bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uniaxial Creep Properties of 316L Stainless Steel Manufactured by Laser Powder Bed Fusion
Authors: Sandmann Paul , Milne Amy J. , Davies Catrin Mair 
Published: November 2023

Abstract
316L stainless steel has long been used in high temperature applications. As a well-established laser powder bed fusion (LPBF) alloy, there are opportunities to utilise additive manufacturing in such applications. However, to date there is limited creep data on LPBF material. Uniaxial round bar creep tests have been performed at 700 °C and characterised using power-law relations to evaluate the creep strain and rupture properties of LPBF 316 L. Samples were manufactured in two orientations denoted (i) vertical i.e. loading direction parallel to the build direction and (ii) horizontal, i.e. loading direction perpendicular to the build direction. The creep response was found to be anisotropic with specimen build orientation, with samples loaded perpendicular to the build direction (Horizontal) exhibiting faster minimum creep rates than samples built parallel to the build direction (Vertical). This was mainly attributed to the columnar grain structure revealed by electron back scattering diffraction (EBSD), which was aligned with the build direction of the LPBF samples. The vertical samples generally exhibited significantly longer rupture lives than horizontal samples, unless influenced by deleterious porosity. The results were compared to existing test data performed at 650 °C and similar trends were seen at both temperatures, though higher creep rates and shorter rupture times resulted from the higher temperature, as expected.
Fatigue Crack Initiation and Fatigue Life Testing of High-Strength Austenitic Stainless Steel Tubing With Internal Hydrogen
Authors: San Marchi Chris , Ronevich Joseph A. , Pohl Johan , Ramseyer Severin , Cortinovis Davide , Eckmann Stefan 
Published: November 2023

Abstract
Austenitic stainless steels have been extensively tested in hydrogen environments; however, limited information exists for the effects of hydrogen on the fatigue life of high-strength grades of austenitic stainless steels. Moreover, fatigue life testing of finished product forms (such as tubing and welds) is challenging. A novel test method for evaluating the influence of internal hydrogen on fatigue of orbital tube welds was reported, where a cross hole in a tubing specimen is used to establish a stress concentration analogous to circumferentially notched bar fatigue specimens for constant-load, axial fatigue testing. In that study (Kagay et al, ASME PVP2020-8576), annealed 316L tubing with a cross hole displayed similar fatigue performance as more conventional materials test specimens. A similar cross-hole tubing geometry is adopted here to evaluate the fatigue crack initiation and fatigue life of XM-19 austenitic stainless steel with high concentration of internal hydrogen. XM-19 is a nitrogen-strengthened Fe-Cr-Ni-Mn austenitic stainless steel that offers higher strength than conventional 3XX series stainless steels. A uniform hydrogen concentration in the test specimen is achieved by thermal precharging (exposure to high-pressure hydrogen at elevated temperature for two weeks) prior to testing in air to simulate the equilibrium hydrogen concentration near a stress concentration in gaseous hydrogen service. Specimens are also instrumented for direct current potential difference measurements to identify crack initiation. After accounting for the strengthening associated with thermal precharging, the fatigue crack initiation and fatigue life of XM-19 tubing were virtually unchanged by internal hydrogen.
Effect of Hydrogen Partial Pressure on Fatigue Crack Growth Rates of Low Alloy, Quenched and Tempered Steels
Authors: Bortot Paolo , Ortolani Matteo , San Marchi Christopher , Ronevich Joseph 
Published: November 2023

