bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coatings Formed on Steel by Cathodic Protection And Their Evaluation by Polarization Measurements
Authors: SCHWERDTFEGER W. J. , MANUELE RAUL J. 
Published: February 2013

Abstract
Three steel specimens were continuously exposed in the laboratory for almost 5 years in city water to which was added 3 percent by weight of sodium chloride. Two of these specimens were under continuous cathodic protection, one by current from a zinc anode, and the other by current from a rectifier through a carbon anode. The third specimen was left to corrode freely.
As a result of the cathodic protection, carbonates and silicates formed protective coatings which eventually reduced the current density required for protection from about 5 to 0.02 ma/sq ft. A coated specimen, after being without protective current for 32 days (including 12 days out of the salt water), required only 0.3 ma/sq ft for initial protection.
The instantaneous corrosion rates on the coated specimens (scratched and unscratched) while without protective currents were measured by changes-in-slope (breaks) in polarization curves. The currents at which breaks occurred in the cathodic curves were found to be related to ΔV/ΔI values from the curves, which values in turn bore a relation to the corrosion rates as measured by weight loss.
Polarization Studies of Aluminum Alloys In Water at 200 C and 300 C
Authors: GREENBLATT J. H. , McMILLAN A. F. 
Published: February 2013

Abstract
Specimens of commercial 2S aluminum and two special alloys containing iron and nickel were polarized anodically and cathodically at a number of different current densities at 200 C and 300 C. Weight gains were obtained and the potentials relative to the stainless steel autoclave were measured by an interrupter method. The weight gain data indicated that the polarizing current is being carried by electronic conduction.
The potential-time curves for anodic polarization indicate differences between 2S aluminum and the alloys in that greater polarization is obtained with the latter. These curves also indicate that the impressed current decreases the film resistance. In all cases the potential reached a plateau value with time and this time was shorter for the alloys.
The potential-time curves for cathodic polarization also show plateau values but the rise to a plateau value is in the opposite sense to the applied current. With increasing cathodic polarization the plateau values occur at more negative values of the potential. This latter trend is in the same direction as the applied polarizing current. This apparently is explained in terms of the build-up of the aluminum oxidation potential which acts in a sense opposite to the applied current. Again the time to reach plateau values was shorter for the alloys.
Voltage current curves were also obtained on specimens left overnight (approximately 17 hours) at two different anodic polarizing currents. These curves indicated differences between 2S aluminum and the alloys; these differences are discussed in terms of the semi-conducting properties of the oxide film.
The observations made on the differences in the properties of the oxide films on the materials examined as revealed by potential and polarization curves are discussed as to their significance in determining corrosion resistance.
Effect of CO2 on the Strength and Ductility of Type 304 Stainless Steel at Elevated Temperatures
Authors: MARTIN W. R. , McCOY H. E. 
Published: February 2013

Abstract
One of the important problems in determining the usefulness of stainless steels as cladding materials in high-temperature gas-cooled reactors is the effect of chemical reactions between clad and coolant on the cladding strength and ductility. The mechanism by which the coolant (CO2 in this investigation) affects the strength properties of Type 304 stainless steel are being investigated in the range 1300 to 1700 F (704–927 C). Creep- and stress-rupture results obtained on sheet materials in wet and dry CO2 and argon are compared. The effect of annealing in CO2 on the tensile strength and ductility is also reported.
The question of whether the strengthening observed in CO2 was due to oxidation or carburization was investigated. Experiments on the effect of various partial pressures of oxygen in argon showed that the creep rate was minimum at approximately 10 ppm. The creep rate in CO2 at equivalent stress and temperature was one-third the minimum rate observed in oxygen. Chemical analyses, metallography, and experiments with isotopic carbon showed that carburization occurred in pure flowing CO2 in the temperature range studied. From this evidence it was concluded that the strengthening observed in CO2 was primarily due to carburization.
The creep- and tensile-fracture strains were adversely affected by exposure to CO2 with the magnitude of the effect dependent on the time and temperature of exposure.
Effect of Platinum, Copper and Iron Ions On Corrosion and Passivity of Titanium In 15 Percent Hydrochloric Acid
Authors: TOMASHOV N. D. , AL'TOVSKII R. M. 
Published: February 2013

