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Showing papers on "Corrosion published in 1988"


Book
22 Apr 1988

1,980 citations


Journal ArticleDOI
TL;DR: In this article, the results of corrosion rate and simultaneous electrical resistance values of rebars in mortar fabricated with six different types of cements are given and the relation between those values is presented.

352 citations


Journal ArticleDOI
TL;DR: In this article, the electrochemical behavior of a rotating disc electrode in neutral aerated NaCl solution was investigated in the cathodic and anodic ranges and at the corrosion potential.
Abstract: The electrochemical behaviour of a Cu rotating disc electrode in neutral aerated NaCl solution was investigated in the cathodic and anodic ranges and at the corrosion potential In the cathodic range, where the reduction of oxygen takes place, reduction peaks allow the identification and quantitative evaluation of insoluble corrosion products (CuCl and Cu2O) In the anodic range Cu is dissolved, most likely as CuCl 2 − A new mechanism for the anodic dissolution is proposed after comparing our data with previously published mechanisms Corrosion currents were found to decrease with time and to be a function of the rotation rate of the electrode Both the mixed kinetics of the anodic partial reaction and diffusion through a porous layer seem to be relevant in controllingl corr

226 citations


Journal ArticleDOI
TL;DR: In this article, Electrochemical impedance spectroscopy (EIS) has been used to characterize the surfaces of anodized Al alloys during exposure to, and the EIS data show pronounced effects of anodic procedure (sulfuric acid, chromic acid), sealing procedure (unsealed, hot water, dichromate), and alloy chemistry (Al 2024, Al 6061, Al 7075).
Abstract: Electrochemical impedance spectroscopy (EIS) has been used to characterize the surfaces of anodized Al alloys during exposure to . The EIS‐data show pronounced effects of anodizing procedure (sulfuric acid, chromic acid), sealing procedure (unsealed, hot water, dichromate), and alloy chemistry (Al 2024, Al 6061, Al 7075). Tests conducted after short exposure times (about 2h) can be used as a quality control test, while tests over longer exposure times give information concerning the corrosion resistance of the anodized surface. The high frequency impedance data show a pronounced difference for hot water and dichromate sealed surfaces which suggests different mechanisms of sealing. The corrosion resistance cannot be determined from the high frequency region in all cases, but becomes evident from the changes with exposure time of the low frequency region which is dominated by the properties of the barrier layer. A damage function based on the impedance at 0.1 Hz describes the corrosion behavior. EIS‐data for an anodized metal matrix composite are different from those obtained for the other Al alloys studied here. Models for the anodized Al surfaces discussed so far in the literature explain some of the features of the experimental EIS‐data, but modifications are needed to explain the spectra observed for dichromate sealing.

208 citations


Journal ArticleDOI
TL;DR: Electrochemical techniques of polarization resistance and Tafel slope measurements were used to study effects of proteins on the anodic and cathodic corrosion reactions and it was found that proteins increased the corrosion rate of the stainless steel and C.P. titanium cylindrical specimens, but did not have an effect on the Ti-6AI-4V cylinders.

185 citations


Journal ArticleDOI
15 Apr 1988-Wear
TL;DR: A slurry wear test recently developed by the Bureau of Mines was used for the measurement of wear rates and electrochemical corrosion rates during slurries of silica sand and aqueous solutions were continuously fed into the test chamber, where they abraded and corroded the test specimens.

158 citations


Journal ArticleDOI

151 citations


Journal ArticleDOI
TL;DR: In this paper, the corrosion mechanism of steel in concrete and the so-called threshold chloride content are discussed based on the results obtained by electrochemical measurement, pore solution analysis, and scanning electron microscopy (SEM) observation.
Abstract: The corrosion mechanism of steel in concrete and the so-called threshold chloride content are discussed based on the results obtained by electrochemical measurement, pore solution analysis, and scanning electron microscopy (SEM) observation. It is shown that mortar (or concrete) provides better protection to steel than alkaline solutions. One of the protective mechanisms provided by mortar is found to be the pH control action of calcium hydroxide crystals located at the steel-mortar interface. For the protective mechanisms provided by mortar to operate, adhesion between the steel and the mortar is necessary and formation of voids at the steel-mortar interface is essential for active corrosion to start. The critical threshold chloride content is not determined simply by a parameter of the pore solution such as [Cl−]/[OH−] ratio; it is shown that the threshold value depends on the steel-mortar interface conditions.

