Properties of metals at elevated temperatures

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BOOK REVIEWS

[J. F. 1.

out the book the ramifications of the various subjects are minimized and frequent examples presented to clarify the theory. For a subject as complex as steam turbine design, such an approach aids greatly in comprehension. Steam Turbines and Their Cycles is divided into four parts: Fundamentals of Turbine Design, The Regenerative Cycle, Cycle Analysis, and Application Engineering. Part I commences with a chapter on thermodynamics, con mining, however, only those fundamentals necessary to an understanding of steam turbines. Following, then, are chapters on power-plant cycles, the flow of fluids, a general description of turbines, turbine external characteristics, and steam path design. Part I I contains chapters on regeneration and non-extraction performance, heat-balance practice, and a short cut to turbine-cycle heat rate. Part III has chapters on heater-cycle losses, cycle equations for homogeneous arrangements, arrangement and distribution losses, terminal difference and pressure-drop loss, evaporation of make-up and miscellaneous cycle corrections. In Part IV are chapters on design detail, estimating steam rates and heat rates. An appendix contains such valuable data as theoretical steam rates in pounds per kilowatt hour, large scale Mollier charts, properties of superheated steam, saturation-temperature and saturation-pressure tables, and selected references on steam turbines. In addition to the many illustrative examples, there are problems for the student at the end of each chapter. The usual steam turbine design calculations are long and laborious. Mr. Salisbury has presented short cut methods to eliminate much of this lengthy computation, providing, for example, such labor-saving devices as curves for the design of a nozzle-bucket combination, charts for calculatlng partial-load steam rates, and approximations to the usual steam flow equations. Containing such a wealth of practical data, Steam Turbines and Their Cycles is, in addition to an excellent text, an excellent handbook, furnishing sufficient information to approximate quite accurately the design of a steam turbine. E. W. HAMMER, JR. PROPERTIES OF METALS AT ELEVATED TEMPERATURES,by George V. Smith. Edition 1,401 pages, illustrations, 16 X 23 cm. New York, McGraw-Hill Book Co., 1950. Price, $7.00. Wlth the development of more efficient power production and advances in the oil and chemical industries, increasingly higher temperatures of operation are required. Such operations demand materials that will withstand the effects of high temperature. Consequently, it is imperative to know the reactions of metals at elevated temperatures. Generally, the physical properties of metals are not so good at abnormal as at normal temperatures. While the knowledge of the metallurgy of metals at elevated temperatures is far from complete, Dr. Smith, in Properties of Metals at Elevated Temperatures, performs a valuable service to the metallurgical and design engineer by compiling all available information and correlating the research results of the past twenty-five years on plastic deformation at high temperatures, effect of grain size, recrystallization and phase changes with the use of metals at elevated temperatures. Recognizing that information is scarce, Dr. Smith frequently indicates where additional research, or review of existing data, is necessary to bridge the numerous gaps in the knowledge. Briefly, plastic deformation, creep and fracture of single crystals and polycrystalllne metals, and theories of flow and fracture are discussed in the first six chapters. The nature and means of physical testing for the above characteristics are then described in a chapter on tests and test equipment. The effect of chemical composition, melting and deoxidation practices, heat treatment, grain size, varying temperature, the state of stress, and varying stress on creep are treated in three succeeding chapters. Scaling and microstructural changes during service at high temperatures are discussed in the eleventh chapter. In the concluding chapter the author briefly but ably surveys the theoretical and practical considerations in the problem of adequately designing for elevated-temperature service. When reading this book, it might be well to scan the last chapter first, to obtain the general view of the problem of design of engineering structures and the various factors that must be considered. The numerous charts and graphs and the almost five hundred references add greatly to the value of the book. E. W. HAMMER, JR.