Abstract

Near-threshold fatigue crack growth behavior for distributed cracks in Hastelloy-X has been examined with reference to the effects of crack size and environment on the threshold stress intensity ΔK.The threshold stress intensity value for a large crack in air was lower than in vacuum. This result was same for a small crack in air and vacuum experiments. But the value for a small crack was about 50% lower than for a large crack in vacuum. In air, the small crack threshold was lower than the large one. These results were discussed in terms of fatigue crack closure. Observation of crystallographic fracture surface in vacuum suggested the roughness induced crack closure mechanisms.The distributed-small-cracks specimen was obtained by low cycle fatigue loading tests. The threshold stress intensity for the distibuted-fatigue-crack growth could be estimated by the maximum crack size of the distributed cracks. The coalescence of small cracks did not affect the near-threshold fatigue crack growth behavior.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.