146 citations


Journal ArticleDOI
TL;DR: In this article, the performance reliability of phase change materials (PCM) for heat storage after repeated thermal cycling was investigated. But the most corrosion resistant alloy to all the hydrated salts tested was stainless steel.

139 citations


Journal ArticleDOI
TL;DR: In this paper, a predictive and self-consistent mathematical model incorporating the electrochemical, chemical and ionic migration processes characterizing the propagation stage of crevice and pitting corrosion in metals is described.

128 citations


Journal ArticleDOI
TL;DR: In this paper, the authors have demonstrated the importance of incorporating the sulfide-chloride synergisms into reproduced indoor field environments in order to simulate the observed corrosion response by adjusting these variables, large differences can be found in materials reaction rates, corrosion mechanisms, and chemistries.
Abstract: Three flowing mixed gases have been developed to achieve realistic simulation through the synergistic effects of (1) low concentrations of relevant pollutants, (2) humidity, and (3) temperature. The authors have demonstrated the importance of incorporating the sulfide-chloride synergisms into reproduced indoor field environments in order to simulate the observed corrosion response. By adjusting these variables, large differences can be found in materials reaction rates, corrosion mechanisms, and chemistries. Data were taken that demonstrate the effects of critical variables on corrosion processes. Relative humidity, reactive chloride concentration, and reactive sulfide concentration were consistently identified as the most important in all cases. Temperature, gas velocity, and NO/sub 2/ concentration were found to be far less critical. Sulfur dioxide was relatively unimportant for either indoor, field, or laboratory mixtures. It is concluded that three-component mixtures based on low levels of H/sub 2/S, NO/sub 2/, and Cl/sub 2/ can be used to simulate all reactive environment classes. >

Journal ArticleDOI
TL;DR: In this paper, the antimony-tin and lead-tin solders were compared after soldering to copper under similar conditions and the results showed that the lead-solder was more susceptible to localized corrosion whereas the Antimony-Solder was passive.

Journal ArticleDOI
TL;DR: Developpement d'un modele physique decrivant les processus de corrosion sur une surface inhomogene a 3D dimension as discussed by the authors derived from the fonction de transfert theorique derivee.
Abstract: Developpement d'un modele physique decrivant les processus de corrosion sur une surface inhomogene a 3 dimensions. Discussion de la fonction de transfert theorique derivee. Verification du modele a partir des resultats experimentaux obtenus pour le systeme Fe/0,5 M Na 2 SO 4 aeree, 6≤pH≤8, T=298 K en presence ou non d'inhibiteur

Journal ArticleDOI
TL;DR: An electrochemical cell for pitting corrosion testing, the Avesta pitting cell as mentioned in this paper, was proposed to eliminate crevice corrosion in the crevice formed between the specimen and the specimen holder.

01 Jan 1988
TL;DR: The First European Federation of Corrosion Workshop on Microbial Corrosions was held in Sintra, Portugal, 7-9 March 1988 as mentioned in this paper, with a focus on microbial degradation.
Abstract: Proceedings of the First European Federation of Corrosion Workshop on Microbial Corrosion held in Sintra, Portugal, 7-9 March 1988

Journal ArticleDOI
TL;DR: A galvanostatic pulse technique was used to study corrosion of steel in mortar immersed in simulated sea water and steel exposed to 03 M NaOH + 06 M NaCl, both as aqueous solution and set with agar gel as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss electrocoagulation of waterborne polymers and coupling of anodic electropolymerization of (hetero) aromatics, and combine these two methods for corrosion protection of iron substrates.

Journal ArticleDOI
Kenneth B. Stokes1
TL;DR: Two cracking mechanisms have been identified, in vivo stress cracking and metal ion oxidation, both of which are controllable and do not necessarily preclude the use of polyether polyurethanes in implantable devices.
Abstract: Certain polyether polyurethanes have been shown to be biostable in long-term implant studies. Others retain good bulk properties, but have been shown to develop cracks on their tissue contacting surfaces. Two cracking mechanisms have been identified, in vivo stress cracking and metal ion oxidation. Stress cracking is the result of an interaction between the in vivo mammalian environment and residual stress (strain) in the implanted polymer. Mild autooxidation can be initiated by stress cracking. More extensive autooxidation can be initiated and propagated by corrosion of metallic device components, especially the corrosion products of cobalt. Both mechanisms are controllable, thus, do not necessarily preclude the use of polyether polyurethanes in implantable devices.

