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Showing 1 to 20 of 162 for “"Pitting"”.
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Local Environment in Pitting Corrosion of Aluminum
The pH and chloride microsensors were used to study propagation and repassivation of pits on pure aluminum in pH 11 NaCl solution. It was concluded that the pH inside a growing pit was around 2.7, and the chloride concentration was higher than the saturation concentration. After current to the pit …
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Pitting corrosion initiation in AISI 316 austenitic stainless steel
The initiation of pitting corrosion on AISI 316 stainless steel has been examined from a phenomenological viewpoint with emphasis on the role of the metal in this complex, interaction. A modified potentiodynamic technique was used to prepare specimens corresponding with a series of different points …
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An Experimental Evaluation of Micro-pitting Performance of Two Bearing Steels
… speed, sliding ratio, and load on micro-pitting performance of two typical bearing steels. Case hardened roller specimens made of alloy 9310 and through-hardened roller specimens made of alloy 485-2 are procured. Test matrices are defined according to the Latin Hypercube Space Filling …
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Investigation of nanoscale mechanisms driving erosion and pitting in graphitic carbon
… the fundamental mechanisms that causes oxidative pitting in carbon materials is essential to accurately predict ablation rates of Thermal Protection Systems (TPS) during hypersonic reentry. The extreme heat and unique gas phase chemistry encountered during hypersonic reentry necessitates an …
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Investigation of Copper Pitting Propensity Using Bench and Field Scale Testing
A range of techniques designed to monitor copper pitting propensity were applied at two water utilities with known pitting disposition. In addition to traditional approaches including ECorr rise, chlorine decay kinetics, and surface analyses, a novel method was attempted to develop "pitting …
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Initiation, Propagation, and Mitigation of Aluminum and Chlorine Induced Pitting Corrosion
… and 4) try to determine the scope of this pitting problem in other distribution systems and on a national level. The first set of experiments clearly defined the controversial trends from earlier work. At certain pH values, the presence of chlorine and aluminum solids does seem to initiate …
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Experimental and Theoretical Investigation of Pitting Corrosion of Nickel in Chloride Solution
Pitting corrosion of nickel in 0.5M NaCl (pH 6.3) was investigated with use of single corrosion pits under both stagnant and flow conditions. The pit dissolution current was found to vary as a function of the applied potential. The pit surfaces were crystallographic, although the general shape of …
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The influence of water composition on the pitting behaviour of stainless steel
The new concept of hydropower has been found to be technically feasible in South African gold mines. Chilled mine service water is piped from the surface to deep level stope; where the hydrostatic pressure provides power for stoping machinery. This water varies widely in composition and acidity. …
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Pitting and crack initiation in high strength aluminum alloys for aircraft applications
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996.
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Sacral preauricular extensions and notches and dorsal pubic pitting as indicators of parity
… preauricular notches (SPN), and dorsal pubic pitting (DPP) on the sacra and pubic bones of modern assigned females at birth (AFAB; parous=150; non-parous=97) and assigned males at birth (AMAB; n=150) from the University of Tennessee, Knoxville’s Donated Skeletal Collection. SPE, SPN, and DPP …
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Interactions Between Copper and Chlorine Disinfectants: Chlorine Decay, Chloramine Decay and Copper Pitting
… the perspective of disinfectant decay and copper pitting corrosion. Sparingly soluble cupric hydroxide catalyzed the rapid decay of free chlorine, which in turn, led to production of less soluble and more crystalline phases of cupric hydroxide. The catalytic activity of the cupric hydroxide was …
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Experimental and Theoretical Investigations of Electrode Shape Change Taking Place During Pitting Corrosion of Iron
The present study included experimental measurements of corrosion pit shapes and theoretical calculations on the effect of pit shape on the mass transport of dissolved metal ions within pits. The system studied was pure iron in 1N H(,2)SO(,4) containing small amounts of chloride ion.
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The influence of water composition on the pitting behaviour of newly developed corrosion resistant steels
… and nitrate ions. In order to minimise the pitting corrosion of piping and stoping machinery a compromise between selecting a suitable corrosion resistant material and treating the mine water to an acceptable level of corrosiveness is being sought.
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The Effects of Fluid Flow on The Pitting Corrosion of Pure Iron in Acidic Chloride Media
The fluid flow effects on electrobright pitting of pure iron were investigated. A rectangular channel with minimized wall and entrance effects was used. The electrolytic solution consisted of an aqueous solution of 0.5 M sulfuric acid and 0.003 M sodium chloride. The experiments were carried out …
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Experimental and Numerical Studies of Single Manganese Sulfide Inclusions in Stainless Steel During Initiation of Pitting Corrosion
… acidification occurs after the initiation of pitting rather than trigger initiation. In addition, the model supported the hypothesis that pit initiation occurs due to the accumulation of an aggressive dissolved sulfur species, such as thiosulfate, as a result of inclusion dissolution. Critical …
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Experimental and Modeling Studies of the Stability of Pitting Corrosion on Pure Aluminum in Basic Chloride Solutions
The quasi steady state model was expanded to include homogeneous bulk reactions for hydrolysis and complexation reactions. The model predicted pH values of 2.5 to 3.0, values that agreed well with experimental measurements, only when the first two hydrolysis reactions of aluminum were included in …
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Studies on the Control of Metal Passivation in the Electrochemical Tunnel Etching of Aluminum (Corrosion, Passivity, Pitting Potential, Aluminum)
… was considered to be identical to the empirical pitting potential.
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Pitting corrosion of aluminum-alloys at aluminum(3) iron inclusions: The effect of local chemical environment and transport phenomena
… local alkalization results in either ditching or pitting at the interfacial region between the particles and the aluminum matrix. A micro-disk electrode concept was adopted to calculate the oxygen reduction limiting current at intermetallics to explain the mechanism and predict the related …
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