Showing papers in "Corrosion Science in 1990"

TL;DR: In this article, the authors used a Kelvin probe as a reference electrode for the measurement of electrode potentials and showed that the potential drop across the oxide scale formed on top of the iron surface is small if the surface is kept in a humid environment (e.g. 95% relative humidity).

TL;DR: In this paper, the corrosion properties of pure iron and the alloys Fe-0.5Cu and Fe-3.4Cu are investigated during several wet/dry transitions, and the corrosion potential is measured with a Kelvin probe without touching the surface under investigation.

TL;DR: In this paper, a circuit was presented which allows the measurement of polarisation curves on metal surfaces which are covered by electrolyte layers as thin as 2 μm, and the circuit does not need any Luggin capillary but uses a Kelvin probe as a reference electrode which does not touch the surface under investigation.

TL;DR: In this article, a review is made of essential subjects on the passivtion process, the passive film, and the film breakdown, which is followed either by repassivation or by pitting corrosion depending on the degree of metal salt enrichment at the break sites.

TL;DR: In this article, the ESCA analysis of the passive film formed on stainless steel (20Cr18Ni6MoO.2N) during polarization in 0.1 M HCl + 0.4 M NaCl was presented.

TL;DR: In this article, surface nitrides were generated electrochemically at room temperature on the surface of high purity samples of Cr, Mo, Fe and Ni and on the surfaces of types 304, 317LX, 904L and AL6X stainless steels.

TL;DR: The role of inclusions as initiators of pitting corrosion has been studied from the very inception of attack in stainless steel 316 relative to the bulk composition as mentioned in this paper, and it is suggested from this investigation that corrosive attack starts on MnS inclusions or on small MnS precipitates associated with oxide inclusions.

TL;DR: In this article, the inhibitive action of thiourea, allylthioure and n-phenylthiamourea on the corrosion behavior of martensitic 410 stainless steel in 1 N H2SO4 was investigated using weight loss measurements, potentiodynamic polarization and scanning electron microscopy.

TL;DR: In this paper, the anodic dissolution and hydrogen evolution current densities in the pit were both constant with time and the pit morphology was dependent on the pit growth potential, indicating that mass transport was rate limiting.

TL;DR: In this paper, the results from morphological studies on aluminum pitting in chloride solutions are discussed on the basis of in situ optical microscopy observation of pit propagation, and it is shown that corrosion tunnelling plays the prominent part, irrespective of chloride concentration, electrolyte temperature or the value of the applied electrode potential.

TL;DR: In this paper, a theoretical model is developed to evaluate transport processes and chemical reaction in crevices and pits, which is general in form, allowing application to a variety of systems.

TL;DR: In this article, the localized corrosion behavior of some nickel titanium shape memory alloys in chloride environments has been studied and it has been shown that localized corrosion resistance of Ni-Ti alloy is increasing in the following order: Ni- Ti-Ti, Ti-6AI-4V, and Ti-746.

TL;DR: In this paper, it is shown how difficult it sometimes is to obtain direct information on this reaction on the basis of the diagrams obtained, and the use of peelable films has been demonstrated to be very useful for this research.

TL;DR: In this article, a birth and death stochastic model was used for analyzing the distribution of induction time of pit generation as well as pitting potential, which is defined as a potential at which the rate of pitting generation is equal to the level of pit repassivation.

TL;DR: In this paper, the authors used repassivation kinetics of metals to detect passivity breakdown in metals; a step which followed by localized acidification leads to pitting and crevice corrosion.

TL;DR: In this paper, the XPS and UPS signals in the transpassive range are interpreted by a change of Ni(OH)2 to NiOOH on the basis of a simple semiconductor model.

TL;DR: In this article, the pionner works of Fritz Haber, Walther Nernst, Ulick Evans and Carl Wagner are paid tribute to the pioneer works of the electrochemical thermodynamics and kinetics.

TL;DR: In this paper, the sputter-deposition method is successfully used for preparing amorphous AlTi, AlZr, Al ǫ, Al nb, Alǫ and Ta alloys in wide composition ranges and their corrosion behavior was investigated in 1 M HCl at 30°C.

TL;DR: In this paper, the prediction of corrosion rates of copper and cupronickel in flowing seawater (up to 16 m per second) and for filmed copper and Cupronickel up to 3.5m per second).

TL;DR: In this paper, a general model was proposed to explain the divergencies at the metal/film and film/solution interfaces and within the film giving rise to an enrichement or depletion of some of the components.

TL;DR: In this article, the existence of a thin intermediate layer composed of phosphatic rust was found between the outer and the inner layers showing that phosphorus in steel is converted to phosphatic compound during the protective rust formation.

TL;DR: The ennoblement of the electrode potential is caused not by the metabolism but by the metabolite of the sea diatoms included in the thin organic film under the slime layer as mentioned in this paper.

TL;DR: In this article, the authors studied the behavior of titanium in HNO3-HF pickling baths and understood the titanium dissolution process in such solutions using the passivation models described in the literature.

TL;DR: In this paper, the chromium concentration along grain boundaries of sensitized austenitic 308 stainless steel was measured as a function of sensitizing treatment and the results were compared to values of chromium depletion calculated from several theoretical models.

TL;DR: In this article, a single pit was produced on binary iron-chromium (Fe17Cr), iron-molybdenum (Fe1Mo, Fe3Mo, and Fe5Mo), and ternary ironchromium-mophium alloys (Fe 17CrxMo, x = 1, 3, 7 w%) in 1 N H 2 SO 4 with Cl − additions (0.02 to 0.08 molar).

TL;DR: In this paper, it was shown that galvanized steel in the presence of chlorides is controlled by the medium pH, which depends on the calcium or sodium salt which provides the chloride ions.

TL;DR: In this article, photoelectrochemical and ESCA methods were applied to the passive films formed on a variety of amorphous NiTi alloys and pure titanium in a deaerated sulfuric acid at 303 K polarized at various anodic potentials.

TL;DR: In this paper, three zinc-rich coatings, two with polyamide cured epoxy binders and one with an ethyl silicate binder applied to grit blasted mild steel were chosen for examination.

TL;DR: The sulfidation and sulfidation-oxidation processes with and without preoxidation of the alloys Fe20Cr and Fe20Cr12Ni have been studied in H 2 ǫ-H 2 O-mixtures at 973 and 1173 K, applying thermogravimetry, tracer (35 S) studies and several analytical and microscopic techniques as mentioned in this paper.