Journal ArticleDOI
TL;DR: The stability of YBa2Cu3O7−x in water and 100% humidity has been investigated at three temperatures using pH measurements, x-ray diffraction, and scanning electron microscopy as discussed by the authors.
Abstract: The stability of YBa2Cu3O7−x in water and 100% humidity has been investigated at three temperatures using pH measurements, x‐ray diffraction, and scanning electron microscopy. The oxide‐ceramic superconductor is highly unstable and reacts rapidly with water and also degrades in moisture. Dissolution of the oxide perovskite in water is highly incongruent. The corrosion products are found to be BaCO3, CuO, O2, etc. Barium hydroxide is first formed which further reacts with atmospheric CO2 to form needle‐shaped crystals of BaCO3. For any practical applications, devices made from these materials would have to be protected with an impermeable coating to prevent deterioration from atmosphere.


Journal ArticleDOI
Joong Keun Park1
TL;DR: In this paper, the influence of retrogression and reaging (RRA) treatments on high strength aluminium alloy 7075 was studied using hardness and tensile testing and by measuring the stress corrosion crack growth rate using doublecantilever-beam specimens.
Abstract: The influence of retrogression and reaging (RRA) treatments on high strength aluminium alloy 7075 was studied using hardness and tensile testing and by measuring the stress corrosion crack growth rate using double-cantilever-beam specimens. Transmission electron microscopy was used to study the microstructures at both the matrix and the grain boundary. The RRA treatments result in a significant improvement of the stress corrosion resistance of aluminium alloy 7075-T651 without sacrificing its maximum strength. The crack velocity decreases to a level comparable with that of the T73 structure as a result of the optimum RRA treatments. The initial strength decrease during the retrogression treatment is mainly due to a dissolution of small η′ particles. The coarsening of grain boundary precipitates occurs during the retrogression treatment. The steady state crack velocity decreases logarithmically with increase in the volume fraction of grain boundary precipitates.

Journal ArticleDOI
02 May 1988-Wear
TL;DR: In this paper, the wear rates of mild steel, zinc and magnesium specimens under simultaneous abrasion and corrosion were measured and compared with static corrosion and dry arborization rates.

Patent
08 Aug 1988
TL;DR: In this paper, the anti-microbial effect of a strong oxidizing agent, such as peracetic acid, is improved with a wetting agent, which is provided by triazole or other component for inhibiting the corrosion of copper and brass.
Abstract: Medical instruments, which may include brass, copper, aluminum, stainless steel, carbon steel, or plastic parts are sterilized or disinfected in an anti-microbial solution. The anti-microbial effect of a strong oxidizing agent, such as peracetic acid, is improved with a wetting agent. The solution further includes a triazole or other component for inhibiting the corrosion of copper and brass. Phosphates or other buffering agents adjust the oxidizing agent generally to a neutral pH for preventing the corrosion of steel. Molybdates or analogous compounds also buffer the pH and inhibit corrosion of aluminum by the oxidizing agent. The corrosion inhibiting is enhanced by the wetting agent. Optionally, a sequestering agent is provided for inhibiting hard water precipitation.

Journal ArticleDOI
TL;DR: The nickel/chromium ratio in the albumin and gamma globulin solutions was increased relative to that predicted indicating preferential release of nickel in protein solutions, indicating the effect of proteins on fretting corrosion is dependent on the charge on the protein.
Abstract: The objectives of this study were to determine the effect of proteins and protein charge on the corrosion of stainless steel. As Zwitter ions, proteins have a positive charge in solutions acidic to their isoelectric point (pI) and a negative charge in solutions basic to the pI. Fretting corrosion rates of stainless-steel plates and screws as determined by weight loss and metal ion release were studied in saline and protein solutions with the pH adjusted to 3, 5, and 8. Alterations in pH did not affect the corrosion rate in saline solutions. However, alterations of the pH in albumin solutions did affect the corrosion rate. In protein solutions acidic to the isoelectric point the presence of the positively charged albumin did not alter the corrosion rates as compared to that in saline. However, the presence of negatively charged proteins in solutions basic to their isoelectric points decreased the amount of corrosion. Thus, the effect of proteins on fretting corrosion is dependent on the charge on the protein. When the release of nickel was compared to the release of chromium, it was shown that the release was in proportion to the composition of the alloy when fretting corrosion took place in saline. The nickel/chromium ratio in the albumin and gamma globulin solutions was increased relative to that predicted indicating preferential release of nickel in protein solutions.

