scholarly journals New Flame Retardant and Antimicrobial Paints Based on Epoxy Paint Incorporated by Hexachlorocylodiphosphazane Derivatives for Protective Coating

2019 ◽  
Vol 5 (3) ◽  
pp. 85-96
Author(s):  
H. Abd El-Wahab ◽  
◽  
Salah A.A. Mohamed ◽  
Islam Gomaa

The concrete is a highly alkaline material and it is highly susceptible to acid attack. The concrete is one of the most useful materials for storage tank of different types of acids in Industries. Thus the durability of concrete against acid attack is one of the great concern in industries. In this paper the research work was carried out on influence of different types of cement, pozzolonic materials and Epoxy coating on concrete durability against different types of acid attack like H2SO4, HNO3 & H3PO4 . From the research work it has been observed that concrete with normal Portland cement shows more deterioration than concrete with Portland composite cement and also concrete with Pozzolonic materials like Fly ash & GGBS shows extensive resistance against acid attack in concrete due to consumption of Ca(OH)2 in concrete through Pozzolonic reaction. The research work also shows that concrete with GGBS in concrete & also concrete with external protective coating of Epoxy paint has high potential resistance against acid attack in concrete.


2020 ◽  
Vol 117 (6) ◽  
pp. 610
Author(s):  
Nadia Hammouda ◽  
Kamel Belmokre

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in chloride environment (3% NaCl) by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness. Microscopic analyses have shown that oxidation dominates the corroded surfaces.


The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.


2020 ◽  
Vol 56 (1) ◽  
pp. 57-69
Author(s):  
S. P. Rogalskiy ◽  
I. A. Morozovskaya ◽  
M. A. Boretskaya ◽  
T. V. Cherniavskaya ◽  
O. P. Tarasiuk ◽  
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2019 ◽  
Vol 9 (2) ◽  
pp. 182-191
Author(s):  
Akihiro Minami ◽  
Hirokazu Tamura ◽  
Hidetoshi Sakamoto ◽  
Yoshifumi Ohbuchi ◽  
Yasuo Marumo

Author(s):  
Amanda Silva ◽  
Enio Henrique Pires da Silva ◽  
Danilo Janes ◽  
Romeu Rony Cavalcante da Costa ◽  
Giovanna Gabriela Crem Silva

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.


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