Influence of electrosynthesis conditions and Al2O3 nanoparticles on corrosion protection effect of polypyrrole films

2014 ◽  
Vol 61 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Ali Ehsani ◽  
Mohammad Ghasem Mahjani ◽  
Maryam Nasseri ◽  
Majid Jafarian
Keyword(s):  
Oxygen Reduction ◽  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Reduction Process ◽  
Artificial Seawater ◽  
Alumina Nanoparticles ◽  
Al2o3 Nanoparticles ◽  
Active Dissolution ◽  
Content Type

Purpose – The purpose of this paper was to investigate the anti-corrosion behavior of polypyrrole (PPy) films in different states and presence of alumina nanoparticles synthesized by galvanostatic electropolymerization on stainless steel (SS) electrodes in an artificial seawater solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Design/methodology/approach – The electrochemical measurements were used to examine the effects of PPy and its nanocomposite on the corrosion behavior of SS type 316L in artificial seawater. A standard electrochemical cell with three electrodes was used for the measurements. The electrochemical response of the coated electrodes in the doped and the undoped state was compared with that of a bare electrode. Corrosion rate information was obtained by the Tafel extrapolation method, where the intersection point of a cathodic and an anodic polarization curve provides both the corrosion potential and the corrosion current. EIS measurements confirmed the potentiodynamic and open circuit potential (OCP) results. The microstructure of the obtained films was investigated by scanning electron microscopy. Findings – The results showed that the coated polymer films shifted the electrode potential toward more positive potentials, but this shift did not lead to passivation. However, a notable synergy was observed between PPy undoped film, oxygen reduction and iron dissolution. The potential of the SS remained in the active dissolution region, and it was not possible to produce a passive oxide layer in this region. PPy separates the metal dissolution process from the oxygen reduction process. This would prevent the local pH increase at the metal surface and subsequent delamination. The polarization curves, EOCP and impedance measurements showed that PPy undoped/Al2O3 layers show promise as good candidates for the corrosion protection of reactive metals. Originality/value – This paper presents that electrodes coated with undoped PPy synthesized in the presence of dodecyl sulfate anions and Al2O3 nanoparticles offered a noticeable enhancement of protection against corrosion processes.

Corrosion Protection of Nano-Silica Powder Coatingon Artificial Seawater

2021 ◽  
Vol 904 ◽  
pp. 519-524
Author(s):  
Gui Yun Zhang ◽  
Yong Wang ◽  
Tian Wei Zhang ◽  
Chen Yu Zhao
Keyword(s):  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Sea Water ◽  
Electrochemical Impedance ◽  
Water Solution ◽  
Electrochemical Corrosion ◽  
Artificial Seawater ◽  
Protection Effect ◽  
Aluminum Sheets ◽  
Electrochemical Corrosion Behavior

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.

Performance of coatings containing treated silica fume in the corrosion protection of reinforced concrete

2018 ◽  
Vol 47 (4) ◽  
pp. 350-359 ◽  
Author(s):  
Nivin M. Ahmed ◽  
Mostafa G. Mohamed ◽  
Reham H. Tammam ◽  
Mohamed R. Mabrouk
Keyword(s):  
Reinforced Concrete ◽  
Silica Fume ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Dual Function ◽  
Core Shell ◽  
Protection Efficiency ◽  
Content Type ◽  
Anticorrosive Pigments

Purpose This study aims to apply novel anticorrosive pigments containing silica fume-phosphates (Si-Ph), which were prepared using core-shell technique by covering 80-90 per cent silica fume (core) with 10-20 per cent phosphates (shell) previously, to play dual functions simultaneously as anticorrosive pigments in coating formulations and as an anticorrosive admixture in concrete even if it is not present in the concrete itself. Two comparisons were held out to show the results of coatings on rebars containing core-shell pigments in concrete, and concrete admixtured with silica fume can perform a dual function as anticorrosive pigment and concrete admixture. The evaluation of corrosion protection efficiency of coatings containing core-shell pigments and those containing phosphates was performed. Design/methodology/approach Simple chemical techniques were used to prepare core-shell pigments, and their characterization was carried out in a previous work. These pigments were incorporated in solvent-based paint formulations based on epoxy resin. Different electrochemical techniques such as open-circuit potential and electrochemical impedance spectroscopy were used to evaluate the anticorrosive efficiency of the new pigments. Findings The electrochemical measurements showed that concrete containing coated rebars with core-shell pigments exhibited almost similar results to that of concrete admixtured with silica fume. Also, the anticorrosive performance of coatings containing Si-Ph pigments offered protection efficiency almost similar to that of phosphates, proving that these new pigments can perform both roles as anticorrosive pigment and concrete admixture. Originality/value Although the new Si-Ph pigments contain more than 80 per cent waste material, its performance can be compared to original phosphate pigments in the reinforced concrete.

