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Corrosion Potential (corrosion + potential)
Selected AbstractsUse of Physicochemical Property Limits to Develop Rules for Identifying Chemical Substances with no Skin Irritation or Corrosion PotentialMOLECULAR INFORMATICS, Issue 9 2004Ingrid Gerner Abstract This is believed to be the first paper to promote the use of rules based on (quantitative) structure-activity relationship [(Q)SAR] models for identifying chemicals that are not likely to cause a specific adverse health effect, viz., skin irritation or corrosion. The purpose of this paper is to describe limit values for specific physicochemical properties that are appropriate for identifying chemical substances that have no skin irritation or corrosion potential. These physicochemical properties include melting point, molecular weight, octanol-water partition coefficient, surface tension, vapour pressure, aqueous solubility and lipid solubility. Based on analyses of 1833 chemicals, physicochemical properties for limits were defined to determine that when a chemical's physicochemical properties were either greater or less than these limits that these chemicals would have no skin irritation or corrosion potential. To facilitate classification and labeling, the application domains of these limits were constructed to correspond with the European Union's risk phrases for chemicals classified for skin irritation/corrosion, viz., R 34, R35 or R38. This is the second paper of four companion papers. The first paper discussed mechanisms that can lead to significant skin irritation or corrosion after acute exposures to chemicals. The third paper described the application of structural alerts to identify chemical substances with skin irritation or corrosion potential. The fourth paper described the Skin Irritation Corrosion Rules Estimation Tool (SICRET), a user-friendly tool that allows non-(Q)SAR experts to identify chemical substances with skin irritation or corrosion potential based on physicochemical property limits and structural alerts. [source] Corrosion behaviour of high copper dental amalgamsJOURNAL OF ORAL REHABILITATION, Issue 6 2004A. U. J. Yap summary, This study evaluated the corrosion behaviour of two high copper dental amalgam alloys [Dispersalloy (Dentsply-Caulk) and Tytin (Kerr)] in different electrolytes. Amalgam specimens were prepared, coupled to a copper wire, cemented into glass tubes and polished to a 600-grit finish. A corrosion cell was prepared using a carbon counter-electrode, a standard calomel electrode as the reference and amalgam as the working electrode. The alloys were tested in the following mediums at 37 °C: (i) artificial saliva based on Fusayama's solution (FS), (ii) artificial saliva with citric acid adjusted to pH 4·0 (FC) and (iii) 1% sodium chloride solution (SC). Corrosion potentials (Ecorr) and corrosion rates (Icorr) were determined using potentiostatic and impedance spectroscopy methods. Data was subjected to anova/Scheffe's post hoc test at 0·05 significance level. For both alloys, the corrosion potential in FS was significantly greater than in SC. Corrosion potential of Tytin in FS and SC was also significantly greater than in FC. The corrosion rate of Dispersalloy in FC was significantly greater than in FS and SC. For Tytin, corrosion rate in SC was significantly greater than in FS and FC. Although no significant difference in corrosion potential/rate was observed between the alloys when tested in FS, significant differences were observed when electrochemical testing was carried out in FC and SC. The corrosion behaviour of high copper amalgam alloys are both material and environment dependent. Certain food substances may increase the corrosion of high copper amalgams. [source] Corrosion Behavior of PM Processed Ti,Ca,P Bioceramic Composites in Hank's Balanced Salt Solution Using Potentiodynamic StudiesINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2010Malobika Karanjai Ti,Ca,P bioceramic composites for load bearing implants developed by a new powder metallurgy processing technique were studied for their electrochemical corrosion properties. For determining corrosion behavior of such composites having in situ formed bioactive Ca,P phases, potentiodynamic and studies were conducted in simulated body fluid namely Hank's balanced salt solution. Potentiodynamic polarization tests showed no evidence of pitting corrosion. Corrosion potentials (,0.27 to ,0.53 V) and corrosion rates (0.17,4.46 mills per year) of Ti,Ca,P bioceramic composite samples were superior to earlier reported results for coated Ti implants due to the formation of passive layer of bone-like calcium phosphate on the sample surface. [source] Corrosion behaviour of high copper dental amalgamsJOURNAL OF ORAL REHABILITATION, Issue 6 2004A. U. J. Yap summary, This study evaluated the corrosion behaviour of two high copper dental amalgam alloys [Dispersalloy (Dentsply-Caulk) and Tytin (Kerr)] in different electrolytes. Amalgam specimens were prepared, coupled to a copper wire, cemented into glass tubes and polished to a 600-grit finish. A corrosion cell was prepared using a carbon counter-electrode, a standard calomel electrode as the reference and amalgam as the working electrode. The alloys were tested in the following mediums at 37 °C: (i) artificial saliva based on Fusayama's solution (FS), (ii) artificial saliva with citric acid adjusted to pH 4·0 (FC) and (iii) 1% sodium chloride solution (SC). Corrosion potentials (Ecorr) and corrosion rates (Icorr) were determined using potentiostatic and impedance spectroscopy methods. Data was subjected to anova/Scheffe's post hoc test at 0·05 significance level. For both alloys, the corrosion potential in FS was significantly greater than in SC. Corrosion potential of Tytin in FS and SC was also significantly greater than in FC. The corrosion rate of Dispersalloy in FC was significantly greater than in FS and SC. For Tytin, corrosion rate in SC was significantly greater than in FS and FC. Although no significant difference in corrosion potential/rate was observed between the alloys when tested in FS, significant differences were observed when electrochemical testing was carried out in FC and SC. The corrosion behaviour of high copper amalgam alloys are both material and environment dependent. Certain food substances may increase the corrosion of high copper amalgams. [source] Pilot-scale combustion of fast-pyrolysis bio-oil: Ash deposition and gaseous emissionsENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2009Ala Khodier Abstract Fast pyrolysis is a promising method to transform solid biomass into a liquid product called "bio-oil" with an energy density of four to five times greater than the feedstock. The process involves rapidly heating biomass to 450,600°C in the absence of air and condensing the vapor produced to give bio-oil. Typically, 50,75% (weight) of the feedstock is converted into bio-oil that has a number of uses, for example energy production or bio-refinery feedstock. This study investigated the gaseous emissions and ash deposition characteristics resulting from bio-oil combustion in a pilot scale combustion test rig at Cranfield University. A feeding system with heated lines and heated/stirred reservoir was used to feed a spray nozzle in the combustion chamber. Ash deposit samples were collected from the resulting flue gas using three air-cooled probes that simulate heat exchanger tubes with surface temperatures of 500, 600, and 700°C. The deposits formed were analyzed using SEM/EDX and XRD techniques to assess the corrosion potential of the deposits. The results are compared to measured ash deposit compositions formed from biomass combustion. Thermodynamic modeling software was used to make predictions for the partitioning of a range of elements for bio-oil combustion and the results compared to the measured data. © 2009 American Institute of Chemical Engineers Environ Prog, 2009 [source] The electrochemical behavior of Ti-6Al-7Nb alloy with and without plasma-sprayed hydroxyapatite coating in Hank's solutionJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 5 2002I. C. Lavos-Valereto Abstract The electrochemical behavior of Ti-6Al-7Nb alloy with and without plasma-sprayed hydroxyapatite (HA) coating was investigated in Hank's balanced salt solution at 37 °C. This behavior was evaluated by analyzing both corrosion potential variation with time curves and potentiodynamic polarization curves. The polarization curves were determined both in aerated and deaerated solutions. It was found that the corrosion potential of uncoated sample is always more noble than that of coated one. In aerated solutions the polarization curve of a coating-free alloy presents a typical passive/transpassive behavior, which is absent in the HA-coated alloy and in deaerated solution for both coated and uncoated conditions. In the latter polarization curves, the current density continuously increases with the increase of the potential. The corrosion rate determined from polarization curves is higher for HA-coated alloys, but it still can be considered negligible (less than 1 ,A/cm2). © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 664,670, 2002 [source] Corrosion behaviour of high copper dental amalgamsJOURNAL OF ORAL REHABILITATION, Issue 6 2004A. U. J. Yap summary, This study evaluated the corrosion behaviour of two high copper dental amalgam alloys [Dispersalloy (Dentsply-Caulk) and Tytin (Kerr)] in different electrolytes. Amalgam specimens were prepared, coupled to a copper wire, cemented into glass tubes and polished to a 600-grit finish. A corrosion cell was prepared using a carbon counter-electrode, a standard calomel electrode as the reference and amalgam as the working electrode. The alloys were tested in the following mediums at 37 °C: (i) artificial saliva based on Fusayama's