Engineering Commons^™

Protection Of Steel Using Aluminum Sacrificial Anodes In Artificial Seawater, Tai-Ming Tsai

Journal of Marine Science and Technology–Taiwan

The performance of aluminum alloys used as sacrificial anodes for cathodic protection in seawater was investigated in this study, Results show that A1 -3.5%Zn -0.05%In sacrificial anode alloy C has the best current efficiency, most negative open circuit potential and energy characteristics among five different Al-Zn-In alloys. Polarization curve of alloy C also shows no passivation behavior in artificial seawater. The corrosion rate of mild steel in artificial seawater was determined as a function of applied cathodic potential. The cathodic protection potential determined for mild steel in seawater was -0.78 V,SCE for a corrosion rate of less than 1 mpy. …

The Inhibition Of Amphipathic S- And N-Containing Compounds On Carbon Steel Corrosion, Wei Xing, Yibin Shan, Du Guo, Tianhog Lu, Shiquan Xi

Journal of Electrochemistry

Ordered monolayers of S- and N-containing amphipathic corrosion inhibitors were depoitod onto the surfaces of carbon steel electrode with super-molecular assembly technique. The effect of molecular aggregation of monolayers on carbon steel corrosion in 0.05 mol·cm^-3 H₂SO₄ and the mechanisms of these inhibitors were discussed in details. It was found that the transport of hydrated hydrogen ion to the surface of steel depends strongly on the inhibitor molecular aggregation in the monolayers.

Effects Of Solidification Conditions And Heat Treatment On The Microstructure And Vickers Hardness Of Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, Stanley G. Vermilyea, Efstratios Papazoglou, John C. Mitchell, Alan B. Carr

Cells and Materials

Two representative Pd-Cu-Ga dental alloys, one with a dendritic as-cast microstructure containing a eutectic interdendritic constituent and the other with an equiaxed fine-grained as-cast microstructure containing a near-surface eutectic constituent, have been subjected to rapid quenching following casting, in addition to the conventional bench cooling recommended by the manufacturers. The quenched alloys were subsequently heat treated at temperatures of 1200°, 1500° and 1800 op that span the range of the firing cycles for dental porcelain. Scanning electron microscopic examination showed that the lamellar eutectic constituents normally present in the microstructures of the as-cast and bench-cooled alloys persisted when the alloys …

Optical Fiber Fourier Transform Infrared Evanescent Wave Absorption Spectroscopy Of Aluminum Hydroxide And Natural Corrosion, Juock S. Namkung

Electrical & Computer Engineering Theses & Dissertations

A new technique for continuous, real-time, in-situ detection of natural corrosion of aluminum alloys is presented. The technique is a generalized version of attenuated total reflectance (ATR) spectroscopy, that combines optical fibers and a Michelson interferometer spectrometer to make evanescent wave absorption measurements. Aluminum hydroxide is one of the major corrosion products of aluminum. Absorption spectra of powdered samples of aluminum corrosion, in the spectral region around three micrometers have been studied and compared with the spectra from pure powdered aluminum hydroxide. A chalcogenide optical fiber was used as an attenuated total reflectance (ATR) optical element. The same samples were …

The Composition Structure And Corrosion Resistance Of Al-Mn Alloy Plating, Jiaju Guo, Naiming Guo

Journal of Electrochemistry

The Al-Mn alloy plating was electrodeposition from low temperature molten salts (below 200℃), its chemical composition control, corrosion resistance as well as the relationshipbetween chemical composition and structure were studied. The results indicate that the main effect onchemical composition of Al-Mn alloy plating is Mn ion concentration in molten salts. The Mn contentin the range of 25～40(wt)%, Al-Mn alloy plating has amorphous structure. In 0.5 mol/L H₂SO₄ and NaCl solution ,corrosion resistance of the alloy plating is much better. When the alloy has amorphous structure, corrosion resistance of plating has been remarkably increased.

Application Of Inhibitor To Improve The Anticorrosion Performance Of Electrophoretic Coating, Changshou Cai, Fangteng Su, Bihuan Liu, Guomou Wen, Jingdong Guo, Renxin Liu, Weidong Tian

Journal of Electrochemistry

To improve the anti-corrosion performance of electrocoating, organic andinorganic inhibitors are applied in an anodic electrophoretic-coating. The results show that the deposition of polymer with zinc phospate exhibits a high inbihition efficiency. The inhibition mechanism of the inhibitor in electrocoating has been studied.

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski

Mechanical Engineering Faculty Research

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, …

Pitting Of Fe-Mn-Al Alloys In Nacl Solution, M Ruscak, T.P Perng

Journal of Marine Science and Technology–Taiwan

the increase of ferrite content. However, the nearly ferritic alloy showed much better passivation behavior, presumably due to the addition of 6% Cr.In aerated solution, no or very small passive region was observed. From the immersion test, the general corrosion was found to be minor. Pitting corrosion was the primary corrosion except for the ferritic alloy. The pits were found more frequently in the ferrite phase or at the interface between the ferrite and austenite phases.

