Investigation of the Initial Stage of Hot Dip Zinc Coatings on Iron Alloys with Various Silicon Contents

2013 ◽  
Vol 212 ◽  
pp. 121-126 ◽  
Author(s):  
Piotr Liberski ◽  
Adam Tatarek ◽  
Jacek Mendala
Keyword(s):  
Zinc Coating ◽  
Iron Alloys ◽  
Silicon Steel ◽  
Liquid Phases ◽  
Initial Stage ◽  
Coating Formation ◽  
Zinc Coatings ◽  
Solid Liquid ◽  
The Impact ◽  
Short Times

In this work tests on the course of zinc coating formation on model iron alloys with diversified silicon additions in molten zinc, with short times of contact at the solid-liquid border have been presented. The experiments were carried out at the temperature of 440°C. The assumed time of contact between solid and liquid phases was: 1, 4, 9, 14, 29, 59 seconds. The test stand was designed. The structure and thickness of coatings obtained on steel without silicon, on Sandelin steel and on high-silicon steel was defined. Based on the results we may ascertain that in the first stadium of the galvanizing process the impact of silicon upon the intensity of coating growth is small. Increased reactivity of silicon is already observed after about 29-59 seconds of the process.

The Impact of Zinc Coating Specifications on Corrosion Resistance аnd Durability of Steels

2019 ◽  
Vol 945 ◽  
pp. 740-745
Author(s):  
I.A. Kovalenko ◽  
D.V. Laskin ◽  
A.Y. Trifonova
Keyword(s):  
Corrosion Resistance ◽  
Statistical Analysis ◽  
Chemical Composition ◽  
Service Life ◽  
Zinc Coating ◽  
Useful Life ◽  
Galvanized Coating ◽  
Zinc Coatings ◽  
The Impact ◽  
High Chloride

The article contains the findings on impact of zinc coating specifications on corrosion resistance and service life of steels of various chemical composition used often in modern industries. Characteristics such as type, class, chemical compound and thickness of zinc-based coatings are also addressed. Experiments were performed in which corrosion rate and useful life of zinc coatings in probable operating-like conditions — i.e., in environments of varying degrees of corrosive power (humid and high-chloride environments) were determined. It has been established which one of the environments is the most corrosive for steels depending on the zinc-based coatings’ specifications. Qualitative (visual) and quantitative (gravimetric) assessment of corrosion resistance and service life of chosen steels is presented. Optimal hot dip galvanized coating specifications were determined using statistical analysis.

Resistance of Chromated Zinc Coatings to the Impact of Microscopic Fungi

1970 ◽  
Vol 17 (1) ◽  
pp. 20-26
Author(s):  
Albinas LUGAUSKAS ◽  
Irina DEMČENKO ◽  
Aušra SELSKIENĖ ◽  
Vidas PAKŠTAS ◽  
Bronius JASKELEVIČIUS ◽  
...  
Keyword(s):  
New Technologies ◽  
Acidic Solution ◽  
Protective Coatings ◽  
Zinc Coating ◽  
Surface Damage ◽  
Steel Plates ◽  
Atmospheric Conditions ◽  
Microscopic Fungi ◽  
Zinc Coatings ◽  
The Impact

