Metallurgy Commons^™

Improving Fatigue Strength And Life Of Single Crystal Cmsx-4, Jochen Peter Fuhr, Lloyd Hackel, Nicolau I. Morar, Noah Holtham, Keivan Davami, Montu Sharma, Rajkumar Roy

15th International Conference on Shot Peening

The deep penetration of laser peening (LP) and retention of residual stress at high temperature by LP is significant in improving fatigue life and strength of superalloys exposed to high temperature and corrosion. Single crystal CMSX-4, was evaluated for stress relaxation and both fatigue life and fatigue strength of material that was LP-treated compared to non-LP and shot-peened (SP) specimens. LP was done with multiple layers using a 20 J/pulse laser where the laser high energy enabled using a 5 mm spot size on the metal surface. Stress measurements by the slitting technique showed the plastic penetration depth exceeded SP …

Potential Of Lidar And Hyperspectral Sensing For Overcoming Challenges In Current Maritime Ballast Tank Corrosion Inspection, Sergio Pallas Enguita, Jiajun Jiang, Chung-Hao Chen, Samuel Kovacic, Richard Lebel

Electrical & Computer Engineering Faculty Publications

Corrosion in maritime ballast tanks is a major driver of maintenance costs and operational risks for maritime assets. Inspections are hampered by complex geometries, hazardous conditions, and the limitations of conventional methods, particularly visual assessment, which struggles with subjectivity, accessibility, and early detection, especially under coatings. This paper critically examines these challenges and explores the potential of Light Detection and Ranging (LiDAR) and Hyperspectral Imaging (HSI) to form the basis of improved inspection approaches. We discuss LiDAR’s utility for accurate 3D mapping and providing a spatial framework and HSI’s potential for objective material identification and surface characterization based on spectral …

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin

All Dissertations

The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn …

Effects Of Ac Interference On Pipelines Under Cathodic Protection And Cathodic Disbondment Of Pipeline Coatings, Tanner Laughorn

Williams Honors College, Honors Research Projects

This project is split into two parts. The first revolves around AC interference on pipeline steel under cathodic protection. The corrosion rate of steel samples will be measured after they are exposed to varying levels of AC interference and cathodic protection. The results will be used to help develop new guidelines for appropriate cathodic protection of steel pipelines. The second part of this project revolves around the cathodic disbondment of pipeline coatings while under cathodic protection. The disbondment distance, electrolyte pH, and electrochemical impedance spectroscopy will be tested for multiple industry standard coatings under various conditions. The results will be …

Corrosion Inhibitors: Mitigating The Degradation Of Rebar, Jake R. Hughes

Williams Honors College, Honors Research Projects

Our conjecture was twofold: first, that two compounds historically used as food preservatives could act as environmentally friendly inhibitors against rebar corrosion, and second, that molecular properties have a quantifiable influence on inhibition efficiency (%IE). To evaluate the two compounds, cyclic potentiodynamic polarization was used to determine corrosion current density (i_corr) and %IE. The “green” inhibitor candidates included sodium metabisulfite and ascorbic acid, which yielded maximum %IE values of -123900% and 91%, respectively. Results indicated that sodium metabisulfite is not a suitable inhibitor, while ascorbic acid showed potential to extend reinforced concrete’s design life without posing health or …

Change Of Metal Oxidation State At High Temperature, Impact Of Temperature And Reactive Gases, Yegor Nikitin

Dissertations and Theses

The fundamental understanding of gas-solid reactions enables a wide range of applications to be developed and improved. Specifically, the use of metal-based materials is critical to ensuring robust, safe, and long-term operations. For example, in power systems where boilers are used to generate steam for heat or electricity generation the use of stainless metal alloys is critical to allow high quality steam to be produced in a very harsh environment. Alternatively, in catalysis, the use of metal doped heterogeneous catalysts are essential in achieving selectivity and conversion performance for chemical synthesis to emissions abatement. Typically, these metal alloys must withstand …

Corrosion Case Study On Pipeline, Kangze Ren

Corrosion Research

The Kashagan pipeline leaks were likely caused by sulfur stress corrosion cracking, a combined corrosion mechanism developed by the presence of high pressure, the high level of hydrogen sulfide(the main "ingredient" of sour gas), and poor metallurgical choice. Improper welding and poor metallurgical examination were blamed for causing the leaking issue. The purpose of the current review is to raise the alarm about the inappropriate corrosion management of Kashagan oil production and its societal and environmental consequences.

