The Impact of Zinc Coating Specifications on Corrosion Resistance аnd Durability of Steels

2019 ◽  
Vol 945 ◽  
pp. 740-745
Author(s):  
I.A. Kovalenko ◽  
D.V. Laskin ◽  
A.Y. Trifonova
Keyword(s):  
Corrosion Resistance ◽  
Statistical Analysis ◽  
Chemical Composition ◽  
Service Life ◽  
Zinc Coating ◽  
Useful Life ◽  
Galvanized Coating ◽  
Zinc Coatings ◽  
The Impact ◽  
High Chloride

The article contains the findings on impact of zinc coating specifications on corrosion resistance and service life of steels of various chemical composition used often in modern industries. Characteristics such as type, class, chemical compound and thickness of zinc-based coatings are also addressed. Experiments were performed in which corrosion rate and useful life of zinc coatings in probable operating-like conditions — i.e., in environments of varying degrees of corrosive power (humid and high-chloride environments) were determined. It has been established which one of the environments is the most corrosive for steels depending on the zinc-based coatings’ specifications. Qualitative (visual) and quantitative (gravimetric) assessment of corrosion resistance and service life of chosen steels is presented. Optimal hot dip galvanized coating specifications were determined using statistical analysis.

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 Application of Bonded Joints for Quantitative Analysis of Adhesion

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Jarmila Trpčevská ◽  
Mária Kollárová ◽  
Eva Zdravecká ◽  
Jana Tkáčová
Keyword(s):  
Steel Substrate ◽  
Zinc Coating ◽  
Experimental Tests ◽  
Coated Steel ◽  
Bonded Joints ◽  
Steel Sheets ◽  
Galvanized Coating ◽  
Zinc Coatings ◽  
Peel Tests

The performance of hot-dip coated steel sheets is associated with properties of the zinc coatings on steel substrate. For the characterization of the adhesion behaviour of zinc coating on steel various tests were employed. The study was focused on quantification assessment of galvanized coating adhesion to substrates. Methods for evaluation of the bonding strength of zinc coating by the shear strength and the T-peel tests applying four special types of adhesives were used. The experimental tests of bonded joints show that the adhesion of the zinc coating to the substrate was higher than that of the applied adhesive with the highest strength.

Study of the Temperature Effect on the Structure and Thickness of Hot-Dip Zinc Coatings on Fixing Products

2014 ◽  
Vol 698 ◽  
pp. 355-359 ◽  
Author(s):  
Olga Bondareva
Keyword(s):  
Coating Thickness ◽  
Elevated Temperatures ◽  
Zinc Coating ◽  
High Strength ◽  
Bath Temperature ◽  
X Ray ◽  
Minimal Thickness ◽  
Galvanized Coating ◽  
Zinc Coatings ◽  
Scanning Electron

Hot-dip galvanizing of steels is usually performed by immersing the metal in a bath with molten zinc in the temperature range from 450 to 460 °C. In some cases it is necessary to obtain a minimal coating thickness. For example, high-strength bolts and other fixing products require a minimal thickness of the coating because a too thick zinc coating requires additional work on re-threading, which leads to spalling of coatings, a loss of corrosion resistance and, consequently, failure of the entire product. The main aim of this work was to study the influence of elevated temperatures of hot-dip galvanizing on the thickness and microstructure of zinc coatings on bolts and nut preform. The microstructure and elemental composition of the coating were studied by scanning electron microscopy and energy dispersion X-ray microanalysis. It was found that the coating thickness obtained in the range between 475 and 535°C decreases with temperature and reaches a minimum at 535°C. The structure of the coating after high-temperature hot-dip galvanizing was fundamentally different from the structure of the coating made at standard temperatures 450-460°C. This coating formed at 535°C was dense, homogeneous, non-porous and composed of a mixture of the δ and ζ-phases without distinct phase boundaries. That’s why it was recommended to maintain the bath temperature in the range between 533°C and 537°C. It allows us to obtain a hot-dip galvanized coating of a minimal thickness and a good quality on fixing products.

Corrosion resistance of zinc electrodeposited from acidic and alkaline electrolytes using pulse current

2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Matilda Zemanová
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Test ◽  
Pulse Current ◽  
Zinc Coating ◽  
Accelerated Corrosion ◽  
X Ray ◽  
Before And After ◽  
Alkaline Electrolytes ◽  
Zinc Coatings ◽  
Chrome Iii

AbstractCorrosion resistance of zinc coatings was investigated in an accelerated corrosion test in a condensation chamber. Zinc was electrodeposited from alkaline and acidic electrolytes using direct current (DC) or pulse current (PC). The zinc coating was subsequently protected against corrosion with a chrome (III) layer. Morphology and structure of the coatings was investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD) before and after the corrosion test. Corrosion resistance of alkaline zinc coatings electrodeposited with DC and PC under test conditions was found to be comparable. The corrosion resistance of zinc coatings deposited from acidic electrolytes by PC was lower in comparison with corrosion resistance of zinc coatings deposited using DC.

