scholarly journals Electrochemical Corrosion Properties of 316LSS and Titanium in Various Corrosion Media

2020 ◽  
Vol 6 (7) ◽  
pp. 1-4
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Corrosion ◽  
Corrosion Damage ◽  
Corrosion Products ◽  
Corrosion Properties ◽  
Corrosion Studies ◽  
Spectroscopy Studies ◽  
Selection Of ◽  
Metal And Alloys

The work was carried on biomedical implants and the selection of correct methods for corrosion studies and study of the corrosion products, electrochemical methods are used to determine the metal and alloys corrosion rate and to characterize the corrosion damage. Microscopy and spectroscopy studies are used for characterization and determination of thickness and nature of the corrosion products.

scholarly journals Determination of corrosion characteristics of steel protected by a latex coating in Nyquist coordinates

2021 ◽  
Vol 25 (4) ◽  
pp. 519-527
Author(s):  
A. А. Yakovleva ◽  
E. A. Antsiferov ◽  
S. V. Sadlovsky
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Corrosion Process ◽  
Working Environment ◽  
Corrosion Properties ◽  
Corrosion Studies ◽  
Limiting Stage ◽  
Reference Samples

This paper investigates the corrosion process of steel St3 protected by latex coating 69Б-2к produced by Kapitel Ltd (Irkutsk). Electrochemical impedance spectroscopy of steel samples with a threefold latex coating was carried out by a PGSTAT302 + FRA2 potentiostat-galvanostat equipped with NOVA 1.8. Corrosion studies were carried out under thermostating (25 ± 0.2°C) of the working environment. The corrosion rate was determined by gravimetric tests with the recording of mass changes over a controlled period of time (up to 10 h). A 3% sodium chloride solution was used as the electrolyte. In most cases, the mechanism of the corrosion process can be reliably described by an equivalent electrochemical circuit with Warburg and Cotangent Hyperbolic elements, which simulates the reaction at the electrodeelectrolyte interface. According to the conducted visual, gravimetric and electrochemical studies of the St3 steel surface protected with the 69B-2k latex coating, the impedance remains almost unchanged for a prolonged period of time. It is obvious that the surface process is associated with the limiting stage of solvent diffusion through the protective layer. Thus, the electrochemically determined corrosion rate was low and amounted to ~ 0.164 mm/year (for reference samples – 0.75 mm / year). Our studies confirmed high protective qualities of latex 69B-2k. The corrosion properties of the coating under study are related to its composition, the components of which not only exhibit good adhesion, but are also active with respect to other interactions, including chemical interactions of the components with each other and with metal surface crystallites. The model calculation of the process, carried out using the developed equivalent electrochemical circuit, describes experimental curves in Nyquist coordinates almost comprehensively.

scholarly journals Dissolution of chromium in sulfuric acid

2002 ◽  
Vol 67 (11) ◽  
pp. 777-782 ◽  
Author(s):  
Dragutin Drazic ◽  
Jovan Popic
Keyword(s):  
Corrosion Rate ◽  
Room Temperature ◽  
Corrosion Potential ◽  
Analytical Data ◽  
Electrochemical Corrosion ◽  
Spectrophotometric Analysis ◽  
Weight Loss Method ◽  
Loss Method ◽  
Anomalous Dissolution

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1M Na2SO4 + H2SO4 (pH1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II):Cr(III)?7:1. This process was stable over 4h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, "anomalous" dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process.

Influence of various sterilization methods on hardness, grain size and corrosion rate of a Mg6Ag-alloy

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Frank Feyerabend ◽  
Martin Johannisson ◽  
Zhidan Liu ◽  
Regine Willumeit-Römer
Keyword(s):  
Grain Size ◽  
Corrosion Rate ◽  
Optimum Ratio ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Materials Properties ◽  
Physiological Conditions ◽  
Alloying System ◽  
Dry Heat

AbstractSterilization is a necessary step for all implant materials. Different methods can influence the materials properties. Especially important for magnesium as degradable materials is the determination of the corrosion properties. In this study the influence of 70% ethanol, glutaraldehyde, autoclaving, dry heat, UV-, gamma- and electron beam-irradiation on mechanical and corrosion parameters were analyzed. As mechanical parameters hardness and grain size were determined. The corrosion rate under physiological conditions, weight of the corrosion layer and corrosion morphology was determined. It could be demonstrated that irradiation treatments and 70% ethanol are suitable methods, as they decrease the corrosion rate. Heat-introducing methods (autoclaving and dry heat) acted as incomplete ageing treatments on this alloy and therefore increased the corrosion rate. Furthermore, osmolality showed a better correlation to the actual corrosion rate than the pH. Therefore an optimum ratio between alloying system, implant and sterilization method has to be established, depending on the intended application.

scholarly journals Corrosion of Biocompatible Mg66+xZn30-xCa4 (x=0.2) Bulk Metallic Glasses