Journal ArticleDOI
TL;DR: Despite the more rapid corrosion observed in growing cultures relative to that in resting cultures, corrosion products that were isolated under strictly anaerobic conditions from the two culture modes had similar bulk compositions which varied with the phosphate content of the medium.
Abstract: A field isolate of Desulfovibrio desulfuricans was grown in defined medium in a two-stage continuous culture apparatus with different concentrations of phosphate in the feed medium. The first state (V1) was operated as a conventional chemostat (D = 0.045 h−1) that was limited in energy source (lactate) or phosphate. The second stage (V2) received effluent from V1 but no additional nutrients, and contained a healthy population of transiently starved or resting cells. An increase in the concentration of phosphate in the medium fed to V1 resulted in increased corrosion rates of carbon steel in both V1 and V2. Despite the more rapid corrosion observed in growing cultures relative to that in resting cultures, corrosion products that were isolated under strictly anaerobic conditions from the two culture modes had similar bulk compositions which varied with the phosphate content of the medium. Crystalline mackinawite (Fe9S8), vivianite [Fe3(PO4)2 · 8H2O], and goethite [FeO(OH)] were detected in amounts which varied with the culture conditions. Chemical analyses indicated that the S in the corrosion product was almost exclusively in the form of sulfides, while the P was present both as phosphate and as unidentified components, possibly reduced P species. Some differential localization of S and P was observed in intact corrosion products. Cells from lactate-limited, but not from phosphate-limited, cultures contained intracellular granules that were enriched in P and Fe. The results are discussed in terms of several proposed mechanisms of microbiologically influenced corrosion.

Journal ArticleDOI
TL;DR: The results with stainless steel showed that the weight loss and metal ion release from stainless steel in vitro and in vivo can be calculated using Faraday's Law, assuming release in proportion to alloy composition.
Abstract: A series of experiments was conducted to study in vitro and in vivo metal ion release and the urine excretion of metal ions. Metal salts were injected and urine analyzed. Anodic potentials were applied to stainless steel and cobalt-chromium-molybdenum (CCM) specimens to cause an acceleration of corrosion rates. Corrosion experiments were done in saline, 10% serum and in a subcutaneous space in hamsters. Corrosion rates were determined by measurements of weight loss and calculations of net charge transfer. Metal ion concentrations were determined with graphite furnace atomic absorption spectroscopy, and were calculated from total charge using Faraday's law. The results with stainless steel showed that the weight loss and metal ion release from stainless steel in vitro and in vivo can be calculated using Faraday's Law, assuming release in proportion to alloy composition. The results with CCM indicated that release rates in vitro can be used to determine the proportionality of release in vivo. All the nickel and most of the cobalt was rapidly excreted, while less than 50% of the chromium was excreted. The excretion of metals following salt injection or in vivo corrosion were very similar.

Journal ArticleDOI
TL;DR: In this paper, the corrosion rate of a Pt anode was studied in H2SO4 aqueous solution by measuring the weight loss, which increased linearly with time in the initial period of the corrosion at a fixed current density.

Journal ArticleDOI
David C. Silverman1
TL;DR: In this article, the rotating cylinder electrode has been used as a corrosion prediction tool for liquid flow, which can be accelerated by fluid flowing past a surface. All that are neede...
Abstract: Corrosion can be accelerated by fluid flowing past a surface. The rotating cylinder electrode has practical applicability as a corrosion prediction tool for liquid flow. All that are neede...


Journal ArticleDOI
TL;DR: In this article, the general corrosion behavior of Metglass 2826A was assessed as a function of heat treatment and surface finish by cyclic potentiodynamic anodic polarization, and the authors found that good passivity is achieved by a strong positive (+) Cr−B association and by interactions, (+) Ni−P, (−) P−B, which promote the formation of a Cr−A complex.
Abstract: The general corrosion behavior of , Metglass 2826A, was assessed as a function of heat‐treatment and surface finish by cyclic potentiodynamic anodic polarization. The general corrosion resistance of Metglass 2826A decreased in this order: supersaturated solid solution (SS) anneal, polished, as‐received, subcritical anneal ( then ) and a high temperature primary crystallization (MP) anneal. Ranking of the general corrosion resistance was correlated with the partitioning of elemental species as determined by AES analysis and through the definition of interaction parameters. Good passivity is achieved by a strong positive (+) Cr‐B association and by interactions, (+) Ni‐P, (−) P‐B, which promote the formation of a Cr‐B complex. Passivity is degraded by metal‐metal and metal‐metalloid mixing as reflected in the establishment of positive interactions for Fe‐Cr, Ni‐Cr, and Ni‐B.