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Creep tests of 1000 hours duration and greater were conducted in the temperature range 20000 to 22000 F on a commercially available columbium alloy (FS-85) in vacuum units designed and built to achieve ultimate pressures of 10%% torr. At a stress level of 10 000 pounds per square inch, FS-85 exhibited moderate creep resistance at 2000 F, 1-percent strain being achieved in 775 hours. At 21000 and 22000 F and the same stress level, the alloy was much weaker, 1-percent strain being achieved in 355 and 50 hours, respectively. The Manson-Haferd linear time-temperature parameter proved moderately successful in predicting the long-time creep lives from relatively short-time creep data, the maximum error between predicted and experimental lives being a factor of 1. 7 and the average error being a factor of 1. 3. The agreement is considered good in view of the large scatter generally observed in long-time high-temperature creep tests. In all cases, however, the observed experimental life was shorter than the predicted life. The nonconservative nature of these predictions may be due in part to the fact that the predictions were based on data obtained at a pressure level of approximately to 10 -6 torr, but the long-time tests to which the predictions are compared were made at a lower pressure level, 10 -8 to 10 -9 torr. Creep tests conducted in the conventional-vacuum units (10 -6 torr) and the ultrahigh- vacuum units under the same conditions of temperature and stress yielded creep curves that are virtually identical for the first few hundred hours but that deviate with increasing test time. The conventional-vacuum tests then showed a reduced creep rate compared with that of the ultrahigh-vacuum tests.
As part of the Metalworking Process and Equipment Program, a survey was conducted to collect and summarize information on deformation characteristics of metals and their effect on processing operations. This report presents information obtained from reports on Governmentsponsored work and from articles in technical publications. The report covers eight subjects: extrusion, forging, rolling, thermal mechanical variables affecting the properties of refractory metals and alloys, development of preferred orientations, anisotropy of strength and ductility, high-strain-rate deformation, and strain aging. In order to be useful to engineering students and production engineers the topics are treated in two ways. Generalized discussions of common processes point out why specific variables must be modified in order to deform certain types of metals satisfactorily. When practical, data on the more-difficultto-form metals are used to illustrate the principles, limitations, and effects of the processes. The objective is to help the non-specialist recognize the implications of specific findings and to apply them to specific operations. (Author).