Preparation of Epoxy-Organobentonite Nanocomposites Added ZnO-ZrO2 /Al2O3-ZrO2 Nanoparticles and Investigation on their Corrosion Resistance Property in Coating on Q235 Steel

2014 ◽  
Vol 1033-1034 ◽  
pp. 1249-1253 ◽  
Author(s):  
Quoc Binh Bui ◽  
Qing Dong Zhong ◽  
Qiong Yu Zhou ◽  
Xi Shi ◽  
Dan Ji
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Hardness Test ◽  
Coated Steel ◽  
Pure Epoxy ◽  
Corrosion Resistance Property ◽  
Combined Use ◽  
Oxide Particles ◽  
Positive Effect ◽  
Vickers Hardness Test

For purpose of synthesis new epoxy coatings to protect the structural steel in sea environment, in this paper, two epoxy-based nanocomposite samples containing low-loading of ZnO-ZrO2/ZrO2-Al2O3 nanoparticles and organobentonite nanoparticles were prepared. Pure epoxy sample and epoxy-based composite added organobentonite nanoparticles were also prepared for comparison. Dispersion of metal oxide particles and organobentonite nanoparticles into epoxy-composites were evaluated by using XRD analyses. Microhardness, adhesion and corrosion resistance over 91 days of immersion in artificial seawater (ASW) solution of new composites were studied by Vickers’ hardness test (HV test), cross-cut test, electrochemical impedance spectroscopy (EIS) and polarization curves, respectively. Results showed that combined use of low-loading fillers had a positive effect on the organobentonite exfoliation behavior in resulting epoxy-based nanocomposites. Hardness, adhesion of two novel composites increased in comparison to pure epoxy even though with epoxy-based composite added organobentonite only. Results also showed that nanoparticle fillers could significantly improve the corrosion resistance of the coated steel, with ZnO-ZrO2-organobentonite fillers being the best.

Electrochemical Impedance Spectroscopy (EIS) Study of Nano-Composite Polyurea Coating under the Wet-Dry Cyclic Conditions

2014 ◽  
Vol 789 ◽  
pp. 495-500
Author(s):  
Bing Ying Wang ◽  
Qing Hao Shi ◽  
Wen Long Zhang
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Composite Coating ◽  
Electrochemical Impedance ◽  
Protective Action ◽  
Experimental Result ◽  
Resistance Property ◽  
Corrosion Resistance Property ◽  
Mass Fractions

The polyurea was modified by adding different amounts of nanometer ZnO. The corrosion behavior of polyurea/primer composite coating system in wet-dry cyclic environment of 3.5% NaCl solution was studied by using the Electrochemical Impedance Spectroscopy (EIS) measurement and adhesion test technology. The experimental result showed that, different mass fractions of nanometer ZnO had different influences on the corrosion resistance property of coating. When the mass fraction of nanometer ZnO was 5%, the composite coating had the largest protective action. The corrosion resistance property of nanometer ZnO can be improved by increasing the density of polyurea coating, however, the corrosion resistance property of polyurea coating will be weakened in case of exceeding the critical adding amount.

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.

scholarly journals Influence of Heat Treatment on the Corrosion of Microalloyed Steel in Sodium Chloride Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Asiful Hossain Seikh
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Microalloyed Steel ◽  
High Strength ◽  
Microalloyed Steels ◽  
High Mechanical Property ◽  
Fine Grained ◽  
Corrosion Resistance Property ◽  
Strength And Ductility

Microalloyed Steels find wide application in car bodies and other engineering parts because of its high strength as well as high ductility. Very fine grained microstructure is the reason behind the combination of strength and ductility. It has been reported that repeated quenching leads to further refining of microstructure. In the present investigation, corrosion resistance property of E34 microalloy steel has been studied in 3.5% NaCl solution in different microstructural conditions such as the as rolled one and three repeated quenched conditions. Weight loss, potentiodynamic polarization method, and electrochemical impedance spectroscopy (EIS) techniques have been used. To reveal the corrosion resistance of different treated steels, some significant characterization parameters such asEcorr,Icorr,Rp, andRctin linear polarization and EIS curves were analyzed and compared. It is found that with repeated recrystallization grains become finer, and corrosion rate increases suggesting that a compromise has to strike between high mechanical property and corrosion rate.

