Hydrogen Embrittlement Challenges Tubular Goods Performance

Reviewed by: Chronicles of Mechanical Engineering in the United States ed. by Thomas H. Fehring and Terry S. Reynolds Peter Liebhold (bio) Chronicles of Mechanical Engineering in the United States Edited by Thomas H. Fehring and Terry S. Reynolds. New York: American Society of Mechanical Engineers, 2021. Pp. xvi + 405. A fiftieth anniversary is a milestone of longevity that many organizations never achieve. It takes a lot to maintain leadership continuity, overcome economic challenges, and keep membership involved for half of a century. To mark the golden anniversary of the History and Heritage Committee of the American Society of Mechanical Engineers (ASME), the society commissioned Chronicles of Mechanical Engineering in the United States. This book is a collection of over seventy vignettes, mostly biographical and thematic with a few landmark stories. In a surprising organizational decision, 90 percent of the entries—many written by Fritz Hirschfeld between 1976 and 1980—are reprints from the last fifty years of the ASME journal Mechanical Engineering. The book editors, Thomas Fehring and Terry Reynolds, contribute short chapter heads. Organized into eight topical chapters, Fehring and Reynolds do not argue a grand theory of engineering through their selection of articles. The simple goal of this book is to celebrate the achievements of engineers and the ASME. Other historians have followed a different approach: Bruce Sinclair's Centennial History of ASME explored the role of engineers and professional societies through the tensions of professionalizing the group. Eugene Ferguson's Engineering and the Mind's Eye railed against engineering's dependency on academic mathematical modeling and suggested the need for practical experience. Henry Petroski argued in Success through Failure that engineering success leads to overconfidence and catastrophe and that humility and insight stem from disaster. The intended audience for Chronicles of Mechanical Engineering is a bit mysterious. Fehring and Reynolds explain the articles lack academic rigor (footnotes, bibliography, etc.) and are not for historians. They suggest the collection of stories presents an important learning opportunity for the general public. But what if the sum is less than the parts? The real audience here is ASME members reifying the importance of their organization. Most historians agree that technology played a critical role (both positive and negative) in the development of the United States. As the nation matured and society transitioned from agrarian to industrial, engineers acted as innovators and agents for change. In this crucible of transformation, engineers were at the center, developing machines, engines, and the infrastructure of modern society. A book that broadly tells the history of engineering is a great opportunity for presenting epiphany moments, helping readers learn from the past and understand the complexity of life moving forward. [End Page 649] A challenge for the book is whether old versions of history are still useful. Some of the entries may be old but are interesting and resonate today. Frank Wicks's "First Flights" uses the birth of powered flight to provide insight into the failure of a government-supported academic engineer (Samuel Langley) and the success of untrained independent tinkerers (Frank and Wilbur Wright). Charles Beardsley's retrospective on the Hydrolevel case is one of the few essays that are not celebratory. Instead, he details how the ASME, a voluntary standards-setting organization, got into serious antitrust troubles through conflicts of interest. Reprinting classics can be challenging, and not all the entries weather well. Written for audiences of the day, most do not address questions of race, class, or gender. In fact, one of the most surprising problems in this book is diversity. ASME should be painfully aware of STEM stereotypes and the need to bring women and people of color into their organization. This book could have reinvented the ASME through a revisionist history that highlights both old heroes and the contributions of people overlooked in the past. Today, ASME membership is 53 percent white, 16 percent Latino, 14 percent Asian, and about 82 percent male. But the book is mostly a "great man" history highlighting only two women (Lilian Gilbreth and Emily Roebling) and no people of color. The editors acknowledge that "the articles are generally not critical and that they focus primarily on engineering success rather than failure." The concept...

The required thickness of welding tees is neither specified in ASME (2012, “Factory-Made Wrought Buttwelding Fittings,” American Society of Mechanical Engineers, New York, Standard No. B16.9-2012) nor is a clear calculation method provided in codes such as ASME (2016, “Process Piping,” American Society of Mechanical Engineers, New York, Standard No. B31.3-2016). This can lead to uncertainty regarding the pressure capacity of a tee fitting, particularly one that has suffered from erosion or corrosion. Code methods including area replacement (ASME, 2016, “Process Piping,” American Society of Mechanical Engineers, New York, Standard No. B31.3-2016) or pressure-area (ASME, 2015, “Boiler and Pressure Vessel Code Section VIII Division 2,” American Society of Mechanical Engineers, New York, Standard No. BPVC-VIII-2-2015; BSI, 2014, “Unfired Pressure Vessels Part 3: Design,” BSI, London, UK, Standard No. BS EN 13445-3) do not directly account for the effect which the curvature of the crotch region may have on the stress state in the tee. The approach adopted in this work is to liken the geometry of the tee crotch to the intrados of a torus or pipe bend. The shell theory applicable to the torus is adapted for the tee in order to derive a relationship for circumferential membrane stress. An equivalent tube radius is assigned by determining the local radius of shell curvature in the plane passing through the crotch center of the curvature. The actual stresses in the tee crotch are significantly reduced by the adjoining straight portions. This effect is difficult to quantify theoretically and has thus been investigated by means of finite element analysis (FEA)-based assessments. An empirical relationship was then established providing a conservative correlation between the theoretical stresses and the program calculated local stress intensities.