Abstract
An investigation has been made of the effect on corrosion rate of titanium in 15 percent hydrochloric acid of introducing cations of more noble metals, particularly Pt4+, Cu2+ and Fe3+. It was found that such ions cause a shift in metal potential in the positive direction, enhancing the cathodic process and resulting in anodic passivity of the titanium.
In addition to acting initially as cathodic depolarizers, the noble metals deposit galvanically, forming more effective cathodic areas and further accelerating cathodic depolarization. However, in concentrations lower than those required to attain passivity, the noble metal ions increase rather than decrease the corrosion rate of titanium in 15 percent hydrochloric acid.
In the presence of the fluoride ion, Pt4+ ions accelerate the corrosion rate of titanium in HCI with increases in their concentration, the opposite of the effect when concentrating Pt4+ ions before fluoride is introduced.
Linear Polarization Measurements In the Study of Corrosion Inhibition
Authors: LEGAULT R. A. , WALKER M. S. 
Published: February 2013

Abstract
A reliable and accurate method of determining metal dissolution rates in a relatively short time is much needed in studies of corrosion inhibition. Weight-loss determinations on specimens supply only average rate data over the interval of the test. Rate determinations by chemical analysis of the corrosive environment are also subject to this limitation. Both of these methods are subject to errors arising from intermittent removal of the sample from the environment.
Knowledge of corrosion rate changes during the period of exposure is valuable to understanding of the mechanism of the reaction involved. The linear polarization method has been found very rapid and convenient for studying rate changes and evaluating corrosion inhibitors. It has also made possbile observations of the synergistic effects that may exist between inhibitor and environment.
Effect of Metal Composition and Structure On Corrosion and Oxidation
Authors: UHLIG HERBERT H. 
Published: February 2013

Abstract
Metallurgical factors such as heat treatment and cold-work are not important when corrosion in aqueous media is controlled by diffusion of reactants, e.g. dissolved O2, from the environment. They become important when corrosion control is focused at the metal surface, e.g. steel in acids. In this instance, galvanic cells depend less on where or how metal atoms are placed in their lattice, and more on compositional differences along the metal surface produced by heat treatment or plastic deformation.
At elevated temperatures, compositional gradients within a metal are less important. The rate depends instead on diffusion through thick corrosion product layers and on the tendency for spoiling to occur during temperature fluctuations. Metallurgical factors assume greatest importance during initial oxidation, or for thin film formation.
Electrodeposition of Iron from Aqueous Solutions Onto an Aluminum Alloy
Authors: COOK E. H. , McGEARY F. L 
Published: February 2013

Abstract
Heavy metal contaminants such as copper, nickel and cobalt have long been recognized as corrosion hazards in aqueous solutions because their reduction is a comparatively common electrochemical corrosion reaction. It has been known for many years that Fe (III) is corrosive to various metals if the ferric salt is soluble, that is, if the solution is sufficiently acid to maintain the Fe (III) ion in solution. Metals such as aluminum, zinc, cadmium, iron, etc., reduce Fe (III) to Fe (II). Furthermore, if dissolved oxygen is available, more corrosive conditions can result by the oxidation of Fe (II) to soluble Fe (III).
Recently a service situation was encountered where ferrous iron in solution was reduced to metallic iron as the result of electrochemical action in an aluminum alloy pipe handling a brine solution. This article describes the laboratory studies conducted to define the mechanism of iron electrodeposition on certain metal alloys from aqueous solutions. Methods to control or prevent such reduction are discussed.
Corrosion Characteristics Of the Rare Earth and Yttrium Metals
Authors: LEE LINDA , GREENE N. D. 
Published: February 2013

Abstract
The corrosion of rare earth metals in air, water, and aqueous solutions at different temperatures has been measured by conventional weight loss and weight gain tests. The metals oxidize slowly in air, corrode slowly in water and alkaline solutions, and are readily soluble in most acids.
Correlations of corrosion behavior with the electronic and physical properties of the rare earths are discussed.
Effect of Supplementary Alloying Elements On Pitting Corrosion Susceptibility Of 18Cr-14Ni Stainless Steel
Authors: TOMASHOV N. D. , CHERNOVA G. P. , MARCOVA O. N. 
Published: February 2013