Corrosion behavior of a new 25Cr-3Ni-7Mn-0.66 N duplex stainless steel in artificial seawater

2021 ◽  
Vol 63 (6) ◽  
pp. 505-511
Author(s):  
Songkran Vongsilathai ◽  
Anchaleeporn Waritswat Lothongkum ◽  
Gobboon Lothongkum
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Passive Film ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Melting Furnace ◽  
Artificial Seawater ◽  
Vacuum Arc ◽  
Significant Difference ◽  
Type Semiconductor

Abstract A new duplex 25Cr-3Ni-7Mn-0.66 N alloy was prepared in a vacuum arc re-melting furnace and characterized by metallographic and EPMA methods. Its corrosion behavior was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and a Mott-Schottky (M-S) analysis in artificial seawater at room temperature and compared with those of super and normal commercial duplex stainless steel (SDSS and DSS). No significant difference in the open circuit potentials and pitting potentials was observed. Its passive film current density lies between those of SDSS and DSS. This was confirmed by EIS analysis. A pit attack was observed on the δ-phase for all duplex samples, because the PREN16 of the δ-phase was lower than that of the γ-phase. From the Mott-Schottky analysis, the passive films were found to be composed of bi-layer structures, a p-type semiconductor inner layer, and a n-type semiconductor outer layer. The degree of defect as well as the effect of nitrogen in passive film layer are discussed with respect to the point defect model.

Evaluation of the corrosion behavior of AZ31 magnesium alloy with different protein concentrations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yucong Ma ◽  
Mohd Talha ◽  
Qi Wang ◽  
Zhonghui Li ◽  
Yuanhua Lin
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Surface Film ◽  
Energy Dispersive Spectrometer ◽  
Inhibitory Effect ◽  
Corrosion Process ◽  
High Concentration ◽  
Content Type ◽  
Atomic Force

Purpose The purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L). Design/methodology/approach Electrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film. Findings Experimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance. Originality/value When the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.

Role of phytic acid in the corrosion protection of epoxy-coated rusty steel

2019 ◽  
Vol 66 (2) ◽  
pp. 188-194
Author(s):  
Yingjun Zhang ◽  
Xue-Jun Cui ◽  
Yawei Shao ◽  
Yanqiu Wang ◽  
Guozhe Meng ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Phytic Acid ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Complex Compounds ◽  
Epoxy Coating ◽  
Stable Complex ◽  
Content Type ◽  
Action Mechanisms ◽  
New Compounds

PurposeThis paper aims to prepare a residual rust epoxy coating by adding different quantities of phytic acid (PA) on the surface of the rusty steel and investigate the corrosion protection of PA and its action mechanisms.Design/methodology/approachA residual rust epoxy coating by adding different quantities of PA was prepared on the surface of the rusty steel. The influence of PA on the corrosion resistance of epoxy-coated rusty steel was investigated by means of electrochemical impedance spectroscopy and adhesion testing.FindingsResults indicated that PA can substantially improve the corrosion resistance of epoxy-coated rusty steel. This improvement is due to the reaction of PA with residual rust and generation of new compounds with protection properties and increased adhesive strength effects on the coating/metal interface. The coating showed better protection performance when 2 per cent PA was added.Originality/valueConsidering the structure of the active groups, PA has strong chelating capability with many metal ions and can form stable complex compounds on the surface of a metal substrate, thereby improving corrosion resistance. In recent years, PA has been reported to be useful in the conversion of coatings or as green corrosion inhibitor. To the best of the authors’ knowledge, few studies have reported the use of PA as a rust converter or residual rust coating. The present work aims to improve the corrosion resistance of residual rust epoxy coating by adding PA.

