scholarly journals Role of Coating Processes on the Corrosion Kinetics and Mechanism of Zinc in Artificial Seawater

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7464
Author(s):  
Jitendra Kumar Singh ◽  
Soumen Mandal ◽  
Raihana Jannat Adnin ◽  
Han-Seung Lee ◽  
Hyun-Min Yang
Keyword(s):  
Corrosion Resistance ◽  
Thermal Spray ◽  
Steel Substrate ◽  
Spray Coating ◽  
Steel Structures ◽  
Thermal Spray Coating ◽  
Artificial Seawater ◽  
Arc Spraying ◽  
Plasma Arc ◽  
Resistance Performance

Zinc (Zn) coating is being used to protect steel structures from corrosion. There are different processes to deposit the coating onto a steel substrate. Therefore, in the present study, a 100 µm thick Zn coating was deposited by arc and plasma arc thermal spray coating processes, and the corrosion resistance performance was evaluated in artificial seawater. Scanning electron microscopy (SEM) results showed that the arc thermal spray coating exhibited splats and inflight particles, whereas plasma arc spraying showed a uniform and dense morphology. When the exposure periods were extended up to 23 d, the corrosion resistance of the arc as well as the plasma arc thermal spray coating increased considerably. This is attributed to the blocking characteristics of the defects by the stable hydrozincite (Zn5(OH)6(CO3)2).

Polarization characteristics of four types of coating films by thermal spray in seawater solution

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540019 ◽  
Author(s):  
Kyung-Man Moon ◽  
Yun-Hae Kim ◽  
Myeong-Hoon Lee ◽  
Tae-Sil Baek
Keyword(s):  
Corrosion Resistance ◽  
Thermal Spray ◽  
Pure Aluminum ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Arc Spraying ◽  
Coating Film ◽  
Coating Films ◽  
Pure Zinc ◽  
Aluminum Sample

Thermal spray coating method has been known to be an attractive technique due to its relatively high coating speed. However, a high corrosion resistance of the coating film deposited by thermal spray method should be improved to prolong its lifetime. In this study, four types of coated films (DFT: 400 μm), that is, pure zinc, pure aluminum and two Al – Zn alloy ( Al : Zn = 85:15 and Al : Zn = 95:5) films were coated onto a carbon steel (SS401) with arc spraying, and the corrosion behaviors of these samples were investigated using the electrochemical method. The pure aluminum sample had the best corrosion resistance in seawater solution and alloy ( Al : Zn = 85:15) film, so called galvalume followed the pure aluminum sample, moreover, the alloy ( Al : Zn = 95:5) sample exhibited the worst corrosion resistance.

THE EFFECT OF COATING THICKNESS ON FATIGUE PROPERTIES OF STEEL THERMALLY SPRAYED WITH Ni-BASED SELF-FLUXING ALLOY

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3599-3604 ◽  
Author(s):  
HIROYUKI AKEBONO ◽  
JUN KOMOTORI ◽  
HIDETO SUZUKI
Keyword(s):  
Fatigue Strength ◽  
Thermal Spray ◽  
Coating Thickness ◽  
Volume Fraction ◽  
Steel Substrate ◽  
Fatigue Cracks ◽  
Spray Coating ◽  
Maximum Size ◽  
Thermal Spray Coating ◽  
Fatigue Properties

The Thermal spraying is one of the most popular surface coating techniques. To achieve the most efficient use of this technique in practice, it is very important to clarify the fatigue properties of steel coated with a thermal spray coating. In this study, to clarify the effects of coating thickness on the fatigue properties of the steel substrate, three types of sprayed specimens with different coating thickness (0.2, 0.5 and 1.0mm) were prepared and fatigue tests were carried out. Coating thickness strongly affected the fatigue properties; the thinner the coating thickness, the higher the fatigue strength. Fatigue crack propagation behaviors were observed. Accordingly the fatigue cracks propagated through many defects on the coated surface. The sizes and number of the coating defects were determined by coating thickness; the thicker the coating thickness, the larger the defect and number. Therefore, the sprayed specimens with thinner coatings indicated higher fatigue strength. Furthermore, estimations of the fatigue strength were performed by using Murakami's equation. The fatigue strengths of thermal spray coated specimens were estimated by three parameters; (i) maximum size of coating defects estimated by statistics of extreme value, (ii) hardness of the matrix and (iii) volume fraction of coating defects.

