Deformation Characteristics and Time-Dependent Notch Sensitivity of Udimet 700 at Intermediate Temperatures

摘要

A research program has been carried out to characterize the susceptibility of sheet, bar, and cast Udimet 700 to time-dependent notch sensitivity in the temperature range 1000° to l600℉ (538°-871℃). The results were evaluated in terms of the mechanical characteristics and the dislocation motion mechanisms operative.nTime-dependent notch sensitivity occurred at the lower test temperatures for several heat treatments of all test materials. The severity of the time-dependent notch sensitivity decreased with increasing test temperature so that none was observed at l600℉ (871℃). The susceptibility to notch sensitivity was dependent on the notched specimen geometry and the γ’ size distribution. The sheet and cast materials behaved similarly as they were both evaluated using edge-notched "flat" specimens (notches introduced biaxial stress concen¬trations). The bar materials, with circumferential notches, were less suscep¬tible to notch sensitivity.