Abstract
This investigation was conducted because the development of new alloys with increased resistance to pitting corrosion appears to be largely dependent on an understanding of the effects of various concentrations of alloying elements on the initiation and steady operation of localized pitting sites on the metal surface.
Corrosion tests in 0.5N FeCl3 and determinations of passivity breakdown potentials in 0.1 N NaCl were employed to study the pitting tendencies of 18 Cr-14Ni stainless steels to which alloying elements in various concentrations had been added. The alloying elements, chosen for their stability in solutions containing chloride ions and their solubility in austenite, were: Mo, Si, V, W, Ti, Ce, Nb, Ta, Zr and Re.
Mo, Si and V, respectively, at 5 percent concentration, had the most marked effect in increasing resistance to pitting. Re, even in concentrations below 1 percent, was also very effective. The other elements tested had either a negative influence or no effect.
Heat treatment in the dangerous temperature zone (650 C for 2 hours) greatly impaired the resistance of steel alloyed with 5 percent Mo, Si or V, which is not susceptible to pitting corrosion in the quenched state.
Morphology of Stress-Corrosion Cracks In Notched Specimens of Austenitic Stainless Steels
Authors: SCULLY J. C. , HOAR T. P. 
Published: February 2013

Abstract
The pattern of stress-corrosion cracking of notched specimens of an 18 Cr-8 Ni austenitic stainless steel stressed in 42 percent aqueous magnesium chloride solutions is described. It illustrates the action of both tensile and shear stresses in promoting fracture: cracks are nucleated along directions of maximum shear strain and their propagation paths are determined by these and the acting tensile stress.
Passivity of Chromium and Stainless Steel In Hydrofluoric Acid
Authors: SEASTROM C. C. 
Published: February 2013

Abstract
The anodic polarization of chromium and 18Cr-8Ni stainless steel has been investigated in 2 to 48 percent hydrofluoric acid, 40 percent sulfuric acid, and in a solution containing 5 percent hydrofluoric acid and 40 percent sulfuric acid. Chromium can be anodically protected in hydrofluoric acid. The corrosion rate of stainless steel in hydrofluoric acid can be reduced by anodic protection but less than is possible in sulfuric acid. The dissolution rate of passive stainless steel in 5 percent hydrofluoric acid plus 40 percent sulfuric acid is similar to the rate in 5 percent hydrofluoric acid. The breakdown of the passive film on stainless steel probably is accelerated by the formation of stable ferric fluoride complex ions.
Mechanism of Electrochemical Corrosion Of Metals Under Insulating Coatings. II. Kinetics of Cathodic Processes On Insulated Metals in Electrolytes
Authors: TOMASHOV N. D. , MIKHAILOVSKII YU N. , LEONOV V. V. 
Published: February 2013

Abstract
1. Investigations were made of the kinetics of the cathodic process on metal surfaces coated with thin insulating films. It was established that enhancement of the cathodic reaction on insulated electrodes at definite potential values is connected with the emergence of electronic conductivity of the film. Along with this, there can also be observed a nonreversible process of electrochemical perforation of the protective film by the active ions in the electric field.
2. Studies were made of the mechanism possibly involved in the corrosion of metals under porous insulating films. It was shown that on metals with a static potential in the region of emerging electronic conductivity in the film, the cathodic process is active not only on the metal surfaces exposed by the film pores but also on the very thin sections of the insulating film.
Minimizing Corrosion In Uranium Extraction Solutions By Application of Anodic Protection
Authors: ROBINSON F. P. A. , GOLANTE L. 
Published: February 2013

Abstract
Anodic protection was applied to certain special alloys following an investigation into their anodic polarization characteristics in 0.1 percent HNO3 + 5 percent HCOOH + 20 percent NH4F solution saturated with SO2. The effectiveness of this method of corrosion prevention was confirmed by the large reduction in corrosion rate. In addition, intercrystalline corrosion, knifeline attack and weld corrosion were appreciably reduced on application of this technique.
Sulfates in the Passive Iron Layer
Authors: RIGGS O. L. 
Published: February 2013