The Corrosion Behaviors of the Cerium Conversion Coatings on the Zinc Coating in a 5 % NaCl Solution

2017 ◽  
Vol 36 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Jianghong Zhang ◽  
Binfang Meng ◽  
Xinying Wang ◽  
Wei Li
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Zinc Coating ◽  
Conversion Coating ◽  
Corrosion Products ◽  
Nacl Solution ◽  
Cerium Content ◽  
Electrochemical Parameters ◽  
Corrosion Behaviors ◽  
The Impact

AbstractThe present paper investigated the impact of cerium on the corrosion resistance of zinc coating in a 5 % NaCl solution. Electrochemistry was used to measure the electrochemical parameters to compare the corrosion resistance of the zinc coating with that of the cerium conversion coating on the galvanized layer. SEM/EDS and XRD were adopted to analyze the appearance and phases of corrosion products of the cerium conversion coating and to probe the impact of cerium on the corrosion behavior of zinc coating in the Cl–media. The results showed that the cerium conversion coating formed on the zinc coating increased the zinc’s corrosion resistance effectively, conversion coating with lower cerium content protected the substrate poorly, resulting in easy erosion of the zinc coating in the Cl–media. The corrosion products mainly consist of complexes, such as Zn(OH)xClyand Ce(OH)xCly.

Preliminary Study of DLC Coatings Aiming to the Corrosion Protection of Ferrous Materials

2010 ◽  
Vol 10 ◽  
pp. 113-120
Author(s):  
G. Vourlias ◽  
N. Pistofidis ◽  
D. Chaliampalias ◽  
Panos Patsalas ◽  
Efstathios K. Polychroniadis
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Zinc Coating ◽  
Chemical Vapor ◽  
Harsh Environments ◽  
Dlc Coatings ◽  
Preliminary Study ◽  
Diffraction Patterns ◽  
Zinc Coatings ◽  
Galvanized Coatings

Zinc hot-dip galvanizing is one of the most effective methods for the corrosion protection of ferrous substrates. However, the failure of zinc coatings is possible when exposed to harsh environments for rather long periods. The application of a thin diamond like carbon (DLC) film on the top of the zinc coating might be a promising method for promoting their corrosion resistance. In the present work, a DLC thin film was deposited on zinc galvanized coatings by Plasma Enhanced Chemical Vapor Deposition. The as-formed film was composed of nanostructured and amorphous areas. The electron diffraction patterns acquired from the nanograins correspond to carbon phases with d-spacing ranging from diamond to graphite. Additionally, after 18 days of exposure in a simulated marine atmosphere, the DLC coated samples were proven to be more resistant than the naked galvanized coatings indicating its potential to improve the corrosion resistance of galvanized ferrous materials.

scholarly journals Comparative Study on the Corrosion Resistance of Inorganic Zinc-Rich Coating and Thermal-Spray Zinc Coating

2021 ◽  
Author(s):  
Weiliang Ni ◽  
Peng Li ◽  
Yajun Zhu ◽  
Zhigang Di ◽  
Liangliang Guo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Thermal Spray ◽  
Salt Spray ◽  
Zinc Coating ◽  
Steel Structures ◽  
Salt Spray Test ◽  
Shielding Effect ◽  
Corrosion Mechanism ◽  
Time Varying ◽  
Zinc Coatings

Abstract The corrosion resistance of two steel coatings (inorganic zinc-rich coating and thermal-spray zinc coating) was studied in detail by using the electrochemical and salt spray test, and the salt spray corrosion thickness was calculated by the time-varying equation established from the mathematical fitting method. The result show that the corrosion mechanism of the two types of coatings was the same that based on the sacrificed of zinc through anodizing phenomenon. The main reason for the difference of corrosion resistance between the two anticorrosive coatings was that the coating density and shielding effect of corrosion products were different. The 7500-hours salt spray test showed that the corrosion rates and microstructure characteristics of both types of zinc coatings were homogeneous on the premise of ensuring coating reliability. The time-varying equation can be used to evaluate the service life of the zinc coatings and judge their corrosion resistance quickly, that providing theoretical support for the maintenance of steel structures as well as the accelerated selection and design of coating formulations.

scholarly journals Impact of Environmental Exposure on the Service Life of Façade Claddings—A Statistical Analysis

