Behavior of Under-film Corrosion on Zn and Zn-Fe Alloy Coating in Salt Spray Environment

1991 ◽  
Vol 77 (10) ◽  
pp. 1688-1694
Author(s):  
Kimitaka HAYASHI ◽  
Yoichi ITO ◽  
Yasuhiko MIYOSHI
Keyword(s):  
Salt Spray ◽  
Alloy Coating

The Corrosion Mechanism of Zn-5%Al-0.3%Mg Coating

2011 ◽  
Vol 189-193 ◽  
pp. 1284-1287
Author(s):  
Bo Gao ◽  
Shi Wei Li ◽  
Yi Hao ◽  
Gan Feng Tu ◽  
Liang Hu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Alloy Coating ◽  
Mg Alloy ◽  
Corrosion Mechanism ◽  
Neutral Salt ◽  
Test Results ◽  
Crystal Boundary ◽  
Cold Rolled ◽  
Al Coating

A new hot dip Zn-5%Al-0.3%Mg alloy coating was performed on cold rolled common steel. The hot-dip process was executed by self-made hot dip galvanising simulator (China patent, No.201010160353). The corrosion resistance of alloy-coated steels was detected by neutral salt spray test . SEM and EDS test results demonstrate that Mg is mainly distributed in the crystal boundary. XRD test results shows corrosion product of Zn-5%Al-0.3%Mg alloy coating is mainly Zn5(OH)8Cl2•H2O. The characteristic of Zn5 (OH)8Cl2•H2O is dense and insoluble, so it is protective. In order to study the anticorrosion mechanism, all the tests of the Zn-5%Al-0.3%Mg alloy were carried out with Zn-5%Al coating together.

scholarly journals Anticorrosion Properties of Zn–Al Composite Coating Prepared by Cold Spraying

Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 210 ◽  
Author(s):  
Xinqiang Lu ◽  
Shouren Wang ◽  
Tianying Xiong ◽  
Daosheng Wen ◽  
Gaoqi Wang ◽  
...  
Keyword(s):  
Composite Coating ◽  
Energy Dispersive Spectrometer ◽  
Salt Spray ◽  
Cold Spraying ◽  
Alloy Coating ◽  
Raw Material ◽  
Neutral Salt ◽  
Accelerated Corrosion ◽  
Al Composite ◽  
Strong Adhesion

In order to slow down the corrosion and wear of offshore equipment, the Zn–Al composite coating was prepared on Q345 substrate by cold spray technique. The mass fraction of Zn and Al in the raw material was 2:3. The microstructure of the original coating was observed by scanning electron microscopy (SEM) and was characterized by energy dispersive spectrometer (EDS). From the composite alloy coating obtained by cold spraying, it was observed that the Zn and Al particles were uniformly distributed without oxidation product, and the powder particles were significantly plastically deformed. The microstructure of the composite coating is very dense and has strong adhesion to the substrate. Neutral salt spray test (NSS) and electrochemical accelerated corrosion test results showed that Zn–Al composite coating can effectively provide corrosion protection.

Coating Structure and Corrosion Resistance Behavior of Hot Dip Zn-Al-Mg-Si Alloy Coating Steel Sheet

2013 ◽  
Vol 834-836 ◽  
pp. 601-608 ◽  
Author(s):  
She Ming Jiang ◽  
Chong Feng Yue ◽  
Qi Fu Zhang
Keyword(s):  
Corrosion Resistance ◽  
Steel Sheet ◽  
Salt Spray ◽  
Alloy Coating ◽  
Coated Steel ◽  
Coating Structure ◽  
Cross Sectional ◽  
Coating Technology ◽  
Coated Steel Sheet ◽  
Metal Materials

Hot Dip Zn-6Al-3Mg-0.2Si coating steel sheet was prepared in laboratory by Hot-dip Galvanizing Simulator produced by National Engineering Lab of Advanced Coating Technology for Metal Materials. The surface and cross sectional microstructure of the samples were analyzed by using SEM and EDS. Hot dip Zn coated, 55Al-43.3Zn-1.6Si and Zn-6Al-3Mg-0.2Si coated steel sheet samples were exposed to standardized salt spray test. The Zn-6Al-3Mg-0.2Si coating and its erode production were investigated by XRD. The results showed that the hot dip Zn-6Al-3Mg-0.2Si coating had better corrosion resistance than ordinary galvanized layer.

scholarly journals Microstructure and Corrosion Properties of Laser Cladding Fe-Based Alloy Coating on 27SiMn Steel Surface

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 552
Author(s):  
Changyao Ouyang ◽  
Qiaofeng Bai ◽  
Xianguo Yan ◽  
Zhi Chen ◽  
Binhui Han ◽  
...  
Keyword(s):  
Weight Loss ◽  
Corrosion Resistance ◽  
Laser Cladding ◽  
Steel Surface ◽  
Layer Structure ◽  
Salt Spray ◽  
Morphological Characteristics ◽  
Alloy Coating ◽  
Salt Spray Corrosion ◽  
Cladding Layer

