Zinc Coatings

Corrosion ◽  
1994 ◽  
pp. 13:41-13:53 ◽  
Author(s):  
A.R.L. CHIVERS ◽  
F.C. PORTER
Keyword(s):  
2020 ◽  
Vol 4 (141) ◽  
pp. 140-147
Author(s):  
MIKHAIL VIKHAREV ◽  
◽  
VLADIMIR YUDIN ◽  
VESELOVSKIY NIKOLAY ◽  
◽  
...  

The article shows the role of electroplating in the restoration of parts, indicates the advantages of restoring parts with electroplating over other methods, and gives the characteristics and properties of coatings obtained by electroplating. (Research purpose) The research purpose is in increasing the speed of application of zinc electroplating when restoring parts. (Materials and methods) The cathode current density has a decisive influence on the coating speed. The main reason for limiting the cathode current density during galvanizing from sulfuric acid electrolytes is the chemical polarization of the cathode. The article presents a study on the designed installation for the application of galvanic coatings. When applying coatings to the internal surfaces of parts, there was used a device with activating elements having an electromechanical rotation drive. This device prevents depletion of the near-cathode layer of the electrolyte and reduces the chemical polarization of the cathode. Elements made of moisture-resistant skin were used as activators. (Results and discussion) The article presents the results of experiments as a dependence of the coating speed on the speed of the activator relative to the restoring surface. It also presents the relationship between the size of the abrasive grains of the activating elements, the force of their pressing against the cathode surface, the speed of movement of the activator and the speed of applying the zinc coating, as well as its quality. By activating the cathode surface, it was possible to raise the operating current density to 100-150 amperes per square decimeter. The speed of application of zinc coatings is 16-25 micrometers per minute. (Conclusions) In the course of research, authors determined the conditions of electrolysis during galvanizing, which provide a significant increase in the cathode current density and the rate of application of these coatings during the restoration of parts.


2020 ◽  
Vol 64 (5) ◽  
pp. 755-771
Author(s):  
Oleksii Sherepenko ◽  
Vincent Schreiber ◽  
Iwan Schischin ◽  
Maximilian Wohner ◽  
Philipp Wernlein ◽  
...  

2013 ◽  
Vol 212 ◽  
pp. 127-132 ◽  
Author(s):  
Henryk Kania

In the paper the author presents the results of tests defining the characteristics of behaviour of Sandelin steel in the high-temperature galvanizing process. The growth kinetics of hot-dip zinc coatings on the substrate of 0.05% Si steel in the temperature range of 540-580°C has been established. The structure of the coatings and their phase composition have been developed and the chemical composition of structural components of the coating has be defined. It has been determined that the coating is composed of a compact layer δ1 and an area of a two-phase mixture of δ1 and Zn. The conducted tests confirmed the presence of phase Γ1 , which does not form a continuous layer but it forms individual precipitates which are irregular in shape. The growth kinetics of the coating indicates that an increase in temperature causes a decrease in the coating thickness, which might prove that dissolving processes prevailed over the processes of diffuse coating growth.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 325
Author(s):  
Borja Arroyo ◽  
Marion Roth ◽  
José Alberto Álvarez ◽  
Ana Isabel Cimentada ◽  
Sergio Cicero ◽  
...  

The main objective of this work is the study of the hillock and zinc whisker evolution of five different commercial zinc coatings applied on the same base steel wires of the patented EASYCONNECT system cable trays manufactured by VALDINOX Ltd.: white zinc alkaline electrolyte, yellow zinc trivalent electrolyte, acid zinc electrolyte, hot dip galvanized, and zinc nickel coating. The limited literature on the subject is summarized, and then the coating thickness, chemical composition, hardness and surface rugosity are characterized. The hillock and whisker density evolution are evaluated over a period of 12 months, considering the presence of compression bending stresses. It is concluded that the white alkaline and yellow trivalent coatings are the most affected, while the zinc-nickel shows the best behavior with no presence of whiskers; the acid zinc electrolyte also shows good results despite the delayed appearance of whiskers from the ninth month; the hot-dip galvanized coating does not show any presence of zinc whiskers or hillocks.


2021 ◽  
Author(s):  
M. C. van Leeuwen ◽  
P. M. Gangé ◽  
B. Duran ◽  
F. Prenger

<p>Metallic zinc coatings are well established as cost-effective corrosion protection for steel bridges. The zinc coating acts first as barrier protection, isolating the base steel from corrosive elements, and secondly by cathodic protection, acting as a sacrificial anode to protect the steel should the coating be compromised. Bridge operators can be confronted by disproportional high maintenance costs for bridges in use as removal of (in)organic paint systems with hazardous and toxic compounds require expensive waste disposal and environmental protection measures. Metallic zinc coatings are recognized as environmentally friendly, sustainable, and low maintenance, providing the lowest life cycle cost corrosion protection. Various case studies with bridges protected with metallic zinc coatings in and outside Europe are illustrated.</p>


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