CREEP BEHAVIOUR OF THE IN718 SUPERALLOY

C.M. Branco  J. Baptista  J. Byme      

Anales de la Mecánica de la Fractura, nº 15 . 1998 . Pág. 413 -418
Ver (.pdf): Anales15-065

Resumen: Crack growth rate ( daldt) in IN718 nickel hase superalloy has been studied at 600 and 700° C, in both compact tension and comer crack specimens, under sustained constant load conditions, generating an intergranular fracture mode. Using the stress intensity factor, K, as the correlating parameter, slower growth rates are found for comer cracks than for the through cracks in CT specimens together with a greater degree of crack tunneling. In the CT specimens, the introduction oflateral side grooves has increased the crack growth rate. Disparities found between growth rates in the CC geometry are found to correlate with the incubation time for re-initiation of crack growth, which is attributed to a crack tip blunting and creep mechanism. A limited assessment of the correlation of growth rates using C* is made.

LocalizaciónZamora

UME / IST, Technical University of Lisbon, 1096 Lisbon Codex, Portugal
UME / IST, Technical University of Lisbon, 1096 Lisbon Codex, Portugal
Dept. ofMechanical and Manufacturing Engineering, University ofPortsmouth, POI 3DJ, UK