In this paper, the corrosion performance of a laser cladding Fe-based alloy coating on the surface of 27SiMn steel was studied. The Fe-based alloy coating was prepared on a 27SiMn steel surface by high-speed laser cladding. The microstructure, morphological characteristics, element content, and phase composition of the cladding layer were analyzed by an optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and X-ray diffractometer (XRD), respectively. The corrosion resistance of the 27SiMn substrate and Fe-based coating in different corrosive environments was tested through an electrochemical experimental station, a salt spray corrosion test box, and an immersion experiment. The Fe-based alloy cladding layer is mainly composed of a-Fe, M7C3, M2B, and Cr3Si. The cladding layer structure forms planar, cellular, dendrite, and equiaxed dendrite during rapid solidification. The corrosion potential of the cladding layer is higher than that of the substrate, and the arc radius of the cladding layer is larger than that of the substrate. After salt spray corrosion, a large number of red and black corrosion products appeared on the surface of the substrate; the surface of the cladding layer sample was still smooth, and the morphology was almost unchanged. The weight loss results of the cladding layer and 27SiMn matrix after 120 h of immersion are 0.0688 and 0.0993 g·cm−2, respectively. The weight loss of the cladding layer is 30.7% less than that of the matrix. Conclusion: Laser cladding an Fe-based alloy coating on the surface of 27SiMn has better corrosion resistance than the substrate, which improves the corrosion resistance of hydraulic supports.

Salt Spray (Fog) Corrosion Behavior of Cold-Sprayed Aluminum Amorphous/Nanocrystalline Alloy Coating

2022 ◽  
Author(s):  
P. Suresh Babu ◽  
L. Venkatesh ◽  
A. Jyothirmayi ◽  
K. Suresh ◽  
L. Rama Krishna ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Salt Spray ◽  
Nanocrystalline Alloy ◽  
Alloy Coating

scholarly journals Study on the Corrosion Mechanism of Zn-5Al-0.5Mg-0.08Si Coating

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Shiwei Li ◽  
Bo Gao ◽  
Ganfeng Tu ◽  
Yi Hao ◽  
Liang Hu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Microstructural Characterization ◽  
Alloy Coating ◽  
Salt Spray Test ◽  
Corrosion Mechanism ◽  
Neutral Salt ◽  
Test Results ◽  
Coating Surface ◽  
New Type

A new type of hot-dip Zn-5Al-0.5Mg-0.08Si and Zn-5Al alloy coatings was performed on the cold rolled common steel. The hot-dip process was executed by self-made hot-dip galvanising simulator. SEM and EDS test results demonstrated that Mg was mainly distributed in crystal boundaries. XRD test results showed that the corrosion product of Zn-5Al-0.5Mg-0.08Si alloy coating was almost Zn5(OH)8C12⋅H2O. The features of Zn5(OH)8C12⋅H2O are low electric conductivity, insolubility and good adhesion.The corrosion resistance of alloy-coated steels was detected by neutral salt spray test. The microstructural characterization of the coating surface after neutral salt spray test and removing the corrosion products revealed that the corrosion process of Zn-5Al-0.5Mg-0.08Si coating was uniform and the coating surface was almost flat. As a result, the corrosion resistance of Zn-5Al-0.5Mg-0.08Si coating has a remarkable improvement with a factor of 9.2 compared with that of Zn-5Al coating.

Study on Corrosion-Resisting Properties of High-Speed Arc Sprayed Zn-Al Alloy Coating in Caverns

2011 ◽  
Vol 399-401 ◽  
pp. 2072-2078
Author(s):  
Miao Lou ◽  
Yu Feng Lu ◽  
Chun Lin Ma ◽  
Yong Le Hu ◽  
Meng Zhou ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Speed ◽  
Salt Spray ◽  
Alloy Coating ◽  
Arc Spraying ◽  
Al Alloy ◽  
Test Study ◽  
High Velocity Arc Spraying ◽  
Steel Substrates ◽  
Al Coating

Zn、Al alloy coatings were prepared by high velocity arc spraying technology on 16MnR steel substrates, With the design salt spray test, Study on the corrosion resistance of the Zn、Al alloy coating in the grotto environment. The porosity of the metal coating and the compact of the corrosion are infection on the corrosion resistance of the coating. Al coating and Zn/Al(300/100) coating corrosion resistance better than others on 16MnR steel.

scholarly journals Influence of Alloy Content on Microstructure and Corrosion Resistance of Zn-based Alloy Coated Steel Product

2020 ◽  
Vol 58 (3) ◽  
pp. 169-174 ◽  
Author(s):  
Jae-Won Lee ◽  
Sung-Jin Kim ◽  
Min-Suk Oh
Keyword(s):  
Corrosion Resistance ◽  
Flat Surface ◽  
Salt Spray ◽  
Ternary Eutectic ◽  
Alloy Coating ◽  
Corrosion Products ◽  
Coated Steel ◽  
Cut Edge ◽  
Batch Type ◽  
Binary Eutectic

