Showing papers on "Corrosion published in 1987"
TL;DR: In this article, film-induced stress-corrosion cracking (SCC) was studied for many metals including stainless steels, Cu-Al alloys, α-brasses, and pure copper.
437 citations
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05 Jan 1987
TL;DR: In this paper, the authors discussed standards and standards organizations preparation of test pieces conditioning and test atmosphere tests on unvulcanized rubbers density and dimensions short-term stress and strain properties tensile stress/strain dynamic stress, friction and wear creep, relaxation and set fatigue electrical tests thermal properties effect of temperature environment resistance permeability adhesion, corrosion and staining.
Abstract: General considerations standards and standards organizations preparation of test pieces conditioning and test atmosphere tests on unvulcanized rubbers density and dimensions short-term stress and strain properties tensile stress/strain dynamic stress and strain friction and wear creep, relaxation and set fatigue electrical tests thermal properties effect of temperature environment resistance permeability adhesion, corrosion and staining. Appendices: national standards bodies thermal equilibrium times for non-ambient testing.
233 citations
TL;DR: The most important bacteria that play a significant role in the corrosion process are those involved in the sulfur cycle, such as sulfate reducing bacteria (SRB), which are the most significant bacteria found in microbial corrosion processes as discussed by the authors.
Abstract: Publisher Summary Microorganisms play a significant role in the corrosion process. This chapter reviews the deterioration or corrosion of metals induced by the activities of microorganisms. The microorganisms which have been associated with corrosion involve many genera and species. They may be divided into three groups: bacteria, fungi, and algae. The most important bacteria that play a significant role in the corrosion process are those involved in the sulfur cycle. These include those involved in the oxidation as well as in the reduction of sulfur. Of these two groups, the sulfate reducing bacteria (SRB) are the most significant bacteria found in microbial corrosion processes. A fungus, Cladosporium resinae, found to be involved in the corrosion of aluminum integral to fuel tanks of subsonic aircraft, leading to wing perforation and loss of fuel. It is now believed that the aluminum corrosion is caused by carboxylic acid production. Algae appear to have the potential for inducing corrosion by virtue of their role in production of oxygen, corrosive organic acids, and nutrients for other corrosive microorganisms. It is found that in areas where there is decay of the mat the pH was lowered, probably due to the production of corrosive organic acids, causing differential pH corrosion cells as well. Conditions were also found to be rendered favorable for the growth of SRB.
222 citations
TL;DR: An overview of the microbiology of sulfate-reducing bacteria (SRB) and their detrimental effects in oil technology and summarizes a study on SRB in an oil field is presented in this paper.
Abstract: This paper presents an overview of the microbiology of sulfate-reducing bacteria (SRB) and their detrimental effects in oil technology and summarizes a study on SRB in an oil field. SRB are a group of specialized microorganisms that occur in aqueous environments in the absence of oxygen. The main nutrients for SRB are simple organic acids and molecular hydrogen (H//2) from decomposing natural organic matter. The nutrients are oxidized, with sulfate being reduced to sulfide (hydrogen sulfide, H//2S). The formed H//2S is the principal agent in the disastrous effects caused by SRB. It contaminates gas and stored oil, precipitates ferrous sulfide that plugs injection wells, and promotes corrosion of iron and steel in the absence of oxygen (anaerobic corrosion). Another principal mechanism by which SRB are involved in corrosion is their ability to depolarize iron surfaces by consumption of cathodically formed hydrogen.
217 citations
TL;DR: A review of the literature on this modelling is presented with particular reference to crevice and pitting corrosion as discussed by the authors, and both the achievements and the weak areas of the current state of corrosion modelling are demonstrated.
196 citations
TL;DR: In this article, the anodic behavior of high purity stainless steels based on a 316L composition was studied at room temperature in HCl solutions from 1 to 6 M. The effect of 0.22% nitrogen has little or no effect on the active dissolution kinetics at low overpotentials.
193 citations
TL;DR: In this paper, a mechanism for stress corrosion cracking (SCC) is developed from simple metallurgical principles and assuming that high surface mobility is present in the process, and an equation is found for crack velocity as a function of surface mobility and stress concentration at the tip of the crack.
183 citations
TL;DR: In this article, a new method is described, which allows the investigation of the corrosion of metals, covered by ultrathin electrolyte layers, free of a direct contact with the electrolyte film using a Kelvin probe and a differential pressure meter, respectively.
