The protective properties of various phosphate coatings on steel

2007 ◽  
Vol 4 (11) ◽  
pp. 581-595 ◽  
Author(s):  
J. F. Andrew ◽  
S. G. Clarke ◽  
E. E. Longhurst
Keyword(s):  
Protective Properties ◽  
Phosphate Coatings

scholarly journals Obtaining Luminous Phosphate Coatings on Steel by Cold Method

2022 ◽  
Author(s):  
V.S. Konovalova
Keyword(s):  
Uniform Distribution ◽  
Organic Additives ◽  
Green Phosphor ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Steel Surfaces ◽  
Phosphate Film

Abstract. The possibility of obtaining luminous phosphate coatings on steel by cold method has been studied. Modified cold phosphating solutions containing organic additives (glycerin, trilon B, OS-20 emulsifier) were selected as the basis to maintain the pH, stabilize the solution and improve the quality and structure of the deposited coatings. To obtain the glow effect, a green phosphor based on Zn2SiO4 containing manganese as a sensitizer was added to the phosphating solution. During deposition, phosphate coatings are obtained that glow with spots, but constant mixing of the solution during deposition contributes to the uniform distribution of phosphor in the phosphate film. Luminous phosphate coatings have good protective properties, they can be used as an independent protection of steel surfaces from corrosion.

scholarly journals White Phosphate Coatings Obtained on Steel from Modified Cold Phosphating Solutions

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 70
Author(s):  
Evgeniy Rumyantsev ◽  
Varvara Rumyantseva ◽  
Viktoriya Konovalova
Keyword(s):  
Phase Composition ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Steel Product ◽  
Protective Properties ◽  
X Ray ◽  
Atomic Force ◽  
Phosphate Coatings ◽  
Average Grain Size ◽  
Microscope Images

The article presents a method for obtaining white phosphate coatings on steel by cold method. The deposition of protective phosphate coatings was carried out from solutions based on the preparation “Majef”, consisting of manganese and iron phosphates. To obtain phosphate films of white color, it is proposed to introduce zinc and calcium nitrates into phosphating solutions at the rate of 25–30 g/L. The surface of phosphate coatings was studied using the SolverP47-PRO atomic force microscope images, and the average grain size was determined. The structural and phase composition of phosphate coatings was been studied using X-ray diffraction analysis. The protective properties of phosphate coatings were estimated by corrosion rate indicators calculated from corrosion diagrams. Fine-crystalline uniform coatings were obtained from modified phosphating solutions at room temperature on steel. The white color of phosphate coatings is due to the increased content of phosphophyllite, hopeite, and parascholzite in their structural and phase composition. By applying protective phosphate coatings of white color on a steel product, corrosion can be slowed down by 4–4.5 times. However, white phosphate coatings are inferior in protective properties to unpainted coatings. The index of change in the mass of samples with white phosphate coatings because of corrosion is 0.371–0.41 g/(m2·h), and with unpainted coatings is 0.128 g/(m2·h).

scholarly journals Modified phosphate coatings applied to steel by cold method

2021 ◽  
Vol 2131 (4) ◽  
pp. 042027
Author(s):  
V Rumyantseva ◽  
V Konovalova ◽  
B Narmaniya
Keyword(s):  
Low Temperatures ◽  
Smooth Surface ◽  
Phosphate Coating ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Zinc Phosphates ◽  
Speed Up ◽  
Fine Crystalline Structure ◽  
Iron Manganese ◽  
Positive Effect

Abstract The deposition of phosphate coatings occurs on the surface of the product when it is immersed in a solution containing phosphoric acid. The formation of a film on the metal surface occurs during the deposition of insoluble two- and three-substituted phosphates of iron, manganese, and zinc from a solution. To speed up the process and conduct phosphating at low temperatures, nitrates, nitrites, and fluorides of active metals are introduced into the solution. Organic compounds, such as glucose, glycerin, Trilon A, and Trilon B, are buffer additives to maintain the pH of phosphating solutions in the range of 2.6-3.2. It was found that 10-15 minutes at a process temperature of 20-25 °C are sufficient for the formation of a protective phosphate coating from solutions containing modifiers. The content of zinc phosphates in the modified phosphate coatings is increased. Additives in cold phosphating solutions have a positive effect on the quality and protective properties of the resulting phosphate films. Modified phosphate coatings obtained by the cold method have a fine-crystalline structure, a smooth surface and low porosity.

scholarly journals Analysis of the corrosion behavior of steel reinforcement protected by phosphate coatings

2020 ◽  
Vol 329 ◽  
pp. 02001
Author(s):  
Viktoriya Konovalova
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Chloride Ions ◽  
Steel Reinforcement ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Additional Protection ◽  
Corrosion Of Steel ◽  
Kinetics Of

