scholarly journals Diffusion Coatings as Corrosion Inhibitors

2016 ◽  
Vol 3 (1) ◽  
pp. 40-44
Author(s):  
Radoslav Ivanov ◽  
Tsveteslava Ignatova-Ivanova
Keyword(s):  
Corrosion Resistance ◽  
Diffusion Saturation ◽  
Metal Base ◽  
Diffusion Coatings ◽  
Diffusion Layers ◽  
Steel Container ◽  
Structure Thickness ◽  
Metal Products ◽  
Composition Structure ◽  
Harmful Effects

Abstract Corrosion is the cause of irretrievable loss of huge amounts of metals and alloys. The harmful effects of corrosion can be reduced significantly by applying appropriate methods of corrosion protection. One method to protect metals against corrosion is the formation of diffusion coatings on them. High corrosion resistance is typical for the boride diffusion layers. Aluminothermy is one of the main methods for diffusion saturation of the surface of metal products with various elements, including boron, and under certain conditions with aluminum, too. Samples of steel 45 were put to aluminothermic diffusion saturation with boron in a pressurized steel container at a temperature of 1100K, for 6 hours in powdered aluminothermic mixtures. The content of В2О3 in the starting mixtures decreased from the optimum - 20% to 0%, and the content of Al and the activator - (NH4)2.4BF3 is constant, respectively 7% and 0.5%. Al2O3 was used as filler. The borided samples were tested for corrosion resistance in 10% HCl for 72 hours. The results show that their corrosion resistance depends on the composition of the starting saturating mixture (mainly on the content of В2О3), and respectively on the composition, structure, thickness and degree of adhesion of the layer to the metal base.

scholarly journals STRUCTURE AND PROPERTIES OF BORID AND CARBORBORIDE COATINGS FORMED IN MELTS OF BORON AND CARBON SALTS

2020 ◽  
pp. 80-86
Author(s):  
V. Teldekov ◽  
L. Gurevich
Keyword(s):  
Corrosion Resistance ◽  
Heat Resistance ◽  
Structure And Properties ◽  
Comparative Tests ◽  
Diffusion Coatings ◽  
Diffusion Layers ◽  
Melt Composition ◽  
Hcl Solution

Qualitative diffusion layers were obtained by boroning steels 40Cr, 20CrNi3, 25CrMnTi at 950 ° C for 3 to 5 hours in a melt based on borax. The melt composition is determined for the simultaneous diffusion of boron and carbon into steel. Comparative tests of heat resistance and corrosion resistance of the obtained diffusion coatings are carried out. Diffusion layers based on iron borides had the best corrosion resistance during long-term tests in a 10 % HCl solution. Corrosion resistance of hardened cemented steel 25CrMnTi is 5-10 times lower than that of boride layers.

MAGNESIUM AZ91C

Alloy Digest ◽  
1960 ◽  
Vol 9 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Casting Alloy ◽  
Bearing Strength ◽  
Good Strength ◽  
Temperature Performance ◽  
Metal Products

Abstract MAGNESIUM AZ91C is a general sand casting alloy having good strength, pressure tightness and ductility. It was designed to give optimum properties in both the T4 and T6 tempers. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and and bearing strength It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Mg-47. Producer or source: The Dow Metal Products Company.

HOWMET No. 3

Alloy Digest ◽  
1968 ◽  
Vol 17 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Base Alloy ◽  
High Hardness ◽  
Heat Treating ◽  
High Heat ◽  
Cobalt Base Alloy ◽  
Metal Products ◽  
Cobalt Base

Abstract HOWMET No. 3 is a cobalt-base alloy having high hardness and compressive strength, high heat and corrosion resistance, along with excellent abrasion and wear resistance. It is recommended for bushings, scrapers, valve parts, and other machinery components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Co-56. Producer or source: Howmet Corporation Metal Products Division.

