Structural Properties of Zinc and ZnMgAl Coatings on Steel Sheets

2014 ◽  
Vol 782 ◽  
pp. 623-626 ◽  
Author(s):  
Mária Kollárová ◽  
Lucia Hrabčáková ◽  
Juraj Graban ◽  
Marta Šohajová
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Neutral Salt ◽  
Coating Structure ◽  
Properties Of Coatings ◽  
Steel Sheets ◽  
Mutual Comparison ◽  
Excellent Adhesion ◽  
Interdendritic Phase ◽  
Zinc Coatings

In the paper mutual comparison of zinc coatings enriched with small additions of Mg and Al (up to 1 wt.% Mg and 1 wt.% Al) and traditional zinc coatings produced by hot dip galvanizing, concerning some important properties of coatings like coating structure, cracks formation after deformation and corrosion resistance of deformed samples was studied. It was shown, that while traditional hot-dip zinc coatings are formed by homogenous zinc layer, exhibiting only low amount of soluble aluminium, coatings enriched by small amounts of Mg and Al, namely 0.6% Mg and 0.8% Al are formed by dendritic zinc matrix and interdendritic phase containing Zn-Mg-Al eutectics. Development of cracks was investigated in the area of maximal deformation of the samples subjected to stretching. It was found, that while traditional zinc coatings showed sporadic long fine cracks, zinc coatings enriched with Mg and Al exhibited aggregation of short thick cracks in the deformed area. Samples of both materials after stretching were also exposed in neutral salt spray atmosphere in corrosion chamber. It can be concluded, that material with coatings enriched with Mg and Al showed better results in corrosion tests contrary to the presence of massive cracks in the coating. This significantly increased corrosion resistance is possible due to excellent adhesion of zinc coatings, containing Mg and Al on drawing steels.

scholarly journals Impact of Bi and Sn on Microstructure and Corrosion Resistance of Zinc Coatings Obtained in Zn-AlNi Bath

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3788
Author(s):  
Henryk Kania ◽  
Mariola Saternus ◽  
Jan Kudláček
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Neutral Salt ◽  
Energy Dispersion Spectroscopy ◽  
Humid Atmosphere ◽  
Alloying Additions ◽  
Electrochemical Parameters ◽  
Zinc Coatings ◽  
Structural Research ◽  
The Impact

The paper presents results of studies on the impact of bismuth and tin additions to the Zn-AlNi bath on microstructure and corrosion resistance of hot dip galvanizig coatings. The structure at high magnifications on the top surface and cross-section of coatings received in the Zn-AlNiBiSn bath was revealed and the microanalysis EDS (energy dispersion spectroscopy) of chemical composition was determined. The corrosion resistance of the coatings was tested relatively in a neutral salt spray test (NSS), and tests in a humid atmosphere containing SO2. Electrochemical parameters of coatings corrosion were determined. It was found that Zn-AlNiBiSn coatings show lower corrosion resistance in comparison with the coatings received in the Zn-AlNi bath without Sn and Bi alloying additions. Structural research has shown the existence of precipitations of Sn-Bi alloy in the coating. It was found that Sn-Bi precipitations have more electropositive potential in relation to zinc, which promotes the formation of additional corrosion cells.

scholarly journals Structural Aspects of Decreasing the Corrosion Resistance of Zinc Coating Obtained in Baths with Al, Ni, and Pb Additives

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 385 ◽  
Author(s):  
Henryk Kania ◽  
Mariola Saternus ◽  
Jan Kudláček
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Zinc Coating ◽  
Neutral Salt ◽  
Zinc Bath ◽  
Coating Structure ◽  
Humid Atmosphere ◽  
Pure Zinc ◽  
Si Content ◽  
Structural Aspects

The article presented the results of tests determining the synergistic effect of Al, Ni, and Pb additions on a zinc bath on the structure and corrosion resistance of coatings obtained on low silicon steel. Analyzed coatings were produced on S235JRG2 steel with Si content of 0.02 mass%. The corrosion resistance of the coatings was compared with the corrosion resistance of the coating obtained in the "pure" zinc bath. Structure at high magnifications (SEM) was determined, as well as coating thickness and chemical composition in microspheres. The corrosion resistance of the coatings was established comparatively in standard corrosion tests in neutral salt spray and a humid atmosphere containing SO2. It was found that the addition of Pb to the zinc bath reduced the corrosion resistance of the coatings. In the coating structure obtained in the Zn-AlNiPb bath, lead precipitation was observed in both the outer layer and the intermediate layer of the coating. Grain boundaries were the preferred site for lead precipitation. The presence of Pb precipitates favored conditions for the creation of additional corrosion cells, which led to a decrease in the corrosion resistance of the coatings.

