Lexington, KY, United States
Lexington, KY, United States

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Stalheim D.,DGS Metallurgical Solutions , Inc. | Boggess T.,Secat Inc. | Marchi C.S.,Sandia National Laboratories | Jansto S.,Metals USA | And 3 more authors.
Proceedings of the Biennial International Pipeline Conference, IPC | Year: 2010

The continued growth of the world's developing countries has placed an ever increasing demand on traditional fossil fuels. This increased demand for fossil fuels has lead to increasing research and development of alternative energy sources. Hydrogen gas is one of the potential alternatives under development. It is anticipated that the least expensive method of transporting large quantities of hydrogen gas is through steel pipelines. It is well known that hydrogen embrittlement has the potential to degrade steel's mechanical properties. Consequently, the current pipeline infrastructure used in hydrogen transport is typically operated in a conservative fashion, in particular lower operating pressures, lower strength steels, and heavier pipe wall thicknesses. This operational practice is not conducive to economical movement of significant volumes of hydrogen gas as an alternative to fossil fuels. The degradation of the mechanical properties of steels in hydrogen service depends on the microstructure of the steel. An understanding of the relationship of mechanical property degradation of a given microstructure on exposure to hydrogen gas under pressure can be used to evaluate the suitability of the existing pipeline infrastructure for hydrogen service and guide alloy and microstructure design for new hydrogen pipeline infrastructure. To this end, the microstructures of relevant steels and their mechanical properties in relevant gaseous hydrogen environments must be fully characterized to establish suitability for transporting hydrogen. A project to evaluate four commercially available pipeline steels alloy/microstructure performance in the presences of gaseous hydrogen has been funded by the US Department of Energy along with the private sector. The microstructures of four pipeline steels were characterized and tensile testing was conducted in gaseous hydrogen and helium at pressures of 5.5 MPa (800 psi), 11 MPa (1600 psi) and 20.7 MPa (3000 psi). Based on reduction of area, two of the four steels that performed the best across the pressure range were selected for evaluation of fracture and fatigue performance in gaseous hydrogen at 5.5 MPa (800 psi) and 20.7 MPa (3000 psi). This paper describes the work performed on four commercially available pipeline steels in the presence of gaseous hydrogen at pressures relevant for transport of hydrogen in pipelines. Microstructures and mechanical property performances are compared. In addition, recommendations for future work related to gaining a better understanding of steel pipeline performance in hydrogen service are discussed. Copyright © 2010 by ASME.

Wen X.,University of Kentucky | Wen W.,Secat Inc. | Wen W.,Novelis Inc. | Zhang Y.,Shandong Jianzhu University | And 7 more authors.
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2016

Continuous cast AA5052 Al alloys, containing iron contents of 0.120 and 0.466 wt pct, respectively, were cold rolled and annealed at temperatures ranging from 505 K to 755 K (232 °C to 482 °C). The recrystallization textures in the two alloys were analyzed using X-ray diffraction and electron back scatter diffraction, respectively. It was found that higher Fe content promoted the formation of deformation textures and retarded the formation of cube texture in the two alloys. Most cube-oriented grains formed in both these alloys were associated with coarse particles, whereas the P—{011}〈566〉, R—{123}〈634〉, and Goss or randomly oriented grains were often related to particle stringers consisted of fine particles along the rolling direction. It was also found that the volume fraction of each texture component was a Johnson–Mehl–Avrami–Kolmogorov-type function of annealing temperature in the two alloys. The texture evolution rate with the annealing temperature was calculated from this function and used to determine the onset temperature of each recrystallization texture component. © 2016 The Minerals, Metals & Materials Society and ASM International

Marchi C.S.,Sandia National Laboratories | Somerday B.P.,Sandia National Laboratories | Nibur K.A.,Sandia National Laboratories | Stalheim D.G.,DGS Metallurgical Solutions , Inc. | And 2 more authors.
American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP | Year: 2010