Zinc coatings are used to protect metallic parts of automobiles from corrosion. Zinc protective coatings are often chromated additionally treating them in acidic solution of chromium compounds. In recent years new technologies were designed to deposit chromate films of various thickness and resistance on zinc surface from acidic solution of Cr(III) compounds. It has been noticed, that under atmospheric corrosion conditions microscopic fungi are present in the environment affect zinc coating. The aim of the presented study was to determine if zinc coatings treated with Cr(III) solution become more resistant to fungi influence or their resistance diminishes. The analysis of steel plates coated with a zinc film and treated in four different chromium solutions has shown that in all the specimens fungi of Cladosporium herbarium species were detected and their frequency of detection was quite high, sometimes up to 50 %. However, we failed to determine the regularities of distribution of some fungi on the surface of plates chromated in different solution. The comparison of changes in the surfaces of plates treated with the four solutions has shown that the plates treated in the Likonda 3Cr5 passivation solution changed least after being exposed to atmospheric conditions. Chromated plates contaminated with mixtures of different fungi and kept for 60 days at a temperature of (26 ±2) °C under humid conditions were examined by using a scanning electron microscope (EVO 5O XP Carl Zeiss STM AG, Germany) and the peculiarities of their surface damage were determined. The peculiarities of growth of some fungi species were determined on the plates chromated in the Likonda 3Cr5 and Cr(NO3)3*9H2O + malonic acid solutions. Under these conditions the fungi of Chrysosporium merdarium, Fusarium proliferatum, Paecilomyces lilacinus, Penicillium stoloniferum can either generate and promote the damage of metal surface or stabilize its corrosion processes.http://dx.doi.org/10.5755/j01.ms.17.1.243

scholarly journals Mechanical coating formed under conditions of vibration exposure

2020 ◽  
Vol 175 ◽  
pp. 05023 ◽  
Author(s):  
Vladimir Ivanov ◽  
Sergey Popov ◽  
Nikolai Dontsov ◽  
Galina Ekinil ◽  
Julia Oleynikova ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Mechanochemical Synthesis ◽  
Zinc Coating ◽  
Low Frequency ◽  
Vibration Exposure ◽  
Study Results ◽  
Coating Formation ◽  
Zinc Coatings ◽  
Coating Formation Mechanism ◽  
Mechanical Coating

The study results of the zinc coating obtained on the surface of metals in the process of mechanochemical synthesis, implemented in the conditions of vibrowave systems, are presented. The features of coating formation mechanism, an activating role in its formation of free-moving, under the influence of low-frequency vibrations, indenters, are disclosed. The advantages of applying zinc coatings method in comparison with traditional methods are shown.

RESTORATION OF MACHINE PARTS WITH GALVANIZED ZINC COATINGS

2020 ◽  
Vol 4 (141) ◽  
pp. 140-147
Author(s):  
MIKHAIL VIKHAREV ◽  
◽  
VLADIMIR YUDIN ◽  
VESELOVSKIY NIKOLAY ◽  
◽  
...  
Keyword(s):  
Current Density ◽  
Cathode Surface ◽  
Zinc Coating ◽  
Cathode Current Density ◽  
Research Purpose ◽  
Cathode Layer ◽  
Properties Of Coatings ◽  
Chemical Polarization ◽  
Cathode Current ◽  
Zinc Coatings

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.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

Modeling and Experiments of Laser Cladding With Droplet Injection

2005 ◽  
Vol 127 (9) ◽  
pp. 978-986 ◽  
Author(s):  
J. Choi ◽  
L. Han ◽  
Y. Hua
Keyword(s):  
Fluid Flow ◽  
Laser Cladding ◽  
Dynamic Motion ◽  
Cladding Layer ◽  
Melt Pool ◽  
Material Deposition ◽  
Modeling And Experiments ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Impact

Laser aided Directed Material Deposition (DMD) is an additive manufacturing process based on laser cladding. A full understanding of laser cladding is essential in order to achieve a steady state and robust DMD process. A two dimensional mathematical model of laser cladding with droplet injection was developed to understand the influence of fluid flow on the mixing, dilution depth, and deposition dimension, while incorporating melting, solidification, and evaporation phenomena. The fluid flow in the melt pool that is driven by thermal capillary convection and an energy balance at the liquid–vapor and the solid–liquid interface was investigated and the impact of the droplets on the melt pool shape and ripple was also studied. Dynamic motion, development of melt pool and the formation of cladding layer were simulated. The simulated results for average surface roughness were compared with the experimental data and showed a comparable trend.

