0
RESEARCH PAPERS

Effects of Stress Ratio and Hold-Time on Fatigue Crack Growth in Alloy 718

[+] Author and Article Information
P. Shahinian, K. Sadananda

Thermostructural Materials Branch, Material Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375

J. Eng. Mater. Technol 101(3), 224-230 (Jul 01, 1979) (7 pages) doi:10.1115/1.3443681 History: Received January 01, 1979; Online August 17, 2010

Abstract

Crack growth rate da/dN in Alloy 718 at 650°C, compared on the conventional ΔK basis, increased with increase in R (Kmin /Kmax ) and also generally with inclusion of hold time at Kmax and Kmin . An exception, however, was that a 1-min hold at a Kmin just below the threshold K for creep crack growth caused retardation of crack growth. Correlation of da/dN for various R levels was better with Kmax than with other parameters such as Kmin , ΔK, and Δ J-integral. Fatigue crack growth in the alloy was found to be time dependent and Kmax controlled under these test conditions and consequently the best overall correlation was given by da/dt with Kmax . An unusual observation was that the addition of hold time to the loading cycle at near zero Kmin (R = 0.05) caused an increase in da/dN, as the result of an environmental interaction.

Copyright © 1979 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In