Preparation, characteristics and corrosion properties of α-Al2O3 coatings on 10B21 carbon steel by micro-arc oxidation

2019 ◽  
Vol 358 ◽  
pp. 637-645 ◽  
Author(s):  
Yankun Li ◽  
Minfang Chen ◽  
Wei Li ◽  
Qi Wang ◽  
Yansong Wang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Properties ◽  
Micro Arc Oxidation ◽  
Α Al2o3

Anti-corrosion properties of oligoaniline modified silica hybrid coatings for low-carbon steel

2018 ◽  
Vol 235 ◽  
pp. 61-70 ◽  
Author(s):  
Yuwei Ye ◽  
Dawei Zhang ◽  
Zhiyong Liu ◽  
Wei Liu ◽  
Haichao Zhao ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Hybrid Coatings ◽  
Low Carbon ◽  
Modified Silica ◽  
Corrosion Properties ◽  
Silica Hybrid

Experimental study of the mechanical and corrosion properties of ethyl silicate resin applied on low carbon steel

2021 ◽  
Vol 2 (108) ◽  
pp. 68-74
Author(s):  
M. Ali ◽  
J.H. Mohmmed ◽  
A.A. Zainulabdeen
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Open Circuit Potential ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Treatment Temperature ◽  
Ethyl Silicate ◽  
Low Carbon ◽  
Corrosion Properties ◽  
Mixture Ratio

Purpose: This work aimed at evaluating the properties of the ethyl silicate-based coating that can be applied on low carbon steel. Design/methodology/approach: Two mixture ratio types (2:1, and 3:2) of resin and hardener respectively were used to prepared two specimen models (A and B). Findings: It found that some mechanical properties (tensile, hardness, and impact strength) of ethyl silicate resin were evaluated according to standard criteria. Research limitations/implications: The effect of heat treatments at various temperatures (100, 150, and 200°C) and holding at different times (10, 20 & 30) min on hardness was investigated. Practical implications: Moreover, an open circuit potential corrosion test with a solution of 3.5% Sodium Chloride at room temperature and 60°C was used to determine the corrosion resistance of low carbon steel specimens coated with the two mixture types. Originality/value: The effects of mixture ratios (for resin and hardener) and heat treatment conditions on properties of ethyl silicate-based coating were studied. From obtained results, acceptable values of tensile, hardness, and toughness were recorded. Increasing heat treatment temperature and holding time leads to enhance hardness for both model types. An open circuit potential (OCP) tests show that there is an enhancement of protective properties of ethyl silicate coatings with mixture type B in comparison with type A was achieved. Generally, the results indicate that specimen model B has higher properties as compared with specimen model A.

Corrosion and Wear Protection through Micro Arc Oxidation Coatings in Aluminum and Its Alloys

2019 ◽  
Author(s):  
L. Rama Krishna ◽  
G. Sundararajan
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
High Hardness ◽  
Basic Mechanism ◽  
Industrial Applications ◽  
Corrosion Properties ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Wear And Corrosion Resistance ◽  
Technological Limitations

This article presents the brief overview of fairly recent and eco-friendly micro arc oxidation (MAO) coating technology. The weight-cost-performance benefits in general raised the interest to utilize lightweight materials, especially the aluminum and its alloys. Despite numerous engineering advantages, the aluminum alloys themselves do not possess suitable tribology and corrosion resistance. Therefore, improvements in surface properties are essential to enable developing potential industrial applications. For improving wear and corrosion resistance of Al alloys, the most demanding surface properties are high hardness and chemical inertness. The technical and technological limitations associated with traditional anodizing and hard anodizing processes have been the strongest driving force behind the development of new MAO technology. While presenting the key technological elements associated with the MAO process, the basic mechanism of coating formation and its phase gradient nature is presented. Influence of various process parameters including the electrolyte composition has been discussed. The typical microstructural features and distribution of α- and γ-Al2O3 phases across the coating thickness as a key strategy to form dense coatings with required mechanical, tribological, and corrosion properties which are vital to meet potential application demands are briefly illustrated.

scholarly journals Green Approach to Corrosion Inhibition of Carbon Steel by Fucus spiralis extract in 1 M HCl Medium

2021 ◽  
Vol 12 (5) ◽  
pp. 7075-7091
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Adsorption Model ◽  
Corrosion Properties ◽  
Uv Visible ◽  
Fucus Spiralis ◽  
Hcl Medium

The extract of Fucus spiralis (FS) was tested as a corrosion inhibitor of carbon steel in a 1M HCl medium. The anti-corrosion properties were analyzed by gravimetric and electrochemical techniques such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The surface characterization of carbon steel submerged in the optimal solution was carried out using UV-Visible, UV-Vis-NIR, and Optical microscopy analyses. Electrochemical and gravimetric results demonstrated that inhibitory efficiencies increase with increasing inhibitor concentration and the efficiency reaches 87% at a concentration of 0.5 g/L. According to Tafel extrapolated polarisation measurements, the FS also worked as a mixed-type corrosion inhibitor and changed the mechanism of anodic reactions. EIS analysis showed that a depressed capacitive loop dominates the Nyquist plot of impedance and enhances the polarization resistance (Rp) to 161.9 Ω cm2 with a reduction of the double layer capacity (Cdl) of carbon steel to 61.8 μF/cm2. This protection is assured by an adsorption mechanism based on the isothermal Langmuir adsorption model, which positively affects the thermodynamic parameters. UV-Visible, UV-Vis-NIR analyses exhibited that inhibitor decreases the iron oxides like hematite, Magnetite, and Goethite, Maghemite, Lepidocrocite, δ-FeOOH of the metal surface and delays the dissolution of the bare metal of iron to the ferrous ions, notably that optical morphology showed that FS extract decreases the aggressivity of HCl.

