Strain fatigue and tensile behavior of Inconel 718 from room temperature to 650$sup 0$C

Results of tensile and fully reversed strain-controlled fatigue tests conducted on three heats of Inconel 718 that had been subjected to different solution annealing and aging treatments are presented. Tests were conducted at temperatures ranging from 22 to 650 deg C with fatigue tests defining behavior over the cyclic range of 10/sup 2/ to 10/sup 6/ cylces to failure. Average best- fit equations defining true stress-strain, strain-controlled fatigue, and cyclic stress-strain behavior are given for the two heat treatments characterized. Heat- to-heat variations in the elevated temperature tensile and fatigue behavior were found. Fatigue lifetime was seen to be dependent upon grain size, particularly at lower strain ranges. (auth)