solution (FS), (ii) artificial saliva with citric acid adjusted to pH 4·0 (FC) and (iii) 1% sodium chloride solution (SC). Corrosion potentials (Ecorr) and corrosion rates (Icorr) were determined using potentiostatic and impedance spectroscopy methods. Data was subjected to anova/Scheffe's post hoc test at 0·05 significance level. For both alloys, the corrosion potential in FS was significantly greater than in SC. Corrosion potential of Tytin in FS and SC was also significantly greater than in FC. The corrosion rate of Dispersalloy in FC was significantly greater than in FS and SC. For Tytin, corrosion rate in SC was significantly greater than in FS and FC. Although no significant difference in corrosion potential/rate was observed between the alloys when tested in FS, significant differences were observed when electrochemical testing was carried out in FC and SC. The corrosion behaviour of high copper amalgam alloys are both material and environment dependent. Certain food substances may increase the corrosion of high copper amalgams. [source] Monitoring the corrosion and remediation of reinforced concrete on-site: An alternative approachMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 4 2005N. Birbilis Abstract Difficulties associated with the interpretation of site data collected over long periods of time from commonly used electrochemical corrosion monitoring techniques often make it difficult to assess the corrosion of reinforcing steel. An alternative approach for the interpretation of data is proposed, based on a model of the quality of passive film upon the steel surface. This model leads to a representation of the corrosion state by means of the relationship, over a long period of time, of the corrosion potential and the logarithm of the Linear Polarization Resistance, since both are functions inter alia of corrosion rate. It is shown that for the reinforced concrete panels tested, data points representing this relationship closely fitted a family of results; allowing the development of a "monitoring control diagram", MCD. The MCD reveals that for a fixed geometry and experimental conditions, a relationship between the corrosion potential and polarization resistance of steel exists, facilitating a useful monitoring tool for assessment of both the corrosion and remediation of reinforced concrete structures. Particular emphasis is placed on the latter in this work. [source] Theoretical description of the practical possibility of stress corrosion cracking from crevice corrosion sitesMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 1 2005S. Wang Abstract Stress corrosion cracking (SCC) from crevice corrosion sites had been found in an experimental work at polarization potential of + 200 mVSCE. In that work, an occluded U-bend specimen of Type 316L (UNS S31603) stainless steel was used. The testing was done in sodium chloride (NaCl) solution. Based on that work, the practical possibility of SCC from the occluded U-bend specimen was described theoretically. It was shown that it would also be possible for SCC to occur in practice (i.e. at practical corrosion potential), but the crevice needs to be tighter. Meanwhile, it would take a longer time for obvious SCC to emerge. For a practical crevice usually formed by placing a crevice former on a large uniform metal surface, the crevice geometry may have little effect on SCC although the crevice can sustain an acidified solution more easily than pitting. The possibility of SCC should mainly depend on the corrosion system itself, i.e. material and environment. [source] Zum Korrosionsverhalten von Nicrofer 3033 in hochkonzentrierter SchwefelsäureMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 12 2002H. Werner Untersuchungen zum Korrosionsverhalten von Nicrofer 3033 (1.4591) erfolgten in 93%iger und 95,99%iger technischer Schwefelsäure bei Temperaturen von 70,200°C. 6-h-Versuche mit gravimetrischer Auswertung und Messung des Freien Korrosionspotentials und 48-h-Versuche mit gravimetrischer Auswertung dienten zur Ermittlung des Einflusses von Schwefelsäurekonzentration und Temperatur bei An- und Abwesenheit von SO2 auf die Beständigkeit von Blechproben. Der Einfluss der Strömungsgeschwindigkeit wurde in 6-h-Versuchen durch Rotation von Rohrproben bei Umfangsgeschwindigkeiten bis 2 m/s untersucht. Aus den Potential- und gravimetrischen Messungen folgt für Temperaturen ab 100°C eine Beständigkeit mit , 0,1 mm/a für Nicrofer 3033 (1.4591) ab etwa 98,5%. Um 125°C scheint jedoch ein Gebiet zu existieren, wo zumindest bei längerer Versuchsdauer die Beständigkeit bis herab zu etwa 97,5% erhalten bleibt. Untersuchungen zum Strömungseinfluss weisen darauf hin, dass in dem genannten Gebiet mit zunehmender Strömungsgeschwindigkeit wieder eine Aktivierung erfolgt. Bei den anderen Temperaturen ist dagegen der Strömungseinfluss gering. Diese Ausweitung des Beständigkeitsbereiches um 125°C belegt, dass die Temperaturabhängigkeit