scholarly journals Weatherability of Arc Thermal Spray Al-Mg Coating in a Simulated Marine Environment

2020 ◽  
Author(s):  
Atsushi NAKANO
Keyword(s):  
Thermal Spray ◽  
Marine Environment ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Artificial Seawater ◽  
Anticorrosion Property ◽  
Exposure Test ◽  
Atmospheric Exposure ◽  
One Year ◽  
The One

Anticorrosion property of Al-5mass%Mg sprayed coating was evaluated by an atmospheric exposure test simulating marine environment for one-year. The test simulating marine environment means an accelerated exposure test where artificial seawater is sprayed on the coating surface in a general atmospheric exposure test. When the initial film thickness is small, the thickness of Al-Mg thermal spray coating decreased. For both exposure tests for one-year, the corrosion products of Al-Mg thermal spray could not be identified. From the results of EPMA, after the one-year atmospheric exposure test, Cl originating from airborne salts in atmosphere or from sprayed artificial seawater was not observed in the surface or inside of the Al-Mg coating. The spontaneous potential of Al-Mg thermal spray coating shifted to the noble side from that of the initial material after the one-year atmospheric exposure test. The anode polarization exhibited the same behavior in the two kinds of atmospheric exposure tests.

Deterioration Characteristics of Overlapping Layers between Al-5Mg Thermal Spray Coating and Heavy-Duty Paint Coating

2019 ◽  
Vol 972 ◽  
pp. 235-240 ◽  
Author(s):  
Mu Ye Yang ◽  
Kazuyoshi Muto ◽  
Shigenobu Kainuma ◽  
Jin Xuan Du ◽  
Hirokazu Miyata
Keyword(s):  
Thermal Spray ◽  
Spray Coating ◽  
Steel Structures ◽  
Thermal Spray Coating ◽  
Heavy Duty ◽  
Paint Coating ◽  
Spray Coatings ◽  
Steel Base ◽  
Eis Measurements ◽  
Deterioration Characteristics

In recent years, Al-5Mg alloy thermal spray coatings have been used as an anti-corrosion coating applied for various components of steel structures, in some cases it was covered by the conventional heavy-duty coating. However, the deterioration characteristics of overlapping layers between thermal spray layer and heavy-duty paint coating still not clear. In this study, to compare the anti-corrosion characteristics of the single thermal spray coating and overlapping layers, the accelerated cyclic exposure tests were carried out on specimens with three types of coating layers. To clarify the deterioration characteristics, the cross-cut defect were introduced into specimens, and the EIS measurements, glossiness test, EPMA elemental analyses were conducted on test specimens. The test results indicated that the deterioration of the overlapping layer at the steel base-exposed portion occurs earlier than the case of Al-5Mg thermal spray coating. In addition, the deterioration of thermal spray coating was accelerated by the sealing treatment in specimen with overlapping layers.

Impurity Effects on Shear Adhesive Strength of Tungsten Carbide Thermal Spray Coatings on Steel

2001 ◽  
Vol 7 (S2) ◽  
pp. 328-329
Author(s):  
Seetala V. Naidu ◽  
James D. Garber ◽  
Gary A. Glassc
Keyword(s):  
Surface Roughness ◽  
Tungsten Carbide ◽  
Thermal Spray ◽  
Adhesive Strength ◽  
Steel Substrate ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Test Method ◽  
Coating Process ◽  
Ring Shear

We have used High Velocity Oxy-Fuel (HVOF) thermal spray coating process to obtain tungsten carbide coatings on steel. It is important to control the powder quality and surface roughness of the substrate in the thermal spray coating process to obtain good adherence. The adhesive strength is greatly effected by the interfacial impurities. Most commonly used in the thermal spray industry is Al2O3 grit abrasive for good surface roughness of steel substrate to produce anchor patterns for the coating. The previous studies indicated that some fine Al2O3 particles are trapped in the rough surface grooves during this process. The ring shear test method, described previously, appears to give the most accurate results on shear adhesive strength. The ring shear strength test was comprised of a 0.02” thick and 0.25” wide ring coating on a 1” diameter cylindrical substrate rod. This rod is placed in a disk with a cylindrical hole of the rod size and an incremental pressure is applied on the rod.