Increasing of Corrosion Resistance for Metal Products of Livestock Premises

2021 ◽  
Vol 316 ◽  
pp. 758-764
Author(s):  
M.Yu. Karelina ◽  
S.M. Gaidar ◽  
D.I. Petrovskiy
Keyword(s):  
Corrosion Resistance ◽  
Low Carbon Steel ◽  
Industrial Complex ◽  
Low Carbon ◽  
Inhibitor Concentration ◽  
Complex Action ◽  
Protection Efficiency ◽  
Degree Of Protection ◽  
Metal Products ◽  
Increase Corrosion Resistance

The purpose of the work was to identify and analyze the causes of corrosion destruction of metal products, used in conditions of animal keeping on farms of the agro-industrial complex, and to find effective methods of combating it. In order to increase corrosion resistance of metal products of livestock farms and complexes, it is proposed to use the developed preparation, which has fungicidal and anticorrosive properties simultaneously. The rate of metal products corrosion during the experiment was evaluated by the museum strain of Aspergillus niger fungi. The article describes the causes of fungal corrosion, the principle of its effect on metals; proposes an inhibitor of complex action for the control of electrochemical and bio-corrosion. The protection efficiency of metal products by the inhibitor was evaluated by the corrosion braking coefficient and the degree of protection. The effect of inhibitor concentration on the rate of low carbon steel bio-corrosion has been studied. It has been proven that the rate of corrosion processes decreased by 50 times, when exposed to a medium, contaminated with fungus spores, on metal samples treated with an inhibitor.

On a possibility of replacing grey cast iron for manufacturing cast elements of electrolyzer gas collecting bell

2021 ◽  
Vol 77 (9) ◽  
pp. 1063-1070
Author(s):  
A. A. Usol’tsev ◽  
N. A. Kozyrev ◽  
S. V. Knyazev ◽  
A. I. Kutsenko ◽  
A. R. Mikhno
Keyword(s):  
Corrosion Resistance ◽  
Cast Iron ◽  
Heat Resistance ◽  
High Strength ◽  
Grey Cast Iron ◽  
Simultaneous Formation ◽  
Metal Base ◽  
Spherical Graphite ◽  
Grey Cast ◽  
Graphite Inclusions

The main process leading to the destruction of the cast elements of gas-collection bell of electrolyzer, made of grey cast iron, is the oxidation of iron by oxygen, SO2 gas and sulfur vapors to form magnetite, hematite and pyrrhotin. The simultaneous formation of iron oxides and sulfides does not prevent further corrosion, since scale is formed with a loose structure that does not have protective properties. Reducing the length of the interfacial boundaries inside the material of the cast enables to reduce the rate of corrosion destruction, which can be achieved by modifying the cast iron to change the shape of graphite inclusions, i.e. obtaining high-strength cast iron with a spherical shape of graphite inclusions. However, the obtaining spherical graphite in cast iron using magnesium modification does not exclude the access of aggressive gases to the surface of the products and the possibility of their diffusion along the grain boundaries. It was shown that alloying can be an alternative, which leads not only to the exclusion of lamellar secretions of graphite in the structure of cast iron, but also to the formation of surface oxide layers based on the alloying element preventing the corrosion. Alloying with chromium gives cast iron high abrasive resistance due to the presence of a carbide component in the structure, as well as corrosion resistance due to the alloying of the metal base, heat resistance due to increasing the electrochemical potential of the metal base and creating a strong neutral oxide film on the surface of the castings, heat resistance, etc. An experimental comparative analysis of the corrosion resistance of cast iron used for manufacturing of gas collecting bell of electrolyzers showed that chromic cast iron ЧХ3 has a higher corrosion resistance than high-strength cast iron with spherical graphite ВЧ50 and much higher than grey cast iron with lamellar graphite. However, chromic cast iron ЧХ3 has low casting properties, is very sensitive to the cooling rate and has a large heterogeneity in structure, which makes it difficult to use it for the manufacture of gas collecting bell of electrolyzers.

The Microstructure and Properties of CrNx Films Synthesized by Unbalanced Magnetron Sputtering

2008 ◽  
Vol 373-374 ◽  
pp. 176-179
Author(s):  
Yan Ping Wu ◽  
Yong Xiang Leng ◽  
Sun Hong ◽  
Sheng Fa Zhu ◽  
Nan Huang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Corrosion Properties ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
Wear And Corrosion ◽  
Structure Thickness ◽  
Wear And Corrosion Resistance ◽  
N2 Flow Rate

CrNx film was widely used in mechanical engineering field because of its excellent anti-wear and corrosion resistance properties. While most of research was focused on mechanical properties, little attention had been paid to the corrosion resistance and residual stress of CrNx film . In this paper, CrNx films were deposited on silicon wafer (100) and iron substrate by unbalanced magnetron sputtering system (UBMS) at different N2 flow. Then the structure, thickness, residual stress, micro-hardness, wear-resistance and anti-corrosion properties of CrNx films were investigated. The results showed that the phase composition of CrNx films transformed from Cr, single phase Cr2N, Cr2N and CrN coexist to single CrN with the N2 flow rate increasing. The CrNx films composed with Cr2N phase, which deposited at 6 sccm N2 flow, had the highest microhardness and had higher compressive residual stress. Whereas the CrNx films with CrN and Cr2N phase coexist had the best wear and corrosion resistance.

