 ◽  
Author(s):  
H.-G. Kim ◽  
H. J. Jang
Keyword(s):  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Alloy Ribbon ◽  
Solution Temperature ◽  
H2so4 Solution ◽  
Nacl Solution

Abstract The corrosion behavior of amorphous Co69Fe4.5Cr1.5Si10B15 alloy ribbon was investigated using potentiodynamic polarization tests in 0.001 M sulfuric acid (H2SO4) solution, 0.01 M ∼ 0.09 M sodium chloride (NaCl) solution, and solutions at pH levels from 3 to 13 made by mixing hydrochloric acid (HCl) and sodium hydroxide (NaOH). The corrosion potential decreased and the corrosion rate increased with an increase in solution temperature. The influence of solution temperature was more significant in H2SO4 solution than in NaCl solution. The amorphous Co69Fe4.5Cr1.5Si10B15 alloy ribbon showed passivity in solution with a pH higher than 7, and the corrosion rate was minimized at a pH of 9.

scholarly journals The Corrosion Behavior of Sputter?deposited W?xTa Alloys in 0.5 M NaCl Solution

2013 ◽  
Vol 14 (1) ◽  
pp. 103-108
Author(s):  
Jagadeesh Bhattarai ◽  
Susil Baral
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Nacl Solution ◽  
High Corrosion Resistance ◽  
Positive Direction ◽  
Sputter Deposited

The corrosion behavior of the sputter–deposited amorphous and nanocrystalline W–xTa (x = 8–77) alloys was studied in 0.5 M NaCl solution open to air at 25°C using corrosion tests and electrochemical measurements. Tungsten and tantalum metals act synergistically in enhancing the corrosion resistance of the sputter–deposited W–xTa alloys and hence additions of 23 at. % of tantalum or more to the sputter–deposited W–xTa alloys were found to be effective to achieve significantly high corrosion resistance properties of the alloys than those of alloy– constituting elements. In particular, the corrosion rate of the W–60Ta alloy showed the lowest corrosion rate (that is, 2.0×10-3). The open circuit potential of the alloys shifted noble (positive) direction with immersion time. Addition of tantalum metal in W–xTa alloys is effective for ennoblement of the open circuit corrosion potential of the tungsten metal in 0.5 M NaCl solution open to air at 25°C. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 103-108 DOI: http://dx.doi.org/10.3126/njst.v14i1.8929

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.

Effect of Li on the Corrosion Behavior of Al-Cu/SiCp Composites

2009 ◽  
Vol 68 ◽  
pp. 133-144 ◽  
Author(s):  
Jesús Lugo-Quintal ◽  
Luis Díaz-Ballote ◽  
Lucien Veleva ◽  
Antonio Contreras-Cuevas
Keyword(s):  
Electron Microscope ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Pure Aluminum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Aluminum Corrosion ◽  
Scanning Electron

The corrosion behavior in NaCl solutions at different pH values of Al-Cu-Li/SiCp and Al-Cu/SiCp composites fabricated by co-spraying technique was studied. The corrosion behavior of the composites was also compared with the corrosion behavior of pure aluminum. Corrosion potential measurements and potentiodynamic polarization were used to elucidate the corrosion behavior of the composites. In addition the microstructure and morphology of the composites were studied through X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the corrosion rate of Al-Cu-Li/SiCp and Al-Cu/SiCp composites was higher than corrosion rate of pure aluminum for all NaCl solutions tested. Both composites and pure aluminum showed the typical “U” behavior of the corrosion rate as a function of pH. The addition of lithium had little effect on the corrosion behavior of the composites.

Effect of Sn, Zn and Bi Addition on Corrosion Characteristics of Magnesium Alloys Sintered by Spark Plasma Sintering

2018 ◽  
Vol 941 ◽  
pp. 1760-1765
Author(s):  
Satoshi Sunada ◽  
Yoshitaka Matsui ◽  
Syogo Takeuchi ◽  
Taku Iwaoka ◽  
Koichi Sato ◽  
...  
Keyword(s):  
Melting Point ◽  
Corrosion Rate ◽  
Spark Plasma Sintering ◽  
Magnesium Alloys ◽  
Electrochemical Method ◽  
Corrosion Potential ◽  
Elemental Mapping ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Metallic Compounds

Sintered magnesium alloys, which were fabricated by Spark Plasma Sintering (SPS) method, were examined to study corrosion characteristics by electrochemical method, XRD and EPMA. The binary mixtures alloys of a low-melting-point metal powder (Sn, Bi, Sb) of1.0 vol.% and the pure magnesium powder were prepared. In the Mg-1.0vol.%Bi and Mg-1.0vol.%Sn, Mg3Bi2 and Mg2Sn precipitates was recognized by XRD, respectively. In addition, formation of oxide along powder particle boundaries was observed by EPMA elemental mapping in all specimens. In the case of Mg-1.0vol.%Zn, precipitation of metallic compounds was not recognized by these experiments. According to the results of polarization curve measurements, the Mg-1.0vol.%Bi shows highest corrosion potential. However, corrosion rate which was estimated by Tafel method is relatively larger than other alloys due to Mg3Bi2 precipitation. This result suggests that Mg3Bi2 acts as cathode site. The Mg-1.0vol.%Sn shows superior corrosion rale in these alloys.

scholarly journals Effect of Fluid Flow on the Corrosion Performance of as-Cast and Heat-Treated Nickel Aluminum Bronze Alloy (UNS C95800) in Saline Solution

2021 ◽  
Vol 2 (1) ◽  
pp. 61-77
Author(s):  
Hamid Reza Jafari ◽  
Ali Davoodi ◽  
Saman Hosseinpour
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Flow Rate ◽  
Solution Temperature ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Nacl Solution ◽  
Flow Conditions ◽  
Heat Treated ◽  
Nickel Aluminum Bronze

