Effect of molybdate post-sealing on the corrosion resistance of zinc phosphate coatings on hot-dip galvanized steel

2008 ◽  
Vol 50 (4) ◽  
pp. 962-967 ◽  
Author(s):  
Bi-Lan Lin ◽  
Jin-Tang Lu ◽  
Gang Kong
Keyword(s):  
Corrosion Resistance ◽  
Zinc Phosphate ◽  
Galvanized Steel ◽  
Phosphate Coatings

scholarly journals Nano-TiO2 Phosphate Conversion Coatings – A Chemical Approach

2018 ◽  
Vol 4 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Impedance Spectroscopy ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Phosphate Coatings ◽  
Coating Weight

AbstractThe present study aims at deposition of zinc phosphate coatings on low carbon steel with incorporated nano- TiO2 particles by chemical phosphating method. The coated low carbon steel samples were assessed in corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarization techniques (Tafel) in 3.5% NaCl solution. Morphology and chemical composition of the coatings were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy in order to observe growth of coating. Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano- TiO2 in the phosphating bath. Corrosion rate of nano-TiO2 chemical phosphate coated samples was found to be 3.5 milli inches per year which was 3 times less than the normal phosphate-coated sample (8 mpy). Electrochemical impedance spectroscopy studies reveal reduction of porosity of nano-TiO2 phosphate coated samples. It was found that nano-TiO2 particles in the phosphating solution yielded uniform phosphate coatings of higher coating weight, fewer defects and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

Nano zinc phosphate coatings for enhanced corrosion resistance of mild steel

2015 ◽  
Vol 327 ◽  
pp. 218-225 ◽  
Author(s):  
M. Tamilselvi ◽  
P. Kamaraj ◽  
M. Arthanareeswari ◽  
S. Devikala
Keyword(s):  
Corrosion Resistance ◽  
Mild Steel ◽  
Zinc Phosphate ◽  
Phosphate Coatings ◽  
Nano Zinc

Incorporation of boron nitride nanosheets in zinc phosphate coatings on mild steel to enhance corrosion resistance

2019 ◽  
Vol 374 ◽  
pp. 935-943 ◽  
Author(s):  
Haowei Huang ◽  
Huihui Wang ◽  
Yuhui Xie ◽  
Dexuan Dong ◽  
Xiang Jiang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Boron Nitride ◽  
Mild Steel ◽  
Zinc Phosphate ◽  
Boron Nitride Nanosheets ◽  
Phosphate Coatings

scholarly journals Nano Metal Dioxide Incorporated Conversion Phosphate Coatings—A Chemical Approach

2016 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Nano Tio2 ◽  
Phosphate Coatings ◽  
Coating Weight

The present study aims at deposition of zinc phosphate coatings with the incorporation of nano Titanium dioxide particles by chemical phosphating method. Zinc phosphate coatings were developed on low carbon steel by using nano TiO2 in the standard phosphating bath. The Coated low carbon steel samples were assessed for corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarisation techniques in 3.5% NaCl solution. Chemical composition of the coatings was analysed by energy dispersive X-ray spectroscopy (EDX). Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano TiO2 in the phosphating bath. Corrosion rate of nano TiO2 incorporated chemical phosphate coated samples was found to be 3.5 mpy which was 4 times less than the bare uncoated low carbon steel (~14 mpy). Electrochemical impedance spectroscopy studies revels in the reduction of porosity in nano TiO2 phosphate coated samples. It was found that nano TiO2 particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

scholarly journals Nano Metal Dioxide Incorporated Conversion Phosphate Coatings—A Chemical Approach

2016 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Nano Tio2 ◽  
Phosphate Coatings ◽  
Coating Weight

The present study aims at deposition of zinc phosphate coatings with the incorporation of nano Titanium dioxide particles by chemical phosphating method. Zinc phosphate coatings were developed on low carbon steel by using nano TiO2 in the standard phosphating bath. The Coated low carbon steel samples were assessed for corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarisation techniques in 3.5% NaCl solution. Chemical composition of the coatings was analysed by energy dispersive X-ray spectroscopy (EDX). Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano TiO2 in the phosphating bath. Corrosion rate of nano TiO2 incorporated chemical phosphate coated samples was found to be 3.5 mpy which was 4 times less than the bare uncoated low carbon steel (~14 mpy). Electrochemical impedance spectroscopy studies revels in the reduction of porosity in nano TiO2 phosphate coated samples. It was found that nano TiO2 particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

The Effect of pH on Zinc Phosphate Coating Morphology and its Corrosion Resistance on Mild Steel

2012 ◽  
Vol 626 ◽  
pp. 569-574 ◽  
Author(s):  
Khalid Abdalla ◽  
Rahmat Azmi ◽  
Aziz Azizan
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Mild Steel ◽  
Zinc Phosphate ◽  
Phosphate Coating ◽  
Metallic Materials ◽  
X Ray ◽  
Ph Values ◽  
Phosphate Coatings ◽  
Coating Morphology

Zinc phosphate coating is commonly used for corrosion protection of metallic materials, mainly mild steel. In this study, influence of the pH of phosphating bath on the surface morphology and corrosion resistance of zinc phosphate coatings on mild steel was investigated. The phosphate layers were deposited on steel from phosphating bath at different pH values (1.75 ~ 2.75). The surface morphology and composition of phosphate coatings were investigated via scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). The corrosion resistance of the coating was evaluated by polarization curves (anodic and cathodic) in an aerated 3.5% NaCl solution. The results showed that better surface coverage and corrosion resistance for the steel phosphated at pH 2.75.

The Influence of Deposition Temperature on the Morphology and Corrosion Resistance of Zinc Phosphate Coating on Mild Steel

2012 ◽  
Vol 626 ◽  
pp. 183-189
Author(s):  
Khalid Abdalla ◽  
Rahmat Azmi ◽  
Aziz Azizan
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Mild Steel ◽  
Deposition Temperature ◽  
Surface Coverage ◽  
Zinc Phosphate ◽  
Nacl Solution ◽  
X Ray ◽  
Phosphate Coatings ◽  
Different Temperatures

The influence of phosphating temperature on the surface morphology and corrosion resistance of zinc phosphate coatings on mild steel was investigated. The phosphate layers were deposited on steel from phosphating bath at different temperatures (45 ~ 75 C). The surface morphology and composition of phosphate coatings were investigated via scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). The corrosion resistance of the coatings was evaluated by polarization curves (anodic and cathodic) in an aerated 3.5% NaCl solution. The results showed that the increase in temperature of the phosphating bath up to 55 C caused an increase in surface coverage and in turn resulted in better corrosion resistance. At high temperature (65 °C and 75 °C) the deposition coverage decreased indicating that the best coverage for the phosphate layer on the metal surface was achieved at 55 °C

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