scholarly journals Analysis of corrosive properties of zinc-containing coatings based on dispersed waste hot zinc plating

Author(s):  
N. I. Urbanovich ◽  
K. E. Baranovsky ◽  
E. V. Rozenberg ◽  
T. I. Bendik ◽  
A. A. Karpenkin ◽  
...  

A comparative analysis of the corrosion properties of zinc-containing coatings obtained on the basis of metallic powder zinc and dispersed hot-dip galvanized waste has been carried out. The results of a study of the corrosion resistance of zinc-containing coatings by the electrochemical method and in a salt spray chamber have shown that coatings obtained on the basis of dispersed hot-dip galvanized waste are not inferior in protective properties to coatings based on powder standard zinc.

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 384
Author(s):  
Dariusz Ulbrich ◽  
Jakub Kowalczyk ◽  
Arkadiusz Stachowiak ◽  
Wojciech Sawczuk ◽  
Jaroslaw Selech

The article presents the influence of the applied method used for removing the varnish coat on the corrosion resistance of the car body sheet. The tests were carried out on samples prepared from factory-painted car body elements with pearlescent, metallized and acrylic varnish. Removal of the varnish coat was performed by sandpaper grinding, glass bead blasting, disc blaze rapid stripping, soda blasting and abrasive blasting with plastic granules. The average thickness of the factory-painted coating depending on the type of lacquer ranged from about 99 to 140 µm. On the other hand, after removing the varnish, the thickness of the protective zinc coating ranged from 2 to 12.7 µm. The highest values of the zinc coating were obtained for samples in which the varnish was removed by the method such as soda blasting and abrasive blasting with plastic granules. For these two methods of surface preparation, the damage to the zinc layer protecting the steel against corrosion is the smallest and the percentage of zinc in the surface layer ranges from 58% to 78%. The final stage of the research was to test the samples after removing the varnish coat in a two-hour exposure to the corrosive environment in a salt spray chamber. Samples with the surface prepared by grinding with sandpaper reached the level of surface rusting Ri 5, while in the case of soda blasting and the use of plastic granules, no corrosion centers were observed on the surface of the car body sheet.


2010 ◽  
Vol 438 ◽  
pp. 89-96
Author(s):  
Haidar Omar ◽  
Nikolaos Michailidis ◽  
Stefanos Skolianos ◽  
Azarias Mavropoulos ◽  
Sofia Tsipas ◽  
...  

In many applications, even high-performance alloys have to be covered with protective coatings, providing higher corrosion and oxidation resistance, as compared to the alloy itself. This study investigates the feasibility to apply boron coatings on P91 steel by pack cementation process, to increase the steel durability in oxidative and corrosive environments, as well as its mechanical strength. Micro-indentation and the coating impact test were used to characterize the hardness and fatigue properties of the film respectively. The coating corrosion resistance versus the one of the uncoated P91 steel was tested in a salt spray chamber. The coating performance was characterized by optical and scanning electron microscopy to check the consistency of the coated and uncoated surfaces and the oxidation extend. The results show an increased film strength, good fatigue performance and adequate corrosion resistance.


2017 ◽  
Vol 751 ◽  
pp. 119-124
Author(s):  
Kanokwan Saengkiettiyut ◽  
Pranee Rattanawaleedirojn ◽  
Adisak Thueploy ◽  
Jumpot Wanichsampan ◽  
Yuttanant Boonyongmaneerat

In this work, microstructure and corrosion properties of zinc electroplated steel before and after black chromating was investigated. The test samples were prepared by electrodeposition process, using a commercially-available alkaline electrolyte. Subsequently, the galvanized samples were applied with a black chromate-based passivation layer and a clear top-coat layer. Their microstructures were examined using X-ray diffractometry and scanning electron microscopy. The corrosion resistance of the samples was assessed with the salt spray test, following the ASTM B117, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization in 5 wt.% NaCl solutions. The study showed that zinc electroplated steels exhibit (110) crystallographic orientation. The passivation and top-coat layers did not affect the microstructure of the zinc layer, and covered uniformly on the zinc layer for all sets of samples. The corrosion resistant results obtained from salt spray testing and electrochemical testing revealed that the microstructure of zinc coatings prepared by using different applied current did not influence on their corrosion resistance markedly. While black passivation followed by top coating provided a significant improvement on corrosion resistance of the coatings.


2020 ◽  
Vol 1 (2) ◽  
pp. 12-17
Author(s):  
Chao Zhang ◽  
Xiang Yin ◽  
Chun Qing

The objective of the study was to conduct the comparative analysis of steel types corrosion resistance. Three selected steel types were used in the study. The selected types were structural steel, stainless steel, and MMFX steel. The methodology we adopted is that we evaluated the steel parts resistance towards corrosion by doing in-salt spray experiment and the immersion of aqueous solution of sodium chloride. For salt spray test, we used guidelines by ASTM B117. This practice provides a controlled corrosion environment which is used for exposing specimen to salt spray chamber. For immersion test, test specimens are analyzed at regular time interval as the first rust is appeared. For carbon steel, we used three specimen and mostly initial rust appeared in initial 13 to 15 hours. For stainless steel, inter granular corrosion were analyzed. The results show that the first cycle started after about 46 hours; the second cycle started about 1% and the third cycle started with the rage of about 2 to 30%. For MMFX 2 steel, the results show that for MMFX carbon steel, the chloride threshold ratio is about 6 times higher than black bars and more than double of other types. The conclusion of the study is that in big structures like bridges, the MMFX steel should be used.


Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1357 ◽  
Author(s):  
Jaromír Wasserbauer ◽  
Martin Buchtík ◽  
Jakub Tkacz ◽  
Stanislava Fintová ◽  
Jozef Minda ◽  
...  

The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50, 75 and 100 µm were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91 magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing thickness of the Ni-P coating was observed.


2020 ◽  
Vol 22 (4) ◽  
pp. 263
Author(s):  
Ye.G. Bakhytzhan ◽  
A.M. Argimbayeva ◽  
G.S. Rakhymbay ◽  
R.Dzh. Jumanova ◽  
Kh. Avchukir ◽  
...  

Polyanisidine (POA) and polyanisidine-molybdate (POA−MoO42-) coatings have been successfully synthesized on steel grade СТ3 from aqueous solutions of oxalic acid by electrochemical method using cyclic voltammetry. The morphology and composition of these films were characterized by scanning electron microscopy (SEM) and energydispersive X-ray (EDAX) methods. It was proven that the introduction of MoO42- into the polyanisidine matrix raised the corrosion resistance of the POA coating and also improved its adhesion properties. The protective properties of steel grade CT3 with POA and POA-MoO42- films were studied using potentiodynamic polarization in 3.5% NaCl solution. The results showed that ions improve anti-corrosion properties of POA films.


2015 ◽  
Vol 227 ◽  
pp. 147-150
Author(s):  
Agnieszka Nagrabia ◽  
Maciej Sowa ◽  
Wojciech Simka ◽  
Artur Maciej

Zn-Ni and Zn-Co monolayer and Zn-Ni/Zn-Co multilayer (from 2 to 128 layers) alloy coatings were formed on steel substrate by electrodeposition from acidic Zn-Ni bath and neutral Zn-Co bath. Samples were tested in salt chamber for corrosion resistance in neutral salt spray. Open circuit potential measurement and gravimetric study of corrosion were carried for samples immersed in the 5% NaCl solution.It was found that coatings of Zn-Ni surface layer occurred higher corrosion resistance then the coatings of Zn-Co surface layer. Sixteen-layer coating with Zn-Ni surface layer proved to be most effective in protecting the steel substrate. Zn-Ni monolayer showed the lowest corrosion potential, which affects the corrosion properties. Sample weight changes during exposure to a corrosive environment are related to digestion of the coating and the formation of corrosion products.


2014 ◽  
Vol 618 ◽  
pp. 109-113
Author(s):  
Wei Jiang ◽  
Qing Jun Chen ◽  
Jun Shen ◽  
Fa Bi Zhang ◽  
Xian Liang Zhou ◽  
...  

For the bulk amorphous Fe24+xCo24-xCr15Mo14C15B6Y2(X=0, 2, 4, 6 and 17) alloy, the corresponding corrosion properties associated with glass forming ability (GFA) have been carried out. Neutral salt spray corrosion test results show that the Fe28Co20Cr15Mo14C15B6Y2 alloy has the minimum corrosion rate, followed by Fe26Co22Cr15Mo14C15B6Y2, Fe24Co24Cr15Mo14C15B6Y2, Fe30Co18Cr15Mo14C15B6Y2, Fe41Co7Cr15Mo14C15B6Y2 and Ti6Al4V alloys. Specifically, the Fe28Co20Cr15Mo14C15B6Y2 alloy with the highest GFA also has the best corrosion resistance. With the increasing of Co addition, the corrosion resistance of the FeCo-based bulk metallic glasses is first increases and then decreases, which has the same trend of GFA with the change of Co elements. Furthermore, corrosion morphology are different for FeCo-based BMGs with different Co content.


2012 ◽  
Vol 185 ◽  
pp. 113-115 ◽  
Author(s):  
R. Mohanraj ◽  
Kumar D. Rajesh ◽  
Kumar M. Yeswanth ◽  
N. Arivazhagan ◽  
Ramkumar K. Devendranath ◽  
...  

This paper investigated the influence of filler materials such as E308L and ENiCu-7 utilized in the GTA welded AISI 304 with respect to mechanical and corrosion properties. It was found that E308L had shown better tensile strength and corrosion resistance as compared to ENiCu-7. A comparative analysis had been made on the different regions of the weldment subjected to cyclic air oxidation at 700°C. The corrosion products were examined using XRD and SEM/EDAX analysis.


2021 ◽  
pp. 23-33
Author(s):  
A.V. Sviridov ◽  
◽  
A.N. Afanasyev-Khodykin ◽  
I.A. Galushka ◽  
◽  
...  

Presents the results of work on assessing the corrosion resistance of brazed joints of corrosion-resistant steels used in the manufacture of fuel manifolds for gas turbine engines in a salt spray chamber. The main types of corrosion damage of brazed joints made with brazing alloys of various types (based on copper and nickel) have been identified. The influence of the type of brazing alloy and the grade of the brazed materials on the nature of corrosion damage to brazed joints is determined. Based on the research results, assumptions have been made about the mechanism of occurrence and development of corrosion damage in brazed joints of various materials.


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