166 citations
TL;DR: In this article, the oxide films that develop on type 304 stainless steel in lithiated high temperature water are examined by scanning electron microscopy and Auger electron spectroscopy, showing that the precipitated outer layer of iron-rich oxide crystals affords no protection against corrosion.
155 citations
TL;DR: In this paper, the atmospheric corrosion of pure iron and the binary alloy Fe-0.5Cu has been analyzed by a simultaneous measurement of the anodic current density of the metal dissolution and the cathodic currentdensity of the O2 reduction reaction during several wet/dry cycles using a magnetic and a gas volumetric technique, respectively.
151 citations
TL;DR: Pitting of Al-based alloys can be detected by characteristic changes in the low-frequency region of the impedance spectra as discussed by the authors, which can be found in SIC/Al surfaces.
TL;DR: The performance of gas turbines has been improved by the development of alloys with progressively increasing high-temperature capabilities as mentioned in this paper, while both strength and corrosion resistance are importan-...
Abstract: The performance of gas turbines has been improved by the development of alloys with progressively increasing high-temperature capabilities. While both strength and corrosion resistance are importan...
TL;DR: In this article, the grain boundary segregation of magnesium is examined with reference to both direct and indirect experimental evidence for magnesium segregation, and evidence to support both equilibrium and non-equilibrium segregation is presented.
TL;DR: In this paper, a review of recent work on the corrosion resistance and electrocatalytic properties of glassy metals is presented, in terms of the roles played by the composition, both of metal and metalloid, and by the structure.
TL;DR: One of the major causes of magnesium corrosion is the presence of iron as an impurity in commercial alloys, and Alloying the material with manganese may reduce the corrosion rate to acceptable levels.
Abstract: One of the major causes of magnesium corrosion is the presence of iron as an impurity in commercial alloys. Alloying the material with manganese may reduce the corrosion rate to acceptable...
TL;DR: In this article, high temperature Pourbaix-type diagrams are used to interpret the basicity-dependent solubilities for NiO, Co3O4, Al2O3, iron oxides, Cr 2O3 and SiO2 in fused Na2SO4 at 1200 K.
TL;DR: The nitrogen-ion implantation process was found to significantly improve the material's resistance to wear-accelerated corrosion in both saline and serum solutions.
Abstract: The influence of nitrogen-ion implantation on the wear-accelerated corrosion behavior of surgical Ti-6Al-4V was studied. Non-passivated and prepassivated unimplanted Ti-6Al-4V specimens were employed as controls for comparison. Corrosion rates as a function of time at open-circuit corrosion potentials were electrochemically measured in saline and serum solutions under both static and wear conditions. The wear parameters simulated those of a total artificial hip under average walking conditions. The results indicated that prepassivation of the control material was beneficial under static-corrosion conditions, but not under wear-corrosion conditions. The nitrogen-ion implantation process was found to significantly improve the material's resistance to wear-acceler-ated corrosion in both saline and serum solutions.
TL;DR: Cobalt-based alloys have been in use for several decades in the manufacturing of various components such as vanes or combustion chambers in gas turbines (both the industrial type and aeroengines) as discussed by the authors.
TL;DR: In this article, an extensive literature review and assessment of corrosion failure mechanisms encountered during accelerated tests of microelectronic devices is presented, focusing on the failure mechanism of electrolytic metal migration.
Abstract: This paper presents an extensive literature review and assessment of corrosion failure mechanisms encountered during accelerated tests of microelectronic devices. The failure mechanism of primary emphasis is electrolytic metal migration. The metallurgies of interest are silver, gold, copper, and aluminum. Electrochemical investigations of dendritic growth are also reviewed. Mechanistic results from the electrochemical investigations are discussed in light of the empirical results of accelerated tests.
TL;DR: Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments and results imply that methylmercaptan cannot be degraded byThiobACilli.
Abstract: Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli.
TL;DR: In this article, it was shown that the crack velocity-strain rate relationship in the presence of multiple cracked specimens can be computed by considering the number of cracks, in which case it is possible to calculate (involving electrochemical data) the crack velocities.
Abstract: One of the problems in relation to predicting the rates of defect growth in structures displaying stress corrosion cracking (SCC) is that knowledge relating to realistic stress corrosion crack velocities is very limited. In monotonic slow strain rate tests (SSRTs) taken to total failure at usual strain rates and in tests on precracked specimens at stress intensity factors in excess of KISCC, stress corrosion crack velocities may be appreciably higher than are likely to occur in service, except in the very late stages of crack growth before a service failure. These differences probably develop partly because of differences in the effective crack tip strain rate, and consideration is given to various expressions for calculating the latter from the applied strain rate. For multiple cracked specimens, as in SSRTs, the importance of considering the number of cracks is demonstrated, in which case it is possible to calculate (involving electrochemical data) the crack velocity-strain rate relationships i...