The influence of phosphate coatings on the corrosion behavior of steel reinforcement in a chloride-containing environment was studied to determine the need for additional protection against corrosion. The main indicators of the corrosion rate of steel reinforcement with phosphate coatings in chloride-containing solutions were determined, confirming the high protective properties of these coatings. It was found that the corrosion rate of steel reinforcement protected by phosphate coatings is reduced by 3 times. The processes of electrochemical corrosion of steel reinforcement of strength class A500S from steel grade St3ps in concrete under the influence of aggressive environments containing chloride ions (2 % MgCl2 solution and HCl solution with pH = 5) were studied. The kinetics of the corrosion process of steel reinforcement with and without protective phosphate coatings in solutions of various compositions has been studied. The change in mass of steel reinforcement protected by phosphate coatings is 3-4 times less than that of samples without coating. The surface potential of steel reinforcement with phosphate films changes significantly more slowly than that of unprotected samples.

scholarly journals Effect of Modifiers Introduced into Cold Phosphating Solutions on the Physical and Mechanical Properties of the Formed Phosphate Films

2021 ◽  
Vol 346 ◽  
pp. 01034
Author(s):  
Viktoriya Konovalova
Keyword(s):  
Low Temperatures ◽  
Traditional Method ◽  
Physical And Mechanical Properties ◽  
Active Centers ◽  
Protective Properties ◽  
Small Thickness ◽  
High Adhesion ◽  
Phosphate Coatings ◽  
Low Wear ◽  
Electrical Insulation Properties

This work is devoted to the study of the physical-mechanical and protective properties of modified phosphate coatings obtained on steel by cold method. Modifiers introduced into phosphating solutions are buffer additives, stabilize the phosphating process, allow the deposition of coatings at low temperatures, increase the number of active centers on the metal surface, resulting in fine-crystalline uniform coatings of small thickness. It was found that the corrosion rate of modified phosphate films is 2 times less than that of coatings obtained by the traditional method. When the temperature rises above 100 °C, the corrosion resistance of phosphate coatings decreases, and the satisfactory protective properties of the modified films are preserved when heated to 200 °C. Modified phosphate coatings have a high adhesion strength to the metal due to their small thickness. However, thin phosphate coatings have low wear resistance and medium electrical insulation properties.

scholarly journals Phosphate coatings as a way to protect steel reinforcement from corrosion

2019 ◽  
Vol 298 ◽  
pp. 00126 ◽  
Author(s):  
Sergey Fedosov ◽  
Varvara Roumyantseva ◽  
Viktoriya Konovalova
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Chloride Ions ◽  
Steel Reinforcement ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Mass Transfer Mechanism ◽  
Reinforced Steel ◽  
Kinetics Of

Phosphate coatings are successfully applied as a method of protecting steel products and structures from corrosion. Phosphate coatings mechanically prevent the entry of aggressive particles, such as chloride ions, to the surface of steel reinforcement. The parameters of corrosion rate of reinforcing steel in aggressive environment are determined by graphical method. The analysis of corrosion diagrams allows us to judge the effect of protective phosphate coatings on the kinetics of the corrosion process of steel reinforcement in environments of varying degrees of aggressiveness. The tests of the protective properties of phosphate coatings by contact corrosion method show that films with a finer crystal structure, as in modified phosphate coatings, are more resistant to anodic dissolution of steel. In parallel to determination of iron ions content in solutions the potential of steel reinforcement samples was measured. In samples protected by phosphate films, the potential change is not as sharp as in samples without coating, and the “dilution” of steel is slower. The study of anodic behavior of steel reinforcement of reinforced concrete, experimental study of the mass transfer mechanism of electrolyte supply to the surface of reinforced steel allow to develop practical recommendations to improve corrosion resistance and ensure the durability of reinforced concrete building materials.

Heat resistance of coatings metal deposited by nickel-manganese-molybdenum fl ux-cored wire

2020 ◽  
pp. 511-515
Author(s):  
E.N. Eremin ◽  
A.S. Losev ◽  
I.A. Ponomarev ◽  
S.A. Borodikhin
Keyword(s):  
Heat Resistance ◽  
Elevated Temperatures ◽  
Mass Gain ◽  
Cored Wire ◽  
Protective Properties ◽  
Average Mass ◽  
Magnetite Fe3o4 ◽  
Hematite Fe2o3 ◽  
Nickel Manganese

The heat-resistance of coating from deposited steel 15N8G6M3FTB at temperature of 900 °С is studied. It is established that this dependence occurs in the first hours. The average mass gain of the metal scale of such coating at 900 °С is 0.0128 kg/(m2 •h). It is shown that the basis of metal scale of the composition 15N8G6M3FTB is hematite Fe2O3 and magnetite Fe3O4, as well as MnO, which have protective properties. The number of other phase compounds with high protective properties is negligible. The coating from steel 15N8G6M3FTB can be used for applying to the surface of parts operating at elevated temperatures.

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