The American Society of Mechanical Engineers (ASME) Performance Test Codes (PTCs) have provided the power industry with the premier source of guidance for conducting and reporting performance tests of their evolving base technologies of power producing plants and supporting components. With an overwhelming push for renewable energy in recent years, ASME PTCs are in the development of similar standards for the testing of concentrating solar thermal technologies based power plants by the formation of a committee to develop “PTC 52, Performance Test Code on Concentrated Solar Plants”, on July 2009. The U.S. Department of Energy’s (DOE) SunShot Initiative goal is to reduce costs and eliminate market barriers to make large-scale solar energy systems cost-competitive with other forms of energy by the end of the decade. The ASME PTC-52 similarly removes critical barriers hindering deployment and speeds the implementation of concentrating solar power technologies by reducing commercial risk by facilitating performance testing procedures with quantified uncertainty. As with any commercialization of power producing technologies, clearly defining risk and providing methods to mitigate those risks are essential in providing the confidence necessary to secure investment funding. The traditional power market accomplishes this by citation of codes and standards in contracts; specifically ASME PTCs which supply commercially accepted guidelines and technical standards for performance testing to validate the guarantees of the project (Power Output, Heat Rate, Efficiency, etc.). Thus providing the parties to a power project with the tools they need to ensure that the planned project performance was met and the proper transfer of funds are accomplished. To enable solar energy systems to be fully embraced by the power industry, they must have similar codes and standards to mitigate commercial risks associated with contractual acceptance testing. The ASME PTC 52 will provide these standard testing methods to validate Concentrating Solar Power (CSP) systems performance guarantees with confidence. This paper will present the affect that solar resource variability and measurement accuracies have on concentrating solar field performance uncertainty based on calculation methods like those used for conventional fossil power plants. Measurement practices and methods will be discussed to mitigate that uncertainty. These uncertainty values will be correlated to the levelized cost of electricity (LCOE), and LCOE sensitivities will be derived. The results quantify the impact of resource variability during testing, test duration and sampling rate to annual performance calculation. These uncertainties will be further associated with costs and risks based on typical technology performance guarantees. The paper will also discuss how the development of standard measurements and calculation methods help to produce lower uncertainty associated with the overall plant result, which is already being accomplished by ASME PTCs in conventional power genreation.

Fatigue is a common failure mode in mechanical components that are subject to repeated load cycles. In nuclear plants the cyclic loading is usually associated with variations of pressure and temperature. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code provide fatigue evaluation procedures in ASME III Section NB-3220. It is required to calculate a Cumulative Usage Factor (CUF). The Code criterion for acceptance is that the calculated CUF must be less than one. The ASME method is deterministic and it is assumed that uncertainties are accounted for by largely un-quantified inherent safety margins in the assessment. The conservatism in the ASME III Code fatigue evaluation methods may come from the assessment procedure used and/or the fatigue design curve. In this paper the inputs to an ASME III fatigue assessment that is based upon a finite element determination of stresses are outlined and assessed. Based upon these inputs possible areas of conservatism within the analysis are then discussed and conclusion drawn on the inherent margins. In addition a probabilistic model that uses Monte Carlo (MC) methods is developed. By assuming the scatter in the fatigue data, used to generate the design fatigue curve, to be the most significant random variable, the MC model was used to calculate the conditional probability of initiation associated with CUFs from a number of plant representative examples.