2016 ◽  
Vol 61 (2) ◽  
pp. 807-810 ◽  
Author(s):  
R. Nowosielski ◽  
K. Cesarz-Andraczke ◽  
P. Sakiewicz ◽  
A. Maciej ◽  
A. Jakóbik-Kolon ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
X Ray Diffraction ◽  
Electrochemical Tests ◽  
Simulated Environment ◽  
Corrosion Studies ◽  
Physiological Fluid

Abstract The aim of this paper was to investigate the corrosion resistance of Mg66Zn30Ca4 and Mg68Zn28Ca4 metallic glasses and evaluate the ability of this amorphous alloy use for medical applications as biodegradable medical implants. Taking into account the amount of Mg, Zn, Ca elements dissolved in multielectrolyte physiological fluid (MPF) from Mg66+xZn30-xCa4 (x=0.2) alloys the daily dose of evolved ions from alloys components was determined. Additional goal of the paper was determination of corrosion rate (Vcorr) and amount of hydrogen evolved from amorphous magnesium alloys in simulated environment of human body fluids during 24h immersion and during electrochemical tests. Corrosion studies were done in the multielectrolyte physiological fluid (MPF) at 37°C. The amount of hydrogen evolved [ml/cm2] and corrosion rate Vcorr [mm/year] of amorphous Mg66Zn30Ca4 and Mg68Zn28Ca4 alloys were compared. The work also presents characterization of Mg-based bulk metallic glasses structure in the form of 2 mm thickness plates. Samples structure was analyzed by means of X-ray diffraction. Fracture and surface morphology of magnesium alloy samples were identified using scanning electron microscopy.

Corrosion Inhibition Mechanism of Magnetic Field on Carbon Steel

2010 ◽  
Vol 152-153 ◽  
pp. 353-356
Author(s):  
Peng Zhang ◽  
Gang Chen ◽  
Bin Guo ◽  
Shu Kang Cheng
Keyword(s):  
Magnetic Field ◽  
Corrosion Rate ◽  
Sea Water ◽  
Electrochemical Corrosion ◽  
Water Relation ◽  
Corrosion Products ◽  
Alternating Magnetic Field ◽  
Inhibition Mechanism ◽  
X Ray Diffraction ◽  
Corrosion Morphology

The current research explores the effect of alternating magnetic field on corrosion rate and products compositions of 45 steel, by use of electrochemical test, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The calculated inhibition efficiency of the alternating magnetic field based on electrochemical corrosion rate is up to 16.66%. Electrochemical corrosion morphology and surface products were also discussed. The surface of specimen is uniform and compact in magnetized sea water relation to that in 3.5% NaCl solution and sea water. The corrosion products of 45 steel in sea water are FeCl2•4H2O, Fe(OH)3 and FeOOH. However, the corrosion products of 45 steel in magnetized sea water are FeOOH, Fe3O4 and FeCl3•6H2O chiefly.

Study and Characterization of Mechanical and Electrochemical Corrosion Properties of Plasma Sprayed Hydroxyapatite Coatings on AISI 304L Stainless Steel

2018 ◽  
Vol 35 ◽  
pp. 20-34 ◽  
Author(s):  
Vikas Rattan ◽  
T.S. Sidhu ◽  
Manoj Mittal
Keyword(s):  
Mechanical Properties ◽  
Electrochemical Corrosion ◽  
304L Stainless Steel ◽  
Corrosion Properties ◽  
Aisi 304L ◽  
Hydroxyapatite Coatings ◽  
Corrosion Studies ◽  
Aisi 304L Stainless Steel ◽  
Ss Substrates ◽  
Plasma Sprayed

The use of hydroxyapatite coatings is limited by their inferior mechanical properties such as brittle nature, low wear resistance, abrasion, fatigue, and hardness. This ultimately leads to the wear and early rupture of the hydroxyapatite coating on the implant. The main objective of this study is to improve the mechanical properties of hydroxyapatite by using additional reinforcement material such as alumina (Al2O3). The HAp powder has been reinforced with 15wt% Al2O3and its effect on the properties of HAp coatings has been studied. The HAp and HAp +15 wt% Al2O3coatings were deposited on AISI 304 L SS substrates using the plasma spraying technique. The morphology of the coatings developed was characterized using SEM/EDX, XRD, and FTIR techniques. The corrosion resistance studies have been performed on uncoated and coated samples and found that HAp coated samples show superior resistance against corrosion (ICorr= 0.538 μA) than uncoated (ICorr= 3.550 μA) and HAp+15 wt% Al2O3coated (ICorr= 1.440 μA) samples when electrochemical corrosion studies were performed in Ringer’s solution. Surface roughness and microhardness were found to increase with the addition of Al2O3. Crystallinity (%) of the HAp coatings and HAp+15 wt% Al2O3coatings increases after the corrosion testing.