Abrasion Resistance and Corrosion Resistance of Chromium-Free Fingerprint-Resistant Zn and Zn-Al-Mg Coating Cold-Rolled Steel Sheets

2021 ◽  
Vol 1035 ◽  
pp. 545-553
Author(s):  
Yan Huang ◽  
Ren Bo Song ◽  
Huan Jun Wei ◽  
Zhe Rui Zhang ◽  
Li Fang Yang
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Zinc Coating ◽  
Neutral Salt ◽  
Rolled Steel ◽  
Pure Zinc ◽  
Cold Rolled Steel ◽  
Steel Sheets ◽  
Long Time ◽  
Cold Rolled

The wear resistance and corrosion resistance of chromium-free fingerprint-resistant pure zinc and Zn-Al-Mg coated cold-rolled steel sheets were studied by micro-friction wear experiments and neutral salt spray experiments. Two products are worn for a long time with a large load (5N load, 50 times abrasion), the depth of wear zone of Zn-Al-Mg coating product is 9% shallower than that of pure zinc coating product, and the width of wear zone is 15.4% smaller. Both products still meet the requirements of use after corrosion. The corrosion resistance of two products after degreasing treatment was significantly reduced. The Mg and Al in the Zn-Al-Mg coating can hinder the progress of corrosion, so it has better corrosion resistance.

Corrosion Resistance of Zn-31AlMg Coatings Obtained by Batch Hot Dip Method

2013 ◽  
Vol 212 ◽  
pp. 167-172 ◽  
Author(s):  
Henryk Kania ◽  
Marzena Bierońska
Keyword(s):  
Corrosion Resistance ◽  
Sulphur Dioxide ◽  
Salt Spray ◽  
Zinc Coating ◽  
Neutral Salt ◽  
Corrosion Tests ◽  
Good Corrosion Resistance ◽  
Zinc Coatings ◽  
Resistance Tests ◽  
Better Than

In the paper the authors present the results of corrosion resistance tests on coatings obtained in zinc-aluminium baths with the addition of Mg by use of the batch hot dip method. The content of Al in the bath was 31%, while the content of magnesium was 3 and 6%. In order to define corrosion resistance, two standard corrosion tests were performed in neutral salt spray and inmoist atmosphere containing sulphur dioxide. Corrosion resistance of tested pieces was compared with the corrosion resistance of a traditional zinc coating. It was established that Zn-31AlMg coatings have very good corrosion resistance in the tested environments, better than that of zinc coatings.

scholarly journals Design and Multidimensional Screening of Flash-PEO Coatings for Mg in Comparison to Commercial Chromium(VI) Conversion Coating

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Chromium Vi ◽  
Alkaline Electrolytes ◽  
Az31b Alloy ◽  
Plasma Electrolytic

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.

Corrosion resistance of composite coating used for fastener protection

2019 ◽  
Vol 66 (5) ◽  
pp. 595-602
Author(s):  
Zhifeng Lin ◽  
Likun Xu ◽  
Xiangbo Li ◽  
Li Wang ◽  
Weimin Guo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Composite Coating ◽  
Marine Environment ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Diffusion Method ◽  
Economic Losses ◽  
Neutral Salt ◽  
Content Type

Purpose The purpose of this paper is to examine the performance of a fastener composite coating system, sherardized (SD) coating/zinc-aluminum (ZA) coating whether it has good performance in marine environment. Design/methodology/approach In this paper, SD coating was fabricated on fastener surface by solid-diffusion method. ZA coating was fabricated by thermal sintering method. Corrosion behaviours of the composite coating were investigated with potentiodynamic polarization curves, open circuit potential and electrochemical impedance spectroscopy methods. Findings Neutral salt spray (NSS) and deep sea exposure tests revealed that the composite coating had excellent corrosion resistance. Polarization curve tests showed that corrosion current density of the sample with composite coating was significantly decreased, indicating an effective corrosion protection of the composite coating. OCP measurement of the sample in NaCl solution demonstrated that the composite coating had the best cathodic protection effect. The good corrosion resistance of the composite coating was obtained by the synergy of SD and ZA coating. Practical implications SD/ZA coating can be used in marine environment to prolong the life of carbon steel fastener. Social implications SD/ZA composite coating can reduce the risk and accident caused by failed fastener, avoid huge economic losses. Originality/value A new kind of composite coating was explored to protect the carbon steel fastener in marine environment. And the composite coating has the long-term anti-corrosion performance both in simulated and marine environment test.

Effect of Sol-Gel Film on the Corrosion Resistance of Low Carbon Steel Plate

2020 ◽  
Vol 984 ◽  
pp. 43-50
Author(s):  
Hua Yuan Zhang ◽  
Can Wang ◽  
Bing Xue ◽  
Jing Luo
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Steel Plate ◽  
Salt Spray ◽  
Sol Gel ◽  
Low Carbon Steel ◽  
Corrosion Current ◽  
Neutral Salt ◽  
Low Carbon ◽  
Gel Film