In Memoriam: Dr. Clive L. Dym (1942–2016)

Fundamental experimental measurement in heat transfer: By D. E. Beasley & J. L. S. Chen. The American Society of Mechanical Engineers, United Engineering Center, New York. Available from the Institution of Mechanical Engineers, London, 1991. 97 pp. ISBM 0-7918-0831-9. Price: £30.00

Multiphase transport in porous media—1991: Edited by R. R. Eaton, M. Kaviany, M. P. Sharma, K. Vafai & K. S. Udell. The American Society of Mechanical Engineers, United Engineering Center, New York. Available from the Institution of Mechanical Engineers, London, 1991, 132 pp. ISBN 0-7918-0843-2. Price £47.00

Fundamentals of forced-convection heat-transfer: Edited by M. A. Ebadian & D. A. Kaminski. The American Society of Mechanical Engineers, United Engineering Center, New York. Available from the Institution of Mechanical Engineers, London, 1991. 92 pp. ISBN 0-7918-0833-05. Price: £30·00

Convective heat transfer in the presence of an obstructing medium: By K. Vafai, A. Lavine & M. K. Jensen. The American Society of Mechanical Engineers, United Engineering Center, 345 East 47th Street, New York, N.Y. Available from the Institution of Mechanical Engineers, London, 1990, 58pp. ISBN 0-7918-0539-5. Price: £20·00

Effects of Fe 3C and Mo 2C precipitation on hydrogen diffusivity and hydrogen embrittlement in iron alloys

OPTIMIZATION CONSIDERATIONS OF ELECTRICAL SPACE ENGINES

First-principle modeling of hydrogen site solubility and diffusion in disordered Ti–V–Cr alloys

Exposure of metallic parts to cathodic protection (CP) in sea water leads to production and diffusion of atomic Hydrogen into the metal matrix. Absorption of atomic Hydrogen into the metal could lead to hydrogen embrittlement (HE). In order to study the influence of stresses related to HE, FEA and Fracture Mechanics (FM) assessments were performed on a stud bolt threaded geometry. Effects of manufacturing tolerances, interface between nut and stud bolt and a defect in the form of a semi-circular crack placed in highest stress location of a thread root were also considered. Investigations of stress profiles when tension or bending are applied in test samples for measurement of HE threshold were also done, aiming at showing gaps on ASTM F1624-12 [1]. Tolerance assessment shows a relative maximum increase of 260% of nominal linearized membrane plus bending (NLMB) stresses regarding the nut runout [2] and for the proprietary nut geometry, such relative increase drops to 126% of NLMB stresses. Highest Hydrogen concentrations could be observed in the neighborhood of the first loaded thread root. FEA of cracked geometry shows that Hydrogen concentration could increase by around 283% around the crack tip, when compared to stud bolt in unloaded condition. Integrity assessment according to API 579-1 [3] or BS 7910 [4] and tests conducted according to ASTM F1624-12 [1] show less conservative results.

Atomistic simulation study of the hydrogen diffusion in nickel

Within the American Society of Mechanical Engineers (ASME) the Section XI Working Group on Flaw Evaluation (WGFE) is currently working to develop a revision to Code Case N-830. This revision incorporates a complete and self-consistent suite of models that describe completely the temperature dependence, scatter, and interdependencies between all the fracture metrics (i.e., KJc, KIa, JIc, J0.1, and J-R) from the lower shelf through the upper shelf. A paper presented at the 2014 ASME Pressure Vessel and Piping Conference described most of these models; a companion paper at this conference describes the J-R model. This paper also supports the WGFE effort by performing an assessment of the appropriateness of Wallin’s Master Curve model to represent toughness data on the lower shelf, and by comparing the Master Curve with the current Code KIc curve on the lower shelf. The work presented in this paper supports the following conclusions: 1. The Master Curve provides a reasonable representation of cleavage fracture toughness (KJc) data at lower shelf temperatures. A statistical evaluation of a large database demonstrates that the Master Curve works well to temperatures approximately 140 °C below To or, equivalently, approximately 160 °C below RTTo. 2. The percentile of cleavage fracture toughness data falling below a KIc curve indexed to RTTo varies considerably with temperature. At lower shelf temperatures as much as half of the data lie below the KIc curve, while at temperatures close to RTTo this percentage falls to approximately ≈ 1.5%. The current guidance of Nonmandatory Appendix A to Section XI to use structural factors of √10 or √2 is one means of addressing this inconsistency. 3. The inconsistent degree to which the KIc curve, with or without structural factors, bounds fracture toughness data cannot be fixed within the current Code framework for two reasons: the KIc curve does not reflect the actual temperature dependence shown by the fracture toughness of ferritic RPV steels, and the ratio of a mean or median toughness curve to a fixed percentile bound is not a constant value. It is for these reasons that in the next revision of Code Case N-830 the ASME WGFE is moving away from use of the KIc curve coupled with structural factors and, instead, is adopting models of fracture toughness that represent both the temperature trends and the scatter in the data with high accuracy.