Showing papers on "Corrosion published in 1968"
TL;DR: In other alloying variations some of the nickel is replaced with cobalt, in the formula TiNixCo1−x, is an effective substitution element for lowering the transition temperature as discussed by the authors.
368 citations
TL;DR: In this paper, a method is described to study subcritical crack growth in ceramic materials and large macroscopic size cracks were used and quantitative crack velocity measurements were made on glass and sapphire as a function of applied force, temperature and environment.
Abstract: A method is described to study subcritical crack growth in ceramic materials. Large, macroscopic size cracks were used and quantitative crack velocity measurements were made on glass and sapphire as a function of applied force, temperature and environment. The measured crack velocity was a complex function of stress and water vapor concentration in the environment and portions of the data could be adequately explained by the stress corrosion theory of Charles and Hillig.
198 citations
TL;DR: In this article, the effects of alloying additions on the intergranular corrosion of nonsensitized austenitic alloys in boiling nitric acid-dichrornate solutions have been determined.
Abstract: The effects of alloying additions on the intergranular corrosion of nonsensitized austenitic alloys in boiling nitric acid-dichrornate solutions have been determined. Controlled additions of C, N, O, Mn, S, Si and P to a high purity 14% Cr-14% Ni-bal Fe alloy and subsequent corrosion tests in boiling 5 N HNO3–0.46 N Cr+6 solutions have shown that only Si and P promote severe intergranular corrosion susceptibility of nonsensitized alloys. Elimination of Si and P from austenitic alloys of otherwise commercial purity decreases susceptibility to inter-granular attack by a factor of six to eight.
126 citations
TL;DR: In this article, it was shown that crevice corrosion occurs because of the development of a low pH in the solution within the crevice and is not specific to chloride solutions and that the corrosion occurred only in very restricted crevices and attack was greater the higher the salt concentration.
Abstract: Crevice corrosion of titanium in high temperature sodium chloride solutions was investigated. Corrosion occurred only in very restricted crevices and attack was greater the higher the salt concentration It was shown that crevice corrosion occurs because of the development of a low (~ 1) pH in the solution within the crevice and is not specific to chloride solutions. Crevice attack was demonstrated ion iodide, bromide and sulfate solutions. An electrochemical polarization technique was used to determine the effect of temperature and hydrogen and chloride ion concentrations on the corrosion of titanium and to determine the corrosion characteristics of several titanium alloys. Results indicate that titanium alloys containing sufficient molybdenum, nickel, or palladium are more resistant to nonoxidizing acid solutions than commercially pure titanium and, therefore, should be more resistant to crevice corrosion.
95 citations
TL;DR: In this article, the fracture, mechanical properties, stress corrosion and composition relations for maraging steel are reviewed, and a detailed review of fracture and mechanical properties of steel is presented.
Abstract: : Reviews fracture, mechanical properties, stress corrosion and composition relations for maraging steel.
74 citations
TL;DR: An investigation of failures of hard-drawn copper water pipes (phosphorus-deoxidised copper) in service due to pitting corrosion was conducted from November, 1962 to February, 1965.
Abstract: An investigation of failures of hard-drawn copper water pipes (phosphorus-deoxidised copper) in service due to pitting corrosion was conducted from November, 1962 to February, 1965 Fifteen cases were reported All those about which information could be obtained came from hot water installations and occurred in water with a low pH (≤7) and a HCO3- content of, at the most, 100 mg/l but generally below 50 mg/1 Failures not due to pitting corrosion (ie caused by erosion and corrosion or corrosion fatigue) occurred in waters with a higher pH and higher HCO3- contentA laboratory investigation into the ability of the corrosion products to counteract further corrosion in different types of water was also carried out, using an electrolytic cell which, in principle, was a model of an active pit in a copper tube This led to the following conclusions, which are in good agreement with the results obtained from the examination of service failures:If the pH value of the water is high enough, the copper dis
67 citations
TL;DR: Studies of cathodic polarisation of steel in sulphate-reducing bacteria growing without sulphate metabolism, but in the presence or absence of chemically prepared suspensions of ferrous sulphide, indicate that two distinct mechanisms of depolarisation can occur.
Abstract: Studies of cathodic polarisation of steel in sulphate-reducing bacteria growing without sulphate metabolism, but in the presence or absence of chemically prepared suspensions of ferrous sulphide, indicate that two distinct mechanisms of depolarisation can occur. In addition to utilisation of polarising hydrogen by the bacterial hydrogenase system, there is evidence for depolarisation of the cathode by solid ferrous sulphide. The form of the cathodic polarisation curves and the results of complementary weightloss experiments indicate that the second (sulphide) mechanism may make a major contribution to the overall corrosion.
65 citations
TL;DR: In this article, the structure and composition of thin oxide films formed during high temperature oxidation of an Fe-15%Cr-4%Al-1%Y alloy in CO 2 are reported.