Gaseous hydrogen is an alternative to petroleum-based fuels, but it is known to significantly reduce the fatigue and fracture resistance of steels. Steels are commonly used for containment and distribution of gaseous hydrogen, albeit under conservative operating conditions (i.e., large safety factors) to mitigate so-called gaseous hydrogen embrittlement. Economical methods of distributing gaseous hydrogen (such as using existing pipeline infrastructure) are necessary to make hydrogen fuel competitive with alternatives. the effects of gaseous hydrogen on fracture resistance and fatigue resistance of pipeline steels, however, has not been comprehensively evaluated and this data is necessary for structural integrity assessment in gaseous hydrogen environments. In addition, existing standardized test methods for environment assisted cracking under sustained load appear to be inadequate to characterize low-strength steels (such as pipeline steels) exposed to relevant gaseous hydrogen environments. In this study, the principles of fracture mechanics are used to compare the fracture and fatigue performance of two pipeline steels in high-purity gaseous hydrogen at two pressures: 5.5 MPa and 21 MPa. In particular, elastic-plastic fracture toughness and fatigue crack growth rates were measured using the compact tension geometry and a pressure vessel designed for testing materials while exposed to gaseous hydrogen. Copyright © 2010 by ASME.

Wen X.Y.,University of Kentucky | Wen W.,Secat Inc. | Liu Y.,Secat Inc. | Long Z.D.,Secat Inc. | And 4 more authors.
Materials Science and Technology (United Kingdom) | Year: 2015

Microstructure observation and texture analysis of two AA3xxx hotbands made by twin belt casting route and a proprietary pellet casting and compacting process were carried out respectively with the aid of scanning electron microscopy and orientation distribution function from X-ray diffraction. The textures and microstructures of the two alloys made by the two processes were systematically studied and discussed, which showed significant differences through hotband thickness in individual alloys. The results as obtained in the present investigation may provide practically useful reference for the microstructures and textures control and optimisation in production of hotband of aluminium alloys and final downstream rolling products. © 2015 Institute of Materials, Minerals and Mining.

Marchi C.S.,Sandia National Laboratories | Somerday B.P.,Sandia National Laboratories | Nibur K.A.,Hy Performance Materials Testing LLC | Stalheim D.G.,DGS Metallurgical Solutions , Inc. | And 2 more authors.
American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP | Year: 2011

Gaseous hydrogen is a convenient medium to store and transport energy. As existing petroleum-based platforms are electrified, such as with the growth of fuel cell systems, hydrogen is becoming an attractive fuel which must be distributed, stored and dispensed. Hydrogen is used extensively in refining of petroleum products, and often distributed by pipeline. However, there remains a need to quantify the mechanical properties of low-cost steels in gaseous hydrogen and to relate the measured performance to the variety of microstructures that characterize steels. This study is part of a larger effort to characterize a broad range of steels manufactured for pipelines and to measure their fracture and fatigue resistance in gaseous hydrogen. The fracture resistance and fatigue crack growth rates of two microstructural variations of X80 pipeline steel were measured in gaseous hydrogen at pressure of 21 MPa. The performance of these steels was found to be similar to the performance of other ferritic steels that are currently used to distribute gaseous hydrogen. Copyright © 2011 by ASME.

Jha G.,Tri Arrows Aluminum | Ningileri S.,SECAT Inc. | Li X.,SECAT Inc. | Bowers R.,SECAT Inc.
TMS Light Metals | Year: 2013

As technology and innovation advances, so do the materials which we use, and in turn, the raw material stream is continually impacted. Today, plants are faced with the challenge of ideally capitalizing on the positive benefits of trace elements when they exist, or following in previous paths of tolerating the increased levels of the elements, and in the worst case, removing the elements at a large expense in production costs. Presented are recent trends observed for various elements, their origins within the raw material stream, and discussions of the need to reexamine how trace elements are handled today and in the future. What is tolerable in certain aluminum alloy products and potential benefits in properties will be explored in addition to the challenges required to remove the elements effectively when needed.

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