bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anodic Polarization of Anodized Aluminum
Authors: JONES D. A. 
Published: February 2013

Abstract
Potentiostatic anodic polarization of anodized coatings on aluminum was sensitive to both coating thickness and degree of seal. The polarization behavior of anodized coatings parallels their performance in atmospheric service. Thus, anodic polarization could be used as a test for the atmospheric corrosion resistance of anodized coatings. The advantages of an anodic polarization test are discussed.
Corrosion Behavior of Nickel-Chromium-Iron Alloy 600 in Borated Pressurized Water Reactor Environments
Authors: VAN ROOYEN D. , COPSON H. R. , BERRY W. E. 
Published: February 2013

Abstract
Corrosion tests were run for periods up to 5000 hrs in borated water at 600 F (316 C) in a high velocity loop on strip, tubes, and weldments of Alloy 600. During the first 1000 to 2000 hrs of exposure, corrosion rate differences depending upon surface preparation and in the case of weld metal on composition were observed. However, by 3000 to 5000 hrs, the corrosion rates of all samples tested had decreased to around 1.0 mg/dm2 per month, or to rates of scale formation of about 1.4 mg/dm2 per month. Approximately half the scale was adherent, and half was lost to the stream. Comparison with earlier tests in borate—free water seemed to indicate that the addition of boric acid increased corrosion somewhat during the initial exposure periods, but this was a transient effect, and corrosion rates decreased with time.
Use of Infernal Damping Measurements in the Study of Environmental Cracking
Authors: THIRUVENGADAM A. , GUNASEKARAN M. , PREISER H. S. 
Published: February 2013

Abstract
The problem of environmental cracking of metals and their alloys has become very important and warrants a concentrated study with new ideas for its solution. The major objectives of such a study are, (1) detection of susceptibility, (2) quantitative measurement of susceptibility, and (3) understanding the mechanism of susceptibility. An approach utilizing measurements of the internal damping characteristics of materials prone to environmental cracking is presented to show the feasibility of detecting significant changes occurring in the materials long before any macroscopic evidence of such changes becomes noticeable. Tests on 2024-T4 aluminum, 2024-T3 aluminum, Ti-6Al-4V and Ti-8Al-1Mo-1 V are reported wherein considerable changes in the internal damping of these materials were observed following their exposure in a stressed state to environments in which they are known to be susceptible to cracking. (Corroborative tests on 1020 mild steel and electrolytic copper stressed and exposed to a corroding environment of air saturated synthetic sea water produced no changes in internal damping. These materials are normally immune to stress corrosion cracking under the above conditions of exposure.) Theoretical ideas with supporting experimental evidence are presented in an attempt to arrive at a basic understanding of the phenomenon of environmental cracking by correlating the laws of diffusional mechanics of materials to those pertaining to changes in their internal damping.
Recent Applications of Electrode Potential Measurements in the Thermodynamics and Kinetics of Corrosion of Metals
Authors: POURBAIX M. 
Published: February 2013

Abstract
A brief survey is given of recent applications of electrode potential measurements for the study of the corrosion of metals and alloys in the presence of aqueous solutions, molten salts and gaseous atmospheres. Particularly considered are: (1) cathodic and anodic protection of passivable metals and alloys in the presence of chloride containing solutions; (2) pitting corrosion of copper in the presence of cold water; (3) stress corrosion cracking of titanium alloys in the presence of aqueous solutions; (4) diagrams of electrochemical equilibria in the presence of molten carbonates, as a function of the electrode potential and of log PCO2 or log O−−; (5) diagrams of chemical and electrochemical equilibria in the presence of gaseous oxygen as a function of ΔG° or the electrode potential E, and of temperature T; (6) diagrams of electrochemical equilibria of semi-conductive oxides, as a function of the electrode potential E, and of log O−−. Mention is made of the possible usefulness of these three last types of diagrams for studying problems related to corrosion, fuel cells, and high temperature electrochemistry.
The Initial Stages of Oxide Film Formation on Copper and Some Copper Alloys
Authors: SANDERSON M. D. , SCULLY J. C. 
Published: February 2013

