Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications (The Minerals, Metals & Materials Series)

This technical meeting will focus on Alloy 718 and Superalloys in this class relative to alloy and process development, production, product applications, trends and the development of advanced modeling tools. The symposium provides an opportunity for authors to present technical advancements relative to a broad spectrum of areas while assessing their impact on related fields associated with this critical alloy group. There are continuing innovations relative to these alloys as well as novel processing techniques which continue to extend applications in very challenging environments ranging from corrosion resistance in the deep sea to high-stressed space applications. The objective of Comtes700 was a test of components for the 700 °C power plant technology. A test facility of steam generator components up to a wall thickness of 50 mm was erected in an existing power plant. A partial steam flow from the host plant was heated up to 700 °C and operated for 22 400 hours. Compared to ferritic components, machining of nickel-based components lasted a minimum of four times longer. Maximum grain sizes in semi-finished products were achieved by a modified heat treatment. After adjustment of testing technology, overlaps of alloy 617B tubes were avoided. Evaporator materials functioned satisfactorily during operation. Updated material properties and reduced mechanical loads restricted the reliability statement. Superheater materials only failed once in a dissimilar weld. Some superheater materials may not reach a lifetime of 200 000 hours due to fireside corrosion. Thick-walled components from 30 to 50 mm in wall thickness displayed a susceptibility to stress relaxation cracking in welds. Additional stresses were caused by two-phase flow and insufficient design of spray attemperator. A solution for the workshop and repair welds was to conduct different heat treatment procedures. Valves functioned satisfactorily but after dismantling some internal cracks were found which could be avoided by design changes. Steam parameter measurements were proved. Non-destructive testing for initial and periodic inspection was developed during the project, but without having a relevant acceptance criterion. The component test was designed, manufactured, erected and operated, but it revealed challenges which were partly solved. Additional research activities are necessary before construction and operation of a 700 °C power plant in the near future Fundamentals and Applications of Supercritical Carbon Dioxide (SCO2) Based Power Cycles aims to provide engineers and researchers with an authoritative overview of research and technology in this area. Part One introduces the technology and reviews the properties of SCO2 relevant to power cycles. Other sections of the book address components for SCO2 power cycles, such as turbomachinery expanders, compressors, recuperators, and design challenges, such as the need for high-temperature materials. Chapters on key applications, including waste heat, nuclear power, fossil energy, geothermal and concentrated solar power are also included. The final section addresses major international research programs. Readers will learn about the attractive features of SC02 power cycles, which include a lower capital cost potential than the traditional cycle, and the compounding performance benefits from a more efficient thermodynamic cycle on balance of plant requirements, fuel use, and emissions. Represents the first book to focus exclusively on SC02 power cycles Contains detailed coverage of cycle fundamentals, key components, and design challenges Addresses the wide range of applications of SC02 power cycles, from more efficient electricity generation, to ship propulsion