Abstract
Low alloy, quenched and tempered Cr-Mo and Ni-Cr-Mo steels are commonly used for construction of seamless pressure vessels for hydrogen gas storage. Designing such vessels for high-pressure gaseous hydrogen service requires knowledge of fatigue crack growth rates and fracture toughness in the service environment at the design pressure. Measurement of these properties is challenging, and only a few laboratories in the world are equipped to make these measurements at very elevated pressure up to 103 MPa (15,000 psi) which are of interests for pressure vessels to be used as buffers in hydrogen refueling stations. In recent years, these properties for common low alloy steels were published in the ASME Boiler and Pressure Vessel Code Case 2938-1, therefore allowing design and construction without the need for dedicated testing. However, the fatigue crack growth rate curves published in the CC were determined from test data at 100 MPa and above and may be over-conservative for lower pressure applications. Prior publication PVP2019-93907 ([1]) in fact, already proposed a correction factor of fatigue crack growth rates based on hydrogen fugacity. Since then, new data were generated at lower pressures i.e. 55 MPa (8,000 psi). This paper presents the new findings and discusses the applicability of the previously proposed equation, which could allow reducing conservatism in current design of pressure vessels.
Structural Capacity Analysis of Subsea Equipment
Authors: Karpanan Kumarswamy , Kirkemo Finn 
Published: November 2023

Abstract
Subsea oil and gas production equipment such as risers, manifolds, trees, wellheads, tubing hangers, tubing heads, blow out preventers, etc., are predominantly designed to criteria of API 6X, API 6A, API 16A, API 17D, API 17G, ASME VIII-2, ASME VIII-3, and NORSOK U-001 design codes. These industry codes provide design criteria to verify failure modes such as plastic collapse, fatigue failure, ratcheting, local strain failure, brittle failure, etc. Among these failure modes, plastic collapse and fatigue failure can be considered as the primary failure modes. A detailed review of plastic collapse design criteria from these codes and standards is discussed in this paper. These codes allow elastic (linear), limit load (elastic perfectly plastic), and elastic-plastic finite element analysis (FEA) to estimate the structural capacity. Some of these codes allow geometric nonlinearity in limit load FEA and some are not. All elastic-plastic analyses are solved with geometric nonlinearity.
For this study, four components are considered which represent many subsea equipment. A pressure vessel (cylindrical shell) with internal pressure, open-end vessel (cylindrical shell) with external pressure, load shoulder, and pipe (cylindrical shell) bending are considered. Three materials with yield to tensile strength ratio of 0.53, 0.79, and 0.89 are considered in this study. A detailed review of plastic collapse criteria design criteria from these codes and standards is discussed in this paper for the four cases above.
A Simplified Method for Analyzing Pressure Vessel Response to Explosion Generated Drag Loading
Authors: Hundl Jacob , Millet Barry , Kirkpatrick Kenneth , Mosher Bryan 
Published: November 2023

Abstract
A simplified method for analyzing pressure vessel response to blast overpressure incidents was developed, refined, and verified in papers PVP2021-61854 and PVP2022-84746. The simplified method presented in the two papers showed how it was possible to analyze the loading and effects of a blast wave generated by an explosion (positive phase overpressure incident) on vertical pressure vessels without utilizing traditional analysis software. However, the simplified method presented in the two papers did not consider or provide provisions for examining equipment loading solely from explosive generated drag loading (negative phase over-pressure event). During the execution and detailed design of an offshore liquified natural gas (LNG) facility, drag loads were added as part of the design criteria for certain pressure vessels by the offshore classification society and the third-party health safety and environmental (HSE) group contracted to study the possibility and probability of an explosion. This paper will show the development, implementation, and results from a simplified method for analyzing pressure vessel response to drag loading which utilizes the dynamic load factor (DLF) and assumes a single degree of freedom (SDOF) system to remove the use of any specialized finite element analysis (FEA) software from the analysis. The paper will examine the actual pressure vessels andapplicable design loads which were required to be evaluated by the project and compare the results of simplified analysis to a traditional analysis which uses an industry standard structural analysis FEA software. The loadings which were generated by the analysis were compared to the allowable stresses in industry codes and standards for acceptance.
API 582 – 4th Edition – Additions and Clarifications to the 3rd Edition
Authors: Colwell Richard L. , Layo William E. 
Published: November 2023

