Pitting Corrosion of Titanium The Relationship Between Pitting Potential and Competitive Anion Adsorption at the Oxide Film/Electrolyte Interface

2000 ◽  
Vol 147 (4) ◽  
pp. 1376 ◽  
Author(s):  
Solomon B. Basame ◽  
Henry S. White
Keyword(s):  
Oxide Film ◽  
Pitting Corrosion ◽  
Pitting Potential ◽  
Anion Adsorption ◽  
Electrolyte Interface ◽  
Film Electrolyte ◽  
The Relationship

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.

Influence of Sigma Phase Precipitation on Pitting Corrosion of 2507 Super-Duplex Stainless Steel

2010 ◽  
Vol 658 ◽  
pp. 380-383 ◽  
Author(s):  
Ying Han ◽  
De Ning Zou ◽  
Wei Zhang ◽  
Jun Hui Yu ◽  
Yuan Yuan Qiao
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Ambient Temperature ◽  
Duplex Stainless Steel ◽  
Pitting Corrosion ◽  
Super Duplex Stainless Steel ◽  
Phase Precipitation ◽  
Pitting Potential ◽  
Σ Phase ◽  
Pitting Corrosion Resistance

Specimens of 2507 super-duplex stainless steel aging at 850°C for 5 min, 15 min and 60 min were investigated to evaluate the pitting corrosion resistance in 3.5% NaCl solution at 30°C and 50°C. The results are correlated with the microstructures obtained with different aging time. The precipitation of σ phase remarkably decreases the pitting corrosion resistance of the steel and the specimen aged for 60 min presents the lowest pitting potential at both 30°C and 50°C. With increasing the ambient temperature from 30°C to 50°C, the pitting potential exhibits a reduction tendency, while this tendency is less obviously in enhancing the ambient temperature than in extending the isothermal aging duration from 5 to 60 min. SEM analysis shows that the surrounding regions of σ phase are the preferable sites for the formation of corrosion pits which grew up subsequently. This may be attributed to the lower content of corrosion resistance elements in these regions formatted with σ phase precipitation.

scholarly journals Pitting Corrosion Resistance on Annealing Treated Super Duplex Stainless Steel S32750

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 294
Author(s):  
Shuang Liu ◽  
Chaohua Yue ◽  
Xi Chen ◽  
Qiuhua Zhu ◽  
Yiyou Tu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Pitting Corrosion ◽  
Annealing Temperature ◽  
Super Duplex Stainless Steel ◽  
Boundary Area ◽  
Pitting Potential ◽  
Pitting Corrosion Resistance ◽  
Equivalent Number

The pitting corrosion resistance of S32750 super duplex stainless steel, annealing treated at temperatures of 950–1200 °C for 20–60 min, was investigated using potentiodynamic polarization tests. The results show that the volume fractions of ferrite in the S32750 duplex stainless steel increased from 48.9% to 68.4% as annealing temperatures increased from 950 to 1200 °C. The pitting potential of the sample increased first and then decreased from an annealing temperature of 950 to 1050 °C, and the highest pitting potential was observed after annealing at 1050 °C for 35 min. The pitting corrosion resistance of S32750 stainless steel is due to the combination of pitting resistance equivalent number (PREN) value, phase fraction and grain boundary area fraction, and the imbalance of corrosion potential.

Sub-band-gap photoresponse ofTiO2−xthin-film—electrolyte interface

1984 ◽  
Vol 30 (7) ◽  
pp. 3625-3628 ◽  
Author(s):  
Wha-Tek Kim ◽  
Chang-Dae Kim ◽  
Q. Won Choi
Keyword(s):  
Band Gap ◽  
Electrolyte Interface ◽  
Film Electrolyte

Corrosion evaluation of Ti-6Al-4V parts produced with electron beam melting machine

2016 ◽  
Vol 22 (2) ◽  
pp. 322-329 ◽  
Author(s):  
Dana H. Abdeen ◽  
Bruce R. Palmer
Keyword(s):  
Electron Beam ◽  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Electron Beam Melting ◽  
Saturated Calomel Electrode ◽  
Nacl Solution ◽  
Pitting Potential ◽  
Exterior Surface ◽  
Content Type ◽  
Critical Pitting Temperature

Purpose This paper aims to evaluate the corrosion behavior of Ti-6Al-4V parts produced with electron beam melting (EBM) machine and compare it with wrought Ti-6Al-4V alloy. Design/methodology/approach Potentiodynamic and potentiostatic tests were applied on EBM Ti-6Al-4V in 3.5 per cent mass NaCl solution to determine the pitting potential and critical pitting temperature (CPT). A relation between pitting potential and temperature was established for EBM Ti-6Al-4V alloy by conducting potentiodynamic testing under different temperatures. CPT was also measured for EBM Ti-6Al-4V alloy in 3.5 per cent mass NaCl solution at a standard potential of 800 mV vs saturated calomel electrode (SCE). The same tests were performed on wrought Ti-6Al-4V for comparison purposes. Moreover, CPT for EBM Ti-6Al-4V alloy was measured in 3.5 per cent mass NaCl solution of different pH of 2.0, 5.7 and 10.0 to examine the effect of aggressive conditions on the pitting corrosion of EBM alloy. Findings Potentiodynamic test resulted in a relatively high pitting potential of EBM alloy, which was close to the pitting potential of wrought alloy even at higher temperatures. In addition, EBM samples did not pit when potentiostatic test was performed at 800 mV vs SCE, even at high and low values of pH. Originality/value EBM Ti-6Al-4V alloy has been increasingly playing an important role in aerospace, automobile and industrial fields. The technique and conditions of manufacturing form voids and increase roughness of the exterior surface of EBM objects, which might increase the tendency to initiate pitting corrosion within its holes and surface folds. This article shows that, despite surface variations and porosity in EBM Ti-6Al-4V alloy, the material maintained its corrosion resistance. It was found that the corrosion behavior of EBM alloy was close to that of the conventionally made wrought Ti-6Al-4V alloy.

