Tribocorrosion Mechanisms of Martensitic Stainless Steels

2021 ◽  
Vol 76 (3) ◽  
pp. 205-218
Author(s):  
A. Gassner ◽  
L. Waidelich ◽  
H. Palkowski ◽  
J. Wilde ◽  
H. Mozaffari-Jovein
Keyword(s):  
Corrosion Potential ◽  
Passive Layer ◽  
Material Structure ◽  
Material Degradation ◽  
Material Loss ◽  
Mechanical Destruction ◽  
Free Corrosion Potential ◽  
Strong Adhesion ◽  
Cathodic Region ◽  
The Stability

Abstract In the present study, the influence of the electrochemical potential on the tribocorrosion behavior of X20Cr13 in 0.15 molar NaCl-solution was investigated with the aid of a universal-tribometer under potentiostatic control. The resulting material loss was determined through laser confocal microscopy, while the morphology of the wear tracks and the deformation of the material structure near the surface were observed using light and scanning electron microscopy. The results showed a clear dependence of the material loss and the wear mechanisms from the applied potential. Within the cathodic region, a small amount of the material degradation could be attributed to a strong adhesion and resulting strain hardening as a consequence of an electrochemical weakening and mechanical destruction of the passive layer. The maximum of wear during polarization at the free corrosion potential under friction was explained by galvanic coupling between the wear track and the passive surface near the stability threshold between Fe2+-Ion and Fe2O3 development. Through increasing Polarization onto the free corrosion potential in the absence of friction and into the passive region, a decrease in material loss could be observed which is presumably attributed to the stable passive layer that inhibits electrochemical degradation and favors the formation of a grain refinement zone that slows down mechanical destruction.

Experimental Study of Propagation Stage of Pitting Corrosion of 20Cr13 Steel

2008 ◽  
Vol 38 ◽  
pp. 238-247
Author(s):  
A.D. Davydov ◽  
V.S. Shaldaev
Keyword(s):  
Pitting Corrosion ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Ph Value ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Pitting Potential ◽  
Free Corrosion Potential ◽  
External Power Source ◽  
Corrosion Of Steel

The initiation and development of pitting corrosion of steel 20Cr13 in the NaCl solutions with various concentrations, temperatures, and pH values are studied under the potentiostatic conditions and at the free-corrosion potential. The pitting and repassivation potentials are determined using the method of cycling voltammetry. In spite of the fact that thus determined pitting potential is more positive than the corrosion potential (the open-circuit potential Eo.c.), the long-term experiments, which were performed at the free-corrosion potential, showed that pitting corrosion takes place without imposing a potential using an external power source. It is concluded that the probability of pitting corrosion of steel should be determined by comparing the corrosion potential (the open-circuit potential) with the repassivation potential Erp. Steel 20Cr13 is prone to the pitting corrosion, because Erp is more negative than Eo.c.. In the potentiostatic experiments, the variation of the depth and diameter of pits and their number with the time and the effect of temperature and electrode rotation on the pit propagation are studied. The results, which were obtained at the free-corrosion potential, are much less reproducible. In this case, in contrast to the potentiostatic conditions, the pit depth increased only slightly and the pit width increased to a larger extent. The effect of concentration, pH value, and temperature of NaCl solutions on the pit propagation is considered. It is concluded that the data on the development of pitting corrosion under the potentiostatic conditions can be hardly extended to the conditions of free corrosion potential.

Hot Corrosion of Nimonic 105 in Sodium Sulfate-Sodium Chloride Melts

CORROSION ◽  
1981 ◽  
Vol 37 (7) ◽  
pp. 392-407 ◽  
Author(s):  
C. A. C. Sequeira ◽  
M. G. Hocking
Keyword(s):  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Analytical Methods ◽  
Sodium Sulfate ◽  
Hot Corrosion ◽  
Corrosion Potential ◽  
Free Corrosion Potential ◽  
Chloride Melts ◽  
Ni Alloy ◽  
Potential Decay

Abstract The corrosion behavior of Nimonic 105 in molten Na2SO4, NaCl, and mixtures of these two salts, at 900 C, in laboratory air and under O2 + SO2/SO3 atmospheres has been evaluated by potentiodynamic, potential decay, and free corrosion potential measurements. In addition, the corrosion products were examined using several electron-optical techniques, and by other analytical methods. Pure Na2SO4 in air did not seem to be very corrosive towards Nimonic 105. Addition of NaCl to the molten Na2SO4 resulted in increased dissolution of Nimonic 105, which was in general nonuniform, alloy constituents nickel and cobalt dissolving more than others. Evidence of internal attack and enhancement of dissolution of the Ni alloy by SO3 was significant only when the corrosion conditions were prolonged. In pure NaCl, catastrophic corrosion occurs, which has been attributed to the depletion, dissolution, and vaporization of some alloy species.