59 citations
Journal Article•
01 Jan 1968-Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy
TL;DR: In this paper, the dezincification of copper-zinc alloys was studied by means of a potentiostat and an electron probe micro-analyser, and the electrochemical behaviour of α and α + β phase brasses were essentially similar to those of copper in a 3% NaCl aqueous solution.
Abstract: Dezincification of copper-zinc alloys has been studied by means of a potentiostat and an electron probe micro-analyser. The electrochemical behaviour of α and α + β phase brasses are essentially similar to those of copper in a 3% NaCl aqueous solution. The corrosion potential of copper-zinc alloys becomes less noble with increasing zinc content. The surface film consisting of Cu2O or CuCl is formed in the early stage of corrosion and a complex potential distribution is shown in the surface films and the matrix. The dissolution rates of brass are accelerated by the complex potential distribution, leading to dezincification. The process of dezincification is considered to be the redeposition of copper.
57 citations
TL;DR: In this article, the authors measured the rate at which Ag tarnishes under laboratory conditions which were realistic with respect to the levels of H 2 S, SO 2 and water vapour found under natural conditions and show the need for caution in designing accelerated tests.
56 citations
TL;DR: Experiments using resting-cell suspensions of the hydrogenase-positive sulphate-reducing bacterium, Desulfovidrio vulgaris have shown that the organisms can depolarize the cathodic areas of a mild-steel surface, utilizing the polarizing hydrogen for the reduction of a suitable substrate and stimulating corrosion of the steel to a degree equivalent to the hydrogen used.
TL;DR: In this article, the A.G.R. (Advanced Gas Cooled Reactor) fuel cans were heated in carbon dioxide and other oxidising gases at temperatures between 750 and 900° for periods up to 2500 h. Length increases of up to approximately 2% were observed, the growth being greater under conditions of thermal cycling than under isothermal conditions.
Abstract: Sample lengths from A.G.R. (Advanced Gas Cooled Reactor) fuel cans in 20Cr/25Ni/Nb and 18Cr/12Ni/Nb steels and specimens of thin 18Cr/8Ni/Ti foil have been heated in carbon dioxide and other oxidising gases at temperatures between 750 and 900° for periods up to 2500 h. Length increases of up to approximately 2% have been observed, the growth being greater under conditions of thermal cycling than under isothermal conditions. Extensions have been related in part to carbon pick-upand the formation of carbides but the major proportion of the observed extensions has been due to tensile stresses produced in the thin sectioned steels as a result of the oxidation processes.
TL;DR: Transgranular stress corrosion cracks are formed in Ti-5Al-2.5Sn alloy immersed in a 3 percent NaCl aqueous solution when tensile specimens are dynamically strained over a narrow range of...
Abstract: Transgranular stress corrosion cracks are formed in Ti-5Al-2.5Sn alloy immersed in a 3 percent NaCl aqueous solution when tensile specimens are dynamically strained over a narrow range of ...
TL;DR: In this article, the results of laboratory sulfide corrosion cracking tests on commercial steel alloys are presented, focusing on effects of environmental factors, alloy composition and metallurgical properties.
Abstract: Results of laboratory sulfide corrosion cracking tests on commercial steel alloys are presented. Emphasis is placed on effects of environmental factors, alloy composition and metallurgical...
TL;DR: In this article, a lepidocrocite film was used to protect the Cu against corrosion by polarizing the local cathodes, but the film had no detectable effect on the anodic dissolution of Cu.
TL;DR: In this paper, failure to passivate of a slip step produced at the tip of a transgranular stress-corrosion crack is discussed in detail, and the importance of ionic strength, anodic polarization, alloy compositional alterations and pH changes is considered.
TL;DR: The reaction kinetics between high purity oxygen and six binary Fe-Cr-alloys, containing 2-40% Cr, at temperatures between 650° and 950° have been studied for periods of up to 50 hours' duration.
Abstract: The reaction kinetics between high purity oxygen and six binary Fe–Cr-alloys, containing 2–40% Cr, at temperatures between 650° and 950° have been studied for periods of up to 50 hours' duration. A precise method of surface preparation was employed to secure reproducible results. Oxidised samples were investigated by metallography, electron-probe microanalysis and X-ray diffraction.In all cases the rate of oxidation decreased progressively with the duration of exposure although some short periods of increased oxidation were observed on some alloys at the lower temperatures. The scale thickness after 40 hours' oxidation varied from 0·3 μm at 650° to 14 μm at 950° for Cr-rich oxides and to 600 μm for Fe-rich oxides. The 20% Cr-alloy was generally the most resistant to oxidation. The 8% Cralloy was about as resistant as the others at 650°–750° but oxidised more rapidly at higher temperatures. For alloys containing more than 16% Cr, the activation energies for oxidation were almost constant over the ...
Patent•
02 Aug 1968
TL;DR: In this article, the authors present a scheme for the protection of Corridible Metallic Surfaces, which consists of a Binder and a Filler, with the FILLer being composed of a mix of conformive metals.