Pitting Resistance of Domestic Super Martensitic Stainless Steel 00Cr13Ni5Mo2

2013 ◽  
Vol 834-836 ◽  
pp. 370-373
Author(s):  
Shi Dong Zhu ◽  
Jin Ling Li ◽  
Hai Xia Ma ◽  
Li Liu
Keyword(s):  
Stainless Steel ◽  
Corrosion Rate ◽  
Pitting Corrosion ◽  
Martensitic Stainless Steel ◽  
Pitting Potential ◽  
Electrochemical Technology ◽  
Super Martensitic Stainless Steel ◽  
Nacl Concentration ◽  
Made In China ◽  
Made In

Pitting resistance of super martensitic stainless steel 00Cr13Ni5Mo2 made in China has been investigated by employing electrochemical technology and chemical immersion methods. The results showed that pitting potential of super martensitic stainless steel decreased with the increasing of NaCl concentration and temperature, respectively. And corrosion rate of super martensitic stainless steel increased with the increasing of temperature. Furthermore, compared to super martensitic stainless steel made in Japan, the domestic one was better in terms of pitting potential, pitting corrosion rate and the density of the pits, but worse in terms of the depth of the pits.

The Relationship Between Repassivation Behavior and Pitting Corrosion for Ti and Ti6AI4V

CORROSION ◽  
1978 ◽  
Vol 34 (12) ◽  
pp. 437-442 ◽  
Author(s):  
H. -J. RAETZER-SCHEIBE
Keyword(s):  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Metallic Surface ◽  
Current Time ◽  
The Relationship ◽  
Current Potential ◽  
Potential Curves

Abstract The characteristic pitting potentials of Ti and Ti6AI4V were determined by measurement of potentiodynamic current-potential curves in solutions of 1N NaCl, 1N Nal, and 1N NaBr. Under the same conditions current-time curves were measured for various potentials after generation of a new metallic surface. By means of these curves, one can study the repassivation behavior of materials. The comparison between the potential of pit repassivation and the repassivation/nonrepassivation potential shows a relatively good correlation. The determination of the critical repassivation potentials enables us to predict the pitting corrosion behavior.

Theory Of Stainless Steel Pitting

CORROSION ◽  
1964 ◽  
Vol 20 (4) ◽  
pp. 129t-137t ◽  
Author(s):  
W. SCHWENK
Keyword(s):  
Pitting Corrosion ◽  
Theoretical Explanation ◽  
Potential Range ◽  
Etch Pits ◽  
Pitting Potential ◽  
Current Time ◽  
Chemical Corrosion ◽  
Points Of View ◽  
Kinetics Of ◽  
Anodic Metal Dissolution

Abstract Pit origin and formation in stainless steels are discussed according to results of investigations from the following points of view: 1. Conditions for the Existence of Pitting Corrosion. Pitting potential range and pitting potentials. Functions dependent on the potential which are important for pitting corrosion, effect of inhibitors and results of different methods of investigation are described. 2. Kinetics of Pitting Corrosion. Analysis of the current-time relationship gives information on dependence of potential on the anodic metal dissolution process. Pit growth under potentiostatic, galvanostatic and chemical corrosion conditions can be explained theoretically. 3. Physical Forms of Pitting Corrosion. Shape of pits that can be observed in different potential ranges and under different corrosion conditions are discussed: regular etch pits, hemispherically-shaped pits, under-hollowing and elongated areal pits. 4. Theoretical Explanation of Pitting Corrosion. In connection with the “all-or-none” principle of passivity, which holds that the active and passive states should not coexist at the same potential, it is shown under which circumstances stable pitting corrosion is possible. A concentration effect and a resistance polarization effect are discussed in detail. The origin of pitting corrosion and the pitting potentials are discussed in terms of a chemisorption process and a transport and/or transference theory.

Pitting Corrosion of Zn Peculiarly Caused by Acetate Anions

2016 ◽  
Vol 230 (10) ◽  
Author(s):  
Hesham S. Abdel-Samad ◽  
Hamdy H. Hassan
Keyword(s):  
Passive Film ◽  
Pitting Corrosion ◽  
Potentiodynamic Polarization ◽  
Corrosion Behaviour ◽  
Passive Layer ◽  
Acetate Solution ◽  
Layer Formation ◽  
Potentiodynamic Polarization Curve ◽  
Pitting Potential ◽  
Formation Region

AbstractThe corrosion behaviour of zinc metal was studied in acetate solutions. The potentiodynamic polarization curve in 0.1 M acetate solution displays an anodic peak (A1) owing to the anodic dissolution of zinc followed by a passive layer formation region. Breakdown of the passive film and the initiation of pitting corrosion were observed beyond the pitting potential (

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