Abstract
Anodic polarization data were obtained on iron in 20 N H2SO4 at 25 C (77 F). Along the polarization curve, the potential was held constant at 20 mv increments and the current was recorded at the end of 60 minutes. Minimum currents, the average of four experiments, were noted at 260, 520, 810, 1060, 1320 and 1600 mv noble potential with reference to the saturated calomel electrode (S.C.E.).
The various chemical compositions were identified with reproducible X-ray diffraction data. A technique involving an ethyl alcohol rinse permitted the X-ray study of the passive surface. The passive iron layer was identified as FeSO4.H2O, Fe2(SO4)3 H2O,FeSO4.4H2O and as FeSO4.7H2O at 260, 520, 810 and 1320 mv noble to S.C.E., respectively. The structures were reported to be responsible for the steady-state minimum currents. The X-ray diffraction values of the specimens held at 1060 and 1600 mv (S.C.E.) were not identified.
The anodic polarization curve was discussed in terms of specific electrochemical events.
Elevated Temperature Stress Corrosion Resistance of Titanium Alloys
Authors: NEWCOMER R. , TOURKAKIS H. C. , TURNER H. C. 
Published: February 2013

Abstract
A number of titanium alloys considered suitable for use in Mach II and III transports were tested for resistance to stress corrosion in the presence of chlorides. These included 4A1-3Mo-1V, 6A1-4V, 8A1-1M0-1V, 5A1-2.5Sn and RS-140. Samples were exposed stressed (smooth and fatigue pre-cracked) at 600, 700 and 800 F (316–427 C) 100 hours for smooth and 50 hours for precracked specimens. Welded and heat-treated specimens were among those tested.
All alloys were found susceptible to stress corrosion cracking. Welding appeared to increase susceptibility, but existing fatigue cracks did not seem to increase susceptibility.
Corrosion of Iron in an H2S-CO2-H2O System Composition and Protectiveness of the Sulfide Film as a Function off pH
Authors: SARDISCO J. B. , PITTS R. E. 
Published: February 2013

Abstract
Composition and protectiveness of the-iron sulfide film, formed as a result of the liquid phase H2S-CO2-H2O corrosion of Armco iron, have been related to the initial pH of the solution. Composition of the film was determined by electron diffraction analysis. Protectiveness of the film was determined by measuring the weight loss of iron specimens previously corroded and covered by sulfide films formed in H2S-CO2-H2O solutions of different pH values.
Composition and the protectiveness of the iron sulfide film were affected by the initial pH of the H2S-CO2-H2O solution. The film was least protective in the pH region of about 6.5 to 8.8. The film that was least protective contained essentially kansite, whereas the film that was most protective contained pyrite and troilite along with kansite.
Because the HS− anion is the predominant species in the pH region of about 6.5 to 8.8, it is indicated that the HS− was at least partially responsible for the film being less protective.
A Critical Survey off Possible Factors Contributing to Internal Boiler Corrosion
Authors: HOLMES D. R. , MANN G. M. W. 
Published: February 2013

Abstract
Main factors contributing to boiler corrosion are reviewed. Published data and work at authors' laboratories on the following causes of boiler pitting and corrosion are reviewed and discussed: Dissolved oxygen, copper deposition, concentration of sodium hydroxide, phosphate hideout, suspended solids, chlorides, thermal effects, thermogalvanic effects, breakdown of magnetite films from cyclic expansion and contraction, strain, weld and tube defects, compositional inhomogeneities.
Authors believe caustic and chloride attacks are mutually exclusive but that they may be found in combination with others. Changes in attitude about magnetite caused by recent discoveries indicate that radical concept changes can be expected.
Effect of Metallic Additives On Mercury Corrosion of Titanium
Authors: WANG JAMES Y. N. 
Published: February 2013

Abstract
Mass transfer of nickel to the hot leg (454 C, 850 F) of a mercury thermal convection loop in which titanium samples were exposed has been observed. This involved dissolution of nickel in mercury at 320 C (608 F), its transfer to the surface of the sample in the hot leg, and subsequent interdiffusion of nickel and titanium. Microprobe study of surface layers on the titanium sample indicated stratification of nickel. Outer layer contained two materials with compositions closely approximating those of TiNi and TiNi3, and an inner layer a material with nickel content close to the reported solubility limit for nickel in β-Ti, even though the reaction was conducted below α-β transformation temperature. Effects of other metallic additives are also discussed.
General Concepts of Gas-Metal Reactions
Authors: GULBRANSEN EARL A. 
Published: February 2013

