Influence of Zinc Content on Anti-Corrosion Performance of Zinc-Rich Coatings

2013 ◽  
Vol 423-426 ◽  
pp. 169-172
Author(s):  
Guo Xin Li ◽  
Bing Jie Li ◽  
Yi Liang Peng ◽  
Wei Tong Yue

The zinc-rich coating prevents steel from corrosion by sacrificing electrochemical cathode anode protection, but the zinc content is the most important parameter. In this paper, the zinc-rich coatings made with the amino resin, acrylic resin, complex solvents, auxiliary agents and high purity zinc powder. The coatings were applied onto steel substrate and then placed in neutral salt spray for 3000 h in order to study the anti-corrosion performance. The results showed that the anti-corrosion performance was promoted with the zinc content increasing. When the zinc content was higher than 86 wt. %, the anti-corrosion performance can be reached 3000 h. The anticorrosion mechanisms were studied by polarization curves and scanning electron microscope (SEM).

2012 ◽  
Vol 598 ◽  
pp. 561-564
Author(s):  
Zhi Ming Cao ◽  
Guo Xin Li ◽  
Yi Liang Peng ◽  
Da Wei Hu

Four zinc-rich coatings were applied onto steel substrate and then placed in neutral salt spray for 4000 h in order to study the anti-corrosion performance of the coatings. The results showed that the samples with two kinds of the coatings were more seriously eroded than the others. The reasons could be that the zinc particles were dispersed inhomogeneous in the binder and the zinc content was very lower than 96 wt. % obtained through the analysis of Scanning Electron Microscope and Differential Scanning Calorimetry.


2012 ◽  
Vol 598 ◽  
pp. 520-523
Author(s):  
Zhi Min Cao ◽  
Guo Xin Li ◽  
Hui Lian ◽  
Da Wei Hu

Samples covered two kinds of hot-dip coatings were purchased and placed in neutral salt spray to study the anti-corrosion performance. The results showed that one sample was eroded more seriously than the other. The reasons were analyzed through surface morphology and the reaction products of the hot-dip coatings by scanning electron microscope and element composition. The results showed that might be the fractures developed of the corroded sample during the productive process that made O2 and solution contact with the substrate.


2010 ◽  
Vol 163-167 ◽  
pp. 4555-4558 ◽  
Author(s):  
Yun Ying Fan ◽  
Ye Hua Jiang ◽  
Rong Zhou

As the increasing environmental awareness, to explore no-chromium passivation technique on galvanized Zn coatings becomes one of the most urgent affair. In this paper, one kind of silicate passivation technics was invented and by which method silicate conversion film on galvanized Zn coatings with satisfactory property was got. It is found that solution composition and operating conditions of passivation affect the property of conversion film markedly, and the optimal technics is: Na2SiO3 20 g/L, H2SO4 5 mL/L, HNO3 5 mL/L, H2O2 10 ml/L, pH 2.0, passivation time 20 s, temperature 25°C. The corrosion resistance of galvanized Zn coatings with different passivated method, including no passivated, Cr(VI) passivated, Cr(III) passivated and silicate passivated, were investigated by NSS test (5% Neutral Salt Spray). The silicate conversion film can keep no rust for 72 h and obviously shows the best property. All the results show that silicate passivation can provide galvanized Zn coatings superior anti-corrosion performance, so this new technics can replace the conventional chromate passivation technology to avoid the pollution of chromium and has a wider application in future.


2013 ◽  
Vol 634-638 ◽  
pp. 2931-2934
Author(s):  
Ping Yuan

The hot dip Al-Zn alloy coated steel sheet was passivated with chromium-free passivation solution which adopted the molybdate and acrylic resin as the main film-forming substances. The surface morphology and corrosion performance of the coating were studied experimentally by using glow discharge optical emission spectroscopy(GD-OES), scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDS), polarization curves and the neutral salt spray test. The GD-OES and SEM results show that the molybdate-containing thin organic coating is deposited on the substrate compactly and homogeneously without obvious tiny cracks. The test results of corrosion performance show that the corrosion potential and current density of the passive films decrease obviously in comparison with those of the substrate, and the corrosion resistance of the coating is comparable with that of the chromate passivation coating.


2013 ◽  
Vol 423-426 ◽  
pp. 173-176 ◽  
Author(s):  
Guo Xin Li ◽  
Dong Yang ◽  
Yi Liang Peng ◽  
Wei Tong Yue

The hot-dip coatings containing Zn-Al-Mg-Ce were prepared through congruent melting. The anti-corrosion performance of the coatings was researched using the weight loss rate by the neutral salt spray testing. The reasons of the effects of the elements Al, Mg, Ce on the anti-corrosion performance promoting were researched through the analysis of Scanning Electron Microscope and the polarization curves. The results showed that Al, Mg, Ce embedded in the Zn matrix uniformly and the protective effect for the steel was enhanced by the electrochemical action.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4045
Author(s):  
Rafał Mech ◽  
Jolanta Gąsiorek ◽  
Amadeusz Łaszcz ◽  
Bartosz Babiarczuk

The paper presents a comparison of the results of the corrosion resistance for three Fe-B-Co-Si-based newly developed alloys with the addition of Nb and V. The corrosion performance differences and microstructure variations were systematically studied using scanning electron microscope, electric corrosion equipment, X-ray diffractometer, and differential calorimeter. It has been shown that each alloying addition increased the corrosion resistance. The highest corrosion resistance obtained by potentiodynamic polarization was found for the alloy with both Nb and V addons (Fe57Co10B20Si5Nb4V4) and lowest in the case of the basic four-element Fe62Co15B14Si9 material. This shows that the proper choice of additions is of significant influence on the final performance of the alloy and allows tailoring of the material for specific applications.


