Engineering Commons^™

Effects Of Perforations On Internal Cathodic Protection And Recruitment Of Marine Organisms To Steel Pipes, Alexander John Paluzzi

Theses and Dissertations

Steel monopile support structures for offshore wind turbines require protection from corrosion on their external and internal surfaces. Cathodic protection (CP) works effectively to protect the external surfaces of monopiles, but internally, byproducts from aluminum sacrificial anode CP (SACP) and impressed current CP (ICCP) induce acidification that accelerates steel corrosion. This project investigated the effects of perforations on the performance of aluminum SACP and ICCP when used inside of steel pipes. Additionally, marine growth on the external and internal surfaces of the pipes was assessed to determine if CP byproducts affect marine organism development.

Two sealed and two perforated steel …

Evaluation Of Accelerated Testing Methods To Predict The Effects Of Chemical Exposure On Mechanical Properties Of Polyester Composites In Municipal Wastewater Service, Roberto A. Garcia

Theses and Dissertations

Composite Access Products (CAP) is a company that is determined to replace traditional steel manhole covers with fiber reinforced polymer alternatives that have similar performance while also introducing several advantages. CAP can achieve this by manufacturing the polymer manhole covers using high-speed, high pressure compressing molding to produce lightweight, long-lasting, corrosive resistant covers. CAP’s composite covers have been approved for use by TXDOT in roadway zones. Despite this, they must now undergo more testing and verification for use in environments with highly corrosive elements such as sewage environments and waste processing plants. In these situations, the polymer manhole covers will …

Toward A Production Ready Fbj Process For Joining Dissimilar Combinations Of Gadp 1180 Steel And Aa 7085-T76, Kevin Alexander Shirley

Theses and Dissertations

Friction Bit Joining (FBJ) is a new technology that can be used to join dissimilar materials together. This ability makes it a good candidate for creating light weight structures for the automotive industry by combining lightweight materials such as aluminum to stronger materials like advanced high-strength steels. The automotive industry and many other industries have great interest in reducing structure weight to increase fuel efficiency. The purpose of this research is to make FBJ of GADP 1180 to AA 7085-T76 a production ready process by (1) better understanding the effects of process parameters, bit design and tool design on joint …

Microstructure, Wetting Angle And Corrosion Of Aluminum-Silicon Alloys, Shvetashva Suri

Theses and Dissertations

In this study the effect of composition, surface roughness and water droplet size on contact angle and corrosion properties of cast Aluminum-Silicon alloys containing Si from 5% to 50% have been examined. The water contact angle was measured on a given sample using a goniometer. In addition, the effect of surface roughness and droplet size on contact angle has been measured for alloys at a fixed composition. The microstructures can be found in this report with sizes of primary and eutectic Silicon as well as inter-particle spacing between Silicon. Contact angle measurements are accompanied with a photographic validation of the …

Corrosion-Related Gas Measurements And Analysis For A Suite Of Coals In Staged Pulverized Coal Combustion, Todd A. Reeder

Theses and Dissertations

Eleven gas species, including CO, CO2, H2, H2O, H2S, HCl, NOX, O2, SO2, COS and SO3, were measured in a 150 kWth, staged, pulverized coal, down-fired combustor using a Fourier transform infrared (FTIR) spectrometer, gas chromatograph (GC), and a Horiba PG-250 5-gas analyzer. Additional gases such as HCN, NH3, CH4, and other hydrocarbons were also measured. Seven coals of varying rank and composition were investigated. Measurements were obtained in reducing (S.R. = 0.85) and oxidizing (S.R. = 1.15) conditions. In particular, sulfur- and chlorine-containing species including H2S, SO2, COS, SO3, and HCl are discussed. In the reducing zone, all four …

An Analysis Of Microstructure And Corrosion Resistance In Underwater Friction Stir Welded 304l Stainless Steel, Tad Dee Clark

Theses and Dissertations

An effective procedure and parameter window was developed for underwater friction stir welding (UWFSW) 304L stainless steel with a PCBN tool. UWFSW produced statistically significant: increases in yield strengths, decreases in percent elongation. The ultimate tensile strength was found to be significantly higher at certain parameters. Although sigma was identified in the UWFSWs, a significant reduction of sigma was found in UWFSWs compared to ambient FSWs. The degree of sensitization in UWFSWs was evaluated using double loop EPR testing and oxalic acid electro-etched metallography. Results were compared to base metal, ambient FSW, and arc welds. Upper and lower sensitization localization …

Effects Of Friction Stir Processing On The Microstructure And Mechanical Properties Of Fusion Welded 304l Stainless Steel, Colin J. Sterling

Theses and Dissertations

Friction stir processing (FSP) has been utilized to locally process regions of arc weldments in 304L stainless steel to improve the microstructure and mechanical performance. The cast microstructure and coarse delta-ferrite has been replaced with a fine-grained wrought microstructure. Furthermore, twins were introduced throughout the friction stir processed region. Although sub-surface sigma and carbides were introduced during FSP, their presence is not expected to adversely affect the resulting mechanical or corrosion properties of friction stir processed 304L arc welds. The resulting mechanical properties of FS processed weldments were also an improvement over as-welded arc welds. FSP resulted in an increase …