scholarly journals Phase composition of coatings on the D16 alloy during micro-arc oxdation in alkaline and silicate electrolytes

2020 ◽  
Vol 1,2020 (1,2020 (124)) ◽  
pp. 51-55
Author(s):  
Subbotina V ◽  
Belozerov V ◽  
Sobol’ O
Keyword(s):  
Phase Composition ◽  
Liquid Glass ◽  
Amorphous State ◽  
Practical Significance ◽  
Alkaline Electrolyte ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Al2o3 Phase ◽  
Α Al2o3

Goal. The influence of electrolysis conditions at different electrolyte compositions on the phase formation of coatings obtained by micro-arc oxidation (MDO) on an aluminum alloy D16 was studied. Method. For electrolysis, two types of electrolytes were used: alkaline electrolyte (solution (KOH) in distilled water), silicate electrolyte (with different percentages of Na2SiO3 component). Research results. It was found that the phase composition of the MAO coatings obtained in an alkaline (KOH) electrolyte mainly consists of γ - Al2O3 phases and, to a much lesser extent, the α-Al2O3 phases. An increase in the KOH concentration leads to a shift in the γ – Al2O3 → α – Al2O3 polymorphic reaction toward the formation of the hardest α-Al2O3 phase (corundum). The formation of the preferred orientation of the growth of crystallites of γ – Al2O3 and α – Al2O3 phases during their formation in an alkaline electrolyte was not detected. Scientific novelty. A significant influence on the mechanism and processes of coating formation is made by the addition of liquid glass (Na2SiO3) in the electrolyte. In this case, the growth rate of the coating increases significantly, but the size of the ordering regions decreases from crystalline to X-ray amorphous. The phase composition of the MAO coatings, when they are formed in a silicate electrolyte, varies from a mixture of the γ - Al2O3 phase and mullite (3Al2O3 • 2SiO2) with a low content of liquid glass (10 g/l Na2SiO3) to the formation of only the X-ray amorphous phase with a high content of liquid glass in the electrolyte (50 g/l Na2SiO3). Practical significance. It was concluded that the use of an alkaline or silicate electrolyte with different percentages allows a wide variation of both the phase composition and structural state (α- Al2O3 and γ- Al2O3 phases, mullite (3Al2O3 • 2SiO2) or X-ray amorphous state) and the kinetics of growth the coating itself.

scholarly journals Structural Properties Ni20Cr10Al2Y Coatings for Geothermal Conditions

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1434 ◽  
Author(s):  
Aurelian Buzaianu ◽  
Petra Motoiu ◽  
Ioana Csaki ◽  
Anghel Ioncea ◽  
Vlad Motoiu
Keyword(s):  
Carbon Steel ◽  
Chemical Properties ◽  
Mechanical Tests ◽  
Steel Plates ◽  
Geothermal System ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Protective Layers ◽  
Diffraction Patterns ◽  
Oxygen Fuel

The chromium carbide hard phases powders are used for the high velocity oxygen fuel (HVOF) coating technique. This paper investigates samples coated with Ni20Cr10Al2Y on carbon steel plates. The coatings were designed to improve the erosion corrosion properties of carbon steel. The specific agglomerated nanosized Cr3C2 particles on the coated layer provide new physical, mechanical and chemical properties. The multilayer composite technique could be successfully used to protect turbine working in geothermal system. The samples were investigated using nanoindentation to determine the coated samples mechanical properties. The experimental procedure involved obtaining X-ray diffraction patterns of the specimens, micro mechanical tests and SEM investigation to provide detailed information about adhesion of protective layers and morphological modifications.

scholarly journals Investigation of Microstructure, Nanohardness and Corrosion Resistance for Oxi-Nitrocarburized Low Carbon Steel

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 190 ◽  
Author(s):  
Young-Wook Cho ◽  
Young-Joon Kang ◽  
Ju-Hwan Baek ◽  
Jeong-Ho Woo ◽  
Young-Rae Cho
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Oxide Layer ◽  
Potentiodynamic Polarization ◽  
Low Carbon Steel ◽  
Nanoindentation Test ◽  
Low Carbon ◽  
Electron Backscattered Diffraction ◽  
Corrosion Properties ◽  
Process Gas

A role of oxi-nitrocarburizing technique for low-carbon steel was intensively evaluated as a means of reducing the problem of corrosion in gas nitrocarburizing, which is a vital disadvantage of gas nitrocarburizing. Oxi-nitrocarburizing was carried out by a two-step process: Gas nitrocarburizing at 560 °C and oxidation. In order to characterize two different methods of oxi-nitrocarburizing, oxidation was performed under two different conditions: Air and steam as oxygen sources. To analyze the microstructural, physical, and chemical properties of the thin oxide layer and nitride layer, which are the surface hardened layers formed on low-carbon steel by oxi-nitrocarburizing, several methods, such as electron probe microanalysis (EPMA), electron backscattered diffraction (EBSD), scanning electron microscopy (SEM), nanoindentation tests, and potentiodynamic polarization tests were applied. The results indicated that the EPMA and EBSD methods are powerful techniques for the analysis of microstructure, such as phase analysis and metallic element distribution in the oxide layer of magnetite and compound layer of ε-phase and γ'-phase, for oxi-nitrocarburized low-carbon steel. Additionally, the nanohardness using the nanoindentation test and corrosion resistance using the potentiodynamic polarization test for the oxi-nitrocarburized specimens are useful methods to understand the mechanical and corrosion properties of the surface hardened layer.

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