2020 ◽  
Vol 20 (10) ◽  
pp. 6389-6395 ◽  
Author(s):  
Chuan-Chun Li ◽  
Tang-Yu Lai ◽  
Te-Hua Fang

In this study, corrosion-resistant composite coatings were produced by incorporating zinc (Zn) nanoparticles in an epoxy resin and a hybrid silicone resin. While performing sodium chloride saltspray tests, the corrosion performance of the nano-composite coatings was evaluated by applying these corrosion-resistant composite coatings on a carbon steel substrate. The nano-composite coatings on the substrates were characterized by an adhesion test, scanning electron microscope (SEM), and transmission electron microscope (TEM) with energy-dispersive X-ray spectroscopy (EDX). The results of the salt-spray tests showed that the Zn nanoparticles in the epoxy and hybrid silicone resins could react with permeated oxygen, thereby improving the anticorrosion properties of the Zn nano-composites. The corroded area of the epoxy resin samples decreased from more than 80% without Zn doping to less than 5% in a 3000-ppm Zn-doped sample after a 500-h saltspray test. An evaluation of the bactericidal properties showed that the Zn/epoxy and Zn/hybrid silicone resin nano-composites with at least 360 ppm of Zn nanoparticles exhibited bactericidal ability, which remarkably increased with the Zn nanoparticles content. The corrosion-resistant properties improved with the addition of Zn nano-composites coatings.


2013 ◽  
Vol 20 (05) ◽  
pp. 1350048 ◽  
Author(s):  
Xiaodong Hu ◽  
Yajiang Li

Effect of the tempering on the microstructures and tribological properties of the laser alloying coatings is investigated. Laser alloying of the T - Co 50/ TiC mixed powders on a 45 steel substrate can form a hard composite coating, which increased the micro-hardness and wear resistance of the substrate greatly. Such laser alloying coating was investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Experimental results indicate that the tempering is able to remove the accumulation of the residual stress in a certain extent, improving the plastic and toughness properties of such coating; moreover, tempering also improves greatly the formation mechanism, making the coating have enough ability of the intensity transfer, which is beneficial in preventing the crack propagation of the interface in such coating, leading to an improvement of the wear resistance.


2014 ◽  
Vol 971-973 ◽  
pp. 135-138
Author(s):  
Zhen Dong Sun ◽  
Yan Ning Yang ◽  
Qing Peng Li ◽  
Jian Guo Liu ◽  
Chuan Wei Yan

The mixed silane films were obtained on the surface of the Q235 steel sheets by directly immersing in a mixed silane solution containing γ-Glycidoxypropyltriethoxysilane (γ-GPS) and 1, 2-bis (triethoxysilyl) ethane (BTSE), The chemical compositions and microstructures of the films were examined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared spectroscopy (FTIR).The corrosion resistances were investigated by electrochemical measurements and neutral salt spray (NSS) test. The effects of silane films to the epoxy coating were investigated through the adhesive property test. The results showed that the γ-GPS/BTSE mixed silane film could remarkably improve the corrosion resistance of epoxy coating and prolong its service life.


Author(s):  
Viona Diansari ◽  
Subhaini ◽  
Arihta Putri

The water absorption on self-cured acrylic resin is higher than the heat cured acrylic resin. Incoming water positions itself between the polymer chains and affects the surface microstructure of self-cured acrylic resin. The absorption of liquids such as Arabica Gayo coffee may aggravate the surface structure of self-cured acrylic resins due to their acid content. This study aims to find out the microstructure of self-cured acrylic resin surface after immersed in Arabica Gayo coffee for 2 and 7 days. This study used 5 specimens of self-cured acrylic resin (MeliodentTM) with size 10x10x1,5 mm3. Each specimen was immersed in aquades for 24 hours to reduce the residual monomer and then be given different immersion treatments. The immersion temperature used was 55°C. After immersion, surface microstructure observation was done using Scanning Electron Microscope (JEOL JSM 6510 LA). The images obtained were bubbles after being immersed in aquades for 2 days and more on day 7, micro porous after being immersed in Arabica Gayo coffee for 2 days and more on day 7 than untreated specimens. The conclusion of this study is micro porous formed more on the surface of self-cured acrylic resin along with the duration of self-cured acrylic resin immersion in Arabica Gayo coffee.


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