Abstract
The initial stages of oxide formation on thin foils of copper, Cu-2.5Al-2.5Si, and Cu-7.5Al-2Si alloys in moist atmospheres of oxygen and sulfur dioxide have been studied by transmission electron microscopy and electron diffraction over the temperature range 200-380 C (392-716 F). On the Cu-2.5Al-2.5Si alloy grain boundaries and twin boundaries are preferential sites for oxide nucleation. On the Cu-7.5Al-2Si alloy no preferential sites are observed. The relative reactivities of different crystallographic planes are the same for the alloys as for the metal. On oxidized thin foils a prenucleation thermal pitting phenomenon has been observed at temperatures very much lower than the thermal pitting observed by other workers. Oxide nuclei have been observed to form on a thin amorphous layer of oxide even when there is no metal directly underneath. These results are discussed with reference to current theories on the initial stages of oxide formation. It is concluded that in the prenucleation stage the metal surface is covered with a highly mobile layer of cations and anions.
Film and pH Effects in the Stress Corrosion Cracking of Type 304 Stainless Steel
Authors: BAKER H. R. , BLOOM M. C. , BOLSTER R. N. , SINGLETERRY C. R. 
Published: February 2013

Abstract
Rapid stress corrosion cracking of 304 stainless steel in MgCl2-FeCl3 solutions at 125 C has been shown to occur only when the pH of the corrodent liquid within the crack lay between 1.2 and 2.5. A film of more acidic corrodent solution is raised to pH = 1.2 by reaction with the metal within a few seconds after isolation in a pit, crack, or crevice. MgCl2 solutions of pH higher than 2 became more acidic when in contact with stainless steel as a result of corrosion processes. The pH of small amounts of such solution isolated in pits or crevices eventually fell to near 1.5, where stress corrosion cracking could occur. This pH range is considered to be critical for stress corrosion cracking of 304 stainless steel because it is the range in which a corrosion resistant protective film is formed in the presence of the corrodent solution. This film is essential to crack propagation. If there is added to a corrodent , solution in this pH range an organic complexing agent such as glycerine or glycol which prevents-formation of the protective oxide film, the general corrosion process continues unchecked but no stress corrosion cracking occurs. The data support a model in which stress corrosion cracking is driven by a highly localized galvanic cell within the crack. The cell operates in such a way that there is no large change in pH of the solution in the crack. These results emphasize the importance of the corrosion resistant film in the chemical aspect of the stress corrosion mechanism.
Use of Precracked Specimens in Stress Corrosion Testing of High Strength Aluminum Alloys
Authors: HYATT M. V. 
Published: February 2013

Abstract
Resistance to stress corrosion cracking of 10 high strength aluminum alloys in a variety of heat treatment conditions has been measured using precracked double cantilever beam (DCB) specimens. A new technique is described, and stress corrosion crack growth rates for the alloys tested are presented as a function of the plane-strain stress intensity KI. Crack growth rates for alloys in the T3 and T6 tempers showed both KI-independent and KI-dependent behavior, whereas alloys in the more resistant tempers showed only KI independent behavior over the KI range studied. Double cantilever beam specimen data correlated with established trends from smooth specimens tested by alternate immersion in 3.5% NaCl solution. From the crack growth rate data and the speed and simplicity with which it is obtained, it is concluded that the DCB specimen will be highly useful for (1) comparing and rating alloys, (2) developing new alloys and heat treatments, (3) comparing the effects of environments, (4) achieving or ensuring product uniformity, and (5) studying mechanisms of cracking.
Acceleration of Liquid Mercury Embrittlement of Titanium Alloys by Ultrasonic Oscillations
Authors: CHEN C. M. , KIRKPATRICK H. B. 
Published: February 2013

Abstract
Ultrasonic oscillations were found to markedly accelerate the fracture in liquid mercury of Ti-8Al-1Mo-1 V and Ti-6Al-4V alloys. Unalloyed RMI 70 titanium was unaffected. Likewise, fracture by CH3OH-HCl-H2O solution was unaffected. The results are taken as indicating a stress-sorption failure mechanism.
Effect of Time on Corrosion Rates in Sulfuric Acid Predicted from Electrochemical Data
Authors: WAGNER A. H. , MYERS J. R. 
Published: February 2013

Abstract
Effect of time on the cathodic polarization behavior of Ni, Cr, Ti, Al, and six Ni-Cr-Al and Ni-Cr-Ti alloys was determined in hydrogen saturated, 1N sulfuric acid at 22 C (71 F). Corrosion current densities (icorr) obtained for these specimens, using the beta-extrapolation technique, were generally found to be strongly time dependent. Corrosion current densities for Ni, Cr, and the six ternary alloys decreased with time and approached steady state values after about 72 hours exposure to the electrolyte. Corrosion current density for Al decreased markedly during the initial 24-hour period; further exposure did not appreciably affect the corrosion current density. The corrosion current density for titanium decreased only slightly as the exposure time was increased. All materials exhibited steady state corrosion current densities after sufficient exposure to the acid. Corrosion rates predicted using the steady state corrosion current densities correlated well with rates obtained from long time, weight loss tests. It was established that accurate corrosion rates can be predicted from electrochemical data only after steady state corrosion current densities have been obtained.
Effect of pH on Sea Water Stress Corrosion Cracking Behavior of the Ti-7Al-2Cb-1Ta Alloy
Authors: LITVIN D. A. , HILL B. 
Published: February 2013