von Nicrofer 3033 (1.4591) in hochkonzentrierter Schwefelsäure nicht monoton ist. Es treten in Abhängigkeit von der Schwefelsäurekonzentration bei unterschiedlichen Temperaturen Korrosionsmaxima und -minima auf. Bei Anwesenheit von SO2 erfolgt nur bei niedrigen Versuchstemperaturen, 80°C, 100°C im 6-h-Versuch und 70°C, 80°C im 48-h-Versuch, eine Einengung des Beständigkeitsbereiches. Contribution to corrosion behaviour of Alloy 33 in high concentrated sulfuric acid Investigations on the corrosive behaviour of Alloy 33 were conducted in 93% and 95,99% technical sulfuric acid at temperatures of 70,200°C. 6-h-tests with gravimetric evaluation and measurement of the free corrosion potential and 48-h-tests with gravimetric evaluation served to determine the influence of the sulfuric acid concentration and the temperature on the resistance of sheet samples at presence and absence of SO2. The influence of the flow rate was examined in 6-h-tests via rotation of pipe samples at circumferential speeds up to 2 m/s. The potential and gravimetric measurements showed that there is a resistance with , 0.1 mm/a for Alloy 33 as from about 98.5% at temperatures from 100°C. However, about 125°C there seems to be a zone at which the resistance down to about 97.5% is kept at least for a long test duration. Examinations on the flow influence indicate that there is a reactivation in the said zone with increasing flow speed. However, the flow influence is low at the other temperatures. This extension of the resistance zone about 125°C proves that the temperature sensitivity of Alloy 33 is not monotonous in highly concentrated sulfuric acid. There are corrosion maxima and minima as a function of the sulfuric acid concentration at different temperatures. If SO2 is present, there is only a limitation of the resistance zone at low test temperatures, 80°C, 100°C in the 6-h-test and 70°C, 80°C in the 48-h-test. [source] Use of structural alerts to develop rules for identifying chemical substances with skin irritation or skin corrosion potentialMOLECULAR INFORMATICS, Issue 3 2005Etje Hulzebos Abstract In this paper structural alerts for acute skin lesions were categorized as irritation or corrosion or a combination of corrosion/irritation alerts. Categorizing the alerts according to their mechanisms of skin irritation and corrosion and connecting them with physicochemical property limits characterizing their domain of applicability provides strategies to save test animals and costs. These alerts can be used for positive classification of chemicals causing skin irritation or skin corrosion according to EU and OECD guidelines. This paper is the third in the series of four papers describing practical, user-friendly and mechanism-based approaches for predicting when chemicals are likely to irritate or corrode the skin. In the first paper the mechanisms of skin irritation and corrosion were described. In the second paper the physicochemical property limit values for chemicals not causing skin irritation and corrosion were given. In the third paper, described here, structural alerts associated with chemicals causing skin irritation and corrosion were identified and characterized. In the fourth paper, the Skin Irritation Corrosion Rules Estimation Tool (SICRET) was described that allows users to classify chemicals as either not causing skin irritation and corrosion based on physicochemical property limit values or irritating or corrosive to the skin based on structural alerts. [source] (Q)SARs for Predicting Skin Irritation and Corrosion: Mechanisms, Transparency and Applicability of PredictionsMOLECULAR INFORMATICS, Issue 9 2004Abstract This paper describes previously-developed (quantitative) structure-activity relationships [(Q)SARs]for predicting skin irritation and corrosion, proposes mechanisms of skin irritation and corrosion, and discusses the transparency and applicability of predictions. This paper was written to set the tone for companion papers that describe three applications of skin irritation and corrosion (Q)SARs. The first companion paper describes physicochemical property limits that can be used to develop rules for identifying chemical substances with no skin irritation or corrosion potential. The second companion paper describes structural alerts that can be used to develop rules for identifying chemical substances with skin irritation or corrosion potential. The third companion paper describes the Skin Irritation Corrosion Rules Estimation Tool (SICRET), a user-friendly tool that allows non-(Q)SAR experts to identify chemical substances with skin irritation or corrosion potential based on physicochemical property limits and structural alerts. [source] Use of Physicochemical Property Limits to Develop Rules for Identifying Chemical Substances with no Skin Irritation or Corrosion PotentialMOLECULAR INFORMATICS, Issue 9 2004Ingrid Gerner Abstract This is believed to be the first paper to