Investigation Of Oxidation And Corrosion Resistance Of Ni-Based Alloys And Stainless Steels Under Co2 Environments At Elevated Temperatures, Spencer Roy Fultineer

Graduate Theses, Dissertations, and Problem Reports (ETD)

High mechanical strength integrity, high robustness towards oxidation, and high resistance to carburization under CO2 environments at elevated temperatures are usually required for metallic systems that are employed for power generation. INCONEL 625 is a nickel-based superalloy that started development in the 1950s. This material was designed with the distinct purpose of use in high-temperature and high-pressure systems. While various materials possess the physical properties to handle these conditions, the creation of IN625 addresses the need for a material to withstand the highly corrosive properties of these kinds of environments. In order to evaluate the oxidation and corrosion resistance of …

Understanding Charge Effects On Marked Ball Wear Rates – A Corrosion Study, John Bailey Fletcher

Masters Theses

"To measure the wear rates of grinding balls within a ball mill, marked ball wear tests (MBWTs) have been used extensively. Using the wear rates from a MBWT, operators select the most cost-effective media for their grinding application. One factor that a MBWT does not account for is the possible interaction between different media materials which could affect their corrosion rates. Galvanic coupling between dissimilar metals can cause significant changes in their corrosion rates. While galvanic interactions between minerals and grinding media have been studied, the interaction between dissimilar media has not. Corrosion rates and potentials of modern high carbon …

Austenitic, Duplex, And Lean Duplex Stainless Steel Critical Pitting Temperature In Simulated Concrete Environment, Bobby Giebel

Williams Honors College, Honors Research Projects

In this work, the critical pitting temperature (CPT) will be observed for a selection of austenitic (316LN and 24100) and duplex (2205), and lean duplex (2304, 2001) stainless steels in simulated concrete pore solution. To study the influence of temperature on the pitting stability of the stainless steels, three temperatures were tested: 25oC, 45oC, and 65oC for cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS). Electrochemical properties of the interfaces we studied via EIS analysis. Kinetics were studied via CPP testing. To reveal the critical pitting temperature of the stainless steels, cyclic thermammetry was used. Characterization of the pits …

Corrosion Protection Mechanisms Of Trivalent Chromium Based Passivations On Γ-Znni Coated Al6061-T6 Alloy, Kevin Foster

Doctoral Dissertations

“The role of cobalt in trivalent chromium passivations (TCPs) to improve corrosion resistance of γ-ZnNi coated steel and aluminum is based on its effect on hexavalent chromium content in the passive layer. Investigations of both a cobalt-containing and cobalt-free TCP on SAE 1008 steel indicated that both passivations protect well for up to 1000 hours in neutral salt spray exposure (SSE). A repetition on Al 6061-T6 alloy indicated that TCP performed much better than cobalt-free TCP implicating the underlying substrate. Optical and electron micrographs indicated physical changes such as crack thickness, crack density, passivation porosity, and passivation thickness existed between …

Effect Of Dissolved Oxygen On Corrosion Of Carbon And 13cr Steel In A Brine Environment, Kevin Peter Iu, Andy Zhou

Materials Engineering

Oxygen corrosion is a major threat to seawater injection systems that are part of offshore drilling operations. Seawater is typically deoxygenated to an industry standard of(DO) by injection through a deaeration column followed by treatment with oxygen scavenging chemicals. Commercial simulation software like OLI Studio: Corrosion Analyzer predicts high corrosion rates when injection seawater contains high DO levels, justifying deoxygenation. However, a notable lack of experimental data exists concerning the effect of varying levels of dissolved oxygen on corrosion rate. The goal of this project is to measure the effect of three dissolved oxygen levels (0, 62, and 620 ppb) …

Exploring Rapid Solidification And Equal Channel Angular Pressing In The Fabrication Of Mg-Based Alloys For Medical Applications, Emily Tom

