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

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.

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Characteristics Evaluation of Coating Film by Thermal Spray in Seawater Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2098 ◽

2013 ◽

Vol 690-693 ◽

pp. 2098-2106

Author(s):

Kyung Man Moon ◽

Mun Jin Nam ◽

Yeon Chang Lee ◽

Yun Hae Kim ◽

Jae Hyun Jeong

Keyword(s):

Corrosion Resistance ◽

Thermal Spray ◽

Pure Aluminum ◽

Arc Spraying ◽

General Corrosion ◽

Coating Film ◽

Pure Zinc ◽

Surface Protection ◽

Aluminum Sample ◽

Porosity Ratio

Many surface protection methods have been developed to apply to constructional steels to be used under severe corrosive environments. Thermal spray coating has been known to be an attractive technique due to its relatively high coating speed. However, the high corrosion resistance of coating films deposited by thermal spray method is increasingly required to expand its application. Four types of coated films (DFT: 200um), that is, pure zinc, pure aluminum, and two Al-Zn alloy (Al:Zn=85:15 and Al:Zn=95:5), were coated onto carbon steel (SS401) with arc spraying, and the corrosion behavior of their samples were evaluated by the electrochemical method in this study. The pure aluminum sample had the best corrosion resistance when exposed to seawater solution and alloy (Al:Zn=85:15), so called galvalume and alloy (Al:Zn=95:5) samples followed the pure aluminum sample. The pure zinc sample ranked 4thin corrosion resistance in this study. Morphology of corroded surfaces of pure aluminum and alloy (Al:Zn=85:15) samples exhibited a general corrosion pattern, however, the patterns of intergranular and pitting corrosion were observed for the pure zinc and alloy (Al:Zn=95:5) samples respectively. Pure zinc sample had the smallest value of porosity ratio compared to other samples due to its heavier density. Keywords : Surface protection methods, Thermal spray, Corrosion resistance, Pure aluminum, Pure zinc, Porosity ratio

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OBSERVATION OF THE CORROSION CHARACTERISTICS OF METALIZING FILM IN SEAWATER SOLUTION

International Journal of Modern Physics B ◽

10.1142/s0217979211066672 ◽

2011 ◽

Vol 25 (31) ◽

pp. 4241-4244 ◽

Cited By ~ 1

Author(s):

KYUNG-MAN MOON ◽

YUN-HAE KIM ◽

MIN-SEOK OH ◽

DONG-HYUN PARK ◽

JONG-PIL WON

Keyword(s):

Corrosion Resistance ◽

Carbon Steel ◽

Electrochemical Method ◽

Pure Aluminum ◽

Arc Spraying ◽

High Corrosion Resistance ◽

Pure Zinc ◽

Aluminum Sample ◽

Porosity Ratio ◽

Zn Alloy

Four types of coated films (DFT: 300um), that is pure zinc, pure aluminum, and two Al - Zn alloy ( Al : Zn =85:15 and Al : Zn =95:5), were coated onto carbon steel (SS401) with arc spraying, and the corrosion behavior of their samples were evaluated by the electrochemical method in this study. The pure aluminum sample had the high corrosion resistance when exposed to seawater solution and pure zinc and alloy ( Al : Zn =95:5) samples followed the pure aluminum sample. The other alloy ( Al : Zn =85:15), the so-called galvalume that was coated onto the carbon steel, ranked 4th in corrosion resistance in this study. The results of the porosity ratio of those samples are well matched with the electrochemical data

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

Materials ◽

10.3390/ma14237464 ◽

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).

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