Luminescent Polystyrene Composition Characteristics Stability Forecasting

2001 ◽  
Vol 708 ◽  
Author(s):  
Artem Yu. Borisenko ◽  
Vitalij G. Senchishin
Keyword(s):  
Injection Molding ◽  
Molecular Mass ◽  
Mass Distribution ◽  
Supramolecular Structure ◽  
Molecular Mass Distribution ◽  
Bulk Polymerization ◽  
Material Structure ◽  
Geometrical Size ◽  
The Stability ◽  
Plasticizer Concentration

ABSTRACTThe stability of properties of luminescent polystyrene compositions depending on their material structure has been studied. The samples obtained by the methods of bulk polymerization and injection molding were used for the experiment. The influence of molecular mass distribution, supramolecular structure, plasticizer concentration and geometrical size of samples on the stability of their properties in severe conditions of natural and radiation aging has been investigated.

Preparation and Corrosion Protection Effect of Electroactive Polyurethane Containing Amino-Capped Aniline Trimer

2010 ◽  
Vol 123-125 ◽  
pp. 1255-1258
Author(s):  
Chih Wei Peng ◽  
Jui Ming Yeh
Keyword(s):  
Corrosion Protection ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Passive Layer ◽  
Visible Absorption ◽  
Protection Effect ◽  
Reversible Redox ◽  
Cold Rolled ◽  
Uv Visible

Electroactive polyurethane (EPU) containing conjugated segments of electroactive amino-capped aniline trimer (ACAT) has been successfully synthesized and characterized through Fourier-Transformation infrared and UV–visible absorption spectroscopy. Subsequently, electroactivity (i.e., redox capability) of as-prepared EPU was investigated by electrochemical cyclic voltammetry (CV) studies. It was noticed that the as-prepared EPU exhibited reversible redox capability was found to reveal better corrosion protection effect on cold-rolled steel (CRS) electrodes than that of non-electroactive polyurethane based on a series of electrochemical measurements such as corrosion potential, polarization resistance, corrosion current and electrochemical impedance spectroscopy (EIS) studies in 5 wt-% NaCl electrolyte. This significant enhancement of corrosion protection on CRS electrodes as compared to non-electroactive polyurethane might be probably ascribed to the redox catalytic property of as-prepared EPU coatings inducing the formation of passive layer of metal oxide, as evidenced by the SEM and ESCA studies.

scholarly journals Peculiarities in structure formation and corrosion of cast quasicrystalline Al63Cu25Fe12 and Al63Co24Cu13 alloys in sodium chloride aqueous solution

2020 ◽  
Vol 21 (3) ◽  
pp. 530-536
Author(s):  
O. V. Sukhova ◽  
V. A. Polonskyy
Keyword(s):  
Sodium Chloride ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Free Corrosion Potential ◽  
X Ray ◽  
Marine Climate ◽  
Potentiodynamic Method

In this work the structure and corrosion behavior of quasicrystalline cast Al63Cu25Fe12 and Al63Co24Cu13 alloys in 5-% sodium chloride solution (рН 6.9–7.1) were investigated. The alloys were cooled at 5 К/s. The structure of the samples was studied by methods of quantitative metallography, X-ray analysis, and scanning electron microscopy. Corrosion properties were determined by the potentiodynamic method. The made investigations confirm the formation of stable quasicrystalline icosahedral (y) and decagonal (D) phases in the structure of Al63Cu25Fe12 and Al63Co24Cu13 alloys correspondingly. In 5-% sodium chloride solution, the investigated alloys corrode under electrochemical mechanisms with oxygen depolarization. Compared with Al63Cu25Fe12 alloy, Al63Co24Cu13 alloy has a less negative value of free corrosion potential (–0.43 V and–0.66 V, respectively), and its electrochemical passivity region extends due to the inhibition of anodic processes. A corrosion current density, calculated from (E,lgi)-curve, for Al63Co24Cu13 alloy amounts to 0.18 mА/сm2 and for Al63Cu25Fe12 alloy – to 0.20 mА/сm2. The lower corrosion resistance of Al63Cu25Fe12 alloy may be explained by the presence of iron-containing phases in its structure. Based on obtained results, the Al63Co24Cu13 alloy was recommended as a coating material for rocket-and-space equipment working in a marine climate.