Dissertations, Master's Theses and Master's Reports

The development of magnesium bioresorbable implants has become increasingly popular due to the increased need for temporary implants and magnesium’s excellent biocompatibility and suitable elastic modulus. Even though magnesium is an excellent candidate, when alloyed with other metals magnesium’s corrosion rate becomes too rapid for bioresorbable medical applications. The investigation into novel processing techniques to control the formation of precipitates to improve mechanical strength and ductility as well as corrosion rates has become of interest. This work investigates the combination of two nonequilibrium processing techniques, rapid solidification (RS) and equal channel angular pressing (ECAP), and the effects it has on …

Pitting Corrosion Of Oerlikon’S Abrasion Resistant Ferritic Stainless Steels, Matthew P. Nalty, Emma Wagstaff

Materials Engineering

Existing hardfacing coatings for hydraulic cylinders and brake disc applications crack during use leaving the components susceptible to corrosion. To address this problem, Oerlikon has designed three new alloys to be abrasion and corrosion resistant. This paper reviews the literature necessary to understand and quantify pitting resistance of stainless-steel alloys. It documents one round of testing ASTM G48 method A: Ferric Chloride Pitting Test of Stainless Steels on the new alloys P72-X9, P72-X13, P129-X9, as well as samples of 431, 316, and 2205 stainless steels. This paper also discusses improvements to the G48 testing method and industry use of the …

The Influence Of Heat Treatment On Corrosion Behavior Of Martensitic Stainless Steel Uns 42670, Armen Kvryan

Boise State University Theses and Dissertations

Ceaseless demand for lighter, faster, and more efficient aircraft has been one of the greatest driving forces behind bearing steel innovations. Recent studies demonstrate that corrosion is one of the leading causes of bearing failure in both military and commercial aircraft. High-performing bearing steels are available but are not being used in US military applications due to high cost and security issues when steels are produced outside of the continental United States. One approach to address this issue is to engineer steels that are cost-efficient and heat treated for corrosion resistance, long wear life, etc.

This dissertation presents information on …

Process-Property-Microstructure Relationships In Laser-Powder Bed Fusion Of 420 Stainless Steel., Subrata Deb Nath

Electronic Theses and Dissertations

Laser-powder bed fusion (L-PBF) is an additive manufacturing technique for fabricating metal components with complex design and customized features. However, only a limited number of materials have been widely studied using L-PBF. AISI 420 stainless steel, an alloy with a useful combination of high strength, hardness, and corrosion resistance, is an example of one such material where few L-PBF investigations have emerged to date. In this dissertation, L-PBF experiments were conducted using 420 stainless steel powders to understand the effects of chemical composition, particle size distribution and processing parameters on ensuing physical, mechanical and corrosion properties and microstructure in comparison …

Corrosion Performance Of Zirconium-Based Passivations On Electroplated Zinc Nickel, Madison Morgan Reed

Masters Theses

“Performance requirements for Department of Defense (DoD) electrical components include corrosion and electrical contact resistance. Historically, electroplated cadmium with a chromate conversion coating (CrCC) has been used to meet corrosion and contact resistance standards. However, replacements are needed for these materials because they are toxic and carcinogenic. Electroplated γ-ZnNi has been identified as an acceptable alternative to Cd. This study evaluated commercially available Zr-based thin films and sealers as passivations for potential replacement of CrCCs. Ten different passivations were tested and compared with bare γ-ZnNi. X-Bond and Zircobond passivations were found to provide some improvement to the bare ZnNi corrosion …

Comparison Of Intrusive And Non-Intrusive Methods For Corrosion Monitoring Of Fuel Processing Systems, Armando Jacob Espinoza, Thomas Conner Field

Materials Engineering

This presentation contains an assessment of the best overall corrosion monitoring device, intrusive or non-intrusive, for use in the petrochemical industry. Corrosion in the petrochemical industry is a large issue because it causes a deterioration of pipe integrity in fuel processing systems. A reduction of pipe wall integrity due to corrosion could result in a leak or an explosion of fuel processing lines since those systems function at high pressures. The use of corrosion monitoring systems in the petrochemical industry helps to detect early signs of corrosion prior to failure so that proper maintenance can be performed to prevent catastrophe. …

Nano-Channels Early Formation Investigation On Stainless Steel 316ti After Immersion In Molten Pb-Bi, Abu Khalid Rivai, Mardiyanto Mardiyanto, Annette Heinzel