Corrosion behavior of in situ (TiC-TiB2)p/AZ91 magnesium matrix composites in Harrison solution

2014 ◽  
Vol 61 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Mohamed Gobara ◽  
Mohamed Shamekh
Keyword(s):  
Mechanical Properties ◽  
Corrosion Behavior ◽  
Matrix Composite ◽  
Electrochemical Impedance ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Content Type ◽  
X Ray ◽  
Az91 Magnesium

Purpose – This paper aims to study both the mechanical properties and the corrosion behavior of the synthesized in situ (TiC-TiB2) particulates/AZ91 magnesium matrix composite and compare the results with that of the conventional AZ91D alloy. Design/methodology/approach – Scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were used to study the surface morphology and crystalline structure. Mechanical compression tests were used to investigate the mechanical performance according to ASTM E9-89a. The corrosion behavior of the synthesized magnesium alloy was examined using both electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques in dilute Harrison solutions. Findings – The microstructure of the Mg composite showed a uniform distribution of reinforcing phases. Also, the reinforcing phases were formed without residual intermediate phases. The addition of titanium and boron carbides not only enhanced the mechanical properties of the matrix but also improve its corrosion behavior. Originality/value – This is the first time that magnesium matrix composite has been to synthesized with TiC and TiB2 particulates starting from starting from Ti and B carbides powder without adding aluminium using practical and low-cost technique (in situ reactive infiltration technique). This paper studies the corrosion behavior of synthesized Mg matrix in dilute Harrison solution and compares the results with that of conventional AZ91D.

Influence of phytic acid on the corrosion behavior of carbon steel with different surface treatments

2018 ◽  
Vol 65 (6) ◽  
pp. 658-667 ◽  
Author(s):  
Yingjun Zhang ◽  
Baojie Dou ◽  
Yawei Shao ◽  
Xue-Jun Cui ◽  
Yanqiu Wang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Corrosion Inhibition ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Surface Condition ◽  
Energy Dispersive Spectrometer ◽  
Surface Treatments ◽  
Inhibition Mechanism ◽  
Content Type

Purpose This paper aim to investigate the influence of PA on the corrosion behavior of carbon steel with blast cleaned or pre-rusted treatments, and interpret the inhibition mechanism of PA on the steel with different surface treatments. Design/methodology/approach The influence of PA on the corrosion behavior of blast cleaned or rusty steel was investigated by means of electrochemical impedance spectroscopy (EIS). The EIS data were analyzed using the @ZsimpWin commercial software. The morphology and component of steel after immersion were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), Fourier transformation infrared (FTIR) and X-ray diffractometer (XRD). Findings EIS analysis results indicated that PA had good corrosion inhibition for blast cleaned or rusty steel. SEM, EDS, FTIR and XRD further indicated that PA had two main corrosion inhibition processes for the corrosion inhibition of blast cleaned or rusty steel: corrosion dissolution and formation of protective barrier layers. Originality/value Most published works focus the attention only toward the effect of corrosion inhibitor for the clean metal surfaces. However, the surface condition of metal sometimes is unsatisfactory in the practical application of corrosion inhibitor, such as existing residual rust. Some studies also have shown that several corrosion inhibitors could be applied on partially rusted substrates. These inhibitors mainly include tannins and phosphoric acid, but not PA. Therefore, the authors investigated the influence of PA on the corrosion behavior of carbon steel with blast cleaned or pre-rusted treatments in this paper.

Effects of potassium silicate on corrosion behavior of dacromet coating

2019 ◽  
Vol 66 (6) ◽  
pp. 819-826
Author(s):  
Khashayar Tabi ◽  
Mansour Farzam ◽  
Davood Zaarei
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Automobile Industry ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Corrosion Current ◽  
Potassium Silicate ◽  
Coated Steel ◽  
Content Type ◽  
New Information