Abstract
In 2023 the 4th Edition of API Recommended Practice 582, “Welding Guidelines for the Chemical, Oil, and Gas Industries” will be issued. The document has undergone a significant revision, including major restructuring, and inclusion of new consensus industry recommendations for welding creep-strength enhanced ferritic alloys (e.g. P91), welding Heat Resistant Alloys, and Controlled Deposition Welding. This paper will outline the new structure, and provide a detailed explanations of recent changes in the recommended practice.
The Effect of Lubrication on Percent of Red Rust and Break-Out Torque of PTFE Coated Fasteners
Authors: General Justinn , Norman Dale , Bao Tommie 
Published: November 2023

Abstract
Polytetrafluoroethylene (PTFE) coated fasteners have been commonly used in various industry applications for both its corrosion resistance and lubricity during bolt up. There is a wide array of different brands and various process methods to apply PTFE on fasteners, that offer similar performance. However, there is a resounding question regarding if lubrication is needed during bolt up of PTFE fasteners and if there are any benefits to corrosion resistance and break-out.
For this study, we used two applicators of Xylan 1424 and one applicator of Flurokote #1, all PTFE based coatings. The samples were subjected to salt spray environment in accordance with ASTM B117 at 1,500 hours, 2,000 hours, 2,500 hours, and 4,000 hours. The studs were torqued to load the ASTM A193 B7 fasteners to 50% of the minimum yield, where half of the studs were torqued without lubrication and the other half were lubricated with Jet-Lube 550 Extreme. At each of the time intervals, the percentage of red rust on the stud and two nuts were measured and the break-out torque was recorded.
Numerous observations were made as to the relationship between application of lubrication and without regarding both corrosion and break out torques. This paper will talk in depth as to the benefits of using lubrication on PTFE coated fasteners.
Notch Effect on Creep-Fatigue Behavior of Alloy 617 at Elevated Temperature
Authors: Hou Peijun , Wang Yanli , Sham Ting-Leung 
Published: November 2023

Abstract
High-temperature reactor structural components are often under the complex multiaxial creep-fatigue (CF) loading conditions throughout the lifetime because of geometric and/or metallurgical discontinuities and complex loading paths. To assess the multiaxial CF deformation behavior and to evaluate the CF design rules in the ASME BPVC Section III, Division 5, Subsection HB, Subpart B, experimental and numerical studies are performed on Alloy 617 at 950°C using notch specimen geometries under CF loading in this study.
Two types of notch specimen geometries, shallow-notch and sharp V-notch were designed for Alloy 617 per ASTM Standard E292-09. Experimental procedures were developed, and tests at 950°C were performed under CF loading with tension hold time using the two notch specimen geometries. The information collected from the experiments included the average axial stress relaxation histories, the changes in the relaxation behavior as a function of applied cycles, and failure information. Additionally, an inelastic constitutive model of Alloy 617 was used in the finite element analyses of the notch specimens to determine the stress triaxiality distributions, local and average stress relaxation behavior, and local elastic follow-up. The results from the experimental and numerical studies on the CF of notch specimens are compared with those on standard uniaxial smooth bar specimens. The notch effect on the CF deformation and failure of Alloy 617 is summarized and the assessment of the design rules regarding the treatment of multiaxial stress relaxation is discussed.
Considerations for Graphite in the Design, Qualification and Operation of Advanced Reactor Cores
Authors: Booler Owen A. , Davies Mike W. 
Published: November 2023

Abstract
Graphite has been used historically in nuclear reactor cores for its excellent neutron moderation properties. However, the complex material behaviour inherent in irradiated graphite has resulted in several structural integrity challenges that has constrained the lifetime of the reactor core. Working towards understanding how graphite behaves in irradiated core conditions and its safety performance has allowed for the successful life extension of the UK Advanced Gas-cooled Reactors (AGR) fleet to operate beyond their original design limits. Some of the key challenges with graphite is that due to its polycrystalline nature, the material behaviour is complex which is compounded when considering the irradiated environment; where degradation changes the material behaviour, leading to differential shrinkage and significant tensile stresses. This in turn affects the structural performance and thermal hydraulics, all of which have a consequence to the safe operation of the reactor core. Therefore, serious consideration of graphite in the design of next generation reactors will not only primarily secure safety in the design but could also reduce cost and increase the return on investment. Here, we identify seven main considerations for graphite in the design, qualification and operation of advanced reactor cores that will not only aid in meeting design code requirements (specifically ASME III Division 5) and regulator conformance, but will also improve the commercial viability of future nuclear power.
The Fundamental Sealing Characteristics Evaluation for Metal Hollow O-Ring Gaskets
Authors: Yamamoto Kohei , Sawa Toshiyuki , Itano Kohei 
Published: November 2023