scholarly journals Effect of Inclusions on the Corrosion Properties of the Nickel-Based Alloys 718 and EP718

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1177 ◽  
Author(s):  
Ekaterina Alekseeva ◽  
Andrey Karasev ◽  
Pär G. Jönsson ◽  
Aleksey Alkhimenko
Keyword(s):  
Corrosion Resistance ◽  
Alloy 718 ◽  
Corrosion Properties ◽  
Electrolytic Extraction ◽  
Operational Conditions ◽  
Large Size ◽  
Size Number ◽  
Resistance To Deformation ◽  
The Given ◽  
Harmful Effects

Inclusions in steels and alloys are known to lower the resistance to deformation, as well as to lower the mechanical, corrosion and other properties. Studies of inclusions in nickel-based alloys are important since these materials could suffer from corrosion degradation in harsh operational conditions. This, in fact, could lead to a pitting initiation around the inclusions. Two industrial Ni-based alloys (alloy 718 and EP718) were investigated to determine the harmful effects of different inclusions on the corrosion resistance of Ni-based alloys. Specifically, the inclusion characteristics (such as composition, morphology, size, number and location) were determined for inclusions collected on film filters after electrolytic extraction and dissolution of a metal matrix around different inclusions on surfaces of metal samples after electrolytic extraction (EE). It was found that both Ni-based alloys contain various inclusion types: carbides (large size NbTi-C and small multicomponent carbides), nitrides TiNb-N and sulphides (TiNb-S in EP718 alloy). The most harmful effects on the corrosion resistance of metal were detected around sulphides and small carbides containing Mo, W, Cr. Dissolution effects were also observed around large carbides and nitrides, especially around inclusions larger than 10 µm. Moreover, the dissolution of a matrix around inclusions and clusters located on the grain boundaries were found to be 2.1–2.7 times larger compared to inclusions found inside of grains of the given alloy samples.

Structure and Property of Micro Arc Oxidation Ceramic Coatings on Al Alloy in K2ZrF6 Solution

2010 ◽  
Vol 105-106 ◽  
pp. 505-508 ◽  
Author(s):  
Zhen Dong Wu ◽  
Zhong Wen Yao ◽  
Fang Zhou Jia ◽  
Zhao Hua Jiang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Friction And Wear ◽  
Ceramic Coatings ◽  
Al Alloy ◽  
Structure And Property ◽  
Micro Arc Oxidation ◽  
Disk Friction ◽  
Composition Structure

The coatings containing zirconia were produced on LY12 Aluminium alloy by micro-arc oxidation in K2ZrF6 and NaH2PO2 solution. The composition, structure, hardness, friction and wear resistance and corrosion resistance of the coating were studied by XRD, SEM, EDS, ball-on-disk friction tester and electrochemical analyzer, respectively. The results show that coating was composed of m-ZrO2 and t-ZrO2. There were a large amount of Zr and O and a little Al, P and K in the coating. The thickness of coating prepared for 3h was 168μm and the maximum value of the hardness was up to 16.75GPa. The friction and wear resistance and corrosion resistance were improved, compared with the LY12 aluminium alloy substrate.

scholarly journals A High-Performance Corrosion-Resistant Iron-Based Amorphous Metal - The Effects of Composition, Structure and Environment on Corrosion Resistance

2006 ◽  
Vol 985 ◽  
Author(s):  
Joseph Collin Farmer ◽  
J. Haslam ◽  
D. Day ◽  
T. Lian ◽  
C. Saw ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Passive Film ◽  
High Performance ◽  
Amorphous Metal ◽  
General Corrosion ◽  
Film Stability ◽  
Neutron Absorber ◽  
High Boron ◽  
Effective Neutron ◽  
Composition Structure

ABSTRACTThe passive film stability of several Fe-based amorphous metal formulations have been found to be comparable to that of high-performance Ni-based alloys, and superior to that of stainless steels, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. Chromium (Cr), molybdenum (Mo) and tungsten (W) provide corrosion resistance; boron (B) enables glass formation; and rare earths such as yttrium (Y) lower critical cooling rate (CCR). The high boron content of this particular amorphous metal also makes it an effective neutron absorber, and suitable for criticality control applications, as discussed in companion publications. Corrosion data for SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) is discussed here.

Sign in / Sign up

Export Citation Format

Share Document