The Anti-Corrosion Study on Zn-Al-Mg Coated Steel Sheets

2014 ◽  
Vol 490-491 ◽  
pp. 186-191 ◽  
Author(s):  
Feng Li ◽  
Fang Zhou ◽  
Jia Shun Lv ◽  
Hong Gang Yang ◽  
Leng Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Polarization Curve ◽  
Electrochemical Impedance ◽  
Decomposition Reaction ◽  
Galvanized Steel ◽  
Coated Steel ◽  
Corrosion Study ◽  
Steel Sheets ◽  
Ph Buffer ◽  
Superior Corrosion Resistance

Z11A3M, Z6A3M, Z1.6A1.6M, and Z1A1M coating samples were prepared in HDPS by traditional continuous hot dipping method. The anti-corrosion ability of these coatings was determined by SST, polarization curve and electrochemical impedance. The corrosion products were analyzed by XRD. The surface and section microstructures were observed by SEM. The results showed, the corrosion resistance of 4 kinds of Zn-Al-Mg coated steel is 4 times as galvanized steel. The Zn-Al-Mg coated steel sheets can be self-cured. MgZn2 and eutectic could be found in all ZAM coating. Zn/Al/Zn2Mg eutectic can be found in all 4 kind of coatings. The reason for superior corrosion resistance of Zn-Al-Mg coated steel is the decomposition reaction of Zn5(OH)8Cl2 which is retained by Mg. Thus the O2 diffusing rate is lowered down. Mg acts as PH buffer and the Zn dissolving rate can be reduced. According the results, the application of Zn-Al-Mg coated steel sheets is forecasted.

Electrochemical property analysis of SiO2-Al2O3-coated steel by electrochemical impedance spectroscopy

2017 ◽  
Vol 64 (4) ◽  
pp. 365-370 ◽  
Author(s):  
Sebahattin Kirtay
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Dip Coating ◽  
Coated Steel ◽  
Content Type ◽  
Coated Materials ◽  
Uncoated Specimen

Purpose The purpose of this paper is to investigate the corrosion resistance of SiO2-Al2O3 coating on mild steel. Design/methodology/approach SiO2-Al2O3 was coated using sol-gel method, and electrochemical measurements were applied to assess the performance of the coated steel. Findings The main conclusion is that SiO2-Al2O3-coated specimens acquired a higher corrosion resistance than that of uncoated specimen. icorr values of the coated specimens were between 12 and 14 times smaller than those of uncoated specimen. The coated specimens exhibited a higher Rcor value at electrochemical impedance spectroscopy analysis. The high values of Rcor and low values of CPEdl observed within the SiO2-Al2O3-coated samples imply an improved anti-corrosion capability. Originality/value In this work, there are three points of originality. First, steel specimens were coated with ormosil-based solution by applying sol-gel dip coating method. Second, both SiO2 and Al2O3 coatings were applied simultaneously at a considerably low temperature, i.e. 200 °C. Finally, the performance of the coated materials against wet corrosion was improved significantly.

DETECTING CORROSION RESISTANCE OF COATED STEEL REBARS BY ELECTROCHEMICAL TECHNIQUE (EIS)

2006 ◽  
Vol 13 (04) ◽  
pp. 345-349 ◽  
Author(s):  
J. RYOU ◽  
S. SHAH
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Materials Science ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Electrochemical Technique ◽  
Coated Steel ◽  
Coating Materials ◽  
Steel Rebars

Electrochemical impedance spectroscopy (EIS) is one of the electrochemical techniques used in materials science. The present measurements are used to evaluate the corrosion resistance of new types of coated steel rebar used in reinforced concrete. In this study, Si -based coating materials are used and evaluated, because adding Si to metals and alloys, including steel, generally increases their corrosion, oxidation, and erosion resistance. The result suggests that electrochemical impedance spectroscopy may be useful for monitoring corrosion activity on coated steel rebars. Based upon impedance changes, it appears that the silicon powder coating bonds well to the steel, and that the coating has a good performance.

scholarly journals Protection of Steel Rebar in Salt-Contaminated Cement Mortar Using Epoxy Nanocomposite Coatings

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
The Huu Nguyen ◽  
Tuan Anh Nguyen
Keyword(s):  
Corrosion Resistance ◽  
Critical Level ◽  
Cement Mortar ◽  
Electrochemical Impedance ◽  
Chloride Concentration ◽  
Corrosion Current ◽  
Chloride Ions ◽  
Coated Steel ◽  
Steel Rebar ◽  
Electrochemical Monitoring

Epoxy reinforced with two kinds of nanoparticles dealing with nano-SiO2 and nano-Fe2O3 was coated on steel rebar embedded in a chloride contaminated cement mortar. NaCl was added to the fresh Portland cement paste (at 0.3% and 0.5% by weight of cement) to simulate the chloride contamination at the critical level. The effect of incorporating nanoparticles on the corrosion resistance of epoxy-coated steel rebar was investigated by linear potentiodynamic polarization and electrochemical impedance spectroscopy. For the 0.3 wt.% chloride mortars, the electrochemical monitoring of the coated steel rebars during immersion for 56 days in 0.1 M NaOH solutions suggested the beneficial role of nano-Fe2O3 particles in significantly improving the corrosion resistance of the epoxy-coated rebar. After 56 days of immersion, the nano-Fe2O3 reduced the corrosion current of epoxy-coated rebar by a factor of 7.9. When the chloride concentration in the cement mortar was 0.5 wt.%, the incorporation of nanoparticles into the epoxy matrix did not enhance the corrosion resistance of epoxy coating for the rebar. At this critical level, chloride ions initiated rebar corrosion through nanoparticles at the epoxy/rebar interface.

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