Abstract
The purpose of this investigation was to determine the effect of varying the pH of a sea water environment on the stress corrosion cracking behavior of the Ti-7Al-2Cb-1Ta alloy. Various pH levels of 1.0, 3.0, 5.0, 7.4, 9.0, 11.0, and 11.6 were studied by additions of HCl and NaOH to the as-received sea water (pH = 7.4). The titanium specimens were beta-fabricated (rolled 1900 F, 1038 C), and tested using a cantilever weight test. It was found that an increase in the pH level of the sea water from 1.0 to 7.4 decreased the stress corrosion susceptibility of the Ti-7Al-2Cb-1Ta alloy. In all cases, the mode of cracking was transgranular; yet, differences in the angle of cracking through the titanium platelet structure were observed. A distinct low ductility zone on the fracture surface of the sea water samples was noted, but no correlation could be made between the size of this zone and the pH of the solution. Photomicrographs of the specimens are included, along with macrographs of the fractured surfaces.
Effect of Corrosive Environment on Crack Propagation in Alpha Brass and a Copper-Beryllium Alloy
Authors: SYLWESTROWICZ W. D. 
Published: February 2013

Abstract
Notched specimens of a copper-beryllium alloy and of α-brass were tested in tension in an ammonia-containing solution. Specimens were strained at rates ranging from 0.5 cm/min to 5 × 10−4 cm/min. Formation of a plastically deformed zone at the root of the notch appears to be essential to the formation and propagation of the crack. A smaller amount of plastic deformation was needed to start a crack in the corrosive solution than in air. The observation that the effect of the corrosive solution seems to be independent of the strain rate suggests that an adsorption process contributes to specimen failure in stress corrosion fracture.
Sulfide Stress Corrosion Cracking of Steels
Authors: DVORACEK L. M. 
Published: February 2013

Abstract
Critical nominal stress and critical stress intensity factors for sulfide stress corrosion cracking of various steels were determined using fatigue-precracked, laboratory, cantilever beam specimens and short lengths of oil field casing and tubing pressured to failure. The laboratory critical constants were found to be lower than those obtained from short lengths of casing and tubing containing longitudinal internal surface notches. Acceptable steels were defined by statistical methods as those which did not crack in sulfide environments when stressed to their yield strength. The effects of sodium chloride, pH, hydrogen sulfide concentration, temperature, cold working, heat treatment and strength of the steel on these critical constants were determined. Critical flaw sizes which can be used for inspection were calculated from the critical stress intensity factors.
The Role of Sodium and Sulfur in the Accelerated Oxidation Phenomena–Sulfidation
Authors: BORNSTEIN NORMAN S. , DeCRESCENTE MICHAEL A. 
Published: February 2013

Abstract
The oxidation kinetics at 900 C (1652 F) of a sulfur impregnated, a Ni-Ni3S2 eutectic coated, and a NaNO3 coated nickel base alloy were studied. It was determined that Na2O/substrate interactions are more influential than sulfur/substrate interactions on the accelerated oxidation phenomena, sulfidation.
Passivation of Nickel Monocrystal Surfaces
Authors: LATANISION R. M. , OPPERHAUSER H. 
Published: February 2013

Abstract
Steady state potentiostatic polarization measurements on low index nickel monocrystal surfaces in 1N H2SO4 indicate a strong anisotropy in passive current densities. The nature of this orientation dependence appears to be related to such properties of the solid state as the crystal growth axis. For example, in the case of crystal growth parallel to the 〈110〉 axis, the degree of protection provided by the passive film on a {111} surface is greater than that on either {110} or {100} faces, i.e., the passive current densities are in the following order: {111}&lt;{110}&lt;{100}. It is interesting to note than an identical anisotropy has been reported in the rates of gaseous oxidation on nickel surfaces. On the other hand, precisely the reverse dependence is observed in passivation studies when the growth direction of the monocrystal is parallel to the 〈100〉 axis. The above results are examined in terms of the crystallography and defect structure of the film, the metal/film interface, and the metal substrate and their relevance to current theories of passivation is considered.
Observations on Sustained Load Environmental Crack Growth of a Titanium 8Al-lM0-lV Alloy
Authors: BUCCUI R. J. , PARIS P C 
Published: February 2013