Abstract
A metal in a gas atmosphere at high temperature is a complex chemical system. The metal usually is not pure but contains in addition to metallic impurities O, N, H, C, S, etc. The gas atmosphere also is usually complex, containing (in addition to O2) N2, H2, CO2, H2O, etc, A wide variety of chemical and physical phenomena occur in and on the metal surface in a typical gaseous environment at high temperature. The various phenomena are systematized into five zones of activity: metal, metal-oxide interface, oxide, oxide-gas interface, and gas.
The general concepts are considered by setting down classification schemes of diverse observations and phenomena. Eight classification systems are given, then discussed. These are (1) type of reaction, (2) sign and magnitude of free energy change, (3) extent of reaction, (4) crystal structure, (5) empirical and theoretical rate laws, (6) physical and chemical properties of metal and oxide, (7) topology of metal and reaction product and (8) effect of reaction on metal or environment.
Stress Corrosion Behavior Of Maraging Nickel Steels In Natural Environments
Authors: DEAN S. W. , COPSON H. R. 
Published: February 2013

Abstract
Stress corrosion cracking behaviors of several laboratory and commercially produced heats of 18, 20 and 25 percent Ni maraging steels have been observed in marine and industrial atmospheres and in sea water. Resistance of 18 percent Ni maraging steels was strongly affected by their structure and thermal histories. In properly processed materials rate of growth of stress corrosion cracks was low in most environments tested, and many stressed specimens lasted more than 500 days. Lower-yield-strength 18 percent Ni maraging steels were more resistant to stress corrosion cracking than higher strength alloys, also more resistant to hydrogen cracking when cathodically protected in sea water. Composition affected behavior of maraging steels, 20 percent Ni materials having relatively poor resistance and 25 percent Ni maraging steels good resistance, particularly in anoveraged condition. Control specimens of AISI 4340 steel hardened to 240-ksi yield strength failed rapidly in all test environments and conditions.
Anodic Polarization Behavior Of Nickel-Chromium Alloys In Sulfuric Acid Solutions
Authors: MYERS J. R. , BECK F. H. , FONTANA M.G. 
Published: February 2013

Abstract
Anodic polarization behavior of annealed high-purity Ni, Cr and selected Ni-Cr alloys in hydrogen-saturated, 1, 5, 10 and 20N sulfuric acid solutions was investigated at 25 ± 1 C (77 F) using a potentiostatic technique. All specimens except pure Ni in 20N acid had an active-to-passive transition. Decreasing acid concentration increased passive potential range of pure Ni while acid concentration did not appreciably affect the passive region of pure Cr or the Ni-Cr alloys. Increasing acid concentration and decreasing chromium content increased the secondary passivation tendency in the transpassive region. No oxygen evolved in the transpassive region except for pure Ni and the higher nickel alloys. Tafel slopes for anodic dissolution, early transpassive region and oxygen evolution were determined.
Corrosion potentials for pure Ni and Ni-Cr alloys containing up to 90 w/o Cr behaved as a reversible hydrogen electrode over the pH range 1.63 to −0.44. This linear relationship did not exist for the higher acid concentrations. Slope dependence for pure Cr and the 99Cr-1Ni alloy was −0.110.
A minimum in critical current density versus percent Cr curves was established at 90 to 95 w/o Cr. Passivation potentials were determined. Passive current density decreased with increasing chromium content over the composition range 0 to 33 w/o Cr.
It was established that increased specimen purity decreases the magnitude of critical current density and shifts corrosion and passivation potentials in the noble potential direction.
Oxidation Of A Ni-2 Percent ThO2 Alloy And The Logarithmic Rate Law Of Oxidation
Authors: JONES D. A. , WESTERMAN R. E. 
Published: February 2013

Abstract
The oxidation of pure nickel containing a dispersion of submicron size ThO2 particles was investigated in the range 600 to 1000C (1112–1832 F). At 600 and 700 C oxidation was described by a parabolic equation. At 950 and 1000 C a mixed parabolic relationship (partial control by an interface reaction) applied. Logarithmic oxidation, concurrent with a minimum in the oxidation rate, occurred at intermediate temperatures of 800, 850 and 900 C. The partially controlling interface reaction at 95(3 and 1000 C is interpreted to be activated adsorption of oxygen at the oxygen-oxide interface. A logarithmic rate law for oxide film formation is derived by considering oxygen adsorption as the controlling process.