The effects of alloy composition on the coating structure and corrosion resistance of hot-dip Znbased alloy coated steel products were investigated. Zn-based alloy coating layers with different Al and Mg compositions were fabricated using a batch-type galvanizing simulator. Various intermetallic compounds including Zn, Zn/MgZn<sub>2</sub> binary eutectic, Zn/Al binary eutectoid and Zn/Al/MgZn<sub>2</sub> ternary eutectic phases were formed in the coating layer. The surface and cut-edge corrosion resistance of the Zn-based alloy coating were superior to those of the Zn coating. Zn-based alloy coating containing 15% Al and 3% Mg showed the best corrosion resistance, with red rust formed on the flat surface after 120 hours in the salt spray test. The corrosion products of the Zn-based alloy coating consisted of Simonkolleite (Zn<sub>5</sub>(OH)<sub>8</sub>Cl<sub>2</sub>·H<sub>2</sub>O), Hydrozincite (Zn<sub>5</sub>(CO<sub>3</sub>)<sub>2</sub>(OH) and zinc oxide (ZnO). Al-containing corrosion products, Zn<sub>2</sub>Al(OH)<sub>6</sub>Cl<sub>2</sub>·H<sub>2</sub>O and Al<sub>2</sub>O<sub>3</sub>, were formed when more than 5 wt% Al was added. Al-containing corrosion products improved the corrosion resistance of the flat surface of Zn-based alloy coating, but did not affect corrosion resistance in the cut-edge area.

scholarly journals Effect of Ni Concentration on the Surface Morphology and Corrosion Behavior of Zn-Ni Alloy Coatings

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 96
Author(s):  
Ameeq Farooq ◽  
Sohaib Ahmad ◽  
Kotiba Hamad ◽  
Kashif Mairaj Deen
Keyword(s):  
Surface Morphology ◽  
Coating Thickness ◽  
Steel Substrate ◽  
Salt Spray ◽  
Research Work ◽  
Alloy Coating ◽  
Open Circuit ◽  
Dissolution Behavior ◽  
Cyclic Polarization ◽  
Ni Alloy

This research work aims to develop electrodeposited Zn-Ni alloy coatings with controlled dissolution tendencies on a mild steel substrate. The varying Ni concentration in the electroplating bath, i.e., 10, 15, 20 and 25 g·L−1, affected the surface morphology and electrochemical properties of the deposited Zn-Ni alloy coatings. SEM and EDS analysis revealed the resulting variation in surface morphology and composition. The electrochemical behavior of different coatings was evaluated by measuring the open circuit potential and cyclic polarization trends in 3.5 wt.% NaCl solution. The degradation behavior of the electrodeposited Zn-Ni coatings was estimated by conducting a salt spray test for 96 h. The addition of Ni in the coating influenced the coating thickness and surface morphology of the coatings. The coating thickness decreased from 38.2 ± 0.5 μm to 20.7 ± 0.5 μm with the increase in Ni concentration. Relatively negative corrosion potential (<−1074 ± 10 mV) of the Zn-Ni alloy coatings compared to the steel substrate (−969 mV) indicated the sacrificial dissolution behavior of the Zn-rich coatings. On the other hand, compared to the pure Zn (26.12 mpy), ~4 times lower corrosion rate of the Zn-Ni coating (7.85 mpy) was observed by the addition of 25 g·L−1 Ni+2 in the bath solution. These results highlighted that the dissolution rate of the sacrificial Zn-Ni alloy coatings can effectively be tuned by the addition of Ni in the alloy coating during the electrodeposition process.

Corrosion Behaviour of Zn-Al Pseudo-Alloy Coating on Carbon Steel in Chloride Environments

2012 ◽  
Vol 567 ◽  
pp. 45-48 ◽  
Author(s):  
An Qiang Liu ◽  
Kui Xiao ◽  
Chao Fang Dong ◽  
Xiao Gang Li
Keyword(s):  
Carbon Steel ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
Salt Spray ◽  
Alloy Coating ◽  
Salt Spray Test ◽  
Al Alloy ◽  
Electrochemical Tests ◽  
Arc Spray ◽  
Sacrificial Protection

In this work, Zn-Al alloy and Zn-Al pseudo-alloy coatings are deposited on carbon steel by arc spray technology. The corrosion behaviour of the coatings has been studied by salt spray test and electrochemical experiment. The morphology of the coatings exposed to salt spray test for 400 h was analyzed using SEM and EDS. Results show that corrosion rate of Zn-Al alloy coating is faster than that of Zn-Al pseudo-alloy coating and the steel substrate is attacked. The corrosion products formed on the surface of Zn-Al alloy coating were loose, with a large number of cracks and holes, but the Zn-Al pseudo-alloy coating is converted into a stable Al-rich oxide layer, which protects the steel substrate against corrosive attacks and enhances the corrosion resistance of the Zn-Al pseudo-alloy coating. Electrochemical tests show the Zn-Al pseudo-alloy coating as a sacrificial protection coating has the capability of providing sacrificial protection for the steel substrate.

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