promote the use of rules based on (quantitative) structure-activity relationship [(Q)SAR] models for identifying chemicals that are not likely to cause a specific adverse health effect, viz., skin irritation or corrosion. The purpose of this paper is to describe limit values for specific physicochemical properties that are appropriate for identifying chemical substances that have no skin irritation or corrosion potential. These physicochemical properties include melting point, molecular weight, octanol-water partition coefficient, surface tension, vapour pressure, aqueous solubility and lipid solubility. Based on analyses of 1833 chemicals, physicochemical properties for limits were defined to determine that when a chemical's physicochemical properties were either greater or less than these limits that these chemicals would have no skin irritation or corrosion potential. To facilitate classification and labeling, the application domains of these limits were constructed to correspond with the European Union's risk phrases for chemicals classified for skin irritation/corrosion, viz., R 34, R35 or R38. This is the second paper of four companion papers. The first paper discussed mechanisms that can lead to significant skin irritation or corrosion after acute exposures to chemicals. The third paper described the application of structural alerts to identify chemical substances with skin irritation or corrosion potential. The fourth paper described the Skin Irritation Corrosion Rules Estimation Tool (SICRET), a user-friendly tool that allows non-(Q)SAR experts to identify chemical substances with skin irritation or corrosion potential based on physicochemical property limits and structural alerts. [source] Verification of literature-derived SARs for skin irritation and corrosionMOLECULAR INFORMATICS, Issue 3 2003M. Hulzebos Abstract Structural features known to irritate and corrode skin and physical properties associated with skin absorption were used to evaluate the irritation and corrosion potential of chemicals. Chemicals that irritate and corrode skin include organic acids and bases, aldehydes, halogenated esters, and chemicals with reactive groups. The activity of the reactive group decreases when sterically hindered by adjacent substituents or when electrons of the reactive group interfere with electrons of adjacent substituents. The structural features presented are a good basis for the calculation of SAR prediction rules. Also quantitative and qualitative physical conditions are given to predict skin irritation and skin corrosion. [source] Structure and Corrosion of Magnetron Sputtered Pure Mg Films on Silicon SubstratesPLASMA PROCESSES AND POLYMERS, Issue S1 2007Michael Störmer Abstract Physical vapor deposition (PVD) was used to prepare pure magnesium coatings on silicon substrates at various argon pressures and deposition angles. The film morphology was observed to depend on the deposition conditions. The approximately 3 µm thick Mg films exhibited columnar growth with voided boundaries and a fiber texture of the basal planes parallel to the substrate surface, which is typical of low temperature deposition. At low pressure and angle, the films were more compact, the surface roughness was lower, the texture was stronger, and the corrosion performance was improved. A free corrosion potential of ,1,735 mV and a corrosion rate of 335 µm per year were determined. [source] Characteristics of paint systems prepared from dammar with the addition of natural pigmentPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3 2009N. M. Omar Abstract Adhesion and electrochemical properties of paint system prepared from dammar binder or binder from Dipterocarpus grandifolius with the addition of natural pigment have been investigated. In this work, carotenoid pigment obtained from Capsicum annum (dried chili pepper) was added into the mixture of dammar resin and acrylic polyol resin to form the organic paint system. Five different paint systems were formulated on the basis of various concentrations of dammar resin, and their viscosities were measured by using Brookefield Viscometer. The paint systems were proofed on Aluminum steel Q-panels as a substrate. The cured paint systems were then evaluated by using the crosshatch adhesion method to test their adhesion properties according to ASTM D3359 standards. The corrosion potential property of paint was characterized by using electrochemical impedance spectroscopy (EIS) while the coated substrate was exposed to 3% NaCl for 30 days. Comparative results have been presented in terms of number of damage grids for the crosshatch test in each sample at different viscosity conditions and also regarding the ability of the coated sample to resist the corrosion potential. The result shows that the paint system with a composition of 35% dammar (CD35%) possessed the best adhesion performance compared to other CD paint compositions. Furthermore, CD35% also