Makara Journal of Technology

Development of fuel cladding and structural materials in Pb-Bi environment, especially at high temperature, is a critical issue for the deployment of LFR (Lead alloy-cooled Fast Reactor) and ADS (Accelerator Driven Transmutation System). This is because of the corrosive characteristic of Pb-Bi to metals as constituent materials of fuel cladding and structural of the reactors. Corrosion test of a high-chromium austenitic stainless steel i.e. SS316Ti in molten Pb-Bi at 550 ºC has been carried out for about 300 hours continuously. The characterization using SEM-EDS (Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy) showed that an iron oxide as the outer …

Design And Validation Of Novel Potential High Entropy Alloys, Boliang Zhang

LSU Doctoral Dissertations

The design approach and validation of single phase senary refractory high entropy alloys (HEAs) MoNbTaTiVW and HfNbTaTiVZr were presented in first part of this dissertation. The design approach was to combine phase diagram inspection of available binary and ternary systems and Calculation of Phase Diagrams (CALPHAD) prediction. Experiments using X-ray diffraction and scanning electron microscopy techniques verified single phase microstructure in body centered cubic lattice for both alloys. The observed elemental segregation agrees well with the solidification prediction using Scheil model. The lattice constant, density and microhardness were measured to be 0.3216 nm, 4.954 GPa and 11.70 g/cm³ for …

The Effects Of Carboxylic Acids In Aluminum Anodizing, Abby E. Koczera

Honors Theses and Capstones

Hard-anodized alumina coatings were formed in sulfuric acid at low temperature and high current density in the presence of carboxylic acid additives. Citric acid, trimesic acid, mellitic acid and ethylenediaminetetraacetic acid (EDTA) were utilized in varying concentrations. The additives were chosen for their capacity to form complexes with tri-valent aluminum and hence impart chemical stability to the coatings. The coatings were sealed in boiling water, and corrosion resistance was observed in a high pH solution of potassium hydroxide. The coatings were examined using scanning electron microscopy (SEM) to assess coating thickness and pore dimensions. Thicker coatings were produced when the …

Pitting Corrosion Of 410 Stainless Steel In Hcl Solutions, Paul D. Krell

Williams Honors College, Honors Research Projects

410 stainless steel (SS) is a material used in HCl services, such as distillation column trays in oil refineries. Unlike other alloys, however, the oil refining industry lacks a good reference for the corrosion rate of 410 SS at the varying HCl concentrations and temperatures the material might experience as trays in crude unit distillation columns. The goal of this project is to fill that knowledge gap. The corrosion behavior of 410 SS in HCl environments of pH 0.50, 1.25, 2.25, 3.25, and 4.25 at temperatures of 38, 52, 79, and 93°C was investigated using several methods. Cyclic potentiodynamic polarization …

Oxidation Resistance Of Nanocrystalline 316l Stainless Steel Processed By High Pressure Torsion, Kevin J. Meisner

Williams Honors College, Honors Research Projects

High Pressure Torsion (HPT) is a materials processing method used to refine the grain size of metallic materials through the application of simultaneous axial and torsional strain. HPT is reported to result in nanocrystalline structure, which the current scientific literature suggests may improve the high temperature oxidation resistance by enhancing diffusion of solutes, particularly Cr, to the surface to form a protective external oxide scale. If oxidation resistance is improved, this possibly allows the use of 316L in oxidizing environments where more expensive alloys are typically used. However, the influence of grain refinement to nanoscale on various properties have been …

The Examination Of Stress Corrosion Cracking In High Strength Carbon Steel Through Combined Mechanical-Electrochemical Testing, Jacob Sines

Williams Honors College, Honors Research Projects

Through the analysis of materials and environments seen in industry a better understanding of the fundamentals behind degradation mechanisms can be observed. The scope of this project was to better understand the fundamentals behind the degradation of high strength pipeline steels in a lab setting to simulate an environment seen in industry. Specifically the degradation mechanisms of high and nearly neutral pH stress corrosion cracking were examined in environments that simulated oil and gas pipelines buried in soil. Experimentation was carried out utilizing X65 carbon steel specimen, a Gamry potentiostat, a CORTEST proof ring, a CORTEST slow strain rate machine, …

Magnesium-Titanium Alloys For Biomedical Applications, Ilona Hoffmann

Theses and Dissertations--Chemical and Materials Engineering

Magnesium has been identified as a promising biodegradable implant material because it does not cause systemic toxicity and can reduce stress shielding. However, it corrodes too quickly in the body. Titanium, which is already used ubiquitously for implants, was chosen as the alloying element because of its proven biocompatibility and corrosion resistance in physiological environments. Thus, alloying magnesium with titanium is expected to improve the corrosion resistance of magnesium.