Abstract
Sustained load environmental cracking of a mill annealed titanium 8Al-1Mo-1V alloy was investigated by methods amenable to fracture mechanics. Two environments were considered: 3.5% NaCl solution and distilled water, both at room temperature. Varying amounts of crack propagation followed by subsequent crack arrest were detected at K levels considerably below an apparent KIscc (almost 2 to 1) that would be determined from a time to failure test technique. At crack arrest locations along the specimen surface, minute amounts of crack division were often observed under magnification.
Effect of H2 S on Differential Aeration Cells With AISI 4340 Steel Electrodes
Authors: KHOKHAR M. INAM , FUGASSI PAUL , HANEY E. G. 
Published: February 2013

Abstract
The effect of H2S upon differential aeration cells using Fe, Mo, Pb, Sn, annealed 4340 steel, and hardened 4340 steel electrodes has been studied. The electrolytes in all cases were 0.6 M aqueous NaCl at pH 2 and pH 6.5. Injection of H2S into the oxygen atmosphere electrode at pH 2 in the case of Fe and both types of 4340 electrodes causes reversal of the cell voltage with the nitrogen atmosphere electrode being cathode. Under all other conditions, the usual behavior is observed with the nitrogen atmosphere electrode serving as anode.
Electrochemical Evaluation of Resistance of Stainless Alloys to Chloride Media
Authors: JACKSON R. P. , VAN ROOYEN D. 
Published: February 2013

Abstract
Electrochemical methods have been used to compare the resistance of several stainless steel.al.loys to corrosion in chloride media. These methods consisted of the determination of critical current densities and pitting potentials, and also the amount of chloride required for passive film breakdown at a fixed passive potential. The results correlated very well with rust staining observed in exposures in a marine atmosphere. Some alloying effects were explored, and the mechanism of pitting and crevice corrosion is also discussed.
Intergranular Corrosion Resistance of Carpenter 20Cb-3
Authors: HENTHORNE M. , DeBOLD T. A. 
Published: February 2013

Abstract
Carpenter 20Cb-3 strip in the stabilized, TIG welded and solution annealed conditions has been sensitized in the range 1050 to 1625 F (566 to 885 C) prior to intergranular corrosion testing in the Huey, ferric sulfate-sulfuric acid, nitric-hydrofluoric acid and Strauss tests. In stabilized annealed material, the sensitization temperature producing maximum susceptibility is about 1450 to 1500 F (788 to 816 C). Welded plus sensitized material showed susceptibility to intergranular corrosion immediately adjacent to the weld with the most severe sensitization temperature being about 1250 F (677 C). Stress relieving stabilize annealed or welded material in the range of about 1100 to 1600 F (593 to 871 C) is not recommended unless prior testing or experience indicate satisfactory performance. Huey rates following a 1250 F (677 C) sensitization increase as the annealing temperature is increased in the range 1725 to 2250 F (941 to 1232 C). Rates following a 1400 F (760 C) sensitization increase with a 2050 F (1121 C) anneal and decrease for 2200 F (1204 C) and higher treatments. The attack in stabilize annealed material sensitized at 1450 F (788 C) is attributed primarily to M6C. M23C6 plays a role at lower temperatures particularly in the as-welded or solution annealed conditions. Sigma phase can form at the higher sensitization temperatures.
The Effect of Some Electrolytes on the Stress Corrosion Cracking of AISI 4340 Steel
Authors: BAKER H. R. , SINGLETERRY C. R. 
Published: February 2013

Abstract
The effects of solutions of 16 different electrolytes on the stress corrosion cracking (SCC) of AISI 4340 steel U-bend specimens have been studied at various concentrations and at 25, 65, and 100 C (77, 149, and 212 F). Stresses were near the yield point of the alloy. In unbuffered solutions of neutral salts, there was poor correlation between time to failure and the initial or final pH of the solution. In strongly buffered solutions, there was a strong pH dependence; the time to failure in 10% NaCl increased about 100 fold between pH 4–5 and pH 7. Susceptibility to cracking increased moderately with the concentration of KNO3 solutions, but decreased with rising concentration of NaCl solutions. The cracking rate increased by 50% per 10 C for NaCl solutions. The rate increased 85% per 10 C for KNO3 solutions. KNO2 or NaNO2, dicyclohexylammonium nitrate, some K2CrO4 solutions and all alkaline solutions with a strong reserve of base inhibited SCC by factors of 10 to 100 times as compared with cracking in distilled H2O.
Role of pH on the Stress Corrosion Cracking of Titanium Alloys
Authors: KHOKHAR M. INAM , BECK F. H. , FONTANA M. G. 
Published: February 2013

