Author/Authors :
Lu، نويسنده , , Samuel Y.L. and Chen، نويسنده , , L.J. and Liaw، نويسنده , , P.K. and Wang، نويسنده , , G.Y. and Brooks، نويسنده , , C.R. and Thompson، نويسنده , , S.A. and Blust، نويسنده , , J.W. and Browning، نويسنده , , P.F. and Bhattacharya، نويسنده , , A.K. and Aurrecoechea، نويسنده , , J.M. and Klarstrom، نويسنده , , D.L.، نويسنده ,
Abstract :
The creep-fatigue crack-growth behavior of a HAYNES 230 superalloy was investigated at the temperatures of 649, 816 and 927 °C in laboratory air. The crack-growth experiments were conducted under the stress-intensity-factor-range or load-range control. Hold times in the range of 3 s to 5 h were imposed at the maximum load to study the influence of hold time on the crack-growth behavior. The fatigue and creep crack-propagation experiments were also performed as zero and infinite hold-time experiments, respectively.
ack-growth rate increased continuously with increasing the test temperature and/or hold time. The fracture surfaces and cross-sections through the fracture surfaces were examined. As the hold time increased, the fracture appearance changed from the transgranular to intergranular mode. At higher temperatures, this transgranular–intergranular transition occurred at a shorter hold time.
Keywords :
Nickel-based superalloys , Fatigue crack-growth , Hold time effect , Oxide removal , fractography