Mg-Ti alloys with a titanium content ranging from 5 to 35 at.-% were successfully synthesized by mechanical alloying. Spark plasma sintering was identified as a processing route to consolidate the alloy …

Evaluation Of Forging Strain For Maximum Grain Size In Open-Die Forged 6061 Aluminum, Eric Strehl

Materials Engineering

In an effort to maximize grain growth of open-die forged 6061 aluminum alloy parts, samples from three of Weber Metals’s suppliers (Hidal Co-Almex USA Inc., TST Inc., and Vista Metals Corp.; to be called Supplier H, Supplier T, Supplier V respectively) were cut into cylinders with diameters of 0.75˝ and heights of 2˝, and put through a simulated forging process and heat treatment. It is possible that additional alloying elements may be promoting or inhibiting grain growth in the final part. Maximizing grain growth for aluminum alloy parts results in improved resistance to intergranular corrosion. Samples from each vendor had …

Analyzing The Corrosion Resistance Of Ni-Shield 200 Coatings At Different Temperatures When Exposed To Sulphuric Acid, Alex Hussinger

Materials Engineering

Six steel samples each were twin wire arc sprayed with Hastelloy C-276 or Nickel-Shield 200 coatings approximately 0.020″ thick. These samples were then cut into 3″ by 3″ squares. A 2″ diamond grit hole saw was used to abrade and polish to a smooth surface a ring in the middle in order to get an O-ring mechanical seal. The samples were then weighed and loaded into a jig that started from the bottom up with a stainless steel plate, then the sample, then a Viton O-ring, a ¾″ thick glass plate with a 1 3/4″ hole cut in it, another …

Process Refinement Through Design Of Experiments (Taguchi) To Reduce Porosity Levels Of Thin Flame Spray Nicrbsi Coatings On Cast Aluminium Alloys, David Culliton, David Kennedy, Tony Betts

Conference Papers

Thin(16matrix of key deposition parameters was constructed to develop the optimum spray parameters. The effects of parameter variations on the porosity levels of these coatings were assessed. Key parameter interactions were reported. Quantifiable interactions between the selected parameters were noted for the LM24 substrate. However, on the LM25 substrate these interactions were much less defined. Corrosion performance of the optimised coatings, based on electrochemical impedance spectroscopy, was reported. The presence of through-pores in the coatings were shown to reduce the corrosion resistance of the coated systems by a factor of 10, in dilute NaCl solutions, compared to bulk 316L stainless …

The Effects Of Heat Treatment On Area Percent Porosity And Corrosion Behavior Of High-Nickel Thermal Spray Coatings, Travis Crowe, Alec Guraydin

Materials Engineering

Samples of two Thermal Spray Coating (TSC) alloys on a low carbon steel substrate were obtained: alloy C276 and Nicko-Shield 200. Specimens of each alloy were subjected to heat treatments at temperatures at 1100° for 60 minutes and 1200° for 10 minutes, with some specimens left in the as-sprayed condition. Three replicates were prepared for each condition. Thin 1” strips were cut using a diamond wafering blade for porosity measurements and 2” x 1” specimens were cut for corrosion testing using a SiC abrasive saw. The porosity specimens were mounted in acrylic resin, polished, and examined using SEM. From these …

Characterization Of Iron Oxides And Atmospheric Corrosion Of Steel, Sei Jin Oh

Physics Theses & Dissertations

The study of corrosion behavior was performed using three different analytical techniques, which provided information on the formation, development and layering of iron oxides on the corrosion products as a function of atmospheric conditions, exposure time and type of steel. In particular, the protective layer formed on weathering steel was investigated as a function of different amounts of alloying elements in the steel, atmospheric conditions and exposure times. Combined together, the results provided a better understanding of the atmospheric corrosion behavior of steel, and formed a part of database of the atmospheric corrosion characteristics.

Accurate characterization of the iron oxides …