Abstract: A COMPOSITION SUITABLE FOR THE PROTECTION OF CORRODIBLE METALLIC SURFACES WHICH COMPRISES A BINDER AND A FILLER, THE FILLER BEING PRESENT IN AN AMOUNT SUFFICIENT TO IMPART CORROSION RESISTANT CHARACTERISTICS TO THE COMPOSITION. THE FILLER IS CONSITIUTED BY A MIXTURE OF CONDUCTIVE METAL PARTICLES WHICH ARE MORE ANODIC THAN THE METAL OF THE METALLIC SURFACE TO BE PROTECTED AND COMMINUTED REFRACTORY FERRO ALLOYS, THE REFRACTORY FERRO ALLOY BEING PRESENT IN AN AMOUNT SUFFICIENT TO ENCHANCE THE CORROSION PROTECTION AND EFFECTIVENESS OF THE METAL PARTICLES. VARIOUS BINDER MATERIALS, BOTH ORGANIC AND INORGANIC MAY BE USED AND THE FILLER IS PREFERABLY A MIXTURE OF ZINC PARTICLES AND THE REFRACTORY FERRO ALLOY.
TL;DR: In this article, the partial spalling that occurs upon cooling after high temperature oxidation has permitted the direct observation of the alloy-oxide interface, as well as the separated interfaces of the Alloy and the oxide.
TL;DR: In this paper, U-bend and axially loaded tensile-type specimens were used in stress corrosion tests performed in boiling 140 C (284 F) magnesium chloride solution.
Abstract: U-bend and axially loaded tensile-type specimens were used in stress corrosion tests performed in boiling 140 C (284 F) magnesium chloride solution. The experimental ferritic alloys tested contained 17 to 25% chromium, 0 to 4% nickel, 0 to 2% copper, and 0 to 5% molybdenum. Alloys essentially free of nickel and copper did not undergo stress corrosion cracking. (Tests on Types 430 and 434 stainless steels confirmed this behavior.) However, alloys containing more than 1% nickel or 0.5% copper were subject to transgi anular stress corrosion cracking in boiling magnesium chloride solution. Critical concentrations of copper and nickel that produce susceptibility to cracking were determined at various chromium and molybdenum levels. Experiments at controlled potentials indicated that cracking in boiling magnesium chloride was not the result of hydrogen embrittlement.
TL;DR: A critical review of the existing literature on the effect of velocity on the corrosion of Fe and steel in water has been made in this paper, where an analytical form required to portray the corrosion amount-time relationship for the steel pipe-water system has been established.
TL;DR: The mechanism by which Si additions affect corrosion behavior has been studied by corrosion testing, electrochemical polarization, electron microscopy, and electron diffraction techniques as mentioned in this paper, which indicates that the corrosion resistance is related to the formation of a Si-rich passive oxide film.
TL;DR: In this paper, the authors describe the failure mode due to corrosion at the contacting surfaces of static contacts in connectors and mechanical wiring connections, and show that this failure mode is due to growth of Cu 2 O film over all or part of the contact surfaces.
Abstract: This paper describes the failure mode due to corrosion at the contacting surfaces of static contacts in connectors and mechanical wiring connections. Copper static contacts with no mechanical separation fail to maintain electrical continuity when temperature-cycled from 20 to 200°C. Electron diffraction analysis and microscopic inspection show that this failure mode is due to growth of Cu 2 O film over all or part of the contacting surfaces. The lay? between the contact members is estimated to be 15 to 3250 A thick and the lifetime of the copper static contact at light loads is proportional to load.
TL;DR: In this paper, stress corrosion tests have been run in pressurized water at 600 F (316 C) using double U-bends and double bent beam specimens in autoclaves for up to 3000 hours.
Abstract: Stress corrosion tests have been run in pressurized water at 600 F (316 C) using double U-bends and double bent beam specimens. The tests were conducted in autoclaves for up to 3000 hours....
TL;DR: In this article, it is suggested that there are two operative processes: transgranular hydride formation and selective dissolution from α-grain boundaries, which can occur in any environment that discharges hydrogen in reaction with Ti and that can cause breakdown of the protective film.
01 Jan 1968
TL;DR: In this paper, the pore-blocking corrosion inhibitor and a lubricant coating having a liquid component were used to prevent corrosion and wear effectively, without significantly increasing contact resistance compared to untreated samples.
Abstract: The increasing reliability requirements for low-voltage electric contacts has led to a search for methods which could make gold plated surfaces impervious to the effects of atmospheric pollutants. The susceptibility of thin gold plate to corrosion is due both to its inherent porosity and its removal by wear. Because of these breaks in the plate, pollutants can attack the substrate metal or underplate to produce insulating corrosion products. The best methods were the application of a pore-blocking corrosion inhibitor and a lubricant coating having a liquid component. They 'inhibited corrosion and wear effectively, without significantly increasing contact resistance compared to untreated samples.