Engineering Commons^™

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 …

Increasing The Corrosion Protection Of Aisi 1008 Carbon Steel By Surface Treatment With Unmodified And Benzotriazole Modified Sol-Gel Films, Shane Thomas Kelliher

Williams Honors College, Honors Research Projects

The corrosion performance of sol-gel coated AISI 1008 carbon steel was investigated in 3.5 wt% NaCl solutions of pH 7, 9, and 12 using electrochemical measurements. A corrosion inhibitor, benzotriazole (BTA) was added to the sol-gel mixture and tested as a second, modified sol-gel coating. Sol-gel films adhered evenly to metal samples and were characterized by FTIR spectroscopy. Electrochemical Impedance Spectroscopy (EIS) showed an increase in polarization resistance from blank to sol-gel coated samples (600-18,800,000 ohms). Cyclic polarization (CPP) curves showed positive hysteresis loops for blank and unmodified sol-gel coated samples which increased at high pH following the backward potential …

Testing The Effectiveness Of Reflective "Cool" Pigments, Ashleigh Carpenter

Williams Honors College, Honors Research Projects

This project is an exploration of reflective "cooling" pigments used in coatings for the exterior of a structure in order to control the temperature inside. The pigments reflect sunlight to reduce the heating effect inside a structure. While the project will include the synthesis and testing of these pigments, the focus will be on the design and construction of an apparatus to test the effectiveness of these pigments. An apparatus will be constructed with a heat source and two structures of identical dimensions. The set-up will allow for the temperature of the inside of the structures to be recorded at …

Controlled Release Of Corrosion Inhibitors: Zinc And Magnesium Containing Sodium Chromate, Andrew Thomas

Williams Honors College, Honors Research Projects

Corrosion can be combated by multiple methods, where the primary purpose is to minimize degradation of metal surfaces. Corrosion inhibitors are one of the most effective methods of corrosion protection. Inhibitors are substances that minimize corrosion in aggressive environments, with only a low concentration required. The inhibitors are chemically adsorbed on the surface of the metal and a protective thin film is formed . The mechanism of the inhibitors could be described as anodic, cathodic, or a mix of the two. Anodic inhibitors, also known as passivation inhibitors, alter an anode reaction. Corrosion potential of the metal is shifted to …

Cataloging The Degree Of Sensitization Via Electrochemical Reactivation For Studying The Corrosion Behavior Of Inconel 718, Austenitic, And Duplex Stainless Steels, Bradley Lynes

Williams Honors College, Honors Research Projects

Corrosion resistant materials can be expensive, but usually reduce the life cycle cost of metallic assets. However, negligent sensitization of these materials can lead to aggressive, intergranular corrosion. Using the methodology of the double loop electrochemical potentiokinetic reactivation (DL-EPR), this project investigates different steel reinforced bars and Inconel to determine the degree of sensitization after a heat treatment of 900°C for 2 hours. The purpose of this research is to validate and determine the appropriate test parameters for performing further DL-EPR test in the future. Additionally, the kinetics observed for each sample during the DL-EPR test will be analyzed and …

Development Of Cardanol-Based Epoxy Coating, Nicholas Pottschmidt

Williams Honors College, Honors Research Projects

The purpose of this project was to determine the suitability of cardanol glycidyl ether (CGE) as a substitute for trimethylolpropane triglycidyl ether (TMPGE) as the reactive diluent in epoxy coatings. CGE may be a naturally-derived alternative to TMPGE, which is a commonly-used petroleum-derived reactive diluent. Epoxy coatings were formulated with CGE replacing increasing amounts of TMPGE in the formulation. Corrosion protection provided by the coatings was evaluated with electrochemical impedance spectroscopy (EIS). Mechanical properties of the coatings (hardness, flexibility, adhesion, and impact resistance) were evaluated with applicable ASTM standards.

EIS results revealed the coating formulated with only CGE had superior …

Evaluation Of Silane-Doped Epoxy Coatings For Resisting Aluminum Corrosion By Oxalic Acid, An A. Niger Metabolite, Alex Pica

Williams Honors College, Honors Research Projects

The goal of this study was to investigate whether silane-doped epoxy coatings are capable of preventing corrosion of aluminum alloy 2024-T3 by oxalic acid, one of the primary metabolites of the fungus Aspergillus Niger. Previous research suggested the success of these types of coatings at preventing AA 2024-T3 corrosion in saline solutions, and this study was meant to build on those findings by investigating the efficacy of the coating in an acidic environment.