scholarly journals FOOD-PACKAGING INTERACTION ON THE STABILITY OF CANNED SWEETENED CUPUAÇU ( Theobroma grandiflorum Schum.) PUREE

2016 ◽  
Vol 29 (4) ◽  
pp. 1006-1014
Author(s):  
MARIA TERESA DE ALVARENGA FREIRE ◽  
RODRIGO RODRIGUES PETRUS ◽  
JOZETI APARECIDA BARBUTTI GATTI ◽  
MARIA FERNANDA BARBOSA LEITE ◽  
MARIANA TOMIE KUNITAKE ◽  
...  
Keyword(s):  
Shelf Life ◽  
Food Packaging ◽  
Corrosion Potential ◽  
International Markets ◽  
Economic Potential ◽  
Protective Properties ◽  
Theobroma Grandiflorum ◽  
Tin Plating ◽  
The Stability ◽  
Sterile Product

ABSTRACT Cupuaçu (Theobroma grandiflorum Schum.) is an exotic fruit with a promising economic potential, particularly due to its strong aroma and creamy texture. This study aimed to produce sweetened cupuaçu puree and evaluate the effects of packaging corrosion on its sensory properties and shelf-life in tinplated cans. After 240 days of storage, the commercially sterile product had average sensory analysis scores of 5.89 ± 0.21, 5.39 ± 0.30, 5.45 ± 0.21 and 5.49 ± 0.25, for appearance, aroma, flavor and overall appreciation, respectively. Sensory acceptance scores did not change during storage (p>0.05). Corrosion potential and low tin and iron levels in the product, which are parameters used to evaluate food-packaging interaction, demonstrated the product remained food-safe throughout its shelf-life. Tinplate is a promising packaging material for sweetened cupuaçu puree due to its mechanical and protective properties. Furthermore, tin plating is an economically viable food technology to extend the shelf-life of cupuaçu products and expand its domestic and international markets.

scholarly journals Analysis and Comparison of the Corrosive Behavior of Nickel-Based and Cobalt-Based Dental Alloys

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4949
Author(s):  
Carmen Marina Garcia-Falcon ◽  
Tomas Gil-Lopez ◽  
Amparo Verdu-Vazquez ◽  
Julia Claudia Mirza-Rosca
Keyword(s):  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Dental Materials ◽  
Electrochemical Treatment ◽  
Ringer Solution ◽  
Passive Layer ◽  
Metal Alloys ◽  
Dental Alloys ◽  
Potentiostatic Polarization ◽  
The Stability

Nickel-based and cobalt-based metal alloys are frequently used in dentistry. The introduction of various elements in the alloy changes its characteristics, and a thorough study of each alloy should be completed to determine its appropriate corrosion resistance and biocompatibility in contact with physiological fluids. There are scarce investigations on these widely used dental alloys in Ringer solution, and findings in this research bring new experimental data and information. The present study evaluated and compared the corrosion behavior of six NiCr- and two CoCr-based dental materials in Ringer solution, using the following techniques: potentiostatic polarization curves (chronoamperometry), microstructural analysis, and EIS (electrochemical impedance spectroscopy). The results obtained in this investigation showed that in the NiCr-based specimens Ni4, Ni5, and Ni6 the stability of the passive layer was destroyed after polarization and a development and growth of stable pits was found in the microstructural analysis after electrochemical treatment. In terms of susceptibility to corrosion, two different groups of specimens were derived from this investigation. A first group which included the two CoCr (Co1 and Co2) and three of the six NiCr alloys studied (Ni1, Ni2, and Ni3). A second group with the other NiCr alloys investigated Ni4, Ni5, and Ni6.