In this work, the corrosion behavior and surface reactivity of as-cast and heat-treated nickel aluminum bronze casting alloy (UNS C95800) in 3.5 wt% NaCl solution is investigated under stagnant and flow conditions. Increasing flow rate conditions are simulated using a rotating disk electrode from 0 to 9000 revolutions per minute (rpm). Optical micrographs confirm the decrease in the phase fraction of corrosion-sensitive β phase in the microstructure of C95800 after annealing, which, in turn, enhances the corrosion resistance of the alloy. Electrochemical studies including open circuit potentiometry, potentiodynamic polarization, and electrochemical impedance spectroscopy are performed to assess the effect of flow rate and heat treatment on the corrosion of samples at 25 and 40 °C in 3.5 wt% NaCl solution. For both as-cast and heat-treated samples, increasing the flow rate (i.e., electrode rotating rate) linearly reduces the corrosion resistance, indicating that the metal dissolution rate is significantly affected by hydrodynamic flow. Increasing the solution temperature negatively impacts the corrosion behavior of the as-cast and heat-treated samples at all flow conditions.

Corrosion Behavior of X70 Pipeline Steel and Corrosion Rate Prediction Under the Combination of Corrosive Medium and Applied Pressure

2017 ◽  
Author(s):  
Kaikai Li ◽  
Wei Wu ◽  
Guangxu Cheng ◽  
Yun Li ◽  
Haijun Hu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Corrosion Rate ◽  
Tensile Stress ◽  
Partial Pressure ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Applied Pressure ◽  
Chloride Concentration ◽  
X70 Pipeline Steel ◽  
Co2 Partial Pressure

Natural gas transmission pipeline is prone to internal corrosion due to the combination of corrosive impurities in the pipe (such as CO2, H2S and chlorides) and applied pressure of the pipeline, which seriously affects the safe operation of the pipeline. In this work, the corrosion behavior of a typical X70 pipeline steel was investigated by using potentiodynamic polarization and electrochemical impendence spectroscopy (EIS). The polarization and EIS data under different CO2 partial pressures (0–1 atm), H2S concentrations (0–150 ppm), chloride concentrations (0–3.5 wt%) and tensile stress (0–400 MPa) were obtained. The results show that corrosion rate increases with the increase of CO2 partial pressure and chloride concentration, respectively, while first increases and then decreases with the increase H2S concentrations. The corrosion rate is less affected by elastic tensile stress. In addition, a quantitative prediction model for corrosion rate of natural gas pipeline based on adaptive neuro-fuzzy inference system (ANFIS) was established by fitting the experimental data which maps the relationship between the key influencing factors (i.e. CO2 partial pressure, H2S concentration, chloride concentration and tensile stress) and the corrosion rate. The prediction results show that the relative percentage errors of the predicted and experimental values are relatively small. The prediction accuracy of the model satisfies the engineering application requirement.

scholarly journals Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Fluoride Concentration ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Nacl Solution ◽  
Galvanic Coupling ◽  
Beta Titanium

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

High-Temperature Corrosion of Ni3Al+ 2.9%Cr Alloy in Ar-0.2%SO2 Gas

2018 ◽  
Vol 775 ◽  
pp. 441-447
Author(s):  
Dong Bok Lee ◽  
Min Jung Kim ◽  
Gyu Chul Cho ◽  
Soon Young Park ◽  
Poonam Yadav
Keyword(s):  
High Temperature ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Kirkendall Effect ◽  
High Temperature Corrosion ◽  
Scale Spallation ◽  
Corrosion Tests ◽  
Cooling Period ◽  
Corrosion Kinetics ◽  
Period 2

The high-temperature corrosion behavior of Ni3Al+2.9 wt% Cr alloy was studied in SO2-containing environment. Corrosion tests were carried out at 900, 1000, and 1100 °C for 100 h in atmospheric Ar-0.2% SO2 gas. The alloy corroded relatively slowly due mainly to formation of Al2O3 in the scale. Its corrosion kinetics deviated from the parabolic corrosion rate law to a certain extent owing to ensuing scale spallation. This was attributed to (1) stress generated during scaling and the subsequent cooling period, (2) voids that formed due to the Kirkendall effect, and (3) incorporation of sulfur in the scale. The scale that formed after corrosion at 900 °C consisted of the outer NiO scale, middle NiAl2O4 scale, and inner Al2O3 scale. The increased corrosion rate at 1000 and 1100 °C led to formation of the outer NiO scale, and inner Al2O3 scale.

Corrosion Behavior of Duplex Stainless Steel in Industrial White Liquor

CORROSION ◽  
10.5006/2558 ◽  
2017 ◽  
Vol 74 (5) ◽  
pp. 543-550 ◽  
Author(s):  
Luiza Esteves ◽  
Mônica M.A.M. Schvartzman ◽  
Wagner Reis da Costa Campos ◽  
Vanessa F.C. Lins
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Corrosion Rate ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Extrapolation Method ◽  
White Liquor ◽  
Duplex Steel ◽  
Kraft Mill ◽  
Lower Corrosion Rate

Specimens of lean duplex and duplex stainless steel were exposed at 200°C in industrial white liquor from a Brazilian kraft mill using an autoclave to simulate the same conditions of digester processing. Tafel extrapolation method and weight loss were used to evaluate corrosion behavior of duplex steel in white liquor. The higher alloy steel, although presenting a lower corrosion rate than the lean duplex, presents a more severe selective attack on ferrite, at 200°C and 1.8 MPa, after Tafel extrapolation method in industrial white liquor.

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