scholarly journals Induced-Pitting Behaviors of MnS Inclusions in Steel

2018 ◽  
Vol 37 (9-10) ◽  
pp. 1007-1016 ◽  
Author(s):  
Shufeng Yang ◽  
Mengjing Zhao ◽  
Jie Feng ◽  
Jingshe Li ◽  
Chengsong Liu
Keyword(s):  
Impedance Spectroscopy ◽  
Pitting Corrosion ◽  
Potentiodynamic Polarization ◽  
Critical Size ◽  
Corrosion Process ◽  
Steel Matrix ◽  
Immersion Experiment ◽  
Average Size ◽  
Inclusions In Steel ◽  
Cooling Methods

AbstractThis paper investigated the effects of MnS inclusions on inducing pitting in steel. Three different cooling methods were used to control the morphology, size, and distribution of MnS inclusions. AC (alternating current) impedance spectroscopy experiments and potentiodynamic polarization experiments were carried out for different sizes of MnS inclusions. The corrosion immersion experiment was conducted to study the pitting corrosion process in different morphologies of MnS inclusions. The experiment results showed that pitting corrosion occurred around MnS inclusions and pitting was induced along the junction of MnS inclusions and their surrounding steel matrix. Also, the sensitivity of inducing-pitting of MnS inclusions was changed with the change of the average size of MnS in steel and it had a critical size of MnS. The deeper the MnS inclusions were buried in steel matrix, the more difficult it was for it to dissolve and fall off. Herein, it would cause greater damage.

scholarly journals Novel pyrimidine-bichalcophene derivatives as corrosion inhibitors for copper in 1 M nitric acid solution

RSC Advances ◽  
2021 ◽  
Vol 11 (41) ◽  
pp. 25314-25333
Author(s):  
Mai A. Khaled ◽  
Mohamed A. Ismail ◽  
Ahmed. A. El-Hossiany ◽  
Abd El-Aziz S. Fouda
Keyword(s):  
Weight Loss ◽  
Electrochemical Impedance Spectroscopy ◽  
Nitric Acid ◽  
Impedance Spectroscopy ◽  
Acid Solution ◽  
Nitric Acid Solution ◽  
Potentiodynamic Polarization ◽  
Corrosion Inhibitors ◽  
Electrochemical Impedance ◽  
Pyrimidine Derivatives

This study targets the investigation of three pyrimidine derivatives (MA-1230, MA-1231, MA-1232) for the prevention of corrosion on copper in 1 M HNO3via weight loss (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) techniques.

The effect of electroplating current density on microstructure, corrosion, and wear behavior of Ni–P–W–TiO2 coating

2021 ◽  
Vol 112 (6) ◽  
pp. 474-485
Author(s):  
Sajjad Sadeghi ◽  
Hadi Ebrahimifar
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Micro Hardness ◽  
Aisi 304L

Abstract The use of ceramic particles in the matrix of alloy coatings during the electroplating process has received considerable attention. These particles can create properties such as high corrosion resistance, insolubility, high-temperature stability, strong hardness, and self-lubrication capability. Herein, an Ni–P–W–TiO2 coating was deposited on an AISI 304L steel substrate using the electroplating method. Electroplating was performed at current densities of 10, 15, 20, and 25 mA · cm–2, and the effect of current density on microstructure, corrosion behavior, and wear behavior was investigated. The coatings were characterized by means of scanning electron microscopy. To investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed in a 3.5% NaCl aqueous solution. A pin-on-disk test was conducted to test the wear resistance of uncoated and coated samples. Sample micro-hardness was also measured by Vickers hardness testing. Examination of the microstructure revealed that the best coating was produced at a current density of 20 mA · cm–2. The results of potentiodynamic polarization and electrochemical impedance spectroscopy tests were consistent with microscopic images. The coating created at the current density of 20 mA · cm–2 had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the wear test showed that increasing the current density of the electroplating path up to 20 mA · cm–2 enhances micro-hardness and wear resistance.

Studies on Corrosion Behavior of S-165 and HP Supermartensitic Stainless Steels in Cl- Environment

2011 ◽  
Vol 695 ◽  
pp. 425-428
Author(s):  
Duo Wang ◽  
De Ning Zou ◽  
Chang Bin Tang ◽  
Kun Wu ◽  
Huan Liu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Polarization Curves ◽  
Chemical Compositions ◽  
Pitting Potential ◽  
Potentiodynamic Polarization Curves

Supermartensitic stainless steel grades are widely used in oil and gas industries to substitute duplex and super duplex stainless steels these years. In this paper the corrosion behavior of supermartensitic stainless steels with different chemical compositions, S-165 and HP, was investigated in Cl-environment. All the samples were treated by quenching at 1000 °C followed by tempering at 630 °C for 2h. After heat treatment, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) were determined on both kinds of samples. Polarization curves shows that the metastable pitting nucleuses were formed in passive area and the Cr content is the most important factor leading to the differences of pitting potential. The potentiodynamic polarization curves were conducted at various NaCl contents (5000, 15000 and 35000 ppm) and emphasized the need to account for the Cl-sensitivity of samples under corrosion environment. The results show that, the pitting potential decrease with the increase of chloride contents. The behavior of passive film was analyzed by electrochemical impedance spectroscopy.