A Preliminary Study on Hybrid Use of Thermal Spray Coating and Ultrasonic Nanocrystalline Surface Modification Technique on the Tribological Properties of Yttria-Stabilized Zirconia Coating

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Auezhan Amanov ◽  
Young-Sik Pyun
Keyword(s):  
Surface Modification ◽  
Thermal Spray ◽  
Tribological Properties ◽  
Steel Substrate ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Mechanical And Tribological Properties ◽  
Sprayed Coating

An ultrasonic nanocrystal surface modification (UNSM) technique was applied to a thermally sprayed yttria-stabilized zirconia (YSZ) ceramic coating deposited onto a hot tool steel substrate to improve the mechanical and tribological properties. The friction test results showed that the UNSM-treated coating had a smoother surface, a lower friction, and a higher resistance to wear compared to that of the as-sprayed coating. It was also demonstrated that the UNSM technique improved the adhesion behavior of the coating by about 24%. Hence, it was found that a hybrid use of thermal spray coating (TSC) and UNSM technique is a meaningful way to bring together synergy effect of two emerging surface technologies in terms of tribology.

scholarly journals Atmospheric Corrosion Behavior of Arc Thermal Spray Zn-Al Coatings Using Accelerated Atmospheric Field Test for Ten-Year

2020 ◽  
Author(s):  
Atsushi NAKANO
Keyword(s):  
Thermal Spray ◽  
Field Test ◽  
Sea Water ◽  
Spray Coating ◽  
Oxide Coating ◽  
Thermal Spray Coating ◽  
Artificial Seawater ◽  
Field Exposure ◽  
Basic Study ◽  
Significant Difference

As a basic study on corrosion life of thermal spray coatings, accelerated field test with artificial seawater for 10-year were carried out for thermal spray Zn-30mass%Al coatings. By using artificial sea water, atmospheric field test accelerates corrosion due to chloride in comparison with a general atmosphere field test. Thermal sprayed specimens were prepared using an arc thermal spray method with compressed air on carbon steel subjected surface treatment. The formation of the oxide coating and the invasion of Cl and S to the inside layer were detected in 10-year of both the atmospheric field and the accelerated atmospheric field exposure tests, but the significant difference in the thickness of the thermal spray coating was not observed. In addition, for the accelerated atmospheric field test with spraying artificial seawater, thermal spray coating part remained satisfactorily, and it showed high corrosion resistance withstanding the 10-year atmospheric field test.

Interfacial Elemental Distribution In Tungsten Carbide Coated Steel

1999 ◽  
Vol 5 (S2) ◽  
pp. 838-839
Author(s):  
S.V. Naidu ◽  
Carlos Green ◽  
Christopher Maxie ◽  
James D. Garber ◽  
Gary A. Glass
Keyword(s):  
Thermal Spray ◽  
Steel Substrate ◽  
Spray Coating ◽  
High Hardness ◽  
Thermal Spray Coating ◽  
Elemental Distribution ◽  
Coated Steel ◽  
X Ray ◽  
Carbide Coatings ◽  
Steel Substrates

Thermal spray of carbide coatings with high hardness and corrosion resistance onto steel substrates has technological importance. The adhesive strength is greatly effected by the interfacial impurities. Low porous and good quality 200 μm thick 86WC10Co4Cr coatings on 4140 steel are obtained by thermal spray methods using SC-HVOF gun at Cooper Oil Tools, Houston, TX. A Carl Zeiss DSM942 SEM with 3.5 nm resolution at 30 keV and Kevex LPX1 Super Dry Quantum Si(Li) Detector with < 145 eV resolution for Energy Dispersive X-ray Spectroscopy (EDXS) were used to study the elemental distribution across the interface. Fig. 1 shows the SEM micrographs of the interface between 86WC10Co4Cr thermal spray coating and 4140 steel substrate. The anchor patterns seen at the interface are believed to improve the adhesive qualities between the coating and the substrate.

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