Comparing Electrochemical Impedance Spectroscopy Methods For Estimating The Degree Of Delamination Of Organic Coatings On Steel, S. A. Mccluney, S. N. Popova, Branko N. Popov, Ralph E. White, R. B. Griffin

Faculty Publications

Electrochemical impedance spectroscopy (EIS) was used to evaluate the degree of delamination of the epoxy primer Uniprime ED-4¹ electrocoated on phosphate-treated cold-rolled steel in 3.5% NaCl exposed to air. Specimens with coating thicknesses of 20.3 and 20.8 µm and surface areas of 78.5 cm² were used. Coating parameters were obtained using a circuit-analog model. The area of delamination was estimated using several EIS parameters, including the pore resistance and the break point frequency. These values were compared to the corroded area determined visually. All methods considered exhibited a strong correlation over some or all of the range of …

Field Inspections Of High-Performance Bridge Paints, Theodore Hopwood Ii, Edgar E. Courtney, James H. Havens

Kentucky Transportation Center Research Report

Paint inspections were performed on 19 steel bridges. Those structures employed various high-performance sacrificial and barrier paints. Those paints were used singly and in combination. The surface preparation varied for some of those paint systems.

The inspections included four girder bridges that had original paint and 15 others, mostly trusses that were repainted. Kentucky Transportation Center personnel also monitored several bridges during repainting operations. The inspections revealed that the original paint was in excellent condition. Most of the coatings on the repainted bridges were performing well. Some of those bridges have some spot corrosion. Only one of those bridges showed …

Calcium Nitrite As A Corrosion Inhibitor In Reinforced Concrete Bridge Decks, Theodore Hopwood Ii, David Q. Hunsucker, Edgar E. Courtney

Kentucky Transportation Center Research Report

The use of calcium nitrite es a corrosion-inhibiting admixture in reinforced concrete hes been studied on two bridges· the Kentucky 152 Bridge in Washington County and the Gose Road Bridge in Boyle County. Calcium nitrite was added to concrete used in the slabs, diaphragms and barriers of the KY 152 bridge and only in the slab of the Good Road bridge.

Construction of both structures was monitored in the fall of 1986. Placement of concrete on both bridges was satisfactory; however, problems were experienced in finishing the concrete. The finishing problems were related to: 1) concrete 'stickiness', 2) use of …

Electrochemical Technique For Corrosion Monitoring, Nadia Mohamed Khattab

Archived Theses and Dissertations

The present work is a study of the applicability of linear polarisation resistance technique as a means for corrosion monitoring. Parameters tested were alloy composition, surface finish of specimens before exposure, concentration of aqueous environment and the additional effect of soil to the aqueou􀀂 medium. A simple galvanostatic polarisation circuit was utilized. A polarisation resistance curve was then plotted from which the corrosion current densities and corrosion rates were calculated. The results of this work show that Corrosion reactions depend on both thermodynamic and kinetic parameters, also these reactions are under mixed control and the potential actually measured at the …

A Mathematical Model For The Initial Corrosion Rate Of A Porous Layer On A Rotating Disk Electrode, William E. Ryan, Ralph E. White, S. L. Kelly

Faculty Publications

A mathematical model is presented for the initial corrosion rate of a porous layer on a rotating disk electrode. The model is used to predict the corrosion potential and corrosion current density for a porous electrode made of pure iron in aerated caustic solutions. The dependence of these predictions on some of the properties of the porous layer is presented. It is shown that the corrosion rate depends significantly on the specific surface area of the porous electrode.

Inspection, Prevention, And Remedy Of Suspension Bridge Cable Corrosion Problems, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

This report discusses methods for visually inspecting cable suspension bridges for corrosion damage. The report discusses how to plan and perform such work, including the locations on cables where corrosion damage is likely to be detected. The report also provides recommendations for assessing the condition of suspension bridge wire. Recommendations also are included for remedial cable repair work should corrosion damage be detected.

Corrosion Of Cable Suspension Bridges, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

This report discusses corrosion problems encountered on the cables of suspension bridges. A historical review is given of past cable suspension bridge corrosion and related laboratory work.

Findings of inspections of suspension bridges at Maysville, KY, Covington, KY, and Portsmouth, OH, are discussed. Recommendations are presented.

Investigation Of Corrosion And Weathering Phenomena In Tropical Marine Environment, K. P. Stormer

Tanzania Journal of Engineering and Technology (TJET)

Abstract

The Anodic Dissolution Of Tungsten, James W. Johnson, Cheng-Hsiao Wu

Chemical and Biochemical Engineering Faculty Research & Creative Works

The anodic dissolution of tungsten was studied in H₂SO₄-K₂SO₄ solutions (pH = -2 to 2.5) and K₂SO₄-K₂CO₃-KOH solutions (pH = 11.5 to 14.5) at 25 C. Faradaic efficiency studies in basic solutions showed the metal to be oxidized to the +6 state. In acid solutions, a thick protective film of yellow WO₃ was formed. Polarization curves possessed linear Tafel regions (slope ~ 2.3 RT/F) at potentials slightly more positive than the rest potentials. An anodic dissolution mechanism is proposed which involves a surface film …

Increased Corrosion Of A 304 Stainless Steel Upon Bending, William C. Tiddy

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Electrolytic Refining Of Copper By The Series System, Jerome Yopps

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis investigation was to determine the characteristics of the series system of electrolytic refining of copper.

An Investigation Into Salt-Bath Heat Treatment For Titanium, Robert Fred Bechtold

Bachelors Theses and Reports, 1928 - 1970

Titanium, although possessing excellent corrosion resistance in some media, is severely attacked by molten inorganic salts such as those employed in heat-treating baths. Since titanium undergoes allotropic changes, many of its alloys are amendable to heat treatment. The purpose of this study was to discover a salt (or other suitable medium) in which titanium alloys can be successfully heat treated without fear of corrosion.