Abstract
Metal hollow O-ring gaskets have been used in bolted flanged connections for high-pressure piping. Some studies have been conducted on their deformation characteristics. However, the sealing performance of the connections, which is important for practical use, has not been fully elucidated. The purpose of this study is to investigate the effects of metal hollow O-ring under compression on the sealing performance. So, the effects of the thickness ratio of O-ring to the diameter of it on the sealing performance are examined using both FEM stress analysis and the leakage measurements in platen tests. A helium leak detector was used to measure the amount of leakage from the O-ring alone in the platen test, and the compression behavior was investigated using FEM analysis to show the relationship between the contact stress and the amount of leak rate. As a result, it is demonstrated that the leak rate can be predicted using the maximum contact stress. Additionally, the relationship between the contact force η per unit length (load per unit length) and the displacement for bolted flange connections with O-ring gaskets is examined both experiments and the FEM analysis.
Graphite-Molten Salt Considerations for Components in Nuclear Applications
Authors: Gallego Nidia C. , Geringer Josina W. , Windes William 
Published: November 2023

Abstract
The new high-temperature reactor (HTR) designs being considered for future Generation IV nuclear reactor deployment include designs using molten salt as the primary coolant. These molten salt-cooled graphite core designs pose new material compatibility challenges that are not considered within the gas-cooled HTR designs that have been previously built and operated. Although early indications from the Molten Salt Reactor Experiment (MSRE) in the 1960s were that molten salts could be considered chemically inert to graphite, recent studies revealed additional physical and thermal interactions that the molten salt imposes that may be just as significant as the chemical reactivity. Specifically, molten salt intrusion into the open pore structure of nuclear graphite grades can cause additional internal stresses within the microstructure, exacerbating the stress accumulation from irradiation-induced dimensional change. Additionally, designs using a molten salt-containing liquid fuel could produce hot spots within graphite structural components, causing local thermal stresses. Abrasion and erosion concerns are magnified with molten salt because of their extremely high density (some salts have higher densities than the structural graphite components). Finally, the graphite-graphite and fuel pebble-graphite tribological behavior are distinctly different within the molten salt from the inert gas environments and must be investigated. These topics and others are currently under investigation within the US Department of Energy Advanced Reactor Technologies graphite program and will be discussed in depth.
Determining Burst Strength of Thin and Thick-Walled Pressure Vessels Through Parametric Finite Element Analysis
Authors: Johnson William R. , Zhu Xian-Kui , Wiersma Bruce , Sindelar Robert 
Published: November 2023

Abstract
Previous work on pressure vessel (PV) burst strength established a numerical technique for determining the more accurate Zhu-Leis burst strength from the pressure-Mises stress curve provided by finite element analyses (FEA). That work was not applied to capture the burst strength for thick-walled pipes. Recent analytical developments have resulted in a thick-walled Zhu-Leis burst strength solution. This work examines this solution using FEA calculations. To do so, the FEA stress was measured at multiple points through the wall thickness of the PV and compared to the analytical thick-walled solution to determine the best measurement location through the thickness. To further examine the burst pressure for different vessel sizes and materials, we developed a parametric code, using the Abaqus Python application programming interface, to rapidly iterate over 60 different combinations of geometries and material properties. This code also extracted stress data from the FEA results and analyzed the numerical pressure-Mises stress curves to find the critical point corresponding to the Zhu-Leis burst pressure. A linear regression model was developed which can very accurately predict the PV burst pressure. This regression model applies over a range of pipeline steels from grade B to X80, and diameter-to-thickness (D/t) ratios from 6 to 120.
Measuring Damping in Linear and Nonlinear Systems
Authors: Goyder Hugh 
Published: November 2023