Abstract
Stress corrosion cracking (SCC) experiments were conducted on Ti-8-1-1 wire specimens in hydrochloric and sulfuric acids of variable pH in order to determine the effect of pH on the susceptibility to cracking. The alloy exhibited increasing susceptibility with decreasing pH. By varying the applied potential, it was observed that susceptibility zones exist both in the cathodic and the anodic ranges. In the cathodic range, susceptibility also increased with decreasing applied potential. Corrosion potential-time data in hydrochloric acid (pH 1.7) and sulfuric acid (pH 1.7) indicate that chloride ions lower the corrosion potential of the specimen which, in turn, increases the susceptibility.
Mechanisms of Stress Corrosion Cracking of Titanium-Aluminum Alloys in Methanol-HCl Solutions
Authors: McMAHON C. J. , TRUAX D. J. 
Published: February 2013

Abstract
Initiation and early slow growth of stress corrosion cracks in Ti-Al alloys in methanol-HCl solutions occurs by slip-induced grain boundary splitting. Later crack propagation occurs by cleavage and other forms of transgranular cracking. Crack initiation and failure by stress corrosion cracking (SCC) can occur at stresses far below the microyield stress because of localized slip in isolated groups of grains. Increases in aluminum content and precipitation of Ti3Al enhance SCC susceptibility because of intensification of slip bands and inhibition of plastic relaxation.
Electrochemical Reactions at Paper Shielded Metal Surfaces
Authors: PICARD ROBERT J. , GREENE NORBERT D. 
Published: February 2013

Abstract
Paper in contact with an electrode during anodic polarization alters the critical anodic current density (Ic) as a result of changes in ionic concentration at the paper-metal interface. This phenomenon appears to be related to crevice corrosion and offers a method for studying electrochemical processes occurring in shielded areas.
Microstructures and Some Properties of Fe-28%Cr-4%Mo Alloys
Authors: STREICHER MICHAEL A. 
Published: February 2013

Abstract
The effect of heat treatment on the microstructure and properties of 28Cr-4Mo and 28Cr-4Mo-2Ni alloys with low carbon and nitrogen levels was investigated. Sigma and chi phases form in these alloys in the range 1300 to 1700 F (704 to 927 C). The rate of formation is slow. Heating 1 hour at 1500 F (816 C) results in only a small amount of sigma phase at grain boundaries. This does not impair corrosion resistance. Annealing at 2000 F (1093 C) readily dissolves this sigma phase, and also much larger amounts of sigma and chi phases formed after heating 100 hours at 1500 F. These alloys are subject to embrittlement by hydrogen. It was shown that embrittlement produced in cold worked material by brief cathodic charging in 10% H2SO4 containing a sulfide can be eliminated by exposure to boiling water or aging at room temperature. Both compositions showed excellent resistance to crevice corrosion in a 9 month test in the ocean at the New Jersey shore. Resistance to caustic cracking was demonstrated by a test in 50% NaOH at 200 C (392 F). A Type 304, 18Cr-8Ni stainless steel was severely cracked in this test with almost no general corrosion. The 28Cr-4Mo alloy was not cracked but was severely attacked by general corrosion, and the 28Cr-4Mo-2Ni alloy resisted cracking and was also resistant to general corrosion.
The Influence of Copper and Bicarbonate Ions on the Corrosion of Aluminum Alloys in Saline Solutions
Authors: BECERRA ALCIBIADES , DARBY RON 
Published: February 2013

Abstract
Corrosion rate studies on three aluminum alloys (1100, 5052, and 6063) have been conducted in saline solutions containing various concentrations of cupric and bicarbonate ions. Corrosion rates determined by linear polarization, Tafel extrapolation, and weight loss are compared. The time average corrosion rates for each alloy are represented by a two dimensional second order response surface as a function of both cupric and bicarbonate ion concentration, including a coupling term representing a synergistic effect. The relative resistance of the three alloys is compared and the mechanism of the effect of the cupric and bicarbonate ions on the corrosion rate is discussed.