scholarly journals The Impact of Heat Treatment on the Behavior of a Hot-Dip Zinc Coating Applied to Steel During Dry Friction

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 660
Author(s):  
Dariusz Jędrzejczyk ◽  
Elżbieta Szatkowska
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Dry Friction ◽  
Zinc Coating ◽  
Pin On Disc ◽  
The One ◽  
The Impact ◽  
Coating Hardness ◽  
Anticorrosion Properties

The analyzed topic refers to the wear resistance and friction coefficient changes resulting from heat treatment (HT) of a hot-dip zinc coating deposited on steel. The aim of research was to evaluate the coating behavior during dry friction after HT as a result of microstructure changes and increase the coating hardness. The HT parameters should be determined by taking into consideration, on the one hand, coating wear resistance and, on the other hand, its anticorrosion properties. A hot-dip zinc coating was deposited in industrial conditions (according EN ISO 10684) on disc-shaped samples and the chosen bolts. The achieved results were assessed on the basis of tribological tests (T11 pin-on-disc tester, Schatz®Analyse device, Sindelfingen, Germany), microscopic observations (with the use of optical and scanning microscopy), EDS (point and linear) analysis, and microhardness measurements. It is proved that properly applied HT of a hot-dip zinc coating results in changes in the coating’s microstructure, hardness, friction coefficient, and wear resistance.

scholarly journals Monitoring of the Impact of Lithium Nitrate on the Alkali–aggregate Reaction Using Acoustic Emission Methods

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Justyna Zapała-Sławeta ◽  
Grzegorz Świt
Keyword(s):  
Acoustic Emission ◽  
Initial Reaction ◽  
Lithium Nitrate ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Acoustic Activity ◽  
Initial Stage ◽  
Chemical Admixture ◽  
Different Characteristics ◽  
The Impact

The study analyzed the possibility of using the acoustic emission method to analyse the reaction of alkali with aggregate in the presence of lithium nitrate. Lithium nitrate is a chemical admixture used to reduce adverse effects of corrosion. The tests were carried out using mortars with reactive opal aggregate, stored under the conditions defined by ASTM C227. The acoustic activity of mortars with a corrosion inhibitor was referred to linear changes and microstructure of specimens in the initial reaction stages. The study found a low acoustic activity of mortars with lithium nitrate. Analysis of characteristic parameters of acoustic emission signals, combined with the observation of changes in the microstructure, made it possible to describe the corrosion processes. As the reaction progressed, signals with different characteristics were recorded, indicating aggregate cracking at the initial stage of the reaction, followed by cracking of the cement paste. The results, which were referred to the acoustic activity of reference mortars, confirmed that the reaction of opal aggregate with alkali was mitigated in mortars with lithium nitrate, and the applied acoustic emission method enabled the detection and monitoring of ASR progress.

A Multiple Aspirator for Separating Solid-Liquid Phases—Application to Radioimmunoassay

1976 ◽  
Vol 7 (9) ◽  
pp. 38-39
Author(s):  
Kenneth J. Schmidt ◽  
Ralph J. Kajdasz
Keyword(s):  
Liquid Phases ◽  
Solid Liquid

Predicting of atmospheric corrosivity and durability of structural materials. Part II. Impact of urban traffic pollution

2021 ◽  
Vol 26 (2) ◽  
pp. 25-33
Author(s):  
Joanna Kobus ◽  
Rafał Lutze
Keyword(s):  
Zinc Coating ◽  
Environmental Parameters ◽  
Structural Materials ◽  
Traffic Volume ◽  
Urban Traffic ◽  
Traffic Pollution ◽  
Street Traffic ◽  
The Impact

The results of the atmospheric corrosivity assessment in the immediate vicinity of streets of different traffic volume in Warsaw, Krakow and Katowice are derived . On the bases of annual exposures in 2014–2018 years an equation describing the impact of environmental parameters and street traffic volume on corrosion losses of zinc and zinc coating on steel was selected.

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