Purpose Potassium silicate sealer was applied on solvent-cleaned, acid-pickled, dacromet-coated steel to improve its corrosion resistance. The purpose of this paper is to study the corrosion behavior of dacromet-coated steel. Design/methodology/approach Potassium silicate sealer was applied on solvent-cleaned, acid-pickled, dacromet-coated steel to improve its corrosion resistance. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and salt spray were carried out. SEM was used to study the morphological appearance of the surface. Findings The EIS behavior indicated that solvent-cleaned dacromet-coated steel sealed with potassium silicate showed that the corrosion current density was 2.664E − 5 A.cm2 which was reduced to 8.752E − 6 A.cm2 and the corrosion rate, which was 2.264E − 2 mm.year−1, was reduced to 7.438E − 3 mm.year−1 in NaCl 3.5 wt.per cent. EIS was used in NaCl 3.5 wt.%, and the Bode plot characteristics showed that the corrosion protection of solvent-cleaned, dacromet-coated steel was enhanced when sealed with potassium silicate. The EDS results of salt-sprayed, solvent-cleaned samples after 10 days indicated that the main corrosion products are composed of SiO2, ZnO and Al2O3. Research limitations/implications The detection of Li element in EDS was not possible because of the device limitation. Originality/value The current paper provides new information about the sealing properties of potassium silicate and its effects on the corrosion resistance of dacromet coating, which is widely used in many industries such as the automobile industry.

In situ study on the influence of bicarbonate, chloride and outer electrode potential on crevice corrosion occurrence and development of X70 steel

2019 ◽  
Vol 66 (5) ◽  
pp. 651-660 ◽  
Author(s):  
Qian Hu ◽  
Saiwen Lu ◽  
Jing Liu ◽  
Feng Huang
Keyword(s):  
Corrosion Behavior ◽  
Electrode Potential ◽  
Crevice Corrosion ◽  
Chloride Concentration ◽  
Current Density Distribution ◽  
Outer Electrode ◽  
Active Dissolution ◽  
Content Type ◽  
Modeling And Experiments

Purpose The purpose of this paper is to clarify the influence of bicarbonate, chloride and outer electrode potential on crevice corrosion occurrence and development of X70 steel. Design/methodology/approach The crevice corrosion behavior in NaHCO3 and NaCl solutions was investigated through modeling and experiments. The electrode potential and current density distribution were simulated, and the acidification of crevice solution was monitored in situ. Findings The bicarbonate concentration and outer electrode potential remarkably influenced the occurrence of crevice corrosion. The former changes the passivation curves, and the latter alters the initial potential. Moreover, chloride concentration exerted minimal influence. The location of acidification and pitting occurrences depended on the potential difference between the outer electrode and electrode at the active dissolution current peak. Originality/value This study provides a better understanding of the crevice corrosion behavior and mechanism under natural conditions.

Corrosion protective properties of coatings doped with inhibitors

2014 ◽  
Vol 61 (6) ◽  
pp. 416-422 ◽  
Author(s):  
Mansoureh Parsa ◽  
Seyed Mohammad Ali Hosseini ◽  
Zahra Hassani ◽  
Effat Jamalizadeh
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Titania Nanoparticles ◽  
Self Healing ◽  
Properties Of Coatings ◽  
Ethylene Imine ◽  
Protective Properties ◽  
Content Type

Purpose – The purpose of this paper was to study the corrosion resistance of water-based sol-gel coatings containing titania nanoparticles doped with organic inhibitors for corrosion protection of AA2024 alloy. Design/methodology/approach – The coatings were obtained using tetraethylorthosilicate, 3-glycidoxypropyltrimethoxysilane, titanium (IV) tetrapropoxide and poly(ethylene imine) polymer as cross-linking agents. As corrosions inhibitors, 2-mercaptobenzoxazole and salicylaldoxime were incorporated into the sol-gel for the improvement of the corrosion resistance. The corrosion protection performance of coatings was studied using the potentiodynamic scan and the electrochemical impedance spectroscopy (EIS) methods. Atomic force microscopy was used to investigate surface morphology of the coatings. Findings – The results indicated that doping the sol-gel coatings with inhibitors leads to improvement of the corrosion protection. The comparison of doped coatings confirmed that corrosion protection performance of the sol-gel coatings doped with 2-mercaptobenzoxazole was better than for the sol-gel coatings doped with salicylaldoxime. Also the EIS results verified self-healing effects for the sol-gel coatings doped with 2-mercaptobenzoxazole. Originality/value – This paper indicates 2-mercaptobenzoxazole and salicylaldoxime can be added as corrosion inhibitors to sol-gel coatings to improve their corrosion protective properties for AA2024 alloy.

Sign in / Sign up

Export Citation Format

Share Document