The effect of an N-heterocyclic compound on corrosion inhibition of J55 steel in sweet corrosive medium

2019 ◽  
Vol 43 (16) ◽  
pp. 6303-6313 ◽  
Author(s):  
Ambrish Singh ◽  
K. R. Ansari ◽  
M. A. Quraishi ◽  
Savas Kaya ◽  
Priyabrata Banerjee
Keyword(s):  
Carbon Dioxide ◽  
Weight Loss ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibition ◽  
Heterocyclic Compound ◽  
Potentiodynamic Polarization ◽  
Corrosive Medium ◽  
Electrochemical Impedance ◽  
Nacl Solution

The corrosion inhibition behavior of a naphthoxazinone derivative 1-phenyl-1,2-dihydronaphtho[1,2-e][1,3]oxazin-3-one (PNO) on J55 steel in 3.5 wt% NaCl solution saturated with carbon dioxide was evaluated using weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization.

Cluster Analysis of Acoustic Emission Signals During Carbon Steel Pitting Corrosion Process

2014 ◽  
Author(s):  
Zhongzheng Zhang ◽  
Cheng Ye ◽  
Jun Jiang
Keyword(s):  
Cluster Analysis ◽  
Acoustic Emission ◽  
Carbon Steel ◽  
Ferric Chloride ◽  
Pitting Corrosion ◽  
Chloride Solution ◽  
Ferric Chloride Solution ◽  
Corrosion Process ◽  
Different Types ◽  
Ae Signals

In order to study acoustic emission (AE) signals characteristics of pitting corrosion on carbon steel, Pitting corrosion process on carbon steel in 6% ferric chloride solution was monitored by AE technology. K-mean cluster algorithm was used to classify the monitored AE signals, in which the duration, counts, amplitude, absolute energy and peak frequency were analyzed as the AE signals characteristics, and different types AE sources were identified. The results showed that there were mainly three type AE sources during carbon steel pitting corrosion process in ferric chloride solution, and the different types AE sources could be classified by cluster analysis. The research results have some certain significance for AE monitoring of pitting corrosion on carbon steel.

Study on Corrosion Process of Al-Mg Coatings Based on Electrochemical Impedance Spectroscopy

2017 ◽  
Vol 744 ◽  
pp. 380-384
Author(s):  
Hui Tong ◽  
Wen Li Han ◽  
Zhong Ping Xu ◽  
Yan Jun Zhang ◽  
Zhu Lin ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Corrosion Process ◽  
Corrosion Products ◽  
Passive Films ◽  
Nacl Solution ◽  
Electrochemical Testing ◽  
Immersion Corrosion

Electrochemical impedance spectroscopy (EIS) is a technology of nondestructive electrochemical testing. In this paper, EIS is applied to study the corrosion processes of Al-Mg coatings. In the initial 24 h of immersion in 3.5% NaCl solution, passive films of Al-Mg coatings dissolve quickly. As time passed, corrosion products increase on surface gradually, which can inhibit corrosion. After 480h of immersion, corrosion products fully cover on Al-Mg coatings’ surface. The EIS of different corrosion processes are fitted by three equivalent circuits corresponding to the three corrosion processes. In the test of open circuit potentials (OCP), OCP is instable in the initial 24 h of immersion. As immersion time goes by, OCP tends to stabilization at about -0.90 V. Measurements of scanning electron microscope (SEM) confirm the conclusions of electrochemical measurements.

Crevice Corrosion Behaviors of X52 Carbon Steel in Chloride Containing Solutions

2013 ◽  
Vol 652-654 ◽  
pp. 1432-1435
Author(s):  
Qian Hu ◽  
Jing Liu ◽  
Jie Zhang ◽  
Feng Huang ◽  
Xing Peng Guo
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Impedance Spectroscopy ◽  
Crevice Corrosion ◽  
Electrochemical Noise ◽  
Electrochemical Impedance ◽  
Corrosion Process ◽  
Nacl Solution ◽  
Concentration Difference ◽  
Corrosion Behaviors

The crevice corrosion behaviors of X52 carbon steel in two typical Cl--containing solutions were investigated by electrochemical noise and electrochemical impedance spectroscopy. Results show that oxygen concentration difference leads to the coupled current in NaCl + NaHCO3 solution while HAc concentration difference causes the coupled current in NaCl solution saturated with CO2 in the presence of HAc. There exists an apparent incubation stage during the crevice corrosion process of X52 carbon steel in the former. However, no obvious incubation period of crevice corrosion can be observed in the latter. Micrography shows that the crevice corrosion occurs indeed and the corrosion inside the crevice is not uniform.

Using Localized Impedance Spectroscopy to Study the Effect of Loading Potential Variation on DMFC Anode Performance

2016 ◽  
Vol 852 ◽  
pp. 785-791
Author(s):  
Nai Bao Huang ◽  
Wan Li ◽  
Cheng Hao Liang ◽  
Li Shuang Xu ◽  
Xiao Ye Wang ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Catalyst Particle ◽  
Local Area ◽  
Anode Surface ◽  
Potential Variation ◽  
Catalyst Particle Size ◽  
Direct Methanol ◽  
The Difference ◽  
Average Size

By localized impedance spectroscopy (LEIS) and electrochemical impedance spectroscopy (EIS), the effect of loading potential variation on the performance of direct methanol fuel cell ( DMFC ) anode was studied. During surface scanning, the local impedance of the anode showed sawtooth-like distribution under potential loading, which meant the electrochemical activity in the anode surface was nonuniform. Meanwhile, the local impedance tended to increase with loading potential increasing. After loading 16h and 72h at 0.6V, the average size of catalysts changed from 3.4nm to 3.6nm and 4.4nm, increased by 5.88% and 29.41%. After loaded for 72h under 0.8V, the ratio of Pt:Ru in catalyst changes from 2:1 to 3.9:1. It is the change of the difference in local area, which showed impedance increase, catalyst particle size growing up and agglomeration, the loss of Ru, that contributed to the performance decay of DMFC anode.

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