Each coating was applied to an AA 2024-T3 coupon by dissolving the epoxy and varying amounts of 3-aminopropyltriethoxysilane in acetone and then dripping the solution onto …

Effects Of Corrosion Inhibitor On The Corrosion Behavior Of Low Carbon Steel In Co2 Environment, Michael Harris

Williams Honors College, Honors Research Projects

The effectiveness of Benzalkonium chloride (C14) as a corrosion inhibitor for mild steel in an aqueous CO₂ environment was studied for dual use. It is a known biocide and currently untested corrosion inhibitor. Potentiodynamic polarization was used to determine the anodic and cathodic reaction kinetics through analysis of the potentiodynamic curves and the corrosion current densities. Electrochemical impedance spectroscopy (EIS) was utilized to analyze the surface characteristics through analysis of the Nyquist and Bode plots. C1010 and C1018 mild steel were tested in a 200mL jacketed Gamery cell, and purged with CO₂ (99.9%). Temperature effects were studied and …

Corrosion Resistance Of Silane Coatings On Aluminum And Magnesium Alloys, John Demopoulos

Williams Honors College, Honors Research Projects

The purpose of this project was to increase the corrosion resistance of aluminum and magnesium alloys by coating the coupons with a silane on the surface. Four different silanes: 3-aminopropyltriethoxysilane (APTES), Bis(triethoxysilylpropyl)amine (Bis), (Heptadecafluoro-1,1,2,2-tetrahydrodecyl)trichlorosilane (FTS), and (Heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane (non Cl FTS) will be used and compared to see which silane would give the best corrosion resistance. Each silane solution was coated on the coupons by using a solution method in which the coupon was submerged for 24 hours and then thermally cured for another 24 hours. Once the coating was applied, the water contact angle and the thickness of the coating …

Evaluation Of Epoxy Coatings For Protecting Aluminum Alloy 2024 From Corrosion Caused By Aspergillus Niger, Kamshat Dukenbaeva

Williams Honors College, Honors Research Projects

The aim of this study was to assess the potentials of using epoxy coatings for the prevention of fungus-induced corrosion. The metal specimen of interest was the aluminum alloy AA 2024-T3. The main intent was to evaluate the behavior of the organic acid producing fungus, Aspergillus niger (A. niger), towards the epoxy-coated aluminum. Two different types of epoxy coatings were used: a two-part resin and a commercially-available Rust-Oleum Specialty Appliance Epoxy. Due to challenges encountered throughout the length of the project and time constraints, limited quantitative data was obtained. However, from optical and visual data it can be concluded that …

Stress Corrosion Cracking Evaluation Of Carbon Steel In Biodiesel And The Effect Of Ultrasonic Nanocrystal Surface Modification (Unsm) On 304 Stainless Steel, Josh Geyer

Williams Honors College, Honors Research Projects

The project that was performed was stress corrosion cracking (SSC) of carbon steel in biodiesel, petroleum diesel and a mixture. The project also included the effect of Ultrasonic Nanocrystal Surface Modification (UNSM) on 304 stainless steel. It included the assembly of a slow strain rate (SSR) machine and carrying out testing using the SSR machine. The assembly of the machine will require purchasing and building a stand to house the electrical equipment which includes the computer, actuator control panel and the actuator power supply. The assembly will also include designing and purchasing the connections to connect the actuator to the …

Passivation And Potential Fluctuation Of Az31b Alloy In Alkaline Environments, Ana C. Bacco

Williams Honors College, Honors Research Projects

Magnesium (Mg) alloys are used in many industries because of their distinctive properties, but their high chemical reactivity and poor oxide film protection make them inferior. This project focused on investigating the effects of secondary phases and intermetallic particles (IMPs) on the corrosion behavior of AZ31B Mg alloy. The test solution was chloride free NaOH with varying pH levels between 10-14, as well as testing under deaerated conditions. The open circuit potential (OCP) measurements using AZ31B in static NaOH solutions showed potential fluctuation between approximately -1.6 V_SCE (active state) and -0.4 V_SCE (passive state) during the 24-h immersion. …