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 615
Author(s):  
Joana Barrelas ◽  
Ilídio S. Dias ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Inês Flores-Colen ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Service Life ◽  
Environmental Exposure ◽  
Degradation Process ◽  
Related Factors ◽  
High Exposure ◽  
Tiling System ◽  
Building Components ◽  
The Impact ◽  
Exposure Conditions

Façade claddings, as the outer protection layer of the building’s envelope, are directly exposed to environmental degradation agents. The façades’ orientation and their distance from the sea, among other location and protection-related factors, influence their vulnerability to climate loads, in particular wind and air humidity. These loads, as well as exposure to air pollution, affect the degradation process of claddings and the durability of façades. Therefore, studying the impact of the environmental exposure conditions on the service life of different external claddings provides useful information on their performance over time, which can support (i) decision-makers in the selection of the best façade cladding solutions and (ii) further research on the impact of climate change on building components. This study covers six types of cladding: rendered façades (R), natural stone cladding (NSC), ceramic tiling system (CTS), painted surfaces (PS), external thermal insulation composite systems (ETICS), and architectural concrete façades (ACF). Three hundred façades located in Portugal are analysed according to three main groups of variables, which characterize (i) the façades, (ii) their degradation condition, and (iii) the environmental deterioration loads and context. The statistical analysis results reveal that the environmental variables affect the cladding degradation process. South-oriented façades present lower degradation conditions than façades facing north. The distance from the sea and high exposure to pollutants add to the degradation conditions, reducing the expected service life of façades. The results reveal that claddings can be organized according to two main groups: the most durable (CTS, NSC, and ACF) and the least durable (R, PS, and ETICS) systems. This study enables a comprehensive analysis of the data, useful to draw conclusions about the influence of environmental exposure conditions on the degradation and service life of façade claddings.

Passivation of Zinc Coatings by Inhibition Chrome-Based Systems

2014 ◽  
Vol 1059 ◽  
pp. 67-73
Author(s):  
Jiří Votava ◽  
Martin Kotus ◽  
Vojtěch Kumbár
Keyword(s):  
Service Life ◽  
Salt Spray ◽  
Current Trend ◽  
Zinc Coating ◽  
Thick Layer ◽  
Self Healing ◽  
Paint Systems ◽  
Inorganic Coatings ◽  
The Individual ◽  
Zinc Coatings

The anticorrosion resistance of metal (inorganic) coatings is defined by the system of anode and cathode protection. As zinc coatings do not load the environment in such an extent like organic paint systems, current trend is to maximally prolong the service life of a zinc coating. This paper is focused on analysis of the speed of corrosion degradation of zinc coatings. The individual samples were prepared by the method of hot-dipping and galvanizing. Inhibition systems were applied only to electrolyte-applied zinc coating. There were prepared three different passivating methods: (1) slim-layer passivation with the content of Cr (III), (2) slim-layer passivation with the inhibitor Cr (VI) and (3) thick-layer passivation with Cr (III). The thickness of anticorrosion coatings has been measured by both destructive and non-destructive methods. The weight of the applied anticorrosion substrate was measured in compliance with the ČSN EN ISO 3892 standard. Ductile characteristics were analysed according to the ČSN EN ISO 1519 standard. The total evaluation of anticorrosion resistance was processed according to the ČSN EN ISO 9227 standard (salt-spray test). Based on the results of corrosion tests, the individual coatings can be analysed and their corrosion resistance can be evaluated. The service life of the zinc coating can be prolonged by sealing off the zinc coating by an appropriate inhibitor which supports the self-healing effect of the whole anticorrosion substrate.

Investigation of the Initial Stage of Hot Dip Zinc Coatings on Iron Alloys with Various Silicon Contents

2013 ◽  
Vol 212 ◽  
pp. 121-126 ◽  
Author(s):  
Piotr Liberski ◽  
Adam Tatarek ◽  
Jacek Mendala
Keyword(s):  
Zinc Coating ◽  
Iron Alloys ◽  
Silicon Steel ◽  
Liquid Phases ◽  
Initial Stage ◽  
Coating Formation ◽  
Zinc Coatings ◽  
Solid Liquid ◽  
The Impact ◽  
Short Times

In this work tests on the course of zinc coating formation on model iron alloys with diversified silicon additions in molten zinc, with short times of contact at the solid-liquid border have been presented. The experiments were carried out at the temperature of 440°C. The assumed time of contact between solid and liquid phases was: 1, 4, 9, 14, 29, 59 seconds. The test stand was designed. The structure and thickness of coatings obtained on steel without silicon, on Sandelin steel and on high-silicon steel was defined. Based on the results we may ascertain that in the first stadium of the galvanizing process the impact of silicon upon the intensity of coating growth is small. Increased reactivity of silicon is already observed after about 29-59 seconds of the process.

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