Detailed mechanisms of hydrogen charging and hydrogen stress cracking of steel in liquid ammonia storage

2019 ◽  
Vol 107 (4) ◽  
pp. 402 ◽  
Author(s):  
Jean-Louis Crolet
Keyword(s):  
Corrosion Potential ◽  
Capital Expenditures ◽  
Test Results ◽  
Redox Equilibrium ◽  
Exposure Test ◽  
Free Corrosion Potential ◽  
Hydrogen Charging ◽  
Stress Cracking ◽  
High Potentials ◽  
The One

The available polarisation curves of the literature are analysed in view of the theoretical analysis of the corrosive medium in Part I (J.-L. Crolet, Matériaux & Techniques 107, 401, 2019) and the new views on passivation and hydrogen charging. The accurate electrochemical conditions of the respective cathodic and “anodic” hydrogen charging are thus defined, or more exactly the paradox of a protonic cathodic reaction only running at high potential. Similarly in the available exposure test results, the locus of the ternary redox equilibrium between ammonia and its two decisive contaminants, oxygen and water, separates contaminated ammonia into two domains, on the one hand, a safe domain where the undersaturated oxygen cannot act as an oxidiser, hence no anodic HSC at the free corrosion potential, and on the other hand, a dangerous domain where oxygen is supersaturated, hence oxidising conditions, steel passivation, high potentials, anodic charging and anodic HSC. Likewise, all the known features of this environmental cracking are also explained, with no exception nor contradiction, including the differences between the liquid and vapour phases. An experimental method is also proposed to directly check the occurrence of anodic charging, and proposals are also made for at the same time improving safety and reducing operational or capital expenditures.

scholarly journals Wear Characteristics of AISI 310 Grade Stainless Steel Material by Carbonitriding Process

2020 ◽  
Vol 184 ◽  
pp. 01024
Author(s):  
Manne Vamshi ◽  
Animesh Bain ◽  
M. Sreekanth ◽  
Ram Subbiah
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Wear Test ◽  
Optical Microscope ◽  
Sem Analysis ◽  
Case Depth ◽  
Material Loss ◽  
Steel Material ◽  
Stainless Steel Material ◽  
Strong Adhesion

The investigation on the microstructure and mechanical behaviour of steel AISI 310 has been carried out during a Carbonitriding process aiming to improve the wear performance. The comparison study was made to treated specimens with untreated sample. Carbonitriding is a viable technique to enhance the wear resistance of the stainless steel material. The present study focused in the direction of investigating the effect of microstructure, hardness and wear resistance of AISI 310 stainless steel material. In carbonitriding process the case depth was found to be from 13, 16.5 and 19 Microns which is treated 2 hrs, 4hrs and 6 hrs respectively. The combination action of strong adhesion, abrasion and severe plastic deformation are the primary reasons for the continuous material loss in the untreated specimens during testing. The Optical microscope, SEM analysis and wear test are conducted to find out the various results.

Influence of Composition, Concentration and Temperature of some Biological Liquids upon the Corrosion Behaviour of Titanum

2008 ◽  
Vol 59 (1) ◽  
pp. 17-24
Author(s):  
Rodica Popescu ◽  
Daniela Ionita ◽  
Florin Minculescu
Keyword(s):  
Lactic Acid ◽  
Body Temperature ◽  
Corrosion Behaviour ◽  
Passive Layer ◽  
Albumin Concentration ◽  
Cyclic Polarization ◽  
Low Concentrations ◽  
Human Body Temperature ◽  
Biological Liquids ◽  
The Stability

In order to investigate the corrosion behaviour of titan in aqueous solutions of lactic acid (1, 3 and 4% w) and albumin (2 and 10 % w) the cyclic polarization curves in potentiodynamic conditions were used. The corrosion parameters were estimated and their values were discussed as a function of acid lactic and albumin concentration and temperature. The stability of titan in investigated biological liquids was interpreted by involvment of the adsorption of either lactic acid or albumin onto the passive layer, a process which is favorised by moderate temperatures (as 370C � the human body temperature) as well as by low concentrations of lactic acid and albumin, respectively.

Sign in / Sign up

Export Citation Format

Share Document