had higher corrosion resistance after 30 days of exposure in the 3% NaCl solution. The decrease in coating resistance values is associated with the electrolyte penetration into the coating system. The results showed that the developed organic paint system prepared from dammar improved the adhesion and electrochemical properties of a paint system. Addition of natural pigment to the formulation may enhance the attractiveness and vibrancy of the color. Copyright © 2009 John Wiley & Sons, Ltd. [source] hytic Acid Conversion Coatings of MagnesiumCHINESE JOURNAL OF CHEMISTRY, Issue 4 2010Jianrui Liu Abstract A chrome-free conversion coating treatment for magnesium by phytic acid solution was developed. The immersion experiments were used for evaluating the effects of the processing parameters (such as conversion temperature and time, concentration and pH value of phytic acid solution) on the corrosion resistance of the phytic acid conversion coating. The morphologies and compositions of the coatings were determined by SEM and EDS respectively. The experimental results indicated that the corrosion resistance of the conversion coating formed in the solution containing 0.5% phytic acid at 25°C and pH=4 for 30 min was higher than that of natural oxide, and the conversion coating formed on the surface of magnesium was of multilayer mainly consisting of Mg, C, O and P. The thicknesses of the conversion coatings were approximately 1.0,15 µm and the conversion coatings presented obvious network-like cracks. The electrochemical potentiodynamic polarization experiment indicated that the free corrosion potential of the magnesium with phytic acid conversion coating was increased, and its corrosion current and corrosion rate declined in 3.5% NaCl solution. Phytic acid conversion coating could improve the electrochemical property of magnesium and provide effective protection, which can improve the corrosion resistance of magnesium. [source] In-situ Corrosion Studies on Wrecked Aircraft of the Imperial Japanese Navy in Chuuk Lagoon, Federated States of MicronesiaINTERNATIONAL JOURNAL OF NAUTICAL ARCHAEOLOGY, Issue 1 2006Ian D. MacLeod A preliminary in-situ corrosion survey of the submerged Japanese WWII aircraft in Chuuk Lagoon, in the Federated States of Micronesia, has provided information on the way in which the wrecks interact with the marine environment. The aircraft are characterised by a lack of encrusting marine organisms and are clearly identifiable. The values of pH and the corrosion potentials vary with depth and the voltage depends on the composition of the underlying metal alloys. It is possible that with additional data from these non-destructive methods techniques it will be possible to provide marine archaeologists with appropriate diagnostic tools. © 2006 The Author. [source] Comparative corrosion performance of black oxide, sandblasted, and fine-drawn nitinol wires in potentiodynamic and potentiostatic tests: Effects of chemical etching and electropolishingJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2004Svetlana Shabalovskaya Abstract The corrosion performance of sandblasted (SB) and smooth fine-drawn (FD) medical-use nitinol wires was compared with the performance of wires with black oxide (BO) formed in air during their manufacture. Potentiodynamic and ASTM F746 potentiostatic tests in a 0.9 % NaCl solution were conducted on wires in their as-received, chemically etched, aged in boiling water, and electropolished states. As-received wires with various surface finishes revealed breakdown potentials in the range from ,100 mV to +500 mV; similar passive current density, 10,6 A/cm2; and a wide hysteresis on the reverse scan, demonstrating strong susceptibility to localized corrosion. Chemically etched wires with original black oxide displayed consistent corrosion performance and surpassed, in corrosion resistance, electropolished wires that showed significantly lower breakdown (400,700 mV) and localized corrosion potentials (,,50 to +113 mV). Sandblasted and fine-drawn wires exhibited rather inconsistent corrosion behavior. In potentiodynamic tests these wires could perform with equal probability either on the level of pretreated BO wires or rather similar to as-received wires. Both SB and FD wires revealed low breakdown potentials in the PS regime. SEM analysis performed before tests indicated that sandblasting was not efficient for the complete removal of the original scaling, and fine drawing aggravated the situation, resulting in a persistent scaling that contributed to the inferior corrosion performance. Inclusions (oxides, carbides, and oxidized carbides) inherited from the bulk and retained on electropolished surfaces are the cause of their inferior performance compared to chemically etched surfaces. In electropolished wires corrosion was initiated around inclusions. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 69B: 223,231, 2004 [source] | |||||||||||||