TL;DR: In this article, the role of the plasma environment for reactive deposition of nitrides, carbides, carbonitrides and oxides is discussed, as well as various applications of this technology to wear resistance, corrosion resistance and decorative coatings.
Abstract: This paper reviews the cathodic arc plasma deposition processes with emphasis on the role of the plasma environment for reactive deposition of nitrides, carbides, carbonitrides and oxides. Also reviewed are various applications of this technology to wear resistance, corrosion resistance and decorative coatings.
TL;DR: In this article, the reaction kinetics of Nd-Fe-B type magnets in oxidizing environments were analyzed using scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX).
Abstract: This corrosion study was performed to determine the reaction kinetics of Nd‐Fe‐B type magnets in oxidizing environments. Thus the oxidation model developed provides basic information for the development of oxidation‐resistant magnets. The oxidation of Nd‐Fe‐B magnets was studied at temperatures between 20 and 150 °C. The oxidation rates of the magnets were measured as functions of humidity in air, temperature, and alloy composition. Aerated salt and distilled water, at room temperature, were used as accelerating environments. The morphology of the reaction products was analyzed with scanning electron microscopy (SEM) and energy dispersive x‐ray analysis (EDX) and used to aid the interpretation of the reaction kinetics. The kinetics for the oxidation of magnets generally exhibit a parabolic weight increase in humid air at room temperature. Minor alloying additions affect the corrosion rate. In aerated distilled water, Nd‐Fe‐B magnets generally exhibit a linear weight loss. The magnets in aerated salt water show an inverse parabolic weight loss. Magnetization of the magnets substantially reduced the oxidation rate in the salt water test. The oxidation mechanism will be discussed.
TL;DR: In this article, the rise in contact resistance of a tin-plated copper alloy under cyclical minute motion has been studied for both dry circuit and with electrical loads, and a consistent picture of fretting corrosion and electrical conduction through such contacts is presented.
Abstract: The rise in contact resistance of a tin-plated copper alloy under cyclical minute motion has been studied for both dry circuit and with electrical loads. In the range of circuit voltage and current investigated, the electrical conduction through slightly corroded contacts is shown not to be affected by the electrical load. For moderately corroded contacts, the resistance characteristic shows a sustained plateau near the melting voltage of Sn; and for severely corroded contacts, plateau occurs in the resistance range corresponding to the voltage range of the melting, sublimation, and decomposition of the oxides and the vaporization of tin. Based on our observation, a consistent picture of fretting corrosion and electrical conduction through such contacts is presented.
TL;DR: The ion implantation processing was found to reduce the wear corrosion rates in both saline and serum solutions at all applied stress levels, and during wear testing, all of the ion-implanted surfaces remained visually unchanged from the polished condition.
Abstract: Wear-accelerated corrosion rates at constant anodic potentials were evaluated for unimplanted and nitrogen-ion-implanted surgical Ti-6Al-4V while wearing against ultrahigh-molecular-weight polyethylene at stress levels up to 6.90 MPa (1000 psi). The ion implantation processing was found to reduce the wear corrosion rates in both saline and serum solutions at all applied stress levels. During wear testing, all of the ion-implanted surfaces remained visually unchanged from the polished condition. However, many of the unimplanted surfaces developed damage zones characterized by wear tracks and black wear debris. A surface-damage mechanism is proposed and discussed which involves disruption of the Ti-6Al-4V protective oxide film, subsequent entrapment of oxide particles in the polyethylene, then self-perpetuating damage due to the abrasive action of the embedded particles.
TL;DR: In this paper, the adsorption on Cu of the corrosion inhibitors benzotriazole (BTA), 2-mercaptobenzothiazole (2-MCO), 2MCO, 2M CO, 2-MERCO, 3M CO and 4MCO were characterized in both neutral and acid chloride solutions using electrochemical techniques and surface enhanced Raman spectroscopy.
TL;DR: In this paper, the conditions in a simulated crevice have been studied for type 304 stainless steel and for 7475 T651 Al-ZnMg alloy in 0.6 M NaCl bulk solutions.