Mechanical properties test data for structural materials. Semiannual progress report for period ending July 31, 1980

Mechanical property investigations of Alloy 718 given either the 9540C conventional or the INEL heat treatment are continuing. Current conventional heat-treat data include tests showing the effects of surface finish, product variability, and thermal exposure on the high-cycle fatigue properties; creep-fatigue tests at 538, 593, 649, and 7040C with 0.1 hour hold times at peak strain; and stress-rupture tests of notched and smooth specimens showing the effect of pretest thermal exposure. A few stress-rupture tests of weld and base metals given the INEL heat treatment are also reported. High-cycle fatigue tests of Type 316 stainless steel at 5930C are reported and compared with previous data from other sources