To improve the corrosion resistance on Q235 low carbon steel, in this paper, tetraethyl orthosilicate (TEOS), N-dodecyl trimethoxysilane and γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560) were used to make organic-inorganic hybrid sol-gel film. Cross cut test adhesion method, neutral salt spray test, electrochemical test and film protective efficiency were taken to value the corrosion resistance property. The corrosion topography was studied by optical microscope. In addition, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) curves and equivalent electric circuit fitting were used to analyze the corrosion mechanism. The cross cut adhesion of sol-gel film can reach 1 class and the protection class can attain 5 class after 72 hours neutral salt spray test. According to the potentiodynamic polarization curve analysis, the corrosion potential of sol-gel film coating sample after 0.5 hours immersion was -0.46 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.74×10-7 A·cm-2. The corrosion potential of bare Q235 low carbon steel plate after 0.5 hours immersion was -0.78 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.75×10-6 A·cm-2. The impedance value on 0.1 Hz (|Z|0.1Hz) (1.27×106 Ω·cm2) of sol-gel film coating sample was more than three orders of magnitude higher than the value of the low carbon steel plate. Even dipping in 3.5 wt. % NaCl for 72 hours, the |Z|0.1Hz value of sol-gel coating sample was still one order of magnitude higher than the low carbon steel plate with 0.5 hours immersion. Sol-gel film with excellent adhesion can significantly improve the corrosion resistance of low carbon steel plate. Sol-gel film can increase the protection efficiency of low carbon steel plate by 90%.

The Influence of Major Defects on the Properties of Continuous Galvanized Steel Sheet

2012 ◽  
Vol 445 ◽  
pp. 661-666 ◽  
Author(s):  
A. Azimi ◽  
F. Shahriari ◽  
F. Ashrafizadeh ◽  
M.R. Toroghinezhad ◽  
J. Jamshidi
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Tensile Test ◽  
Steel Sheet ◽  
Corrosion Behaviour ◽  
Salt Spray ◽  
Galvanized Steel ◽  
Tafel Polarization ◽  
Steel Sheets ◽  
Bare Spot

Production of defect-free galvanized steel sheet is considered a major concern for automotive and other critical applications; nevertheless, the occurrence of some defects in the coated sheets is unavoidable. In order to alleviate the problem, we need to know the extent to which the properties of a galvanized sheet are influenced by the presence of a given defect. In this investigation, specimens including any of the two major defects of continuously galvanized steel sheets were selected from a large number of coated samples. The defects, including furnace roll pimples and bare spots, were microstructurally characterized and their influence on corrosion behaviour and mechanical properties of the steel sheet was evaluated. Corrosion resistance was examined via standard salt spray test and Tafel polarization. Tensile test was employed as a measure of mechanical properties of the defective galvanized sheets. The results indicated that the presence of defects had little influence on the tensile properties of the samples, but considerably reduced their corrosion resistance. Based on the results of salt spray tests, pimples reduced corrosion resistance of galvanized sheets 23 % (50 hours) on average and bare spot defects caused reduction in corrosion resistance up to 39%.

scholarly journals Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Yuh-Chung Hu ◽  
Senthil Kumaran Selvaraj ◽  
Manivannan Subramanian ◽  
Kathiravan Srinivasan ◽  
Srinivasan Narayanan
Keyword(s):  
Corrosion Resistance ◽  
Die Casting ◽  
Pure Aluminum ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Al Alloy ◽  
Neutral Salt ◽  
Powder Coatings ◽  
Acrylic Paint ◽  
Epoxy Primer

A novel phenomenon known as Industry X.0 is becoming extremely popular for digitizing and reinventing business organizations through the adaption of rapid and dynamic technological, innovational, and organizational changes for attaining the profitable revenue. This work investigates the die-casted commercially pure aluminum alloyed with 9% silicon and 3% copper (AlSi9Cu3) that is produced through the gravity die casting process. Further, the degradation of surface coating on die-casted AlSi9Cu3 alloy was explored. The acrylic paint electrodeposition (ED) coat, 2-coat polyester without primer and 3-coat polyester with epoxy primer powder coatings were used in this study. Moreover, the 3.5 wt.% of sodium chloride (3.5 wt.% of NaCl) test solution was used for electrochemical and salt spray test and the tools used to assess electrochemical properties were electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and neutral salt spray test (NSS). The microstructure of AlSi9Cu3 after corrosion exposure was investigated; also, the microstructure of coated and uncoated AlSi9Cu3 samples was analyzed by SEM microscopy after corrosion exposure. Besides, the electrochemical studies were also carried out on the Al alloy die casting. It was found that acrylic paint ED coatings exhibited higher corrosion resistance than 2-coat polyester without primer & 3-coat polyester with epoxy primer powder coatings. Acrylic paint ED coating showed higher corrosion resistance in AC and a lower value in DC and 3-coat polyester with epoxy primer powder coating displayed higher corrosion resistance in DC and a lower value in AC.

Properties Study of Mixed Silane Films on the Surface of Steel

2014 ◽  
Vol 971-973 ◽  
pp. 135-138
Author(s):  
Zhen Dong Sun ◽  
Yan Ning Yang ◽  
Qing Peng Li ◽  
Jian Guo Liu ◽  
Chuan Wei Yan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Salt Spray ◽  
Adhesive Property ◽  
Epoxy Coating ◽  
Chemical Compositions ◽  
Neutral Salt ◽  
X Ray ◽  
Steel Sheets ◽  
Silane Solution ◽  
Scanning Electron

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.

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