Article ID Journal Published Year Pages File Type
10620863 Acta Materialia 2007 9 Pages PDF
Abstract
The fatigue crack growth behavior of two solid-solution-strengthened superalloys, Ni-based HAYNES® 230 and HASTELLOY® X, was studied at 816 and 927 °C in laboratory air. The fatigue crack growth tests were conducted following a baseline triangular waveform of 0.33 Hz. Various hold times were introduced at the maximum load to study the hold-time effect. Fracture mechanics parameters, K, C∗, Ct, and (Ct)avg, were applied to correlate the crack growth rates at different temperatures for both HAYNES 230 and HASTELLOY X alloys. For both alloys, the fatigue cracking path was mainly transgranular at 816 and 927 °C. The cracking path became dominantly intergranular if the hold time increased to 2 min, indicating that the time-dependent creep damage mechanisms were in control. When the time-dependent damage dominated (temperature ⩾816 °C and hold time ⩾2 min), the crack growth rates can be correlated with Ct or (Ct)avg parameters. The Ct and (Ct)avg parameters were capable of consolidating data from different temperatures and different alloys.
Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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