Abstract
It is shown how measurements of the decaying response of a vibrating system, following an initial disturbance, can be analysed to extract natural frequency and damping properties. Typically, such data contains a superposition of many vibration modes. By using filtering, it is demonstrated how individual modes can be extracted. The filtering must be done in a special way that involves reversing the data in time and passing it through a narrow band filter and truncating the data. Reversing the data prevents the filter characteristics contaminating the filter output. If the data is from a linear system then the natural frequency and damping are preserved by this process. If the data is nonlinear then the instantaneous frequency and damping are also preserved but are modified in a way that can be reversed. It is shown how all the effects of the filtering can be eliminated so that the decaying response of each mode is obtained. This approach provides a useful extension to experimental modal analysis that is applicable to nonlinear systems.
CFD Study on High-Pressure Hydrogen Leakage and Explosion of Hydrogen Energy Tram in Tunnel
Authors: Tian Tiantian , Lu Chen , Ha Wenlong , Zhao Yiming , Hua Zhengli , Peng Wenzhu , Gu Chaohua 
Published: November 2023

Abstract
As hydrogen energy is gradually being applied to vehicles, confirming the safety level is becoming important. Meanwhile, tunnels are common in cities. Compared with hydrogen fuel cell cars (HFCVs), hydrogen fuel cell trams have a larger size and the corresponding space of the tram tunnel is also narrower. However, most hydrogen fires in confined spaces are HFCVs. The consequences of hydrogen leakage and explosion in a tunnel of the hydrogen energy tram are different. Therefore, computational fluid dynamics (CFD) method was used to study the hydrogen diffusion and explosion caused by the accidental opening of the thermal pressure relief device (TPRD) of the high-pressure hydrogen storage cylinders on the hydrogen energy tram in the tunnel. The effect of the number of TPRDs opening and the speed of wind on the formation of flammable hydrogen clouds is discussed. The simulation results show that the burning area generated by igniting the hydrogen cloud can cover more than one hundred meters, and overpressure can cause serious injuries to the human body. High temperature and overpressure can be relieved by the wind. In case of accidental hydrogen leakage, the tram should be blocked until the tram continues to move to a safe area and there should be forced ventilation in the tunnel. This research highlights the importance of ensuring the safety of hydrogen fuel cell trams in confined spaces such as tunnels.
Case Study on the Acceptance of a Unique Refractory Material in ASME Section VIII
Authors: Peters Daniel T. , Kapadia Rahul , Hoeijmakers Maarten , Koestenbauer Harald , Niggl Florian 
Published: November 2023

Abstract
The use of hot isostatically pressed isotropic pure molybdenum was recently processed through ASME Section VIII. This is a unique material for the manufacture of pressure vessels as pure molybdenum is typically used for applications such as refractory, resistance wire for heating elements and structural thermal barrier components for internal furnaces for hot isostatic presses. There are several specifications for coverage of molybdenum such as ASTM B387, Standard Specification for Molybdenum and Molybdenum Alloy Bar, Rod, and Wire [1], and ASTM B386/B386M, Standard Specification for Molybdenum and Molybdenum Alloy Plate, Sheet, Strip, Foil, and Ribbon [2].
This paper demonstrates the test data needed for ASME approval of this unique material. The paper highlights the gaps in ASME Section II, Part D Appendix 5 and attempts to illustrate the “other information required by the Construction Committee” which may be needed for new materials today. This includes not only the data required by ASME Section II Part D, Appendix 5 [3,4], but also includes additional data which is required for more modern design by analysis techniques, such as elastic-plastic local strain limits and generation of true stress – true strain curves. This paper will also discuss alternative design philosophy approaches which were adopted in lieu of traditional approaches in areas such as fatigue analysis, determination of minimum design metal temperature (MDMT), and alternative approaches to examination and inspection of the material.