Electrochemistry of Active Chromium: Part 1—Anomalous Corrosion and Products of Chromium Dissolution in Deaerated Sulfuric Acid

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 297-303 ◽  
Author(s):  
D. M. Dražić ◽  
J. P. Popić
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Electrochemical Corrosion ◽  
Metal Corrosion ◽  
Chemical Dissolution ◽  
Rate Measurement ◽  
Electrochemical Processes ◽  
Corrosion Rate Measurement ◽  
Anomalous Dissolution

Abstract Chromium corroding in deaerated aqueous solution of sulfuric acid (H2SO4; pH 1 to 3) produces Cr(II) and Cr(III) ions simultaneously in the ratio 7:1, as well as H2. The corrosion potentials of electrochemically activated chromium are determined by the electrochemical processes as expected according to the Wagner-Traud model. However, the real rates of chromium corrosion determined by collecting evolved hydrogen, spectrophotometric determination of the accumulated Cr ions in the solution, or by weight-loss measurements are higher than the electrochemical dissolution rate by up to 12 times for pH 1.0. The effect is smaller for higher pH. This was due to the simultaneous “anomalous” (or chemical) dissolution process of the direct chemical reaction of Cr with H2O molecules, as proposed some time ago by Kolotyrkin and coworkers. Since “anomalous” dissolution cannot be detected by electrochemical means, it has been pointed out that in the presence of “anomalous” dissolution processes during metal corrosion, electrochemical corrosion rate measurements should be taken only as approximate, while the level of approximation should be determined by some other direct corrosion rate measurement method.

Densification and Corrosion Studies of as-Sintered-Swaged Al Composite Preforms

2014 ◽  
Vol 911 ◽  
pp. 67-71
Author(s):  
Ananthanarayanan Rajeshkannan ◽  
Alok Sharma
Keyword(s):  
Corrosion Rate ◽  
Carbide Particle ◽  
Initial Density ◽  
Corrosion Properties ◽  
Corrosion Studies ◽  
Al Composite

The classical P/M technique was used to produce composites of Al-2WC-4Fe3C, Al-2WC-8Fe3C and Al-2WC-12Fe3C and it is further subjected to hot upsetting to evaluate densification and corrosion characteristics.Process parameters such as initial density, preform geometry and deformation media were kept constant to analyse this behaviour. The as-sintered compacts were subjected to swaging to different height strains, thus expected to eliminate residual porositiesout of classical P/M technique consequently improve its densification and corrosion characteristics. As the known limitation of the classical P/M process is the presence of porosity that restricts structural and corrosion related applications. It is observed from the results that strain induced improves the density substantially, which eventually promoted anti-corrosion properties. Further prediction was the addition of carbide particle in pure Al decreases the densification and increases the corrosion rate.

Study on Corrosion Properties of Medical Mg-Zn Alloy

2018 ◽  
Vol 777 ◽  
pp. 607-611
Author(s):  
Zhi Ling Wang
Keyword(s):  
Simulated Body Fluid ◽  
Corrosion Rate ◽  
Body Fluid ◽  
Body Fluids ◽  
Corrosion Products ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Zn Content ◽  
Simulated Body Fluids ◽  
Zn Alloy

Casting Mg-Zn alloy was corroded on the surface and analyzed the corrosion morphology and corrosion properties under different corrosion conditions. The results show that Mg-Zn alloy is unevenly by corrosion in simulated body fluids and the corrosion products are brittle and easy to break. With the increase of Zn content in Mg-Zn alloy, the corrosion rate of casting Mg-Zn alloy in simulated body fluid is improved obviously.

scholarly journals Impact of Sterilisation and Strain Hardening in Drawing Process on Resistance to Electrochemical Corrosion of Wires Intended in Cardiology

2016 ◽  
Vol 61 (1) ◽  
pp. 249-252 ◽  
Author(s):  
J. Przondziono ◽  
E. Hadasik ◽  
W. Walke ◽  
J. Mendala
Keyword(s):  
Stainless Steel ◽  
Work Hardening ◽  
Electrochemical Corrosion ◽  
Cold Drawing ◽  
Drawing Process ◽  
Corrosion Properties ◽  
Water Steam ◽  
Anodic Polarisation ◽  
Artificial Plasma

The study presents results of tests of impact of work hardening in cold drawing process, surface treatment and sterilisation on resistance to electrochemical corrosion of wires made of stainless steel X2CrNiMo 17-12-2 intended for cardiology. Potentiodynamic tests were performed on the ground of registered anodic polarisation curves in artificial plasma solution. Static uniaxial tension test made the ground for determination of strength characteristics of wires and the flow curve. Functions presenting the change of polarisation resistance according to strain applied in drawing process were selected. Test results show deterioration of corrosion properties of wires with work hardening. Surface modification of passivated surface caused increase of resistance of stainless steel wires to electrochemical corrosion, whereas sterilisation with pressurised water steam deteriorated that resistance.

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